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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/expmed.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/expmed.c | 5753 |
1 files changed, 5753 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/expmed.c b/gcc-4.2.1-5666.3/gcc/expmed.c new file mode 100644 index 000000000..019feaf14 --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/expmed.c @@ -0,0 +1,5753 @@ +/* Medium-level subroutines: convert bit-field store and extract + and shifts, multiplies and divides to rtl instructions. + Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 + Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "toplev.h" +#include "rtl.h" +#include "tree.h" +#include "tm_p.h" +#include "flags.h" +#include "insn-config.h" +#include "expr.h" +#include "optabs.h" +#include "real.h" +#include "recog.h" +#include "langhooks.h" + +static void store_fixed_bit_field (rtx, unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, + /* APPLE LOCAL begin 6020402 */ + unsigned HOST_WIDE_INT, rtx, tree); + /* APPLE LOCAL end 6020402 */ +static void store_split_bit_field (rtx, unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, rtx); +static rtx extract_fixed_bit_field (enum machine_mode, rtx, + unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, rtx, int); +static rtx mask_rtx (enum machine_mode, int, int, int); +static rtx lshift_value (enum machine_mode, rtx, int, int); +static rtx extract_split_bit_field (rtx, unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, int); +static void do_cmp_and_jump (rtx, rtx, enum rtx_code, enum machine_mode, rtx); +static rtx expand_smod_pow2 (enum machine_mode, rtx, HOST_WIDE_INT); +static rtx expand_sdiv_pow2 (enum machine_mode, rtx, HOST_WIDE_INT); +/* APPLE LOCAL begin 6020402 */ +static enum machine_mode +widest_mode_including_no_volatile_fields (tree, unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT); +/* APPLE LOCAL end 6020402 */ + +/* Test whether a value is zero of a power of two. */ +#define EXACT_POWER_OF_2_OR_ZERO_P(x) (((x) & ((x) - 1)) == 0) + +/* Nonzero means divides or modulus operations are relatively cheap for + powers of two, so don't use branches; emit the operation instead. + Usually, this will mean that the MD file will emit non-branch + sequences. */ + +static bool sdiv_pow2_cheap[NUM_MACHINE_MODES]; +static bool smod_pow2_cheap[NUM_MACHINE_MODES]; + +#ifndef SLOW_UNALIGNED_ACCESS +#define SLOW_UNALIGNED_ACCESS(MODE, ALIGN) STRICT_ALIGNMENT +#endif + +/* For compilers that support multiple targets with different word sizes, + MAX_BITS_PER_WORD contains the biggest value of BITS_PER_WORD. An example + is the H8/300(H) compiler. */ + +#ifndef MAX_BITS_PER_WORD +#define MAX_BITS_PER_WORD BITS_PER_WORD +#endif + +/* Reduce conditional compilation elsewhere. */ +#ifndef HAVE_insv +#define HAVE_insv 0 +#define CODE_FOR_insv CODE_FOR_nothing +#define gen_insv(a,b,c,d) NULL_RTX +#endif +#ifndef HAVE_extv +#define HAVE_extv 0 +#define CODE_FOR_extv CODE_FOR_nothing +#define gen_extv(a,b,c,d) NULL_RTX +#endif +#ifndef HAVE_extzv +#define HAVE_extzv 0 +#define CODE_FOR_extzv CODE_FOR_nothing +#define gen_extzv(a,b,c,d) NULL_RTX +#endif + +/* Cost of various pieces of RTL. Note that some of these are indexed by + shift count and some by mode. */ +static int zero_cost; +static int add_cost[NUM_MACHINE_MODES]; +static int neg_cost[NUM_MACHINE_MODES]; +static int shift_cost[NUM_MACHINE_MODES][MAX_BITS_PER_WORD]; +static int shiftadd_cost[NUM_MACHINE_MODES][MAX_BITS_PER_WORD]; +static int shiftsub_cost[NUM_MACHINE_MODES][MAX_BITS_PER_WORD]; +static int mul_cost[NUM_MACHINE_MODES]; +static int sdiv_cost[NUM_MACHINE_MODES]; +static int udiv_cost[NUM_MACHINE_MODES]; +static int mul_widen_cost[NUM_MACHINE_MODES]; +static int mul_highpart_cost[NUM_MACHINE_MODES]; + +void +init_expmed (void) +{ + struct + { + struct rtx_def reg; rtunion reg_fld[2]; + struct rtx_def plus; rtunion plus_fld1; + struct rtx_def neg; + struct rtx_def mult; rtunion mult_fld1; + struct rtx_def sdiv; rtunion sdiv_fld1; + struct rtx_def udiv; rtunion udiv_fld1; + struct rtx_def zext; + struct rtx_def sdiv_32; rtunion sdiv_32_fld1; + struct rtx_def smod_32; rtunion smod_32_fld1; + struct rtx_def wide_mult; rtunion wide_mult_fld1; + struct rtx_def wide_lshr; rtunion wide_lshr_fld1; + struct rtx_def wide_trunc; + struct rtx_def shift; rtunion shift_fld1; + struct rtx_def shift_mult; rtunion shift_mult_fld1; + struct rtx_def shift_add; rtunion shift_add_fld1; + struct rtx_def shift_sub; rtunion shift_sub_fld1; + } all; + + rtx pow2[MAX_BITS_PER_WORD]; + rtx cint[MAX_BITS_PER_WORD]; + int m, n; + enum machine_mode mode, wider_mode; + + zero_cost = rtx_cost (const0_rtx, 0); + + for (m = 1; m < MAX_BITS_PER_WORD; m++) + { + pow2[m] = GEN_INT ((HOST_WIDE_INT) 1 << m); + cint[m] = GEN_INT (m); + } + + memset (&all, 0, sizeof all); + + PUT_CODE (&all.reg, REG); + /* Avoid using hard regs in ways which may be unsupported. */ + REGNO (&all.reg) = LAST_VIRTUAL_REGISTER + 1; + + PUT_CODE (&all.plus, PLUS); + XEXP (&all.plus, 0) = &all.reg; + XEXP (&all.plus, 1) = &all.reg; + + PUT_CODE (&all.neg, NEG); + XEXP (&all.neg, 0) = &all.reg; + + PUT_CODE (&all.mult, MULT); + XEXP (&all.mult, 0) = &all.reg; + XEXP (&all.mult, 1) = &all.reg; + + PUT_CODE (&all.sdiv, DIV); + XEXP (&all.sdiv, 0) = &all.reg; + XEXP (&all.sdiv, 1) = &all.reg; + + PUT_CODE (&all.udiv, UDIV); + XEXP (&all.udiv, 0) = &all.reg; + XEXP (&all.udiv, 1) = &all.reg; + + PUT_CODE (&all.sdiv_32, DIV); + XEXP (&all.sdiv_32, 0) = &all.reg; + XEXP (&all.sdiv_32, 1) = 32 < MAX_BITS_PER_WORD ? cint[32] : GEN_INT (32); + + PUT_CODE (&all.smod_32, MOD); + XEXP (&all.smod_32, 0) = &all.reg; + XEXP (&all.smod_32, 1) = XEXP (&all.sdiv_32, 1); + + PUT_CODE (&all.zext, ZERO_EXTEND); + XEXP (&all.zext, 0) = &all.reg; + + PUT_CODE (&all.wide_mult, MULT); + XEXP (&all.wide_mult, 0) = &all.zext; + XEXP (&all.wide_mult, 1) = &all.zext; + + PUT_CODE (&all.wide_lshr, LSHIFTRT); + XEXP (&all.wide_lshr, 0) = &all.wide_mult; + + PUT_CODE (&all.wide_trunc, TRUNCATE); + XEXP (&all.wide_trunc, 0) = &all.wide_lshr; + + PUT_CODE (&all.shift, ASHIFT); + XEXP (&all.shift, 0) = &all.reg; + + PUT_CODE (&all.shift_mult, MULT); + XEXP (&all.shift_mult, 0) = &all.reg; + + PUT_CODE (&all.shift_add, PLUS); + XEXP (&all.shift_add, 0) = &all.shift_mult; + XEXP (&all.shift_add, 1) = &all.reg; + + PUT_CODE (&all.shift_sub, MINUS); + XEXP (&all.shift_sub, 0) = &all.shift_mult; + XEXP (&all.shift_sub, 1) = &all.reg; + + for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); + mode != VOIDmode; + mode = GET_MODE_WIDER_MODE (mode)) + { + PUT_MODE (&all.reg, mode); + PUT_MODE (&all.plus, mode); + PUT_MODE (&all.neg, mode); + PUT_MODE (&all.mult, mode); + PUT_MODE (&all.sdiv, mode); + PUT_MODE (&all.udiv, mode); + PUT_MODE (&all.sdiv_32, mode); + PUT_MODE (&all.smod_32, mode); + PUT_MODE (&all.wide_trunc, mode); + PUT_MODE (&all.shift, mode); + PUT_MODE (&all.shift_mult, mode); + PUT_MODE (&all.shift_add, mode); + PUT_MODE (&all.shift_sub, mode); + + add_cost[mode] = rtx_cost (&all.plus, SET); + neg_cost[mode] = rtx_cost (&all.neg, SET); + mul_cost[mode] = rtx_cost (&all.mult, SET); + sdiv_cost[mode] = rtx_cost (&all.sdiv, SET); + udiv_cost[mode] = rtx_cost (&all.udiv, SET); + + sdiv_pow2_cheap[mode] = (rtx_cost (&all.sdiv_32, SET) + <= 2 * add_cost[mode]); + smod_pow2_cheap[mode] = (rtx_cost (&all.smod_32, SET) + <= 4 * add_cost[mode]); + + wider_mode = GET_MODE_WIDER_MODE (mode); + if (wider_mode != VOIDmode) + { + PUT_MODE (&all.zext, wider_mode); + PUT_MODE (&all.wide_mult, wider_mode); + PUT_MODE (&all.wide_lshr, wider_mode); + XEXP (&all.wide_lshr, 1) = GEN_INT (GET_MODE_BITSIZE (mode)); + + mul_widen_cost[wider_mode] = rtx_cost (&all.wide_mult, SET); + mul_highpart_cost[mode] = rtx_cost (&all.wide_trunc, SET); + } + + shift_cost[mode][0] = 0; + shiftadd_cost[mode][0] = shiftsub_cost[mode][0] = add_cost[mode]; + + n = MIN (MAX_BITS_PER_WORD, GET_MODE_BITSIZE (mode)); + for (m = 1; m < n; m++) + { + XEXP (&all.shift, 1) = cint[m]; + XEXP (&all.shift_mult, 1) = pow2[m]; + + shift_cost[mode][m] = rtx_cost (&all.shift, SET); + shiftadd_cost[mode][m] = rtx_cost (&all.shift_add, SET); + shiftsub_cost[mode][m] = rtx_cost (&all.shift_sub, SET); + } + } +} + +/* Return an rtx representing minus the value of X. + MODE is the intended mode of the result, + useful if X is a CONST_INT. */ + +rtx +negate_rtx (enum machine_mode mode, rtx x) +{ + rtx result = simplify_unary_operation (NEG, mode, x, mode); + + if (result == 0) + result = expand_unop (mode, neg_optab, x, NULL_RTX, 0); + + return result; +} + +/* Report on the availability of insv/extv/extzv and the desired mode + of each of their operands. Returns MAX_MACHINE_MODE if HAVE_foo + is false; else the mode of the specified operand. If OPNO is -1, + all the caller cares about is whether the insn is available. */ +enum machine_mode +mode_for_extraction (enum extraction_pattern pattern, int opno) +{ + const struct insn_data *data; + + switch (pattern) + { + case EP_insv: + if (HAVE_insv) + { + data = &insn_data[CODE_FOR_insv]; + break; + } + return MAX_MACHINE_MODE; + + case EP_extv: + if (HAVE_extv) + { + data = &insn_data[CODE_FOR_extv]; + break; + } + return MAX_MACHINE_MODE; + + case EP_extzv: + if (HAVE_extzv) + { + data = &insn_data[CODE_FOR_extzv]; + break; + } + return MAX_MACHINE_MODE; + + default: + gcc_unreachable (); + } + + if (opno == -1) + return VOIDmode; + + /* Everyone who uses this function used to follow it with + if (result == VOIDmode) result = word_mode; */ + if (data->operand[opno].mode == VOIDmode) + return word_mode; + return data->operand[opno].mode; +} + + +/* Generate code to store value from rtx VALUE + into a bit-field within structure STR_RTX + containing BITSIZE bits starting at bit BITNUM. + FIELDMODE is the machine-mode of the FIELD_DECL node for this field. + ALIGN is the alignment that STR_RTX is known to have. +APPLE LOCAL begin 6020402 + TOTAL_SIZE is the size of the structure in bytes, or -1 if varying. + STRUCT_TYPE is the type of the struct containing the bitfield, or NULL_TREE + if the struct type is not available. +APPLE LOCAL end 6020402 */ + +/* ??? Note that there are two different ideas here for how + to determine the size to count bits within, for a register. + One is BITS_PER_WORD, and the other is the size of operand 3 + of the insv pattern. + + If operand 3 of the insv pattern is VOIDmode, then we will use BITS_PER_WORD + else, we use the mode of operand 3. */ + +rtx +store_bit_field (rtx str_rtx, unsigned HOST_WIDE_INT bitsize, + unsigned HOST_WIDE_INT bitnum, enum machine_mode fieldmode, + /* APPLE LOCAL begin 6020402 */ + rtx value, tree struct_type) + /* APPLE LOCAL end 6020402 */ +{ + unsigned int unit + = (MEM_P (str_rtx)) ? BITS_PER_UNIT : BITS_PER_WORD; + unsigned HOST_WIDE_INT offset, bitpos; + rtx op0 = str_rtx; + int byte_offset; + rtx orig_value; + + enum machine_mode op_mode = mode_for_extraction (EP_insv, 3); + + while (GET_CODE (op0) == SUBREG) + { + /* The following line once was done only if WORDS_BIG_ENDIAN, + but I think that is a mistake. WORDS_BIG_ENDIAN is + meaningful at a much higher level; when structures are copied + between memory and regs, the higher-numbered regs + always get higher addresses. */ + int inner_mode_size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))); + int outer_mode_size = GET_MODE_SIZE (GET_MODE (op0)); + + byte_offset = 0; + + /* Paradoxical subregs need special handling on big endian machines. */ + if (SUBREG_BYTE (op0) == 0 && inner_mode_size < outer_mode_size) + { + int difference = inner_mode_size - outer_mode_size; + + if (WORDS_BIG_ENDIAN) + byte_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD; + if (BYTES_BIG_ENDIAN) + byte_offset += difference % UNITS_PER_WORD; + } + else + byte_offset = SUBREG_BYTE (op0); + + bitnum += byte_offset * BITS_PER_UNIT; + op0 = SUBREG_REG (op0); + } + + /* No action is needed if the target is a register and if the field + lies completely outside that register. This can occur if the source + code contains an out-of-bounds access to a small array. */ + if (REG_P (op0) && bitnum >= GET_MODE_BITSIZE (GET_MODE (op0))) + return value; + + /* Use vec_set patterns for inserting parts of vectors whenever + available. */ + if (VECTOR_MODE_P (GET_MODE (op0)) + && !MEM_P (op0) + && (vec_set_optab->handlers[GET_MODE (op0)].insn_code + != CODE_FOR_nothing) + && fieldmode == GET_MODE_INNER (GET_MODE (op0)) + && bitsize == GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0))) + && !(bitnum % GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0))))) + { + enum machine_mode outermode = GET_MODE (op0); + enum machine_mode innermode = GET_MODE_INNER (outermode); + int icode = (int) vec_set_optab->handlers[outermode].insn_code; + int pos = bitnum / GET_MODE_BITSIZE (innermode); + rtx rtxpos = GEN_INT (pos); + rtx src = value; + rtx dest = op0; + rtx pat, seq; + enum machine_mode mode0 = insn_data[icode].operand[0].mode; + enum machine_mode mode1 = insn_data[icode].operand[1].mode; + enum machine_mode mode2 = insn_data[icode].operand[2].mode; + + start_sequence (); + + if (! (*insn_data[icode].operand[1].predicate) (src, mode1)) + src = copy_to_mode_reg (mode1, src); + + if (! (*insn_data[icode].operand[2].predicate) (rtxpos, mode2)) + rtxpos = copy_to_mode_reg (mode1, rtxpos); + + /* We could handle this, but we should always be called with a pseudo + for our targets and all insns should take them as outputs. */ + gcc_assert ((*insn_data[icode].operand[0].predicate) (dest, mode0) + && (*insn_data[icode].operand[1].predicate) (src, mode1) + && (*insn_data[icode].operand[2].predicate) (rtxpos, mode2)); + pat = GEN_FCN (icode) (dest, src, rtxpos); + seq = get_insns (); + end_sequence (); + if (pat) + { + emit_insn (seq); + emit_insn (pat); + return dest; + } + } + + /* If the target is a register, overwriting the entire object, or storing + a full-word or multi-word field can be done with just a SUBREG. + + If the target is memory, storing any naturally aligned field can be + done with a simple store. For targets that support fast unaligned + memory, any naturally sized, unit aligned field can be done directly. */ + + offset = bitnum / unit; + bitpos = bitnum % unit; + byte_offset = (bitnum % BITS_PER_WORD) / BITS_PER_UNIT + + (offset * UNITS_PER_WORD); + + if (bitpos == 0 + && bitsize == GET_MODE_BITSIZE (fieldmode) + && (!MEM_P (op0) + ? ((GET_MODE_SIZE (fieldmode) >= UNITS_PER_WORD + || GET_MODE_SIZE (GET_MODE (op0)) == GET_MODE_SIZE (fieldmode)) + && byte_offset % GET_MODE_SIZE (fieldmode) == 0) + : (! SLOW_UNALIGNED_ACCESS (fieldmode, MEM_ALIGN (op0)) + || (offset * BITS_PER_UNIT % bitsize == 0 + && MEM_ALIGN (op0) % GET_MODE_BITSIZE (fieldmode) == 0)))) + { + if (MEM_P (op0)) + op0 = adjust_address (op0, fieldmode, offset); + else if (GET_MODE (op0) != fieldmode) + op0 = simplify_gen_subreg (fieldmode, op0, GET_MODE (op0), + byte_offset); + emit_move_insn (op0, value); + return value; + } + + /* Make sure we are playing with integral modes. Pun with subregs + if we aren't. This must come after the entire register case above, + since that case is valid for any mode. The following cases are only + valid for integral modes. */ + { + enum machine_mode imode = int_mode_for_mode (GET_MODE (op0)); + if (imode != GET_MODE (op0)) + { + if (MEM_P (op0)) + op0 = adjust_address (op0, imode, 0); + else + { + gcc_assert (imode != BLKmode); + op0 = gen_lowpart (imode, op0); + } + } + } + + /* We may be accessing data outside the field, which means + we can alias adjacent data. */ + if (MEM_P (op0)) + { + op0 = shallow_copy_rtx (op0); + set_mem_alias_set (op0, 0); + set_mem_expr (op0, 0); + } + + /* If OP0 is a register, BITPOS must count within a word. + But as we have it, it counts within whatever size OP0 now has. + On a bigendian machine, these are not the same, so convert. */ + if (BYTES_BIG_ENDIAN + && !MEM_P (op0) + && unit > GET_MODE_BITSIZE (GET_MODE (op0))) + bitpos += unit - GET_MODE_BITSIZE (GET_MODE (op0)); + + /* Storing an lsb-aligned field in a register + can be done with a movestrict instruction. */ + + if (!MEM_P (op0) + && (BYTES_BIG_ENDIAN ? bitpos + bitsize == unit : bitpos == 0) + && bitsize == GET_MODE_BITSIZE (fieldmode) + && (movstrict_optab->handlers[fieldmode].insn_code + != CODE_FOR_nothing)) + { + int icode = movstrict_optab->handlers[fieldmode].insn_code; + + /* Get appropriate low part of the value being stored. */ + if (GET_CODE (value) == CONST_INT || REG_P (value)) + value = gen_lowpart (fieldmode, value); + else if (!(GET_CODE (value) == SYMBOL_REF + || GET_CODE (value) == LABEL_REF + || GET_CODE (value) == CONST)) + value = convert_to_mode (fieldmode, value, 0); + + if (! (*insn_data[icode].operand[1].predicate) (value, fieldmode)) + value = copy_to_mode_reg (fieldmode, value); + + if (GET_CODE (op0) == SUBREG) + { + /* Else we've got some float mode source being extracted into + a different float mode destination -- this combination of + subregs results in Severe Tire Damage. */ + gcc_assert (GET_MODE (SUBREG_REG (op0)) == fieldmode + || GET_MODE_CLASS (fieldmode) == MODE_INT + || GET_MODE_CLASS (fieldmode) == MODE_PARTIAL_INT); + op0 = SUBREG_REG (op0); + } + + emit_insn (GEN_FCN (icode) + (gen_rtx_SUBREG (fieldmode, op0, + (bitnum % BITS_PER_WORD) / BITS_PER_UNIT + + (offset * UNITS_PER_WORD)), + value)); + + return value; + } + + /* Handle fields bigger than a word. */ + + if (bitsize > BITS_PER_WORD) + { + /* Here we transfer the words of the field + in the order least significant first. + This is because the most significant word is the one which may + be less than full. + However, only do that if the value is not BLKmode. */ + + unsigned int backwards = WORDS_BIG_ENDIAN && fieldmode != BLKmode; + unsigned int nwords = (bitsize + (BITS_PER_WORD - 1)) / BITS_PER_WORD; + unsigned int i; + + /* This is the mode we must force value to, so that there will be enough + subwords to extract. Note that fieldmode will often (always?) be + VOIDmode, because that is what store_field uses to indicate that this + is a bit field, but passing VOIDmode to operand_subword_force + is not allowed. */ + fieldmode = GET_MODE (value); + if (fieldmode == VOIDmode) + fieldmode = smallest_mode_for_size (nwords * BITS_PER_WORD, MODE_INT); + + for (i = 0; i < nwords; i++) + { + /* If I is 0, use the low-order word in both field and target; + if I is 1, use the next to lowest word; and so on. */ + unsigned int wordnum = (backwards ? nwords - i - 1 : i); + unsigned int bit_offset = (backwards + ? MAX ((int) bitsize - ((int) i + 1) + * BITS_PER_WORD, + 0) + : (int) i * BITS_PER_WORD); + + store_bit_field (op0, MIN (BITS_PER_WORD, + bitsize - i * BITS_PER_WORD), + bitnum + bit_offset, word_mode, + /* APPLE LOCAL begin 6020402 */ + operand_subword_force (value, wordnum, fieldmode), + struct_type); + /* APPLE LOCAL end 6020402 */ + } + return value; + } + + /* From here on we can assume that the field to be stored in is + a full-word (whatever type that is), since it is shorter than a word. */ + + /* OFFSET is the number of words or bytes (UNIT says which) + from STR_RTX to the first word or byte containing part of the field. */ + + if (!MEM_P (op0)) + { + if (offset != 0 + || GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD) + { + if (!REG_P (op0)) + { + /* Since this is a destination (lvalue), we can't copy + it to a pseudo. We can remove a SUBREG that does not + change the size of the operand. Such a SUBREG may + have been added above. */ + gcc_assert (GET_CODE (op0) == SUBREG + && (GET_MODE_SIZE (GET_MODE (op0)) + == GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))); + op0 = SUBREG_REG (op0); + } + op0 = gen_rtx_SUBREG (mode_for_size (BITS_PER_WORD, MODE_INT, 0), + op0, (offset * UNITS_PER_WORD)); + } + offset = 0; + } + + /* If VALUE has a floating-point or complex mode, access it as an + integer of the corresponding size. This can occur on a machine + with 64 bit registers that uses SFmode for float. It can also + occur for unaligned float or complex fields. */ + orig_value = value; + if (GET_MODE (value) != VOIDmode + && GET_MODE_CLASS (GET_MODE (value)) != MODE_INT + && GET_MODE_CLASS (GET_MODE (value)) != MODE_PARTIAL_INT) + { + value = gen_reg_rtx (int_mode_for_mode (GET_MODE (value))); + emit_move_insn (gen_lowpart (GET_MODE (orig_value), value), orig_value); + } + + /* Now OFFSET is nonzero only if OP0 is memory + and is therefore always measured in bytes. */ + + if (HAVE_insv + && GET_MODE (value) != BLKmode + && bitsize > 0 + && GET_MODE_BITSIZE (op_mode) >= bitsize + && ! ((REG_P (op0) || GET_CODE (op0) == SUBREG) + && (bitsize + bitpos > GET_MODE_BITSIZE (op_mode))) + && insn_data[CODE_FOR_insv].operand[1].predicate (GEN_INT (bitsize), + VOIDmode)) + { + int xbitpos = bitpos; + rtx value1; + rtx xop0 = op0; + rtx last = get_last_insn (); + rtx pat; + enum machine_mode maxmode = mode_for_extraction (EP_insv, 3); + int save_volatile_ok = volatile_ok; + + volatile_ok = 1; + + /* If this machine's insv can only insert into a register, copy OP0 + into a register and save it back later. */ + if (MEM_P (op0) + && ! ((*insn_data[(int) CODE_FOR_insv].operand[0].predicate) + (op0, VOIDmode))) + { + rtx tempreg; + enum machine_mode bestmode; + + /* Get the mode to use for inserting into this field. If OP0 is + BLKmode, get the smallest mode consistent with the alignment. If + OP0 is a non-BLKmode object that is no wider than MAXMODE, use its + mode. Otherwise, use the smallest mode containing the field. */ + + if (GET_MODE (op0) == BLKmode + || GET_MODE_SIZE (GET_MODE (op0)) > GET_MODE_SIZE (maxmode)) + bestmode + = get_best_mode (bitsize, bitnum, MEM_ALIGN (op0), maxmode, + MEM_VOLATILE_P (op0)); + else + bestmode = GET_MODE (op0); + + if (bestmode == VOIDmode + || GET_MODE_SIZE (bestmode) < GET_MODE_SIZE (fieldmode) + || (SLOW_UNALIGNED_ACCESS (bestmode, MEM_ALIGN (op0)) + && GET_MODE_BITSIZE (bestmode) > MEM_ALIGN (op0))) + goto insv_loses; + + /* Adjust address to point to the containing unit of that mode. + Compute offset as multiple of this unit, counting in bytes. */ + unit = GET_MODE_BITSIZE (bestmode); + offset = (bitnum / unit) * GET_MODE_SIZE (bestmode); + bitpos = bitnum % unit; + op0 = adjust_address (op0, bestmode, offset); + + /* Fetch that unit, store the bitfield in it, then store + the unit. */ + tempreg = copy_to_reg (op0); + /* APPLE LOCAL begin do not use float fieldmode */ + /* If value was float, we munged it to be int above, so it + is never appropriate to use a float fieldmode here. */ + store_bit_field (tempreg, bitsize, bitpos, + (GET_MODE_CLASS (fieldmode) != MODE_INT + && GET_MODE_CLASS (fieldmode) != MODE_PARTIAL_INT) + ? GET_MODE (orig_value) : fieldmode, + /* APPLE LOCAL begin 6020402 */ + orig_value, struct_type); + /* APPLE LOCAL end 6020402 */ + /* APPLE LOCAL end do not use float fieldmode */ + emit_move_insn (op0, tempreg); + return value; + } + volatile_ok = save_volatile_ok; + + /* Add OFFSET into OP0's address. */ + if (MEM_P (xop0)) + xop0 = adjust_address (xop0, byte_mode, offset); + + /* If xop0 is a register, we need it in MAXMODE + to make it acceptable to the format of insv. */ + if (GET_CODE (xop0) == SUBREG) + /* We can't just change the mode, because this might clobber op0, + and we will need the original value of op0 if insv fails. */ + xop0 = gen_rtx_SUBREG (maxmode, SUBREG_REG (xop0), SUBREG_BYTE (xop0)); + if (REG_P (xop0) && GET_MODE (xop0) != maxmode) + xop0 = gen_rtx_SUBREG (maxmode, xop0, 0); + + /* On big-endian machines, we count bits from the most significant. + If the bit field insn does not, we must invert. */ + + if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN) + xbitpos = unit - bitsize - xbitpos; + + /* We have been counting XBITPOS within UNIT. + Count instead within the size of the register. */ + if (BITS_BIG_ENDIAN && !MEM_P (xop0)) + xbitpos += GET_MODE_BITSIZE (maxmode) - unit; + + unit = GET_MODE_BITSIZE (maxmode); + + /* Convert VALUE to maxmode (which insv insn wants) in VALUE1. */ + value1 = value; + if (GET_MODE (value) != maxmode) + { + if (GET_MODE_BITSIZE (GET_MODE (value)) >= bitsize) + { + /* Optimization: Don't bother really extending VALUE + if it has all the bits we will actually use. However, + if we must narrow it, be sure we do it correctly. */ + + if (GET_MODE_SIZE (GET_MODE (value)) < GET_MODE_SIZE (maxmode)) + { + rtx tmp; + + tmp = simplify_subreg (maxmode, value1, GET_MODE (value), 0); + if (! tmp) + tmp = simplify_gen_subreg (maxmode, + force_reg (GET_MODE (value), + value1), + GET_MODE (value), 0); + value1 = tmp; + } + else + value1 = gen_lowpart (maxmode, value1); + } + else if (GET_CODE (value) == CONST_INT) + value1 = gen_int_mode (INTVAL (value), maxmode); + else + /* Parse phase is supposed to make VALUE's data type + match that of the component reference, which is a type + at least as wide as the field; so VALUE should have + a mode that corresponds to that type. */ + gcc_assert (CONSTANT_P (value)); + } + + /* If this machine's insv insists on a register, + get VALUE1 into a register. */ + if (! ((*insn_data[(int) CODE_FOR_insv].operand[3].predicate) + (value1, maxmode))) + value1 = force_reg (maxmode, value1); + + pat = gen_insv (xop0, GEN_INT (bitsize), GEN_INT (xbitpos), value1); + if (pat) + emit_insn (pat); + else + { + delete_insns_since (last); + /* APPLE LOCAL begin 6020402 */ + store_fixed_bit_field (op0, offset, bitsize, bitpos, value, + struct_type); + /* APPLE LOCAL end 6020402 */ + } + } + else + insv_loses: + /* Insv is not available; store using shifts and boolean ops. */ + /* APPLE LOCAL begin 6020402 */ + store_fixed_bit_field (op0, offset, bitsize, bitpos, value, struct_type); + /* APPLE LOCAL end 6020402 */ + return value; +} + +/* APPLE LOCAL begin 6020402 */ +/* Given a struct type and a bit field corresponding to OFFSET_BYTES, BITSIZE, + and BITPOS, returns the widest mode that can be used to store to the bit + field without also writing to a volatile region of the struct. If no mode + is small enough to fit the bit field, then VOIDmode is returned. It is + assumed that OFFSET_BYTES, BITSIZE, and BITPOS correspond to a field + defined explicitly in STRUCT_TYPE. + + STRUCT_TYPE is the type of the struct containing the bit field. + OFFSET_BYTES is the offset of the target field in the struct in bytes. + BITPOS is the offset of the target field in the struct in bits, not + including the byte offset. + BITSIZE is the size of the bit field in bits. +*/ + +static enum machine_mode +widest_mode_including_no_volatile_fields (tree struct_type, + unsigned HOST_WIDE_INT offset_bytes, + unsigned HOST_WIDE_INT bitpos, + unsigned HOST_WIDE_INT bitsize) +{ + enum machine_mode minmode = VOIDmode, maxmode = VOIDmode, tmode; + unsigned target_low, target_high; + + /* Find the narrowest integer mode that contains the bit field. */ + for (minmode = GET_CLASS_NARROWEST_MODE (MODE_INT); minmode != VOIDmode; + minmode = GET_MODE_WIDER_MODE (minmode)) + { + unsigned unit = GET_MODE_BITSIZE (minmode); + if ((bitpos % unit) + bitsize <= unit) + break; + } + + if (minmode == VOIDmode) + return VOIDmode; /* No mode will fit a bitfield of this size. */ + + target_low = offset_bytes * 8 + bitpos; + target_high = target_low + bitsize; + + maxmode = VOIDmode; + + for (tmode = minmode; + tmode != VOIDmode + && GET_MODE_BITSIZE (tmode) <= GET_MODE_BITSIZE (word_mode); + tmode = GET_MODE_WIDER_MODE (tmode)) + { + tree field; + unsigned mode_bitsize = GET_MODE_BITSIZE (tmode); + unsigned mode_low = (target_low / mode_bitsize) * mode_bitsize; + unsigned mode_high = mode_low + mode_bitsize; + + for (field = TYPE_FIELDS (struct_type); field; + field = TREE_CHAIN (field)) + { + unsigned field_low, field_high; + bool field_is_target_field, field_intersects_with_mode_range; + + /* Make sure all values that we need are present for this field. */ + if (TREE_CODE (field) != FIELD_DECL + || DECL_FIELD_OFFSET (field) == NULL_TREE + || DECL_FIELD_BIT_OFFSET (field) == NULL_TREE + || TREE_TYPE (field) == NULL_TREE + || TYPE_SIZE (TREE_TYPE (field)) == NULL_TREE) + continue; + + if (TREE_CODE (DECL_FIELD_OFFSET (field)) != INTEGER_CST) + return VOIDmode; + + field_low = 8 * TREE_INT_CST_LOW (DECL_FIELD_OFFSET (field)) + + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field)); + + if (DECL_SIZE (field) != NULL_TREE) + field_high = field_low + TREE_INT_CST_LOW (DECL_SIZE (field)); + else + { + if (TREE_CODE (TYPE_SIZE (TYPE_SIZE (TREE_TYPE (field)))) + != INTEGER_CST) + return VOIDmode; + + field_high = field_low + + TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (field))); + } + + /* We assume that this will be true if the current field is the + target field. This may not be the case if the field is + split up, for instance. */ + field_is_target_field = + field_low == target_low && field_high == target_high; + + /* The current field and the current mode intersect if either the + field low or the field high is in the mode range, or if the + field completely contains the mode range. */ + field_intersects_with_mode_range = + (field_high > mode_low && field_high <= mode_high) + || (field_low >= mode_low && field_low < mode_high) + || (field_high >= mode_high && field_low <= mode_low); + + if (!field_is_target_field + && TYPE_VOLATILE (TREE_TYPE (field)) + && field_intersects_with_mode_range) + /* The current field is volatile and within the mode of the + target field. Return the max mode allowed up to this point. */ + return maxmode; + } + + maxmode = tmode; + } + + return maxmode; +} +/* APPLE LOCAL end 6020402 */ + +/* Use shifts and boolean operations to store VALUE + into a bit field of width BITSIZE + in a memory location specified by OP0 except offset by OFFSET bytes. + (OFFSET must be 0 if OP0 is a register.) + The field starts at position BITPOS within the byte. + (If OP0 is a register, it may be a full word or a narrower mode, + but BITPOS still counts within a full word, + which is significant on bigendian machines.) */ + +static void +store_fixed_bit_field (rtx op0, unsigned HOST_WIDE_INT offset, + unsigned HOST_WIDE_INT bitsize, + /* APPLE LOCAL begin 6020402 */ + unsigned HOST_WIDE_INT bitpos, rtx value, + tree struct_type) + /* APPLE LOCAL end 6020402 */ +{ + enum machine_mode mode; + unsigned int total_bits = BITS_PER_WORD; + rtx temp; + int all_zero = 0; + int all_one = 0; + + /* There is a case not handled here: + a structure with a known alignment of just a halfword + and a field split across two aligned halfwords within the structure. + Or likewise a structure with a known alignment of just a byte + and a field split across two bytes. + Such cases are not supposed to be able to occur. */ + + if (REG_P (op0) || GET_CODE (op0) == SUBREG) + { + gcc_assert (!offset); + /* Special treatment for a bit field split across two registers. */ + if (bitsize + bitpos > BITS_PER_WORD) + { + store_split_bit_field (op0, bitsize, bitpos, value); + return; + } + } + else + { + /* Get the proper mode to use for this field. We want a mode that + includes the entire field. If such a mode would be larger than + a word, we won't be doing the extraction the normal way. + We don't want a mode bigger than the destination. */ + + /* APPLE LOCAL begin 6020402 */ + enum machine_mode maxmode = GET_MODE (op0); + + /* Find the largest mode that doesn't interfere with volatile fields in + * the struct. */ + if (struct_type != NULL_TREE && TREE_CODE (struct_type) == RECORD_TYPE) + maxmode = widest_mode_including_no_volatile_fields (struct_type, + offset, + bitpos, bitsize); + + if (GET_MODE_BITSIZE (maxmode) == 0 + || GET_MODE_BITSIZE (maxmode) > GET_MODE_BITSIZE (word_mode)) + maxmode = word_mode; + /* APPLE LOCAL end 6020402 */ + mode = get_best_mode (bitsize, bitpos + offset * BITS_PER_UNIT, + /* APPLE LOCAL begin 6020402 */ + MEM_ALIGN (op0), maxmode, MEM_VOLATILE_P (op0)); + /* APPLE LOCAL end 6020402 */ + + if (mode == VOIDmode) + { + /* The only way this should occur is if the field spans word + boundaries. */ + store_split_bit_field (op0, bitsize, bitpos + offset * BITS_PER_UNIT, + value); + return; + } + + total_bits = GET_MODE_BITSIZE (mode); + + /* Make sure bitpos is valid for the chosen mode. Adjust BITPOS to + be in the range 0 to total_bits-1, and put any excess bytes in + OFFSET. */ + if (bitpos >= total_bits) + { + offset += (bitpos / total_bits) * (total_bits / BITS_PER_UNIT); + bitpos -= ((bitpos / total_bits) * (total_bits / BITS_PER_UNIT) + * BITS_PER_UNIT); + } + + /* Get ref to an aligned byte, halfword, or word containing the field. + Adjust BITPOS to be position within a word, + and OFFSET to be the offset of that word. + Then alter OP0 to refer to that word. */ + bitpos += (offset % (total_bits / BITS_PER_UNIT)) * BITS_PER_UNIT; + offset -= (offset % (total_bits / BITS_PER_UNIT)); + op0 = adjust_address (op0, mode, offset); + } + + mode = GET_MODE (op0); + + /* Now MODE is either some integral mode for a MEM as OP0, + or is a full-word for a REG as OP0. TOTAL_BITS corresponds. + The bit field is contained entirely within OP0. + BITPOS is the starting bit number within OP0. + (OP0's mode may actually be narrower than MODE.) */ + + if (BYTES_BIG_ENDIAN) + /* BITPOS is the distance between our msb + and that of the containing datum. + Convert it to the distance from the lsb. */ + bitpos = total_bits - bitsize - bitpos; + + /* Now BITPOS is always the distance between our lsb + and that of OP0. */ + + /* Shift VALUE left by BITPOS bits. If VALUE is not constant, + we must first convert its mode to MODE. */ + + if (GET_CODE (value) == CONST_INT) + { + HOST_WIDE_INT v = INTVAL (value); + + if (bitsize < HOST_BITS_PER_WIDE_INT) + v &= ((HOST_WIDE_INT) 1 << bitsize) - 1; + + if (v == 0) + all_zero = 1; + else if ((bitsize < HOST_BITS_PER_WIDE_INT + && v == ((HOST_WIDE_INT) 1 << bitsize) - 1) + || (bitsize == HOST_BITS_PER_WIDE_INT && v == -1)) + all_one = 1; + + value = lshift_value (mode, value, bitpos, bitsize); + } + else + { + int must_and = (GET_MODE_BITSIZE (GET_MODE (value)) != bitsize + && bitpos + bitsize != GET_MODE_BITSIZE (mode)); + + if (GET_MODE (value) != mode) + { + if ((REG_P (value) || GET_CODE (value) == SUBREG) + && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (value))) + value = gen_lowpart (mode, value); + else + value = convert_to_mode (mode, value, 1); + } + + if (must_and) + value = expand_binop (mode, and_optab, value, + mask_rtx (mode, 0, bitsize, 0), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + if (bitpos > 0) + value = expand_shift (LSHIFT_EXPR, mode, value, + build_int_cst (NULL_TREE, bitpos), NULL_RTX, 1); + } + + /* Now clear the chosen bits in OP0, + except that if VALUE is -1 we need not bother. */ + /* We keep the intermediates in registers to allow CSE to combine + consecutive bitfield assignments. */ + + temp = force_reg (mode, op0); + + if (! all_one) + { + temp = expand_binop (mode, and_optab, temp, + mask_rtx (mode, bitpos, bitsize, 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = force_reg (mode, temp); + } + + /* Now logical-or VALUE into OP0, unless it is zero. */ + + if (! all_zero) + { + temp = expand_binop (mode, ior_optab, temp, value, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = force_reg (mode, temp); + } + + if (op0 != temp) + emit_move_insn (op0, temp); +} + +/* Store a bit field that is split across multiple accessible memory objects. + + OP0 is the REG, SUBREG or MEM rtx for the first of the objects. + BITSIZE is the field width; BITPOS the position of its first bit + (within the word). + VALUE is the value to store. + + This does not yet handle fields wider than BITS_PER_WORD. */ + +static void +store_split_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize, + unsigned HOST_WIDE_INT bitpos, rtx value) +{ + unsigned int unit; + unsigned int bitsdone = 0; + + /* Make sure UNIT isn't larger than BITS_PER_WORD, we can only handle that + much at a time. */ + if (REG_P (op0) || GET_CODE (op0) == SUBREG) + unit = BITS_PER_WORD; + else + unit = MIN (MEM_ALIGN (op0), BITS_PER_WORD); + + /* If VALUE is a constant other than a CONST_INT, get it into a register in + WORD_MODE. If we can do this using gen_lowpart_common, do so. Note + that VALUE might be a floating-point constant. */ + if (CONSTANT_P (value) && GET_CODE (value) != CONST_INT) + { + rtx word = gen_lowpart_common (word_mode, value); + + if (word && (value != word)) + value = word; + else + value = gen_lowpart_common (word_mode, + force_reg (GET_MODE (value) != VOIDmode + ? GET_MODE (value) + : word_mode, value)); + } + + while (bitsdone < bitsize) + { + unsigned HOST_WIDE_INT thissize; + rtx part, word; + unsigned HOST_WIDE_INT thispos; + unsigned HOST_WIDE_INT offset; + + offset = (bitpos + bitsdone) / unit; + thispos = (bitpos + bitsdone) % unit; + + /* THISSIZE must not overrun a word boundary. Otherwise, + store_fixed_bit_field will call us again, and we will mutually + recurse forever. */ + thissize = MIN (bitsize - bitsdone, BITS_PER_WORD); + thissize = MIN (thissize, unit - thispos); + + if (BYTES_BIG_ENDIAN) + { + int total_bits; + + /* We must do an endian conversion exactly the same way as it is + done in extract_bit_field, so that the two calls to + extract_fixed_bit_field will have comparable arguments. */ + if (!MEM_P (value) || GET_MODE (value) == BLKmode) + total_bits = BITS_PER_WORD; + else + total_bits = GET_MODE_BITSIZE (GET_MODE (value)); + + /* Fetch successively less significant portions. */ + if (GET_CODE (value) == CONST_INT) + part = GEN_INT (((unsigned HOST_WIDE_INT) (INTVAL (value)) + >> (bitsize - bitsdone - thissize)) + & (((HOST_WIDE_INT) 1 << thissize) - 1)); + else + /* The args are chosen so that the last part includes the + lsb. Give extract_bit_field the value it needs (with + endianness compensation) to fetch the piece we want. */ + part = extract_fixed_bit_field (word_mode, value, 0, thissize, + total_bits - bitsize + bitsdone, + NULL_RTX, 1); + } + else + { + /* Fetch successively more significant portions. */ + if (GET_CODE (value) == CONST_INT) + part = GEN_INT (((unsigned HOST_WIDE_INT) (INTVAL (value)) + >> bitsdone) + & (((HOST_WIDE_INT) 1 << thissize) - 1)); + else + part = extract_fixed_bit_field (word_mode, value, 0, thissize, + bitsdone, NULL_RTX, 1); + } + + /* If OP0 is a register, then handle OFFSET here. + + When handling multiword bitfields, extract_bit_field may pass + down a word_mode SUBREG of a larger REG for a bitfield that actually + crosses a word boundary. Thus, for a SUBREG, we must find + the current word starting from the base register. */ + if (GET_CODE (op0) == SUBREG) + { + int word_offset = (SUBREG_BYTE (op0) / UNITS_PER_WORD) + offset; + word = operand_subword_force (SUBREG_REG (op0), word_offset, + GET_MODE (SUBREG_REG (op0))); + offset = 0; + } + else if (REG_P (op0)) + { + word = operand_subword_force (op0, offset, GET_MODE (op0)); + offset = 0; + } + else + word = op0; + + /* OFFSET is in UNITs, and UNIT is in bits. + store_fixed_bit_field wants offset in bytes. */ + store_fixed_bit_field (word, offset * unit / BITS_PER_UNIT, thissize, + /* APPLE LOCAL begin 6020402 */ + thispos, part, NULL_TREE); + /* APPLE LOCAL end 6020402 */ + bitsdone += thissize; + } +} + +/* Generate code to extract a byte-field from STR_RTX + containing BITSIZE bits, starting at BITNUM, + and put it in TARGET if possible (if TARGET is nonzero). + Regardless of TARGET, we return the rtx for where the value is placed. + + STR_RTX is the structure containing the byte (a REG or MEM). + UNSIGNEDP is nonzero if this is an unsigned bit field. + MODE is the natural mode of the field value once extracted. + TMODE is the mode the caller would like the value to have; + but the value may be returned with type MODE instead. + + TOTAL_SIZE is the size in bytes of the containing structure, + or -1 if varying. + + If a TARGET is specified and we can store in it at no extra cost, + we do so, and return TARGET. + Otherwise, we return a REG of mode TMODE or MODE, with TMODE preferred + if they are equally easy. */ + +rtx +extract_bit_field (rtx str_rtx, unsigned HOST_WIDE_INT bitsize, + unsigned HOST_WIDE_INT bitnum, int unsignedp, rtx target, + enum machine_mode mode, enum machine_mode tmode) +{ + unsigned int unit + = (MEM_P (str_rtx)) ? BITS_PER_UNIT : BITS_PER_WORD; + unsigned HOST_WIDE_INT offset, bitpos; + rtx op0 = str_rtx; + rtx spec_target = target; + rtx spec_target_subreg = 0; + enum machine_mode int_mode; + enum machine_mode extv_mode = mode_for_extraction (EP_extv, 0); + enum machine_mode extzv_mode = mode_for_extraction (EP_extzv, 0); + enum machine_mode mode1; + int byte_offset; + + if (tmode == VOIDmode) + tmode = mode; + + while (GET_CODE (op0) == SUBREG) + { + bitnum += SUBREG_BYTE (op0) * BITS_PER_UNIT; + op0 = SUBREG_REG (op0); + } + + /* If we have an out-of-bounds access to a register, just return an + uninitialized register of the required mode. This can occur if the + source code contains an out-of-bounds access to a small array. */ + if (REG_P (op0) && bitnum >= GET_MODE_BITSIZE (GET_MODE (op0))) + return gen_reg_rtx (tmode); + + if (REG_P (op0) + && mode == GET_MODE (op0) + && bitnum == 0 + && bitsize == GET_MODE_BITSIZE (GET_MODE (op0))) + { + /* We're trying to extract a full register from itself. */ + return op0; + } + + /* Use vec_extract patterns for extracting parts of vectors whenever + available. */ + if (VECTOR_MODE_P (GET_MODE (op0)) + && !MEM_P (op0) + && (vec_extract_optab->handlers[GET_MODE (op0)].insn_code + != CODE_FOR_nothing) + && ((bitnum + bitsize - 1) / GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0))) + == bitnum / GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0))))) + { + enum machine_mode outermode = GET_MODE (op0); + enum machine_mode innermode = GET_MODE_INNER (outermode); + int icode = (int) vec_extract_optab->handlers[outermode].insn_code; + unsigned HOST_WIDE_INT pos = bitnum / GET_MODE_BITSIZE (innermode); + rtx rtxpos = GEN_INT (pos); + rtx src = op0; + rtx dest = NULL, pat, seq; + enum machine_mode mode0 = insn_data[icode].operand[0].mode; + enum machine_mode mode1 = insn_data[icode].operand[1].mode; + enum machine_mode mode2 = insn_data[icode].operand[2].mode; + + if (innermode == tmode || innermode == mode) + dest = target; + + if (!dest) + dest = gen_reg_rtx (innermode); + + start_sequence (); + + if (! (*insn_data[icode].operand[0].predicate) (dest, mode0)) + dest = copy_to_mode_reg (mode0, dest); + + if (! (*insn_data[icode].operand[1].predicate) (src, mode1)) + src = copy_to_mode_reg (mode1, src); + + if (! (*insn_data[icode].operand[2].predicate) (rtxpos, mode2)) + rtxpos = copy_to_mode_reg (mode1, rtxpos); + + /* We could handle this, but we should always be called with a pseudo + for our targets and all insns should take them as outputs. */ + gcc_assert ((*insn_data[icode].operand[0].predicate) (dest, mode0) + && (*insn_data[icode].operand[1].predicate) (src, mode1) + && (*insn_data[icode].operand[2].predicate) (rtxpos, mode2)); + + pat = GEN_FCN (icode) (dest, src, rtxpos); + seq = get_insns (); + end_sequence (); + if (pat) + { + emit_insn (seq); + emit_insn (pat); + return dest; + } + } + + /* Make sure we are playing with integral modes. Pun with subregs + if we aren't. */ + { + enum machine_mode imode = int_mode_for_mode (GET_MODE (op0)); + if (imode != GET_MODE (op0)) + { + if (MEM_P (op0)) + op0 = adjust_address (op0, imode, 0); + else + { + gcc_assert (imode != BLKmode); + op0 = gen_lowpart (imode, op0); + + /* If we got a SUBREG, force it into a register since we + aren't going to be able to do another SUBREG on it. */ + if (GET_CODE (op0) == SUBREG) + op0 = force_reg (imode, op0); + } + } + } + + /* We may be accessing data outside the field, which means + we can alias adjacent data. */ + if (MEM_P (op0)) + { + op0 = shallow_copy_rtx (op0); + set_mem_alias_set (op0, 0); + set_mem_expr (op0, 0); + } + + /* Extraction of a full-word or multi-word value from a structure + in a register or aligned memory can be done with just a SUBREG. + A subword value in the least significant part of a register + can also be extracted with a SUBREG. For this, we need the + byte offset of the value in op0. */ + + bitpos = bitnum % unit; + offset = bitnum / unit; + byte_offset = bitpos / BITS_PER_UNIT + offset * UNITS_PER_WORD; + + /* If OP0 is a register, BITPOS must count within a word. + But as we have it, it counts within whatever size OP0 now has. + On a bigendian machine, these are not the same, so convert. */ + if (BYTES_BIG_ENDIAN + && !MEM_P (op0) + && unit > GET_MODE_BITSIZE (GET_MODE (op0))) + bitpos += unit - GET_MODE_BITSIZE (GET_MODE (op0)); + + /* ??? We currently assume TARGET is at least as big as BITSIZE. + If that's wrong, the solution is to test for it and set TARGET to 0 + if needed. */ + + /* Only scalar integer modes can be converted via subregs. There is an + additional problem for FP modes here in that they can have a precision + which is different from the size. mode_for_size uses precision, but + we want a mode based on the size, so we must avoid calling it for FP + modes. */ + mode1 = (SCALAR_INT_MODE_P (tmode) + ? mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0) + : mode); + + if (((bitsize >= BITS_PER_WORD && bitsize == GET_MODE_BITSIZE (mode) + && bitpos % BITS_PER_WORD == 0) + || (mode1 != BLKmode + /* ??? The big endian test here is wrong. This is correct + if the value is in a register, and if mode_for_size is not + the same mode as op0. This causes us to get unnecessarily + inefficient code from the Thumb port when -mbig-endian. */ + && (BYTES_BIG_ENDIAN + ? bitpos + bitsize == BITS_PER_WORD + : bitpos == 0))) + && ((!MEM_P (op0) + && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode), + GET_MODE_BITSIZE (GET_MODE (op0))) + && GET_MODE_SIZE (mode1) != 0 + && byte_offset % GET_MODE_SIZE (mode1) == 0) + || (MEM_P (op0) + && (! SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (op0)) + || (offset * BITS_PER_UNIT % bitsize == 0 + && MEM_ALIGN (op0) % bitsize == 0))))) + { + if (mode1 != GET_MODE (op0)) + { + if (MEM_P (op0)) + op0 = adjust_address (op0, mode1, offset); + else + { + rtx sub = simplify_gen_subreg (mode1, op0, GET_MODE (op0), + byte_offset); + if (sub == NULL) + goto no_subreg_mode_swap; + op0 = sub; + } + } + if (mode1 != mode) + return convert_to_mode (tmode, op0, unsignedp); + return op0; + } + no_subreg_mode_swap: + + /* Handle fields bigger than a word. */ + + if (bitsize > BITS_PER_WORD) + { + /* Here we transfer the words of the field + in the order least significant first. + This is because the most significant word is the one which may + be less than full. */ + + unsigned int nwords = (bitsize + (BITS_PER_WORD - 1)) / BITS_PER_WORD; + unsigned int i; + + if (target == 0 || !REG_P (target)) + target = gen_reg_rtx (mode); + + /* Indicate for flow that the entire target reg is being set. */ + emit_insn (gen_rtx_CLOBBER (VOIDmode, target)); + + for (i = 0; i < nwords; i++) + { + /* If I is 0, use the low-order word in both field and target; + if I is 1, use the next to lowest word; and so on. */ + /* Word number in TARGET to use. */ + unsigned int wordnum + = (WORDS_BIG_ENDIAN + ? GET_MODE_SIZE (GET_MODE (target)) / UNITS_PER_WORD - i - 1 + : i); + /* Offset from start of field in OP0. */ + unsigned int bit_offset = (WORDS_BIG_ENDIAN + ? MAX (0, ((int) bitsize - ((int) i + 1) + * (int) BITS_PER_WORD)) + : (int) i * BITS_PER_WORD); + rtx target_part = operand_subword (target, wordnum, 1, VOIDmode); + rtx result_part + = extract_bit_field (op0, MIN (BITS_PER_WORD, + bitsize - i * BITS_PER_WORD), + bitnum + bit_offset, 1, target_part, mode, + word_mode); + + gcc_assert (target_part); + + if (result_part != target_part) + emit_move_insn (target_part, result_part); + } + + if (unsignedp) + { + /* Unless we've filled TARGET, the upper regs in a multi-reg value + need to be zero'd out. */ + if (GET_MODE_SIZE (GET_MODE (target)) > nwords * UNITS_PER_WORD) + { + unsigned int i, total_words; + + total_words = GET_MODE_SIZE (GET_MODE (target)) / UNITS_PER_WORD; + for (i = nwords; i < total_words; i++) + emit_move_insn + (operand_subword (target, + WORDS_BIG_ENDIAN ? total_words - i - 1 : i, + 1, VOIDmode), + const0_rtx); + } + return target; + } + + /* Signed bit field: sign-extend with two arithmetic shifts. */ + target = expand_shift (LSHIFT_EXPR, mode, target, + build_int_cst (NULL_TREE, + GET_MODE_BITSIZE (mode) - bitsize), + NULL_RTX, 0); + return expand_shift (RSHIFT_EXPR, mode, target, + build_int_cst (NULL_TREE, + GET_MODE_BITSIZE (mode) - bitsize), + NULL_RTX, 0); + } + + /* From here on we know the desired field is smaller than a word. */ + + /* Check if there is a correspondingly-sized integer field, so we can + safely extract it as one size of integer, if necessary; then + truncate or extend to the size that is wanted; then use SUBREGs or + convert_to_mode to get one of the modes we really wanted. */ + + int_mode = int_mode_for_mode (tmode); + if (int_mode == BLKmode) + int_mode = int_mode_for_mode (mode); + /* Should probably push op0 out to memory and then do a load. */ + gcc_assert (int_mode != BLKmode); + + /* OFFSET is the number of words or bytes (UNIT says which) + from STR_RTX to the first word or byte containing part of the field. */ + if (!MEM_P (op0)) + { + if (offset != 0 + || GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD) + { + if (!REG_P (op0)) + op0 = copy_to_reg (op0); + op0 = gen_rtx_SUBREG (mode_for_size (BITS_PER_WORD, MODE_INT, 0), + op0, (offset * UNITS_PER_WORD)); + } + offset = 0; + } + + /* Now OFFSET is nonzero only for memory operands. */ + + if (unsignedp) + { + if (HAVE_extzv + && bitsize > 0 + && GET_MODE_BITSIZE (extzv_mode) >= bitsize + && ! ((REG_P (op0) || GET_CODE (op0) == SUBREG) + && (bitsize + bitpos > GET_MODE_BITSIZE (extzv_mode)))) + { + unsigned HOST_WIDE_INT xbitpos = bitpos, xoffset = offset; + rtx bitsize_rtx, bitpos_rtx; + rtx last = get_last_insn (); + rtx xop0 = op0; + rtx xtarget = target; + rtx xspec_target = spec_target; + rtx xspec_target_subreg = spec_target_subreg; + rtx pat; + enum machine_mode maxmode = mode_for_extraction (EP_extzv, 0); + + if (MEM_P (xop0)) + { + int save_volatile_ok = volatile_ok; + volatile_ok = 1; + + /* Is the memory operand acceptable? */ + if (! ((*insn_data[(int) CODE_FOR_extzv].operand[1].predicate) + (xop0, GET_MODE (xop0)))) + { + /* No, load into a reg and extract from there. */ + enum machine_mode bestmode; + + /* Get the mode to use for inserting into this field. If + OP0 is BLKmode, get the smallest mode consistent with the + alignment. If OP0 is a non-BLKmode object that is no + wider than MAXMODE, use its mode. Otherwise, use the + smallest mode containing the field. */ + + if (GET_MODE (xop0) == BLKmode + || (GET_MODE_SIZE (GET_MODE (op0)) + > GET_MODE_SIZE (maxmode))) + bestmode = get_best_mode (bitsize, bitnum, + MEM_ALIGN (xop0), maxmode, + MEM_VOLATILE_P (xop0)); + else + bestmode = GET_MODE (xop0); + + if (bestmode == VOIDmode + || (SLOW_UNALIGNED_ACCESS (bestmode, MEM_ALIGN (xop0)) + && GET_MODE_BITSIZE (bestmode) > MEM_ALIGN (xop0))) + goto extzv_loses; + + /* Compute offset as multiple of this unit, + counting in bytes. */ + unit = GET_MODE_BITSIZE (bestmode); + xoffset = (bitnum / unit) * GET_MODE_SIZE (bestmode); + xbitpos = bitnum % unit; + xop0 = adjust_address (xop0, bestmode, xoffset); + + /* Make sure register is big enough for the whole field. */ + if (xoffset * BITS_PER_UNIT + unit + < offset * BITS_PER_UNIT + bitsize) + goto extzv_loses; + + /* Fetch it to a register in that size. */ + xop0 = force_reg (bestmode, xop0); + + /* XBITPOS counts within UNIT, which is what is expected. */ + } + else + /* Get ref to first byte containing part of the field. */ + xop0 = adjust_address (xop0, byte_mode, xoffset); + + volatile_ok = save_volatile_ok; + } + + /* If op0 is a register, we need it in MAXMODE (which is usually + SImode). to make it acceptable to the format of extzv. */ + if (GET_CODE (xop0) == SUBREG && GET_MODE (xop0) != maxmode) + goto extzv_loses; + if (REG_P (xop0) && GET_MODE (xop0) != maxmode) + xop0 = gen_rtx_SUBREG (maxmode, xop0, 0); + + /* On big-endian machines, we count bits from the most significant. + If the bit field insn does not, we must invert. */ + if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN) + xbitpos = unit - bitsize - xbitpos; + + /* Now convert from counting within UNIT to counting in MAXMODE. */ + if (BITS_BIG_ENDIAN && !MEM_P (xop0)) + xbitpos += GET_MODE_BITSIZE (maxmode) - unit; + + unit = GET_MODE_BITSIZE (maxmode); + + if (xtarget == 0) + xtarget = xspec_target = gen_reg_rtx (tmode); + + if (GET_MODE (xtarget) != maxmode) + { + if (REG_P (xtarget)) + { + int wider = (GET_MODE_SIZE (maxmode) + > GET_MODE_SIZE (GET_MODE (xtarget))); + xtarget = gen_lowpart (maxmode, xtarget); + if (wider) + xspec_target_subreg = xtarget; + } + else + xtarget = gen_reg_rtx (maxmode); + } + + /* If this machine's extzv insists on a register target, + make sure we have one. */ + if (! ((*insn_data[(int) CODE_FOR_extzv].operand[0].predicate) + (xtarget, maxmode))) + xtarget = gen_reg_rtx (maxmode); + + bitsize_rtx = GEN_INT (bitsize); + bitpos_rtx = GEN_INT (xbitpos); + + pat = gen_extzv (xtarget, xop0, bitsize_rtx, bitpos_rtx); + if (pat) + { + emit_insn (pat); + target = xtarget; + spec_target = xspec_target; + spec_target_subreg = xspec_target_subreg; + } + else + { + delete_insns_since (last); + target = extract_fixed_bit_field (int_mode, op0, offset, bitsize, + bitpos, target, 1); + } + } + else + extzv_loses: + target = extract_fixed_bit_field (int_mode, op0, offset, bitsize, + bitpos, target, 1); + } + else + { + if (HAVE_extv + && bitsize > 0 + && GET_MODE_BITSIZE (extv_mode) >= bitsize + && ! ((REG_P (op0) || GET_CODE (op0) == SUBREG) + && (bitsize + bitpos > GET_MODE_BITSIZE (extv_mode)))) + { + int xbitpos = bitpos, xoffset = offset; + rtx bitsize_rtx, bitpos_rtx; + rtx last = get_last_insn (); + rtx xop0 = op0, xtarget = target; + rtx xspec_target = spec_target; + rtx xspec_target_subreg = spec_target_subreg; + rtx pat; + enum machine_mode maxmode = mode_for_extraction (EP_extv, 0); + + if (MEM_P (xop0)) + { + /* Is the memory operand acceptable? */ + if (! ((*insn_data[(int) CODE_FOR_extv].operand[1].predicate) + (xop0, GET_MODE (xop0)))) + { + /* No, load into a reg and extract from there. */ + enum machine_mode bestmode; + + /* Get the mode to use for inserting into this field. If + OP0 is BLKmode, get the smallest mode consistent with the + alignment. If OP0 is a non-BLKmode object that is no + wider than MAXMODE, use its mode. Otherwise, use the + smallest mode containing the field. */ + + if (GET_MODE (xop0) == BLKmode + || (GET_MODE_SIZE (GET_MODE (op0)) + > GET_MODE_SIZE (maxmode))) + bestmode = get_best_mode (bitsize, bitnum, + MEM_ALIGN (xop0), maxmode, + MEM_VOLATILE_P (xop0)); + else + bestmode = GET_MODE (xop0); + + if (bestmode == VOIDmode + || (SLOW_UNALIGNED_ACCESS (bestmode, MEM_ALIGN (xop0)) + && GET_MODE_BITSIZE (bestmode) > MEM_ALIGN (xop0))) + goto extv_loses; + + /* Compute offset as multiple of this unit, + counting in bytes. */ + unit = GET_MODE_BITSIZE (bestmode); + xoffset = (bitnum / unit) * GET_MODE_SIZE (bestmode); + xbitpos = bitnum % unit; + xop0 = adjust_address (xop0, bestmode, xoffset); + + /* Make sure register is big enough for the whole field. */ + if (xoffset * BITS_PER_UNIT + unit + < offset * BITS_PER_UNIT + bitsize) + goto extv_loses; + + /* Fetch it to a register in that size. */ + xop0 = force_reg (bestmode, xop0); + + /* XBITPOS counts within UNIT, which is what is expected. */ + } + else + /* Get ref to first byte containing part of the field. */ + xop0 = adjust_address (xop0, byte_mode, xoffset); + } + + /* If op0 is a register, we need it in MAXMODE (which is usually + SImode) to make it acceptable to the format of extv. */ + if (GET_CODE (xop0) == SUBREG && GET_MODE (xop0) != maxmode) + goto extv_loses; + if (REG_P (xop0) && GET_MODE (xop0) != maxmode) + xop0 = gen_rtx_SUBREG (maxmode, xop0, 0); + + /* On big-endian machines, we count bits from the most significant. + If the bit field insn does not, we must invert. */ + if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN) + xbitpos = unit - bitsize - xbitpos; + + /* XBITPOS counts within a size of UNIT. + Adjust to count within a size of MAXMODE. */ + if (BITS_BIG_ENDIAN && !MEM_P (xop0)) + xbitpos += (GET_MODE_BITSIZE (maxmode) - unit); + + unit = GET_MODE_BITSIZE (maxmode); + + if (xtarget == 0) + xtarget = xspec_target = gen_reg_rtx (tmode); + + if (GET_MODE (xtarget) != maxmode) + { + if (REG_P (xtarget)) + { + int wider = (GET_MODE_SIZE (maxmode) + > GET_MODE_SIZE (GET_MODE (xtarget))); + xtarget = gen_lowpart (maxmode, xtarget); + if (wider) + xspec_target_subreg = xtarget; + } + else + xtarget = gen_reg_rtx (maxmode); + } + + /* If this machine's extv insists on a register target, + make sure we have one. */ + if (! ((*insn_data[(int) CODE_FOR_extv].operand[0].predicate) + (xtarget, maxmode))) + xtarget = gen_reg_rtx (maxmode); + + bitsize_rtx = GEN_INT (bitsize); + bitpos_rtx = GEN_INT (xbitpos); + + pat = gen_extv (xtarget, xop0, bitsize_rtx, bitpos_rtx); + if (pat) + { + emit_insn (pat); + target = xtarget; + spec_target = xspec_target; + spec_target_subreg = xspec_target_subreg; + } + else + { + delete_insns_since (last); + target = extract_fixed_bit_field (int_mode, op0, offset, bitsize, + bitpos, target, 0); + } + } + else + extv_loses: + target = extract_fixed_bit_field (int_mode, op0, offset, bitsize, + bitpos, target, 0); + } + if (target == spec_target) + return target; + if (target == spec_target_subreg) + return spec_target; + if (GET_MODE (target) != tmode && GET_MODE (target) != mode) + { + /* If the target mode is not a scalar integral, first convert to the + integer mode of that size and then access it as a floating-point + value via a SUBREG. */ + if (!SCALAR_INT_MODE_P (tmode)) + { + enum machine_mode smode + = mode_for_size (GET_MODE_BITSIZE (tmode), MODE_INT, 0); + target = convert_to_mode (smode, target, unsignedp); + target = force_reg (smode, target); + return gen_lowpart (tmode, target); + } + + return convert_to_mode (tmode, target, unsignedp); + } + return target; +} + +/* Extract a bit field using shifts and boolean operations + Returns an rtx to represent the value. + OP0 addresses a register (word) or memory (byte). + BITPOS says which bit within the word or byte the bit field starts in. + OFFSET says how many bytes farther the bit field starts; + it is 0 if OP0 is a register. + BITSIZE says how many bits long the bit field is. + (If OP0 is a register, it may be narrower than a full word, + but BITPOS still counts within a full word, + which is significant on bigendian machines.) + + UNSIGNEDP is nonzero for an unsigned bit field (don't sign-extend value). + If TARGET is nonzero, attempts to store the value there + and return TARGET, but this is not guaranteed. + If TARGET is not used, create a pseudo-reg of mode TMODE for the value. */ + +static rtx +extract_fixed_bit_field (enum machine_mode tmode, rtx op0, + unsigned HOST_WIDE_INT offset, + unsigned HOST_WIDE_INT bitsize, + unsigned HOST_WIDE_INT bitpos, rtx target, + int unsignedp) +{ + unsigned int total_bits = BITS_PER_WORD; + enum machine_mode mode; + + if (GET_CODE (op0) == SUBREG || REG_P (op0)) + { + /* Special treatment for a bit field split across two registers. */ + if (bitsize + bitpos > BITS_PER_WORD) + return extract_split_bit_field (op0, bitsize, bitpos, unsignedp); + } + else + { + /* Get the proper mode to use for this field. We want a mode that + includes the entire field. If such a mode would be larger than + a word, we won't be doing the extraction the normal way. */ + + mode = get_best_mode (bitsize, bitpos + offset * BITS_PER_UNIT, + MEM_ALIGN (op0), word_mode, MEM_VOLATILE_P (op0)); + + if (mode == VOIDmode) + /* The only way this should occur is if the field spans word + boundaries. */ + return extract_split_bit_field (op0, bitsize, + bitpos + offset * BITS_PER_UNIT, + unsignedp); + + total_bits = GET_MODE_BITSIZE (mode); + + /* Make sure bitpos is valid for the chosen mode. Adjust BITPOS to + be in the range 0 to total_bits-1, and put any excess bytes in + OFFSET. */ + if (bitpos >= total_bits) + { + offset += (bitpos / total_bits) * (total_bits / BITS_PER_UNIT); + bitpos -= ((bitpos / total_bits) * (total_bits / BITS_PER_UNIT) + * BITS_PER_UNIT); + } + + /* Get ref to an aligned byte, halfword, or word containing the field. + Adjust BITPOS to be position within a word, + and OFFSET to be the offset of that word. + Then alter OP0 to refer to that word. */ + bitpos += (offset % (total_bits / BITS_PER_UNIT)) * BITS_PER_UNIT; + offset -= (offset % (total_bits / BITS_PER_UNIT)); + op0 = adjust_address (op0, mode, offset); + } + + mode = GET_MODE (op0); + + if (BYTES_BIG_ENDIAN) + /* BITPOS is the distance between our msb and that of OP0. + Convert it to the distance from the lsb. */ + bitpos = total_bits - bitsize - bitpos; + + /* Now BITPOS is always the distance between the field's lsb and that of OP0. + We have reduced the big-endian case to the little-endian case. */ + + if (unsignedp) + { + if (bitpos) + { + /* If the field does not already start at the lsb, + shift it so it does. */ + tree amount = build_int_cst (NULL_TREE, bitpos); + /* Maybe propagate the target for the shift. */ + /* But not if we will return it--could confuse integrate.c. */ + rtx subtarget = (target != 0 && REG_P (target) ? target : 0); + if (tmode != mode) subtarget = 0; + op0 = expand_shift (RSHIFT_EXPR, mode, op0, amount, subtarget, 1); + } + /* Convert the value to the desired mode. */ + if (mode != tmode) + op0 = convert_to_mode (tmode, op0, 1); + + /* Unless the msb of the field used to be the msb when we shifted, + mask out the upper bits. */ + + if (GET_MODE_BITSIZE (mode) != bitpos + bitsize) + return expand_binop (GET_MODE (op0), and_optab, op0, + mask_rtx (GET_MODE (op0), 0, bitsize, 0), + target, 1, OPTAB_LIB_WIDEN); + return op0; + } + + /* To extract a signed bit-field, first shift its msb to the msb of the word, + then arithmetic-shift its lsb to the lsb of the word. */ + op0 = force_reg (mode, op0); + if (mode != tmode) + target = 0; + + /* Find the narrowest integer mode that contains the field. */ + + for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; + mode = GET_MODE_WIDER_MODE (mode)) + if (GET_MODE_BITSIZE (mode) >= bitsize + bitpos) + { + op0 = convert_to_mode (mode, op0, 0); + break; + } + + if (GET_MODE_BITSIZE (mode) != (bitsize + bitpos)) + { + tree amount + = build_int_cst (NULL_TREE, + GET_MODE_BITSIZE (mode) - (bitsize + bitpos)); + /* Maybe propagate the target for the shift. */ + rtx subtarget = (target != 0 && REG_P (target) ? target : 0); + op0 = expand_shift (LSHIFT_EXPR, mode, op0, amount, subtarget, 1); + } + + return expand_shift (RSHIFT_EXPR, mode, op0, + build_int_cst (NULL_TREE, + GET_MODE_BITSIZE (mode) - bitsize), + target, 0); +} + +/* Return a constant integer (CONST_INT or CONST_DOUBLE) mask value + of mode MODE with BITSIZE ones followed by BITPOS zeros, or the + complement of that if COMPLEMENT. The mask is truncated if + necessary to the width of mode MODE. The mask is zero-extended if + BITSIZE+BITPOS is too small for MODE. */ + +static rtx +mask_rtx (enum machine_mode mode, int bitpos, int bitsize, int complement) +{ + HOST_WIDE_INT masklow, maskhigh; + + if (bitsize == 0) + masklow = 0; + else if (bitpos < HOST_BITS_PER_WIDE_INT) + masklow = (HOST_WIDE_INT) -1 << bitpos; + else + masklow = 0; + + if (bitpos + bitsize < HOST_BITS_PER_WIDE_INT) + masklow &= ((unsigned HOST_WIDE_INT) -1 + >> (HOST_BITS_PER_WIDE_INT - bitpos - bitsize)); + + if (bitpos <= HOST_BITS_PER_WIDE_INT) + maskhigh = -1; + else + maskhigh = (HOST_WIDE_INT) -1 << (bitpos - HOST_BITS_PER_WIDE_INT); + + if (bitsize == 0) + maskhigh = 0; + else if (bitpos + bitsize > HOST_BITS_PER_WIDE_INT) + maskhigh &= ((unsigned HOST_WIDE_INT) -1 + >> (2 * HOST_BITS_PER_WIDE_INT - bitpos - bitsize)); + else + maskhigh = 0; + + if (complement) + { + maskhigh = ~maskhigh; + masklow = ~masklow; + } + + return immed_double_const (masklow, maskhigh, mode); +} + +/* Return a constant integer (CONST_INT or CONST_DOUBLE) rtx with the value + VALUE truncated to BITSIZE bits and then shifted left BITPOS bits. */ + +static rtx +lshift_value (enum machine_mode mode, rtx value, int bitpos, int bitsize) +{ + unsigned HOST_WIDE_INT v = INTVAL (value); + HOST_WIDE_INT low, high; + + if (bitsize < HOST_BITS_PER_WIDE_INT) + v &= ~((HOST_WIDE_INT) -1 << bitsize); + + if (bitpos < HOST_BITS_PER_WIDE_INT) + { + low = v << bitpos; + high = (bitpos > 0 ? (v >> (HOST_BITS_PER_WIDE_INT - bitpos)) : 0); + } + else + { + low = 0; + high = v << (bitpos - HOST_BITS_PER_WIDE_INT); + } + + return immed_double_const (low, high, mode); +} + +/* Extract a bit field from a memory by forcing the alignment of the + memory. This efficient only if the field spans at least 4 boundaries. + + OP0 is the MEM. + BITSIZE is the field width; BITPOS is the position of the first bit. + UNSIGNEDP is true if the result should be zero-extended. */ + +static rtx +extract_force_align_mem_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize, + unsigned HOST_WIDE_INT bitpos, + int unsignedp) +{ + enum machine_mode mode, dmode; + unsigned int m_bitsize, m_size; + unsigned int sign_shift_up, sign_shift_dn; + rtx base, a1, a2, v1, v2, comb, shift, result, start; + + /* Choose a mode that will fit BITSIZE. */ + mode = smallest_mode_for_size (bitsize, MODE_INT); + m_size = GET_MODE_SIZE (mode); + m_bitsize = GET_MODE_BITSIZE (mode); + + /* Choose a mode twice as wide. Fail if no such mode exists. */ + dmode = mode_for_size (m_bitsize * 2, MODE_INT, false); + if (dmode == BLKmode) + return NULL; + + do_pending_stack_adjust (); + start = get_last_insn (); + + /* At the end, we'll need an additional shift to deal with sign/zero + extension. By default this will be a left+right shift of the + appropriate size. But we may be able to eliminate one of them. */ + sign_shift_up = sign_shift_dn = m_bitsize - bitsize; + + if (STRICT_ALIGNMENT) + { + base = plus_constant (XEXP (op0, 0), bitpos / BITS_PER_UNIT); + bitpos %= BITS_PER_UNIT; + + /* We load two values to be concatenate. There's an edge condition + that bears notice -- an aligned value at the end of a page can + only load one value lest we segfault. So the two values we load + are at "base & -size" and "(base + size - 1) & -size". If base + is unaligned, the addresses will be aligned and sequential; if + base is aligned, the addresses will both be equal to base. */ + + a1 = expand_simple_binop (Pmode, AND, force_operand (base, NULL), + GEN_INT (-(HOST_WIDE_INT)m_size), + NULL, true, OPTAB_LIB_WIDEN); + mark_reg_pointer (a1, m_bitsize); + v1 = gen_rtx_MEM (mode, a1); + set_mem_align (v1, m_bitsize); + v1 = force_reg (mode, validize_mem (v1)); + + a2 = plus_constant (base, GET_MODE_SIZE (mode) - 1); + a2 = expand_simple_binop (Pmode, AND, force_operand (a2, NULL), + GEN_INT (-(HOST_WIDE_INT)m_size), + NULL, true, OPTAB_LIB_WIDEN); + v2 = gen_rtx_MEM (mode, a2); + set_mem_align (v2, m_bitsize); + v2 = force_reg (mode, validize_mem (v2)); + + /* Combine these two values into a double-word value. */ + if (m_bitsize == BITS_PER_WORD) + { + comb = gen_reg_rtx (dmode); + emit_insn (gen_rtx_CLOBBER (VOIDmode, comb)); + emit_move_insn (gen_rtx_SUBREG (mode, comb, 0), v1); + emit_move_insn (gen_rtx_SUBREG (mode, comb, m_size), v2); + } + else + { + if (BYTES_BIG_ENDIAN) + comb = v1, v1 = v2, v2 = comb; + v1 = convert_modes (dmode, mode, v1, true); + if (v1 == NULL) + goto fail; + v2 = convert_modes (dmode, mode, v2, true); + v2 = expand_simple_binop (dmode, ASHIFT, v2, GEN_INT (m_bitsize), + NULL, true, OPTAB_LIB_WIDEN); + if (v2 == NULL) + goto fail; + comb = expand_simple_binop (dmode, IOR, v1, v2, NULL, + true, OPTAB_LIB_WIDEN); + if (comb == NULL) + goto fail; + } + + shift = expand_simple_binop (Pmode, AND, base, GEN_INT (m_size - 1), + NULL, true, OPTAB_LIB_WIDEN); + shift = expand_mult (Pmode, shift, GEN_INT (BITS_PER_UNIT), NULL, 1); + + if (bitpos != 0) + { + if (sign_shift_up <= bitpos) + bitpos -= sign_shift_up, sign_shift_up = 0; + shift = expand_simple_binop (Pmode, PLUS, shift, GEN_INT (bitpos), + NULL, true, OPTAB_LIB_WIDEN); + } + } + else + { + unsigned HOST_WIDE_INT offset = bitpos / BITS_PER_UNIT; + bitpos %= BITS_PER_UNIT; + + /* When strict alignment is not required, we can just load directly + from memory without masking. If the remaining BITPOS offset is + small enough, we may be able to do all operations in MODE as + opposed to DMODE. */ + if (bitpos + bitsize <= m_bitsize) + dmode = mode; + comb = adjust_address (op0, dmode, offset); + + if (sign_shift_up <= bitpos) + bitpos -= sign_shift_up, sign_shift_up = 0; + shift = GEN_INT (bitpos); + } + + /* Shift down the double-word such that the requested value is at bit 0. */ + if (shift != const0_rtx) + comb = expand_simple_binop (dmode, unsignedp ? LSHIFTRT : ASHIFTRT, + comb, shift, NULL, unsignedp, OPTAB_LIB_WIDEN); + if (comb == NULL) + goto fail; + + /* If the field exactly matches MODE, then all we need to do is return the + lowpart. Otherwise, shift to get the sign bits set properly. */ + result = force_reg (mode, gen_lowpart (mode, comb)); + + if (sign_shift_up) + result = expand_simple_binop (mode, ASHIFT, result, + GEN_INT (sign_shift_up), + NULL_RTX, 0, OPTAB_LIB_WIDEN); + if (sign_shift_dn) + result = expand_simple_binop (mode, unsignedp ? LSHIFTRT : ASHIFTRT, + result, GEN_INT (sign_shift_dn), + NULL_RTX, 0, OPTAB_LIB_WIDEN); + + return result; + + fail: + delete_insns_since (start); + return NULL; +} + +/* Extract a bit field that is split across two words + and return an RTX for the result. + + OP0 is the REG, SUBREG or MEM rtx for the first of the two words. + BITSIZE is the field width; BITPOS, position of its first bit, in the word. + UNSIGNEDP is 1 if should zero-extend the contents; else sign-extend. */ + +static rtx +extract_split_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize, + unsigned HOST_WIDE_INT bitpos, int unsignedp) +{ + unsigned int unit; + unsigned int bitsdone = 0; + rtx result = NULL_RTX; + int first = 1; + + /* Make sure UNIT isn't larger than BITS_PER_WORD, we can only handle that + much at a time. */ + if (REG_P (op0) || GET_CODE (op0) == SUBREG) + unit = BITS_PER_WORD; + else + { + unit = MIN (MEM_ALIGN (op0), BITS_PER_WORD); + if (0 && bitsize / unit > 2) + { + rtx tmp = extract_force_align_mem_bit_field (op0, bitsize, bitpos, + unsignedp); + if (tmp) + return tmp; + } + } + + while (bitsdone < bitsize) + { + unsigned HOST_WIDE_INT thissize; + rtx part, word; + unsigned HOST_WIDE_INT thispos; + unsigned HOST_WIDE_INT offset; + + offset = (bitpos + bitsdone) / unit; + thispos = (bitpos + bitsdone) % unit; + + /* THISSIZE must not overrun a word boundary. Otherwise, + extract_fixed_bit_field will call us again, and we will mutually + recurse forever. */ + thissize = MIN (bitsize - bitsdone, BITS_PER_WORD); + thissize = MIN (thissize, unit - thispos); + + /* If OP0 is a register, then handle OFFSET here. + + When handling multiword bitfields, extract_bit_field may pass + down a word_mode SUBREG of a larger REG for a bitfield that actually + crosses a word boundary. Thus, for a SUBREG, we must find + the current word starting from the base register. */ + if (GET_CODE (op0) == SUBREG) + { + int word_offset = (SUBREG_BYTE (op0) / UNITS_PER_WORD) + offset; + word = operand_subword_force (SUBREG_REG (op0), word_offset, + GET_MODE (SUBREG_REG (op0))); + offset = 0; + } + else if (REG_P (op0)) + { + word = operand_subword_force (op0, offset, GET_MODE (op0)); + offset = 0; + } + else + word = op0; + + /* Extract the parts in bit-counting order, + whose meaning is determined by BYTES_PER_UNIT. + OFFSET is in UNITs, and UNIT is in bits. + extract_fixed_bit_field wants offset in bytes. */ + part = extract_fixed_bit_field (word_mode, word, + offset * unit / BITS_PER_UNIT, + thissize, thispos, 0, 1); + bitsdone += thissize; + + /* Shift this part into place for the result. */ + if (BYTES_BIG_ENDIAN) + { + if (bitsize != bitsdone) + part = expand_shift (LSHIFT_EXPR, word_mode, part, + build_int_cst (NULL_TREE, bitsize - bitsdone), + 0, 1); + } + else + { + if (bitsdone != thissize) + part = expand_shift (LSHIFT_EXPR, word_mode, part, + build_int_cst (NULL_TREE, + bitsdone - thissize), 0, 1); + } + + if (first) + result = part; + else + /* Combine the parts with bitwise or. This works + because we extracted each part as an unsigned bit field. */ + result = expand_binop (word_mode, ior_optab, part, result, NULL_RTX, 1, + OPTAB_LIB_WIDEN); + + first = 0; + } + + /* Unsigned bit field: we are done. */ + if (unsignedp) + return result; + /* Signed bit field: sign-extend with two arithmetic shifts. */ + result = expand_shift (LSHIFT_EXPR, word_mode, result, + build_int_cst (NULL_TREE, BITS_PER_WORD - bitsize), + NULL_RTX, 0); + return expand_shift (RSHIFT_EXPR, word_mode, result, + build_int_cst (NULL_TREE, BITS_PER_WORD - bitsize), + NULL_RTX, 0); +} + +/* Add INC into TARGET. */ + +void +expand_inc (rtx target, rtx inc) +{ + rtx value = expand_binop (GET_MODE (target), add_optab, + target, inc, + target, 0, OPTAB_LIB_WIDEN); + if (value != target) + emit_move_insn (target, value); +} + +/* Subtract DEC from TARGET. */ + +void +expand_dec (rtx target, rtx dec) +{ + rtx value = expand_binop (GET_MODE (target), sub_optab, + target, dec, + target, 0, OPTAB_LIB_WIDEN); + if (value != target) + emit_move_insn (target, value); +} + +/* Output a shift instruction for expression code CODE, + with SHIFTED being the rtx for the value to shift, + and AMOUNT the tree for the amount to shift by. + Store the result in the rtx TARGET, if that is convenient. + If UNSIGNEDP is nonzero, do a logical shift; otherwise, arithmetic. + Return the rtx for where the value is. */ + +rtx +expand_shift (enum tree_code code, enum machine_mode mode, rtx shifted, + tree amount, rtx target, int unsignedp) +{ + rtx op1, temp = 0; + int left = (code == LSHIFT_EXPR || code == LROTATE_EXPR); + int rotate = (code == LROTATE_EXPR || code == RROTATE_EXPR); + int try; + + /* Previously detected shift-counts computed by NEGATE_EXPR + and shifted in the other direction; but that does not work + on all machines. */ + + op1 = expand_normal (amount); + + if (SHIFT_COUNT_TRUNCATED) + { + if (GET_CODE (op1) == CONST_INT + && ((unsigned HOST_WIDE_INT) INTVAL (op1) >= + (unsigned HOST_WIDE_INT) GET_MODE_BITSIZE (mode))) + op1 = GEN_INT ((unsigned HOST_WIDE_INT) INTVAL (op1) + % GET_MODE_BITSIZE (mode)); + else if (GET_CODE (op1) == SUBREG + && subreg_lowpart_p (op1)) + op1 = SUBREG_REG (op1); + } + + if (op1 == const0_rtx) + return shifted; + + /* Check whether its cheaper to implement a left shift by a constant + bit count by a sequence of additions. */ + if (code == LSHIFT_EXPR + && GET_CODE (op1) == CONST_INT + && INTVAL (op1) > 0 + && INTVAL (op1) < GET_MODE_BITSIZE (mode) + && INTVAL (op1) < MAX_BITS_PER_WORD + && shift_cost[mode][INTVAL (op1)] > INTVAL (op1) * add_cost[mode] + && shift_cost[mode][INTVAL (op1)] != MAX_COST) + { + int i; + for (i = 0; i < INTVAL (op1); i++) + { + temp = force_reg (mode, shifted); + shifted = expand_binop (mode, add_optab, temp, temp, NULL_RTX, + unsignedp, OPTAB_LIB_WIDEN); + } + return shifted; + } + + for (try = 0; temp == 0 && try < 3; try++) + { + enum optab_methods methods; + + if (try == 0) + methods = OPTAB_DIRECT; + else if (try == 1) + methods = OPTAB_WIDEN; + else + methods = OPTAB_LIB_WIDEN; + + if (rotate) + { + /* Widening does not work for rotation. */ + if (methods == OPTAB_WIDEN) + continue; + else if (methods == OPTAB_LIB_WIDEN) + { + /* If we have been unable to open-code this by a rotation, + do it as the IOR of two shifts. I.e., to rotate A + by N bits, compute (A << N) | ((unsigned) A >> (C - N)) + where C is the bitsize of A. + + It is theoretically possible that the target machine might + not be able to perform either shift and hence we would + be making two libcalls rather than just the one for the + shift (similarly if IOR could not be done). We will allow + this extremely unlikely lossage to avoid complicating the + code below. */ + + rtx subtarget = target == shifted ? 0 : target; + tree new_amount, other_amount; + rtx temp1; + tree type = TREE_TYPE (amount); + if (GET_MODE (op1) != TYPE_MODE (type) + && GET_MODE (op1) != VOIDmode) + op1 = convert_to_mode (TYPE_MODE (type), op1, 1); + new_amount = make_tree (type, op1); + other_amount + = fold_build2 (MINUS_EXPR, type, + build_int_cst (type, GET_MODE_BITSIZE (mode)), + new_amount); + + shifted = force_reg (mode, shifted); + + temp = expand_shift (left ? LSHIFT_EXPR : RSHIFT_EXPR, + mode, shifted, new_amount, 0, 1); + temp1 = expand_shift (left ? RSHIFT_EXPR : LSHIFT_EXPR, + mode, shifted, other_amount, subtarget, 1); + return expand_binop (mode, ior_optab, temp, temp1, target, + unsignedp, methods); + } + + temp = expand_binop (mode, + left ? rotl_optab : rotr_optab, + shifted, op1, target, unsignedp, methods); + } + else if (unsignedp) + temp = expand_binop (mode, + left ? ashl_optab : lshr_optab, + shifted, op1, target, unsignedp, methods); + + /* Do arithmetic shifts. + Also, if we are going to widen the operand, we can just as well + use an arithmetic right-shift instead of a logical one. */ + if (temp == 0 && ! rotate + && (! unsignedp || (! left && methods == OPTAB_WIDEN))) + { + enum optab_methods methods1 = methods; + + /* If trying to widen a log shift to an arithmetic shift, + don't accept an arithmetic shift of the same size. */ + if (unsignedp) + methods1 = OPTAB_MUST_WIDEN; + + /* Arithmetic shift */ + + temp = expand_binop (mode, + left ? ashl_optab : ashr_optab, + shifted, op1, target, unsignedp, methods1); + } + + /* We used to try extzv here for logical right shifts, but that was + only useful for one machine, the VAX, and caused poor code + generation there for lshrdi3, so the code was deleted and a + define_expand for lshrsi3 was added to vax.md. */ + } + + gcc_assert (temp); + return temp; +} + +enum alg_code { + alg_unknown, + alg_zero, + alg_m, alg_shift, + alg_add_t_m2, + alg_sub_t_m2, + alg_add_factor, + alg_sub_factor, + alg_add_t2_m, + alg_sub_t2_m, + alg_impossible +}; + +/* This structure holds the "cost" of a multiply sequence. The + "cost" field holds the total rtx_cost of every operator in the + synthetic multiplication sequence, hence cost(a op b) is defined + as rtx_cost(op) + cost(a) + cost(b), where cost(leaf) is zero. + The "latency" field holds the minimum possible latency of the + synthetic multiply, on a hypothetical infinitely parallel CPU. + This is the critical path, or the maximum height, of the expression + tree which is the sum of rtx_costs on the most expensive path from + any leaf to the root. Hence latency(a op b) is defined as zero for + leaves and rtx_cost(op) + max(latency(a), latency(b)) otherwise. */ + +struct mult_cost { + short cost; /* Total rtx_cost of the multiplication sequence. */ + short latency; /* The latency of the multiplication sequence. */ +}; + +/* This macro is used to compare a pointer to a mult_cost against an + single integer "rtx_cost" value. This is equivalent to the macro + CHEAPER_MULT_COST(X,Z) where Z = {Y,Y}. */ +#define MULT_COST_LESS(X,Y) ((X)->cost < (Y) \ + || ((X)->cost == (Y) && (X)->latency < (Y))) + +/* This macro is used to compare two pointers to mult_costs against + each other. The macro returns true if X is cheaper than Y. + Currently, the cheaper of two mult_costs is the one with the + lower "cost". If "cost"s are tied, the lower latency is cheaper. */ +#define CHEAPER_MULT_COST(X,Y) ((X)->cost < (Y)->cost \ + || ((X)->cost == (Y)->cost \ + && (X)->latency < (Y)->latency)) + +/* This structure records a sequence of operations. + `ops' is the number of operations recorded. + `cost' is their total cost. + The operations are stored in `op' and the corresponding + logarithms of the integer coefficients in `log'. + + These are the operations: + alg_zero total := 0; + alg_m total := multiplicand; + alg_shift total := total * coeff + alg_add_t_m2 total := total + multiplicand * coeff; + alg_sub_t_m2 total := total - multiplicand * coeff; + alg_add_factor total := total * coeff + total; + alg_sub_factor total := total * coeff - total; + alg_add_t2_m total := total * coeff + multiplicand; + alg_sub_t2_m total := total * coeff - multiplicand; + + The first operand must be either alg_zero or alg_m. */ + +struct algorithm +{ + struct mult_cost cost; + short ops; + /* The size of the OP and LOG fields are not directly related to the + word size, but the worst-case algorithms will be if we have few + consecutive ones or zeros, i.e., a multiplicand like 10101010101... + In that case we will generate shift-by-2, add, shift-by-2, add,..., + in total wordsize operations. */ + enum alg_code op[MAX_BITS_PER_WORD]; + char log[MAX_BITS_PER_WORD]; +}; + +/* The entry for our multiplication cache/hash table. */ +struct alg_hash_entry { + /* The number we are multiplying by. */ + unsigned HOST_WIDE_INT t; + + /* The mode in which we are multiplying something by T. */ + enum machine_mode mode; + + /* The best multiplication algorithm for t. */ + enum alg_code alg; + + /* The cost of multiplication if ALG_CODE is not alg_impossible. + Otherwise, the cost within which multiplication by T is + impossible. */ + struct mult_cost cost; +}; + +/* The number of cache/hash entries. */ +#if HOST_BITS_PER_WIDE_INT == 64 +#define NUM_ALG_HASH_ENTRIES 1031 +#else +#define NUM_ALG_HASH_ENTRIES 307 +#endif + +/* Each entry of ALG_HASH caches alg_code for some integer. This is + actually a hash table. If we have a collision, that the older + entry is kicked out. */ +static struct alg_hash_entry alg_hash[NUM_ALG_HASH_ENTRIES]; + +/* Indicates the type of fixup needed after a constant multiplication. + BASIC_VARIANT means no fixup is needed, NEGATE_VARIANT means that + the result should be negated, and ADD_VARIANT means that the + multiplicand should be added to the result. */ +enum mult_variant {basic_variant, negate_variant, add_variant}; + +static void synth_mult (struct algorithm *, unsigned HOST_WIDE_INT, + const struct mult_cost *, enum machine_mode mode); +static bool choose_mult_variant (enum machine_mode, HOST_WIDE_INT, + struct algorithm *, enum mult_variant *, int); +static rtx expand_mult_const (enum machine_mode, rtx, HOST_WIDE_INT, rtx, + const struct algorithm *, enum mult_variant); +static unsigned HOST_WIDE_INT choose_multiplier (unsigned HOST_WIDE_INT, int, + int, rtx *, int *, int *); +static unsigned HOST_WIDE_INT invert_mod2n (unsigned HOST_WIDE_INT, int); +static rtx extract_high_half (enum machine_mode, rtx); +static rtx expand_mult_highpart (enum machine_mode, rtx, rtx, rtx, int, int); +static rtx expand_mult_highpart_optab (enum machine_mode, rtx, rtx, rtx, + int, int); +/* Compute and return the best algorithm for multiplying by T. + The algorithm must cost less than cost_limit + If retval.cost >= COST_LIMIT, no algorithm was found and all + other field of the returned struct are undefined. + MODE is the machine mode of the multiplication. */ + +static void +synth_mult (struct algorithm *alg_out, unsigned HOST_WIDE_INT t, + const struct mult_cost *cost_limit, enum machine_mode mode) +{ + int m; + struct algorithm *alg_in, *best_alg; + struct mult_cost best_cost; + struct mult_cost new_limit; + int op_cost, op_latency; + unsigned HOST_WIDE_INT q; + int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode)); + int hash_index; + bool cache_hit = false; + enum alg_code cache_alg = alg_zero; + + /* Indicate that no algorithm is yet found. If no algorithm + is found, this value will be returned and indicate failure. */ + alg_out->cost.cost = cost_limit->cost + 1; + alg_out->cost.latency = cost_limit->latency + 1; + + if (cost_limit->cost < 0 + || (cost_limit->cost == 0 && cost_limit->latency <= 0)) + return; + + /* Restrict the bits of "t" to the multiplication's mode. */ + t &= GET_MODE_MASK (mode); + + /* t == 1 can be done in zero cost. */ + if (t == 1) + { + alg_out->ops = 1; + alg_out->cost.cost = 0; + alg_out->cost.latency = 0; + alg_out->op[0] = alg_m; + return; + } + + /* t == 0 sometimes has a cost. If it does and it exceeds our limit, + fail now. */ + if (t == 0) + { + if (MULT_COST_LESS (cost_limit, zero_cost)) + return; + else + { + alg_out->ops = 1; + alg_out->cost.cost = zero_cost; + alg_out->cost.latency = zero_cost; + alg_out->op[0] = alg_zero; + return; + } + } + + /* We'll be needing a couple extra algorithm structures now. */ + + alg_in = alloca (sizeof (struct algorithm)); + best_alg = alloca (sizeof (struct algorithm)); + best_cost = *cost_limit; + + /* Compute the hash index. */ + hash_index = (t ^ (unsigned int) mode) % NUM_ALG_HASH_ENTRIES; + + /* See if we already know what to do for T. */ + if (alg_hash[hash_index].t == t + && alg_hash[hash_index].mode == mode + && alg_hash[hash_index].alg != alg_unknown) + { + cache_alg = alg_hash[hash_index].alg; + + if (cache_alg == alg_impossible) + { + /* The cache tells us that it's impossible to synthesize + multiplication by T within alg_hash[hash_index].cost. */ + if (!CHEAPER_MULT_COST (&alg_hash[hash_index].cost, cost_limit)) + /* COST_LIMIT is at least as restrictive as the one + recorded in the hash table, in which case we have no + hope of synthesizing a multiplication. Just + return. */ + return; + + /* If we get here, COST_LIMIT is less restrictive than the + one recorded in the hash table, so we may be able to + synthesize a multiplication. Proceed as if we didn't + have the cache entry. */ + } + else + { + if (CHEAPER_MULT_COST (cost_limit, &alg_hash[hash_index].cost)) + /* The cached algorithm shows that this multiplication + requires more cost than COST_LIMIT. Just return. This + way, we don't clobber this cache entry with + alg_impossible but retain useful information. */ + return; + + cache_hit = true; + + switch (cache_alg) + { + case alg_shift: + goto do_alg_shift; + + case alg_add_t_m2: + case alg_sub_t_m2: + goto do_alg_addsub_t_m2; + + case alg_add_factor: + case alg_sub_factor: + goto do_alg_addsub_factor; + + case alg_add_t2_m: + goto do_alg_add_t2_m; + + case alg_sub_t2_m: + goto do_alg_sub_t2_m; + + default: + gcc_unreachable (); + } + } + } + + /* If we have a group of zero bits at the low-order part of T, try + multiplying by the remaining bits and then doing a shift. */ + + if ((t & 1) == 0) + { + do_alg_shift: + m = floor_log2 (t & -t); /* m = number of low zero bits */ + if (m < maxm) + { + q = t >> m; + /* The function expand_shift will choose between a shift and + a sequence of additions, so the observed cost is given as + MIN (m * add_cost[mode], shift_cost[mode][m]). */ + op_cost = m * add_cost[mode]; + if (shift_cost[mode][m] < op_cost) + op_cost = shift_cost[mode][m]; + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_cost; + synth_mult (alg_in, q, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_shift; + } + } + if (cache_hit) + goto done; + } + + /* If we have an odd number, add or subtract one. */ + if ((t & 1) != 0) + { + unsigned HOST_WIDE_INT w; + + do_alg_addsub_t_m2: + for (w = 1; (w & t) != 0; w <<= 1) + ; + /* APPLE LOCAL begin 7744816 DImode multiply by 0xffffffffULL */ + if (w > 2 + /* Reject the case where t is 3. + Thus we prefer addition in that case. */ + && t != 3) + /* APPLE LOCAL end 7744816 DImode multiply by 0xffffffffULL */ + { + /* T ends with ...111. Multiply by (T + 1) and subtract 1. */ + + op_cost = add_cost[mode]; + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_cost; + synth_mult (alg_in, t + 1, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = 0; + best_alg->op[best_alg->ops] = alg_sub_t_m2; + } + } + else + { + /* T ends with ...01 or ...011. Multiply by (T - 1) and add 1. */ + + op_cost = add_cost[mode]; + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_cost; + synth_mult (alg_in, t - 1, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = 0; + best_alg->op[best_alg->ops] = alg_add_t_m2; + } + } + if (cache_hit) + goto done; + } + + /* Look for factors of t of the form + t = q(2**m +- 1), 2 <= m <= floor(log2(t - 1)). + If we find such a factor, we can multiply by t using an algorithm that + multiplies by q, shift the result by m and add/subtract it to itself. + + We search for large factors first and loop down, even if large factors + are less probable than small; if we find a large factor we will find a + good sequence quickly, and therefore be able to prune (by decreasing + COST_LIMIT) the search. */ + + do_alg_addsub_factor: + for (m = floor_log2 (t - 1); m >= 2; m--) + { + unsigned HOST_WIDE_INT d; + + d = ((unsigned HOST_WIDE_INT) 1 << m) + 1; + if (t % d == 0 && t > d && m < maxm + && (!cache_hit || cache_alg == alg_add_factor)) + { + /* If the target has a cheap shift-and-add instruction use + that in preference to a shift insn followed by an add insn. + Assume that the shift-and-add is "atomic" with a latency + equal to its cost, otherwise assume that on superscalar + hardware the shift may be executed concurrently with the + earlier steps in the algorithm. */ + op_cost = add_cost[mode] + shift_cost[mode][m]; + if (shiftadd_cost[mode][m] < op_cost) + { + op_cost = shiftadd_cost[mode][m]; + op_latency = op_cost; + } + else + op_latency = add_cost[mode]; + + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_latency; + synth_mult (alg_in, t / d, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_latency; + if (alg_in->cost.latency < op_cost) + alg_in->cost.latency = op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_add_factor; + } + /* Other factors will have been taken care of in the recursion. */ + break; + } + + d = ((unsigned HOST_WIDE_INT) 1 << m) - 1; + if (t % d == 0 && t > d && m < maxm + && (!cache_hit || cache_alg == alg_sub_factor)) + { + /* If the target has a cheap shift-and-subtract insn use + that in preference to a shift insn followed by a sub insn. + Assume that the shift-and-sub is "atomic" with a latency + equal to it's cost, otherwise assume that on superscalar + hardware the shift may be executed concurrently with the + earlier steps in the algorithm. */ + op_cost = add_cost[mode] + shift_cost[mode][m]; + if (shiftsub_cost[mode][m] < op_cost) + { + op_cost = shiftsub_cost[mode][m]; + op_latency = op_cost; + } + else + op_latency = add_cost[mode]; + + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_latency; + synth_mult (alg_in, t / d, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_latency; + if (alg_in->cost.latency < op_cost) + alg_in->cost.latency = op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_sub_factor; + } + break; + } + } + if (cache_hit) + goto done; + + /* Try shift-and-add (load effective address) instructions, + i.e. do a*3, a*5, a*9. */ + if ((t & 1) != 0) + { + do_alg_add_t2_m: + q = t - 1; + q = q & -q; + m = exact_log2 (q); + if (m >= 0 && m < maxm) + { + op_cost = shiftadd_cost[mode][m]; + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_cost; + synth_mult (alg_in, (t - 1) >> m, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_add_t2_m; + } + } + if (cache_hit) + goto done; + + do_alg_sub_t2_m: + q = t + 1; + q = q & -q; + m = exact_log2 (q); + if (m >= 0 && m < maxm) + { + op_cost = shiftsub_cost[mode][m]; + new_limit.cost = best_cost.cost - op_cost; + new_limit.latency = best_cost.latency - op_cost; + synth_mult (alg_in, (t + 1) >> m, &new_limit, mode); + + alg_in->cost.cost += op_cost; + alg_in->cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost)) + { + struct algorithm *x; + best_cost = alg_in->cost; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_sub_t2_m; + } + } + if (cache_hit) + goto done; + } + + done: + /* If best_cost has not decreased, we have not found any algorithm. */ + if (!CHEAPER_MULT_COST (&best_cost, cost_limit)) + { + /* We failed to find an algorithm. Record alg_impossible for + this case (that is, <T, MODE, COST_LIMIT>) so that next time + we are asked to find an algorithm for T within the same or + lower COST_LIMIT, we can immediately return to the + caller. */ + alg_hash[hash_index].t = t; + alg_hash[hash_index].mode = mode; + alg_hash[hash_index].alg = alg_impossible; + alg_hash[hash_index].cost = *cost_limit; + return; + } + + /* Cache the result. */ + if (!cache_hit) + { + alg_hash[hash_index].t = t; + alg_hash[hash_index].mode = mode; + alg_hash[hash_index].alg = best_alg->op[best_alg->ops]; + alg_hash[hash_index].cost.cost = best_cost.cost; + alg_hash[hash_index].cost.latency = best_cost.latency; + } + + /* If we are getting a too long sequence for `struct algorithm' + to record, make this search fail. */ + if (best_alg->ops == MAX_BITS_PER_WORD) + return; + + /* Copy the algorithm from temporary space to the space at alg_out. + We avoid using structure assignment because the majority of + best_alg is normally undefined, and this is a critical function. */ + alg_out->ops = best_alg->ops + 1; + alg_out->cost = best_cost; + memcpy (alg_out->op, best_alg->op, + alg_out->ops * sizeof *alg_out->op); + memcpy (alg_out->log, best_alg->log, + alg_out->ops * sizeof *alg_out->log); +} + +/* Find the cheapest way of multiplying a value of mode MODE by VAL. + Try three variations: + + - a shift/add sequence based on VAL itself + - a shift/add sequence based on -VAL, followed by a negation + - a shift/add sequence based on VAL - 1, followed by an addition. + + Return true if the cheapest of these cost less than MULT_COST, + describing the algorithm in *ALG and final fixup in *VARIANT. */ + +static bool +choose_mult_variant (enum machine_mode mode, HOST_WIDE_INT val, + struct algorithm *alg, enum mult_variant *variant, + int mult_cost) +{ + struct algorithm alg2; + struct mult_cost limit; + int op_cost; + + /* Fail quickly for impossible bounds. */ + if (mult_cost < 0) + return false; + + /* Ensure that mult_cost provides a reasonable upper bound. + Any constant multiplication can be performed with less + than 2 * bits additions. */ + op_cost = 2 * GET_MODE_BITSIZE (mode) * add_cost[mode]; + if (mult_cost > op_cost) + mult_cost = op_cost; + + *variant = basic_variant; + limit.cost = mult_cost; + limit.latency = mult_cost; + synth_mult (alg, val, &limit, mode); + + /* This works only if the inverted value actually fits in an + `unsigned int' */ + if (HOST_BITS_PER_INT >= GET_MODE_BITSIZE (mode)) + { + op_cost = neg_cost[mode]; + if (MULT_COST_LESS (&alg->cost, mult_cost)) + { + limit.cost = alg->cost.cost - op_cost; + limit.latency = alg->cost.latency - op_cost; + } + else + { + limit.cost = mult_cost - op_cost; + limit.latency = mult_cost - op_cost; + } + + synth_mult (&alg2, -val, &limit, mode); + alg2.cost.cost += op_cost; + alg2.cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg2.cost, &alg->cost)) + *alg = alg2, *variant = negate_variant; + } + + /* This proves very useful for division-by-constant. */ + op_cost = add_cost[mode]; + if (MULT_COST_LESS (&alg->cost, mult_cost)) + { + limit.cost = alg->cost.cost - op_cost; + limit.latency = alg->cost.latency - op_cost; + } + else + { + limit.cost = mult_cost - op_cost; + limit.latency = mult_cost - op_cost; + } + + synth_mult (&alg2, val - 1, &limit, mode); + alg2.cost.cost += op_cost; + alg2.cost.latency += op_cost; + if (CHEAPER_MULT_COST (&alg2.cost, &alg->cost)) + *alg = alg2, *variant = add_variant; + + return MULT_COST_LESS (&alg->cost, mult_cost); +} + +/* A subroutine of expand_mult, used for constant multiplications. + Multiply OP0 by VAL in mode MODE, storing the result in TARGET if + convenient. Use the shift/add sequence described by ALG and apply + the final fixup specified by VARIANT. */ + +static rtx +expand_mult_const (enum machine_mode mode, rtx op0, HOST_WIDE_INT val, + rtx target, const struct algorithm *alg, + enum mult_variant variant) +{ + HOST_WIDE_INT val_so_far; + rtx insn, accum, tem; + int opno; + enum machine_mode nmode; + + /* Avoid referencing memory over and over. + For speed, but also for correctness when mem is volatile. */ + if (MEM_P (op0)) + op0 = force_reg (mode, op0); + + /* ACCUM starts out either as OP0 or as a zero, depending on + the first operation. */ + + if (alg->op[0] == alg_zero) + { + accum = copy_to_mode_reg (mode, const0_rtx); + val_so_far = 0; + } + else if (alg->op[0] == alg_m) + { + accum = copy_to_mode_reg (mode, op0); + val_so_far = 1; + } + else + gcc_unreachable (); + + for (opno = 1; opno < alg->ops; opno++) + { + int log = alg->log[opno]; + rtx shift_subtarget = optimize ? 0 : accum; + rtx add_target + = (opno == alg->ops - 1 && target != 0 && variant != add_variant + && !optimize) + ? target : 0; + rtx accum_target = optimize ? 0 : accum; + + switch (alg->op[opno]) + { + case alg_shift: + accum = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_cst (NULL_TREE, log), + NULL_RTX, 0); + val_so_far <<= log; + break; + + case alg_add_t_m2: + tem = expand_shift (LSHIFT_EXPR, mode, op0, + build_int_cst (NULL_TREE, log), + NULL_RTX, 0); + accum = force_operand (gen_rtx_PLUS (mode, accum, tem), + add_target ? add_target : accum_target); + val_so_far += (HOST_WIDE_INT) 1 << log; + break; + + case alg_sub_t_m2: + tem = expand_shift (LSHIFT_EXPR, mode, op0, + build_int_cst (NULL_TREE, log), + NULL_RTX, 0); + accum = force_operand (gen_rtx_MINUS (mode, accum, tem), + add_target ? add_target : accum_target); + val_so_far -= (HOST_WIDE_INT) 1 << log; + break; + + case alg_add_t2_m: + accum = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_cst (NULL_TREE, log), + shift_subtarget, + 0); + accum = force_operand (gen_rtx_PLUS (mode, accum, op0), + add_target ? add_target : accum_target); + val_so_far = (val_so_far << log) + 1; + break; + + case alg_sub_t2_m: + accum = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_cst (NULL_TREE, log), + shift_subtarget, 0); + accum = force_operand (gen_rtx_MINUS (mode, accum, op0), + add_target ? add_target : accum_target); + val_so_far = (val_so_far << log) - 1; + break; + + case alg_add_factor: + tem = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_cst (NULL_TREE, log), + NULL_RTX, 0); + accum = force_operand (gen_rtx_PLUS (mode, accum, tem), + add_target ? add_target : accum_target); + val_so_far += val_so_far << log; + break; + + case alg_sub_factor: + tem = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_cst (NULL_TREE, log), + NULL_RTX, 0); + accum = force_operand (gen_rtx_MINUS (mode, tem, accum), + (add_target + ? add_target : (optimize ? 0 : tem))); + val_so_far = (val_so_far << log) - val_so_far; + break; + + default: + gcc_unreachable (); + } + + /* Write a REG_EQUAL note on the last insn so that we can cse + multiplication sequences. Note that if ACCUM is a SUBREG, + we've set the inner register and must properly indicate + that. */ + + tem = op0, nmode = mode; + if (GET_CODE (accum) == SUBREG) + { + nmode = GET_MODE (SUBREG_REG (accum)); + tem = gen_lowpart (nmode, op0); + } + + insn = get_last_insn (); + set_unique_reg_note (insn, REG_EQUAL, + gen_rtx_MULT (nmode, tem, GEN_INT (val_so_far))); + } + + if (variant == negate_variant) + { + val_so_far = -val_so_far; + accum = expand_unop (mode, neg_optab, accum, target, 0); + } + else if (variant == add_variant) + { + val_so_far = val_so_far + 1; + accum = force_operand (gen_rtx_PLUS (mode, accum, op0), target); + } + + /* Compare only the bits of val and val_so_far that are significant + in the result mode, to avoid sign-/zero-extension confusion. */ + val &= GET_MODE_MASK (mode); + val_so_far &= GET_MODE_MASK (mode); + gcc_assert (val == val_so_far); + + return accum; +} + +/* Perform a multiplication and return an rtx for the result. + MODE is mode of value; OP0 and OP1 are what to multiply (rtx's); + TARGET is a suggestion for where to store the result (an rtx). + + We check specially for a constant integer as OP1. + If you want this check for OP0 as well, then before calling + you should swap the two operands if OP0 would be constant. */ + +rtx +expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, + int unsignedp) +{ + enum mult_variant variant; + struct algorithm algorithm; + int max_cost; + + /* Handling const0_rtx here allows us to use zero as a rogue value for + coeff below. */ + if (op1 == const0_rtx) + return const0_rtx; + if (op1 == const1_rtx) + return op0; + if (op1 == constm1_rtx) + return expand_unop (mode, + GET_MODE_CLASS (mode) == MODE_INT + && !unsignedp && flag_trapv + ? negv_optab : neg_optab, + op0, target, 0); + + /* These are the operations that are potentially turned into a sequence + of shifts and additions. */ + if (SCALAR_INT_MODE_P (mode) + && (unsignedp || !flag_trapv)) + { + HOST_WIDE_INT coeff = 0; + rtx fake_reg = gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 1); + + /* synth_mult does an `unsigned int' multiply. As long as the mode is + less than or equal in size to `unsigned int' this doesn't matter. + If the mode is larger than `unsigned int', then synth_mult works + only if the constant value exactly fits in an `unsigned int' without + any truncation. This means that multiplying by negative values does + not work; results are off by 2^32 on a 32 bit machine. */ + + if (GET_CODE (op1) == CONST_INT) + { + /* Attempt to handle multiplication of DImode values by negative + coefficients, by performing the multiplication by a positive + multiplier and then inverting the result. */ + if (INTVAL (op1) < 0 + && GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT) + { + /* Its safe to use -INTVAL (op1) even for INT_MIN, as the + result is interpreted as an unsigned coefficient. + Exclude cost of op0 from max_cost to match the cost + calculation of the synth_mult. */ + max_cost = rtx_cost (gen_rtx_MULT (mode, fake_reg, op1), SET) + - neg_cost[mode]; + if (max_cost > 0 + && choose_mult_variant (mode, -INTVAL (op1), &algorithm, + &variant, max_cost)) + { + rtx temp = expand_mult_const (mode, op0, -INTVAL (op1), + NULL_RTX, &algorithm, + variant); + return expand_unop (mode, neg_optab, temp, target, 0); + } + } + else coeff = INTVAL (op1); + } + else if (GET_CODE (op1) == CONST_DOUBLE) + { + /* If we are multiplying in DImode, it may still be a win + to try to work with shifts and adds. */ + if (CONST_DOUBLE_HIGH (op1) == 0) + coeff = CONST_DOUBLE_LOW (op1); + else if (CONST_DOUBLE_LOW (op1) == 0 + && EXACT_POWER_OF_2_OR_ZERO_P (CONST_DOUBLE_HIGH (op1))) + { + int shift = floor_log2 (CONST_DOUBLE_HIGH (op1)) + + HOST_BITS_PER_WIDE_INT; + return expand_shift (LSHIFT_EXPR, mode, op0, + build_int_cst (NULL_TREE, shift), + target, unsignedp); + } + } + + /* We used to test optimize here, on the grounds that it's better to + produce a smaller program when -O is not used. But this causes + such a terrible slowdown sometimes that it seems better to always + use synth_mult. */ + if (coeff != 0) + { + /* Special case powers of two. */ + if (EXACT_POWER_OF_2_OR_ZERO_P (coeff)) + return expand_shift (LSHIFT_EXPR, mode, op0, + build_int_cst (NULL_TREE, floor_log2 (coeff)), + target, unsignedp); + + /* Exclude cost of op0 from max_cost to match the cost + calculation of the synth_mult. */ + max_cost = rtx_cost (gen_rtx_MULT (mode, fake_reg, op1), SET); + if (choose_mult_variant (mode, coeff, &algorithm, &variant, + max_cost)) + return expand_mult_const (mode, op0, coeff, target, + &algorithm, variant); + } + } + + if (GET_CODE (op0) == CONST_DOUBLE) + { + rtx temp = op0; + op0 = op1; + op1 = temp; + } + + /* Expand x*2.0 as x+x. */ + if (GET_CODE (op1) == CONST_DOUBLE + && SCALAR_FLOAT_MODE_P (mode)) + { + REAL_VALUE_TYPE d; + REAL_VALUE_FROM_CONST_DOUBLE (d, op1); + + if (REAL_VALUES_EQUAL (d, dconst2)) + { + op0 = force_reg (GET_MODE (op0), op0); + return expand_binop (mode, add_optab, op0, op0, + target, unsignedp, OPTAB_LIB_WIDEN); + } + } + + /* This used to use umul_optab if unsigned, but for non-widening multiply + there is no difference between signed and unsigned. */ + op0 = expand_binop (mode, + ! unsignedp + && flag_trapv && (GET_MODE_CLASS(mode) == MODE_INT) + ? smulv_optab : smul_optab, + op0, op1, target, unsignedp, OPTAB_LIB_WIDEN); + gcc_assert (op0); + return op0; +} + +/* Return the smallest n such that 2**n >= X. */ + +int +ceil_log2 (unsigned HOST_WIDE_INT x) +{ + return floor_log2 (x - 1) + 1; +} + +/* Choose a minimal N + 1 bit approximation to 1/D that can be used to + replace division by D, and put the least significant N bits of the result + in *MULTIPLIER_PTR and return the most significant bit. + + The width of operations is N (should be <= HOST_BITS_PER_WIDE_INT), the + needed precision is in PRECISION (should be <= N). + + PRECISION should be as small as possible so this function can choose + multiplier more freely. + + The rounded-up logarithm of D is placed in *lgup_ptr. A shift count that + is to be used for a final right shift is placed in *POST_SHIFT_PTR. + + Using this function, x/D will be equal to (x * m) >> (*POST_SHIFT_PTR), + where m is the full HOST_BITS_PER_WIDE_INT + 1 bit multiplier. */ + +static +unsigned HOST_WIDE_INT +choose_multiplier (unsigned HOST_WIDE_INT d, int n, int precision, + rtx *multiplier_ptr, int *post_shift_ptr, int *lgup_ptr) +{ + HOST_WIDE_INT mhigh_hi, mlow_hi; + unsigned HOST_WIDE_INT mhigh_lo, mlow_lo; + int lgup, post_shift; + int pow, pow2; + unsigned HOST_WIDE_INT nl, dummy1; + HOST_WIDE_INT nh, dummy2; + + /* lgup = ceil(log2(divisor)); */ + lgup = ceil_log2 (d); + + gcc_assert (lgup <= n); + + pow = n + lgup; + pow2 = n + lgup - precision; + + /* We could handle this with some effort, but this case is much + better handled directly with a scc insn, so rely on caller using + that. */ + gcc_assert (pow != 2 * HOST_BITS_PER_WIDE_INT); + + /* mlow = 2^(N + lgup)/d */ + if (pow >= HOST_BITS_PER_WIDE_INT) + { + nh = (HOST_WIDE_INT) 1 << (pow - HOST_BITS_PER_WIDE_INT); + nl = 0; + } + else + { + nh = 0; + nl = (unsigned HOST_WIDE_INT) 1 << pow; + } + div_and_round_double (TRUNC_DIV_EXPR, 1, nl, nh, d, (HOST_WIDE_INT) 0, + &mlow_lo, &mlow_hi, &dummy1, &dummy2); + + /* mhigh = (2^(N + lgup) + 2^N + lgup - precision)/d */ + if (pow2 >= HOST_BITS_PER_WIDE_INT) + nh |= (HOST_WIDE_INT) 1 << (pow2 - HOST_BITS_PER_WIDE_INT); + else + nl |= (unsigned HOST_WIDE_INT) 1 << pow2; + div_and_round_double (TRUNC_DIV_EXPR, 1, nl, nh, d, (HOST_WIDE_INT) 0, + &mhigh_lo, &mhigh_hi, &dummy1, &dummy2); + + gcc_assert (!mhigh_hi || nh - d < d); + gcc_assert (mhigh_hi <= 1 && mlow_hi <= 1); + /* Assert that mlow < mhigh. */ + gcc_assert (mlow_hi < mhigh_hi + || (mlow_hi == mhigh_hi && mlow_lo < mhigh_lo)); + + /* If precision == N, then mlow, mhigh exceed 2^N + (but they do not exceed 2^(N+1)). */ + + /* Reduce to lowest terms. */ + for (post_shift = lgup; post_shift > 0; post_shift--) + { + unsigned HOST_WIDE_INT ml_lo = (mlow_hi << (HOST_BITS_PER_WIDE_INT - 1)) | (mlow_lo >> 1); + unsigned HOST_WIDE_INT mh_lo = (mhigh_hi << (HOST_BITS_PER_WIDE_INT - 1)) | (mhigh_lo >> 1); + if (ml_lo >= mh_lo) + break; + + mlow_hi = 0; + mlow_lo = ml_lo; + mhigh_hi = 0; + mhigh_lo = mh_lo; + } + + *post_shift_ptr = post_shift; + *lgup_ptr = lgup; + if (n < HOST_BITS_PER_WIDE_INT) + { + unsigned HOST_WIDE_INT mask = ((unsigned HOST_WIDE_INT) 1 << n) - 1; + *multiplier_ptr = GEN_INT (mhigh_lo & mask); + return mhigh_lo >= mask; + } + else + { + *multiplier_ptr = GEN_INT (mhigh_lo); + return mhigh_hi; + } +} + +/* Compute the inverse of X mod 2**n, i.e., find Y such that X * Y is + congruent to 1 (mod 2**N). */ + +static unsigned HOST_WIDE_INT +invert_mod2n (unsigned HOST_WIDE_INT x, int n) +{ + /* Solve x*y == 1 (mod 2^n), where x is odd. Return y. */ + + /* The algorithm notes that the choice y = x satisfies + x*y == 1 mod 2^3, since x is assumed odd. + Each iteration doubles the number of bits of significance in y. */ + + unsigned HOST_WIDE_INT mask; + unsigned HOST_WIDE_INT y = x; + int nbit = 3; + + mask = (n == HOST_BITS_PER_WIDE_INT + ? ~(unsigned HOST_WIDE_INT) 0 + : ((unsigned HOST_WIDE_INT) 1 << n) - 1); + + while (nbit < n) + { + y = y * (2 - x*y) & mask; /* Modulo 2^N */ + nbit *= 2; + } + return y; +} + +/* Emit code to adjust ADJ_OPERAND after multiplication of wrong signedness + flavor of OP0 and OP1. ADJ_OPERAND is already the high half of the + product OP0 x OP1. If UNSIGNEDP is nonzero, adjust the signed product + to become unsigned, if UNSIGNEDP is zero, adjust the unsigned product to + become signed. + + The result is put in TARGET if that is convenient. + + MODE is the mode of operation. */ + +rtx +expand_mult_highpart_adjust (enum machine_mode mode, rtx adj_operand, rtx op0, + rtx op1, rtx target, int unsignedp) +{ + rtx tem; + enum rtx_code adj_code = unsignedp ? PLUS : MINUS; + + tem = expand_shift (RSHIFT_EXPR, mode, op0, + build_int_cst (NULL_TREE, GET_MODE_BITSIZE (mode) - 1), + NULL_RTX, 0); + tem = expand_and (mode, tem, op1, NULL_RTX); + adj_operand + = force_operand (gen_rtx_fmt_ee (adj_code, mode, adj_operand, tem), + adj_operand); + + tem = expand_shift (RSHIFT_EXPR, mode, op1, + build_int_cst (NULL_TREE, GET_MODE_BITSIZE (mode) - 1), + NULL_RTX, 0); + tem = expand_and (mode, tem, op0, NULL_RTX); + target = force_operand (gen_rtx_fmt_ee (adj_code, mode, adj_operand, tem), + target); + + return target; +} + +/* Subroutine of expand_mult_highpart. Return the MODE high part of OP. */ + +static rtx +extract_high_half (enum machine_mode mode, rtx op) +{ + enum machine_mode wider_mode; + + if (mode == word_mode) + return gen_highpart (mode, op); + + gcc_assert (!SCALAR_FLOAT_MODE_P (mode)); + + wider_mode = GET_MODE_WIDER_MODE (mode); + op = expand_shift (RSHIFT_EXPR, wider_mode, op, + build_int_cst (NULL_TREE, GET_MODE_BITSIZE (mode)), 0, 1); + return convert_modes (mode, wider_mode, op, 0); +} + +/* Like expand_mult_highpart, but only consider using a multiplication + optab. OP1 is an rtx for the constant operand. */ + +static rtx +expand_mult_highpart_optab (enum machine_mode mode, rtx op0, rtx op1, + rtx target, int unsignedp, int max_cost) +{ + rtx narrow_op1 = gen_int_mode (INTVAL (op1), mode); + enum machine_mode wider_mode; + optab moptab; + rtx tem; + int size; + + gcc_assert (!SCALAR_FLOAT_MODE_P (mode)); + + wider_mode = GET_MODE_WIDER_MODE (mode); + size = GET_MODE_BITSIZE (mode); + + /* Firstly, try using a multiplication insn that only generates the needed + high part of the product, and in the sign flavor of unsignedp. */ + if (mul_highpart_cost[mode] < max_cost) + { + moptab = unsignedp ? umul_highpart_optab : smul_highpart_optab; + tem = expand_binop (mode, moptab, op0, narrow_op1, target, + unsignedp, OPTAB_DIRECT); + if (tem) + return tem; + } + + /* Secondly, same as above, but use sign flavor opposite of unsignedp. + Need to adjust the result after the multiplication. */ + if (size - 1 < BITS_PER_WORD + && (mul_highpart_cost[mode] + 2 * shift_cost[mode][size-1] + + 4 * add_cost[mode] < max_cost)) + { + moptab = unsignedp ? smul_highpart_optab : umul_highpart_optab; + tem = expand_binop (mode, moptab, op0, narrow_op1, target, + unsignedp, OPTAB_DIRECT); + if (tem) + /* We used the wrong signedness. Adjust the result. */ + return expand_mult_highpart_adjust (mode, tem, op0, narrow_op1, + tem, unsignedp); + } + + /* Try widening multiplication. */ + moptab = unsignedp ? umul_widen_optab : smul_widen_optab; + if (moptab->handlers[wider_mode].insn_code != CODE_FOR_nothing + && mul_widen_cost[wider_mode] < max_cost) + { + tem = expand_binop (wider_mode, moptab, op0, narrow_op1, 0, + unsignedp, OPTAB_WIDEN); + if (tem) + return extract_high_half (mode, tem); + } + + /* Try widening the mode and perform a non-widening multiplication. */ + if (smul_optab->handlers[wider_mode].insn_code != CODE_FOR_nothing + && size - 1 < BITS_PER_WORD + && mul_cost[wider_mode] + shift_cost[mode][size-1] < max_cost) + { + rtx insns, wop0, wop1; + + /* We need to widen the operands, for example to ensure the + constant multiplier is correctly sign or zero extended. + Use a sequence to clean-up any instructions emitted by + the conversions if things don't work out. */ + start_sequence (); + wop0 = convert_modes (wider_mode, mode, op0, unsignedp); + wop1 = convert_modes (wider_mode, mode, op1, unsignedp); + tem = expand_binop (wider_mode, smul_optab, wop0, wop1, 0, + unsignedp, OPTAB_WIDEN); + insns = get_insns (); + end_sequence (); + + if (tem) + { + emit_insn (insns); + return extract_high_half (mode, tem); + } + } + + /* Try widening multiplication of opposite signedness, and adjust. */ + moptab = unsignedp ? smul_widen_optab : umul_widen_optab; + if (moptab->handlers[wider_mode].insn_code != CODE_FOR_nothing + && size - 1 < BITS_PER_WORD + && (mul_widen_cost[wider_mode] + 2 * shift_cost[mode][size-1] + + 4 * add_cost[mode] < max_cost)) + { + tem = expand_binop (wider_mode, moptab, op0, narrow_op1, + NULL_RTX, ! unsignedp, OPTAB_WIDEN); + if (tem != 0) + { + tem = extract_high_half (mode, tem); + /* We used the wrong signedness. Adjust the result. */ + return expand_mult_highpart_adjust (mode, tem, op0, narrow_op1, + target, unsignedp); + } + } + + return 0; +} + +/* Emit code to multiply OP0 and OP1 (where OP1 is an integer constant), + putting the high half of the result in TARGET if that is convenient, + and return where the result is. If the operation can not be performed, + 0 is returned. + + MODE is the mode of operation and result. + + UNSIGNEDP nonzero means unsigned multiply. + + MAX_COST is the total allowed cost for the expanded RTL. */ + +static rtx +expand_mult_highpart (enum machine_mode mode, rtx op0, rtx op1, + rtx target, int unsignedp, int max_cost) +{ + enum machine_mode wider_mode = GET_MODE_WIDER_MODE (mode); + unsigned HOST_WIDE_INT cnst1; + int extra_cost; + bool sign_adjust = false; + enum mult_variant variant; + struct algorithm alg; + rtx tem; + + gcc_assert (!SCALAR_FLOAT_MODE_P (mode)); + /* We can't support modes wider than HOST_BITS_PER_INT. */ + gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT); + + cnst1 = INTVAL (op1) & GET_MODE_MASK (mode); + + /* We can't optimize modes wider than BITS_PER_WORD. + ??? We might be able to perform double-word arithmetic if + mode == word_mode, however all the cost calculations in + synth_mult etc. assume single-word operations. */ + if (GET_MODE_BITSIZE (wider_mode) > BITS_PER_WORD) + return expand_mult_highpart_optab (mode, op0, op1, target, + unsignedp, max_cost); + + extra_cost = shift_cost[mode][GET_MODE_BITSIZE (mode) - 1]; + + /* Check whether we try to multiply by a negative constant. */ + if (!unsignedp && ((cnst1 >> (GET_MODE_BITSIZE (mode) - 1)) & 1)) + { + sign_adjust = true; + extra_cost += add_cost[mode]; + } + + /* See whether shift/add multiplication is cheap enough. */ + if (choose_mult_variant (wider_mode, cnst1, &alg, &variant, + max_cost - extra_cost)) + { + /* See whether the specialized multiplication optabs are + cheaper than the shift/add version. */ + tem = expand_mult_highpart_optab (mode, op0, op1, target, unsignedp, + alg.cost.cost + extra_cost); + if (tem) + return tem; + + tem = convert_to_mode (wider_mode, op0, unsignedp); + tem = expand_mult_const (wider_mode, tem, cnst1, 0, &alg, variant); + tem = extract_high_half (mode, tem); + + /* Adjust result for signedness. */ + if (sign_adjust) + tem = force_operand (gen_rtx_MINUS (mode, tem, op0), tem); + + return tem; + } + return expand_mult_highpart_optab (mode, op0, op1, target, + unsignedp, max_cost); +} + + +/* Expand signed modulus of OP0 by a power of two D in mode MODE. */ + +static rtx +expand_smod_pow2 (enum machine_mode mode, rtx op0, HOST_WIDE_INT d) +{ + unsigned HOST_WIDE_INT masklow, maskhigh; + rtx result, temp, shift, label; + int logd; + + logd = floor_log2 (d); + result = gen_reg_rtx (mode); + + /* Avoid conditional branches when they're expensive. */ + if (BRANCH_COST >= 2 + && !optimize_size) + { + rtx signmask = emit_store_flag (result, LT, op0, const0_rtx, + mode, 0, -1); + if (signmask) + { + signmask = force_reg (mode, signmask); + masklow = ((HOST_WIDE_INT) 1 << logd) - 1; + shift = GEN_INT (GET_MODE_BITSIZE (mode) - logd); + + /* Use the rtx_cost of a LSHIFTRT instruction to determine + which instruction sequence to use. If logical right shifts + are expensive the use 2 XORs, 2 SUBs and an AND, otherwise + use a LSHIFTRT, 1 ADD, 1 SUB and an AND. */ + + temp = gen_rtx_LSHIFTRT (mode, result, shift); + if (lshr_optab->handlers[mode].insn_code == CODE_FOR_nothing + || rtx_cost (temp, SET) > COSTS_N_INSNS (2)) + { + temp = expand_binop (mode, xor_optab, op0, signmask, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, sub_optab, temp, signmask, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, and_optab, temp, GEN_INT (masklow), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, xor_optab, temp, signmask, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, sub_optab, temp, signmask, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + } + else + { + signmask = expand_binop (mode, lshr_optab, signmask, shift, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + signmask = force_reg (mode, signmask); + + temp = expand_binop (mode, add_optab, op0, signmask, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, and_optab, temp, GEN_INT (masklow), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, sub_optab, temp, signmask, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + } + return temp; + } + } + + /* Mask contains the mode's signbit and the significant bits of the + modulus. By including the signbit in the operation, many targets + can avoid an explicit compare operation in the following comparison + against zero. */ + + masklow = ((HOST_WIDE_INT) 1 << logd) - 1; + if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT) + { + masklow |= (HOST_WIDE_INT) -1 << (GET_MODE_BITSIZE (mode) - 1); + maskhigh = -1; + } + else + maskhigh = (HOST_WIDE_INT) -1 + << (GET_MODE_BITSIZE (mode) - HOST_BITS_PER_WIDE_INT - 1); + + temp = expand_binop (mode, and_optab, op0, + immed_double_const (masklow, maskhigh, mode), + result, 1, OPTAB_LIB_WIDEN); + if (temp != result) + emit_move_insn (result, temp); + + label = gen_label_rtx (); + do_cmp_and_jump (result, const0_rtx, GE, mode, label); + + temp = expand_binop (mode, sub_optab, result, const1_rtx, result, + 0, OPTAB_LIB_WIDEN); + masklow = (HOST_WIDE_INT) -1 << logd; + maskhigh = -1; + temp = expand_binop (mode, ior_optab, temp, + immed_double_const (masklow, maskhigh, mode), + result, 1, OPTAB_LIB_WIDEN); + temp = expand_binop (mode, add_optab, temp, const1_rtx, result, + 0, OPTAB_LIB_WIDEN); + if (temp != result) + emit_move_insn (result, temp); + emit_label (label); + return result; +} + +/* Expand signed division of OP0 by a power of two D in mode MODE. + This routine is only called for positive values of D. */ + +static rtx +expand_sdiv_pow2 (enum machine_mode mode, rtx op0, HOST_WIDE_INT d) +{ + rtx temp, label; + tree shift; + int logd; + + logd = floor_log2 (d); + shift = build_int_cst (NULL_TREE, logd); + + if (d == 2 && BRANCH_COST >= 1) + { + temp = gen_reg_rtx (mode); + temp = emit_store_flag (temp, LT, op0, const0_rtx, mode, 0, 1); + temp = expand_binop (mode, add_optab, temp, op0, NULL_RTX, + 0, OPTAB_LIB_WIDEN); + return expand_shift (RSHIFT_EXPR, mode, temp, shift, NULL_RTX, 0); + } + +#ifdef HAVE_conditional_move + if (BRANCH_COST >= 2) + { + rtx temp2; + + /* ??? emit_conditional_move forces a stack adjustment via + compare_from_rtx so, if the sequence is discarded, it will + be lost. Do it now instead. */ + do_pending_stack_adjust (); + + start_sequence (); + temp2 = copy_to_mode_reg (mode, op0); + temp = expand_binop (mode, add_optab, temp2, GEN_INT (d-1), + NULL_RTX, 0, OPTAB_LIB_WIDEN); + temp = force_reg (mode, temp); + + /* Construct "temp2 = (temp2 < 0) ? temp : temp2". */ + temp2 = emit_conditional_move (temp2, LT, temp2, const0_rtx, + mode, temp, temp2, mode, 0); + if (temp2) + { + rtx seq = get_insns (); + end_sequence (); + emit_insn (seq); + return expand_shift (RSHIFT_EXPR, mode, temp2, shift, NULL_RTX, 0); + } + end_sequence (); + } +#endif + + if (BRANCH_COST >= 2) + { + int ushift = GET_MODE_BITSIZE (mode) - logd; + + temp = gen_reg_rtx (mode); + temp = emit_store_flag (temp, LT, op0, const0_rtx, mode, 0, -1); + if (shift_cost[mode][ushift] > COSTS_N_INSNS (1)) + temp = expand_binop (mode, and_optab, temp, GEN_INT (d - 1), + NULL_RTX, 0, OPTAB_LIB_WIDEN); + else + temp = expand_shift (RSHIFT_EXPR, mode, temp, + build_int_cst (NULL_TREE, ushift), + NULL_RTX, 1); + temp = expand_binop (mode, add_optab, temp, op0, NULL_RTX, + 0, OPTAB_LIB_WIDEN); + return expand_shift (RSHIFT_EXPR, mode, temp, shift, NULL_RTX, 0); + } + + label = gen_label_rtx (); + temp = copy_to_mode_reg (mode, op0); + do_cmp_and_jump (temp, const0_rtx, GE, mode, label); + expand_inc (temp, GEN_INT (d - 1)); + emit_label (label); + return expand_shift (RSHIFT_EXPR, mode, temp, shift, NULL_RTX, 0); +} + +/* Emit the code to divide OP0 by OP1, putting the result in TARGET + if that is convenient, and returning where the result is. + You may request either the quotient or the remainder as the result; + specify REM_FLAG nonzero to get the remainder. + + CODE is the expression code for which kind of division this is; + it controls how rounding is done. MODE is the machine mode to use. + UNSIGNEDP nonzero means do unsigned division. */ + +/* ??? For CEIL_MOD_EXPR, can compute incorrect remainder with ANDI + and then correct it by or'ing in missing high bits + if result of ANDI is nonzero. + For ROUND_MOD_EXPR, can use ANDI and then sign-extend the result. + This could optimize to a bfexts instruction. + But C doesn't use these operations, so their optimizations are + left for later. */ +/* ??? For modulo, we don't actually need the highpart of the first product, + the low part will do nicely. And for small divisors, the second multiply + can also be a low-part only multiply or even be completely left out. + E.g. to calculate the remainder of a division by 3 with a 32 bit + multiply, multiply with 0x55555556 and extract the upper two bits; + the result is exact for inputs up to 0x1fffffff. + The input range can be reduced by using cross-sum rules. + For odd divisors >= 3, the following table gives right shift counts + so that if a number is shifted by an integer multiple of the given + amount, the remainder stays the same: + 2, 4, 3, 6, 10, 12, 4, 8, 18, 6, 11, 20, 18, 0, 5, 10, 12, 0, 12, 20, + 14, 12, 23, 21, 8, 0, 20, 18, 0, 0, 6, 12, 0, 22, 0, 18, 20, 30, 0, 0, + 0, 8, 0, 11, 12, 10, 36, 0, 30, 0, 0, 12, 0, 0, 0, 0, 44, 12, 24, 0, + 20, 0, 7, 14, 0, 18, 36, 0, 0, 46, 60, 0, 42, 0, 15, 24, 20, 0, 0, 33, + 0, 20, 0, 0, 18, 0, 60, 0, 0, 0, 0, 0, 40, 18, 0, 0, 12 + + Cross-sum rules for even numbers can be derived by leaving as many bits + to the right alone as the divisor has zeros to the right. + E.g. if x is an unsigned 32 bit number: + (x mod 12) == (((x & 1023) + ((x >> 8) & ~3)) * 0x15555558 >> 2 * 3) >> 28 + */ + +rtx +expand_divmod (int rem_flag, enum tree_code code, enum machine_mode mode, + rtx op0, rtx op1, rtx target, int unsignedp) +{ + enum machine_mode compute_mode; + rtx tquotient; + rtx quotient = 0, remainder = 0; + rtx last; + int size; + rtx insn, set; + optab optab1, optab2; + int op1_is_constant, op1_is_pow2 = 0; + int max_cost, extra_cost; + static HOST_WIDE_INT last_div_const = 0; + static HOST_WIDE_INT ext_op1; + + op1_is_constant = GET_CODE (op1) == CONST_INT; + if (op1_is_constant) + { + ext_op1 = INTVAL (op1); + if (unsignedp) + ext_op1 &= GET_MODE_MASK (mode); + op1_is_pow2 = ((EXACT_POWER_OF_2_OR_ZERO_P (ext_op1) + || (! unsignedp && EXACT_POWER_OF_2_OR_ZERO_P (-ext_op1)))); + } + + /* + This is the structure of expand_divmod: + + First comes code to fix up the operands so we can perform the operations + correctly and efficiently. + + Second comes a switch statement with code specific for each rounding mode. + For some special operands this code emits all RTL for the desired + operation, for other cases, it generates only a quotient and stores it in + QUOTIENT. The case for trunc division/remainder might leave quotient = 0, + to indicate that it has not done anything. + + Last comes code that finishes the operation. If QUOTIENT is set and + REM_FLAG is set, the remainder is computed as OP0 - QUOTIENT * OP1. If + QUOTIENT is not set, it is computed using trunc rounding. + + We try to generate special code for division and remainder when OP1 is a + constant. If |OP1| = 2**n we can use shifts and some other fast + operations. For other values of OP1, we compute a carefully selected + fixed-point approximation m = 1/OP1, and generate code that multiplies OP0 + by m. + + In all cases but EXACT_DIV_EXPR, this multiplication requires the upper + half of the product. Different strategies for generating the product are + implemented in expand_mult_highpart. + + If what we actually want is the remainder, we generate that by another + by-constant multiplication and a subtraction. */ + + /* We shouldn't be called with OP1 == const1_rtx, but some of the + code below will malfunction if we are, so check here and handle + the special case if so. */ + if (op1 == const1_rtx) + return rem_flag ? const0_rtx : op0; + + /* When dividing by -1, we could get an overflow. + negv_optab can handle overflows. */ + if (! unsignedp && op1 == constm1_rtx) + { + if (rem_flag) + return const0_rtx; + return expand_unop (mode, flag_trapv && GET_MODE_CLASS(mode) == MODE_INT + ? negv_optab : neg_optab, op0, target, 0); + } + + if (target + /* Don't use the function value register as a target + since we have to read it as well as write it, + and function-inlining gets confused by this. */ + && ((REG_P (target) && REG_FUNCTION_VALUE_P (target)) + /* Don't clobber an operand while doing a multi-step calculation. */ + || ((rem_flag || op1_is_constant) + && (reg_mentioned_p (target, op0) + || (MEM_P (op0) && MEM_P (target)))) + || reg_mentioned_p (target, op1) + || (MEM_P (op1) && MEM_P (target)))) + target = 0; + + /* Get the mode in which to perform this computation. Normally it will + be MODE, but sometimes we can't do the desired operation in MODE. + If so, pick a wider mode in which we can do the operation. Convert + to that mode at the start to avoid repeated conversions. + + First see what operations we need. These depend on the expression + we are evaluating. (We assume that divxx3 insns exist under the + same conditions that modxx3 insns and that these insns don't normally + fail. If these assumptions are not correct, we may generate less + efficient code in some cases.) + + Then see if we find a mode in which we can open-code that operation + (either a division, modulus, or shift). Finally, check for the smallest + mode for which we can do the operation with a library call. */ + + /* We might want to refine this now that we have division-by-constant + optimization. Since expand_mult_highpart tries so many variants, it is + not straightforward to generalize this. Maybe we should make an array + of possible modes in init_expmed? Save this for GCC 2.7. */ + + optab1 = ((op1_is_pow2 && op1 != const0_rtx) + ? (unsignedp ? lshr_optab : ashr_optab) + : (unsignedp ? udiv_optab : sdiv_optab)); + optab2 = ((op1_is_pow2 && op1 != const0_rtx) + ? optab1 + : (unsignedp ? udivmod_optab : sdivmod_optab)); + + for (compute_mode = mode; compute_mode != VOIDmode; + compute_mode = GET_MODE_WIDER_MODE (compute_mode)) + if (optab1->handlers[compute_mode].insn_code != CODE_FOR_nothing + || optab2->handlers[compute_mode].insn_code != CODE_FOR_nothing) + break; + + if (compute_mode == VOIDmode) + for (compute_mode = mode; compute_mode != VOIDmode; + compute_mode = GET_MODE_WIDER_MODE (compute_mode)) + if (optab1->handlers[compute_mode].libfunc + || optab2->handlers[compute_mode].libfunc) + break; + + /* If we still couldn't find a mode, use MODE, but expand_binop will + probably die. */ + if (compute_mode == VOIDmode) + compute_mode = mode; + + if (target && GET_MODE (target) == compute_mode) + tquotient = target; + else + tquotient = gen_reg_rtx (compute_mode); + + size = GET_MODE_BITSIZE (compute_mode); +#if 0 + /* It should be possible to restrict the precision to GET_MODE_BITSIZE + (mode), and thereby get better code when OP1 is a constant. Do that + later. It will require going over all usages of SIZE below. */ + size = GET_MODE_BITSIZE (mode); +#endif + + /* Only deduct something for a REM if the last divide done was + for a different constant. Then set the constant of the last + divide. */ + max_cost = unsignedp ? udiv_cost[compute_mode] : sdiv_cost[compute_mode]; + if (rem_flag && ! (last_div_const != 0 && op1_is_constant + && INTVAL (op1) == last_div_const)) + max_cost -= mul_cost[compute_mode] + add_cost[compute_mode]; + + last_div_const = ! rem_flag && op1_is_constant ? INTVAL (op1) : 0; + + /* Now convert to the best mode to use. */ + if (compute_mode != mode) + { + op0 = convert_modes (compute_mode, mode, op0, unsignedp); + op1 = convert_modes (compute_mode, mode, op1, unsignedp); + + /* convert_modes may have placed op1 into a register, so we + must recompute the following. */ + op1_is_constant = GET_CODE (op1) == CONST_INT; + op1_is_pow2 = (op1_is_constant + && ((EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)) + || (! unsignedp + && EXACT_POWER_OF_2_OR_ZERO_P (-INTVAL (op1)))))) ; + } + + /* If one of the operands is a volatile MEM, copy it into a register. */ + + if (MEM_P (op0) && MEM_VOLATILE_P (op0)) + op0 = force_reg (compute_mode, op0); + if (MEM_P (op1) && MEM_VOLATILE_P (op1)) + op1 = force_reg (compute_mode, op1); + + /* If we need the remainder or if OP1 is constant, we need to + put OP0 in a register in case it has any queued subexpressions. */ + if (rem_flag || op1_is_constant) + op0 = force_reg (compute_mode, op0); + + last = get_last_insn (); + + /* Promote floor rounding to trunc rounding for unsigned operations. */ + if (unsignedp) + { + if (code == FLOOR_DIV_EXPR) + code = TRUNC_DIV_EXPR; + if (code == FLOOR_MOD_EXPR) + code = TRUNC_MOD_EXPR; + if (code == EXACT_DIV_EXPR && op1_is_pow2) + code = TRUNC_DIV_EXPR; + } + + if (op1 != const0_rtx) + switch (code) + { + case TRUNC_MOD_EXPR: + case TRUNC_DIV_EXPR: + if (op1_is_constant) + { + if (unsignedp) + { + unsigned HOST_WIDE_INT mh; + int pre_shift, post_shift; + int dummy; + rtx ml; + unsigned HOST_WIDE_INT d = (INTVAL (op1) + & GET_MODE_MASK (compute_mode)); + + if (EXACT_POWER_OF_2_OR_ZERO_P (d)) + { + pre_shift = floor_log2 (d); + if (rem_flag) + { + remainder + = expand_binop (compute_mode, and_optab, op0, + GEN_INT (((HOST_WIDE_INT) 1 << pre_shift) - 1), + remainder, 1, + OPTAB_LIB_WIDEN); + if (remainder) + return gen_lowpart (mode, remainder); + } + quotient = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, + pre_shift), + tquotient, 1); + } + else if (size <= HOST_BITS_PER_WIDE_INT) + { + if (d >= ((unsigned HOST_WIDE_INT) 1 << (size - 1))) + { + /* Most significant bit of divisor is set; emit an scc + insn. */ + quotient = emit_store_flag (tquotient, GEU, op0, op1, + compute_mode, 1, 1); + if (quotient == 0) + goto fail1; + } + else + { + /* Find a suitable multiplier and right shift count + instead of multiplying with D. */ + + mh = choose_multiplier (d, size, size, + &ml, &post_shift, &dummy); + + /* If the suggested multiplier is more than SIZE bits, + we can do better for even divisors, using an + initial right shift. */ + if (mh != 0 && (d & 1) == 0) + { + pre_shift = floor_log2 (d & -d); + mh = choose_multiplier (d >> pre_shift, size, + size - pre_shift, + &ml, &post_shift, &dummy); + gcc_assert (!mh); + } + else + pre_shift = 0; + + if (mh != 0) + { + rtx t1, t2, t3, t4; + + if (post_shift - 1 >= BITS_PER_WORD) + goto fail1; + + extra_cost + = (shift_cost[compute_mode][post_shift - 1] + + shift_cost[compute_mode][1] + + 2 * add_cost[compute_mode]); + t1 = expand_mult_highpart (compute_mode, op0, ml, + NULL_RTX, 1, + max_cost - extra_cost); + if (t1 == 0) + goto fail1; + t2 = force_operand (gen_rtx_MINUS (compute_mode, + op0, t1), + NULL_RTX); + t3 = expand_shift + (RSHIFT_EXPR, compute_mode, t2, + build_int_cst (NULL_TREE, 1), + NULL_RTX,1); + t4 = force_operand (gen_rtx_PLUS (compute_mode, + t1, t3), + NULL_RTX); + quotient = expand_shift + (RSHIFT_EXPR, compute_mode, t4, + build_int_cst (NULL_TREE, post_shift - 1), + tquotient, 1); + } + else + { + rtx t1, t2; + + if (pre_shift >= BITS_PER_WORD + || post_shift >= BITS_PER_WORD) + goto fail1; + + t1 = expand_shift + (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, pre_shift), + NULL_RTX, 1); + extra_cost + = (shift_cost[compute_mode][pre_shift] + + shift_cost[compute_mode][post_shift]); + t2 = expand_mult_highpart (compute_mode, t1, ml, + NULL_RTX, 1, + max_cost - extra_cost); + if (t2 == 0) + goto fail1; + quotient = expand_shift + (RSHIFT_EXPR, compute_mode, t2, + build_int_cst (NULL_TREE, post_shift), + tquotient, 1); + } + } + } + else /* Too wide mode to use tricky code */ + break; + + insn = get_last_insn (); + if (insn != last + && (set = single_set (insn)) != 0 + && SET_DEST (set) == quotient) + set_unique_reg_note (insn, + REG_EQUAL, + gen_rtx_UDIV (compute_mode, op0, op1)); + } + else /* TRUNC_DIV, signed */ + { + unsigned HOST_WIDE_INT ml; + int lgup, post_shift; + rtx mlr; + HOST_WIDE_INT d = INTVAL (op1); + unsigned HOST_WIDE_INT abs_d = d >= 0 ? d : -d; + + /* n rem d = n rem -d */ + if (rem_flag && d < 0) + { + d = abs_d; + op1 = gen_int_mode (abs_d, compute_mode); + } + + if (d == 1) + quotient = op0; + else if (d == -1) + quotient = expand_unop (compute_mode, neg_optab, op0, + tquotient, 0); + else if (abs_d == (unsigned HOST_WIDE_INT) 1 << (size - 1)) + { + /* This case is not handled correctly below. */ + quotient = emit_store_flag (tquotient, EQ, op0, op1, + compute_mode, 1, 1); + if (quotient == 0) + goto fail1; + } + else if (EXACT_POWER_OF_2_OR_ZERO_P (d) + && (rem_flag ? smod_pow2_cheap[compute_mode] + : sdiv_pow2_cheap[compute_mode]) + /* We assume that cheap metric is true if the + optab has an expander for this mode. */ + && (((rem_flag ? smod_optab : sdiv_optab) + ->handlers[compute_mode].insn_code + != CODE_FOR_nothing) + || (sdivmod_optab->handlers[compute_mode] + .insn_code != CODE_FOR_nothing))) + ; + else if (EXACT_POWER_OF_2_OR_ZERO_P (abs_d)) + { + if (rem_flag) + { + remainder = expand_smod_pow2 (compute_mode, op0, d); + if (remainder) + return gen_lowpart (mode, remainder); + } + + if (sdiv_pow2_cheap[compute_mode] + && ((sdiv_optab->handlers[compute_mode].insn_code + != CODE_FOR_nothing) + || (sdivmod_optab->handlers[compute_mode].insn_code + != CODE_FOR_nothing))) + quotient = expand_divmod (0, TRUNC_DIV_EXPR, + compute_mode, op0, + gen_int_mode (abs_d, + compute_mode), + NULL_RTX, 0); + else + quotient = expand_sdiv_pow2 (compute_mode, op0, abs_d); + + /* We have computed OP0 / abs(OP1). If OP1 is negative, + negate the quotient. */ + if (d < 0) + { + insn = get_last_insn (); + if (insn != last + && (set = single_set (insn)) != 0 + && SET_DEST (set) == quotient + && abs_d < ((unsigned HOST_WIDE_INT) 1 + << (HOST_BITS_PER_WIDE_INT - 1))) + set_unique_reg_note (insn, + REG_EQUAL, + gen_rtx_DIV (compute_mode, + op0, + GEN_INT + (trunc_int_for_mode + (abs_d, + compute_mode)))); + + quotient = expand_unop (compute_mode, neg_optab, + quotient, quotient, 0); + } + } + else if (size <= HOST_BITS_PER_WIDE_INT) + { + choose_multiplier (abs_d, size, size - 1, + &mlr, &post_shift, &lgup); + ml = (unsigned HOST_WIDE_INT) INTVAL (mlr); + if (ml < (unsigned HOST_WIDE_INT) 1 << (size - 1)) + { + rtx t1, t2, t3; + + if (post_shift >= BITS_PER_WORD + || size - 1 >= BITS_PER_WORD) + goto fail1; + + extra_cost = (shift_cost[compute_mode][post_shift] + + shift_cost[compute_mode][size - 1] + + add_cost[compute_mode]); + t1 = expand_mult_highpart (compute_mode, op0, mlr, + NULL_RTX, 0, + max_cost - extra_cost); + if (t1 == 0) + goto fail1; + t2 = expand_shift + (RSHIFT_EXPR, compute_mode, t1, + build_int_cst (NULL_TREE, post_shift), + NULL_RTX, 0); + t3 = expand_shift + (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, size - 1), + NULL_RTX, 0); + if (d < 0) + quotient + = force_operand (gen_rtx_MINUS (compute_mode, + t3, t2), + tquotient); + else + quotient + = force_operand (gen_rtx_MINUS (compute_mode, + t2, t3), + tquotient); + } + else + { + rtx t1, t2, t3, t4; + + if (post_shift >= BITS_PER_WORD + || size - 1 >= BITS_PER_WORD) + goto fail1; + + ml |= (~(unsigned HOST_WIDE_INT) 0) << (size - 1); + mlr = gen_int_mode (ml, compute_mode); + extra_cost = (shift_cost[compute_mode][post_shift] + + shift_cost[compute_mode][size - 1] + + 2 * add_cost[compute_mode]); + t1 = expand_mult_highpart (compute_mode, op0, mlr, + NULL_RTX, 0, + max_cost - extra_cost); + if (t1 == 0) + goto fail1; + t2 = force_operand (gen_rtx_PLUS (compute_mode, + t1, op0), + NULL_RTX); + t3 = expand_shift + (RSHIFT_EXPR, compute_mode, t2, + build_int_cst (NULL_TREE, post_shift), + NULL_RTX, 0); + t4 = expand_shift + (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, size - 1), + NULL_RTX, 0); + if (d < 0) + quotient + = force_operand (gen_rtx_MINUS (compute_mode, + t4, t3), + tquotient); + else + quotient + = force_operand (gen_rtx_MINUS (compute_mode, + t3, t4), + tquotient); + } + } + else /* Too wide mode to use tricky code */ + break; + + insn = get_last_insn (); + if (insn != last + && (set = single_set (insn)) != 0 + && SET_DEST (set) == quotient) + set_unique_reg_note (insn, + REG_EQUAL, + gen_rtx_DIV (compute_mode, op0, op1)); + } + break; + } + fail1: + delete_insns_since (last); + break; + + case FLOOR_DIV_EXPR: + case FLOOR_MOD_EXPR: + /* We will come here only for signed operations. */ + if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size) + { + unsigned HOST_WIDE_INT mh; + int pre_shift, lgup, post_shift; + HOST_WIDE_INT d = INTVAL (op1); + rtx ml; + + if (d > 0) + { + /* We could just as easily deal with negative constants here, + but it does not seem worth the trouble for GCC 2.6. */ + if (EXACT_POWER_OF_2_OR_ZERO_P (d)) + { + pre_shift = floor_log2 (d); + if (rem_flag) + { + remainder = expand_binop (compute_mode, and_optab, op0, + GEN_INT (((HOST_WIDE_INT) 1 << pre_shift) - 1), + remainder, 0, OPTAB_LIB_WIDEN); + if (remainder) + return gen_lowpart (mode, remainder); + } + quotient = expand_shift + (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, pre_shift), + tquotient, 0); + } + else + { + rtx t1, t2, t3, t4; + + mh = choose_multiplier (d, size, size - 1, + &ml, &post_shift, &lgup); + gcc_assert (!mh); + + if (post_shift < BITS_PER_WORD + && size - 1 < BITS_PER_WORD) + { + t1 = expand_shift + (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, size - 1), + NULL_RTX, 0); + t2 = expand_binop (compute_mode, xor_optab, op0, t1, + NULL_RTX, 0, OPTAB_WIDEN); + extra_cost = (shift_cost[compute_mode][post_shift] + + shift_cost[compute_mode][size - 1] + + 2 * add_cost[compute_mode]); + t3 = expand_mult_highpart (compute_mode, t2, ml, + NULL_RTX, 1, + max_cost - extra_cost); + if (t3 != 0) + { + t4 = expand_shift + (RSHIFT_EXPR, compute_mode, t3, + build_int_cst (NULL_TREE, post_shift), + NULL_RTX, 1); + quotient = expand_binop (compute_mode, xor_optab, + t4, t1, tquotient, 0, + OPTAB_WIDEN); + } + } + } + } + else + { + rtx nsign, t1, t2, t3, t4; + t1 = force_operand (gen_rtx_PLUS (compute_mode, + op0, constm1_rtx), NULL_RTX); + t2 = expand_binop (compute_mode, ior_optab, op0, t1, NULL_RTX, + 0, OPTAB_WIDEN); + nsign = expand_shift + (RSHIFT_EXPR, compute_mode, t2, + build_int_cst (NULL_TREE, size - 1), + NULL_RTX, 0); + t3 = force_operand (gen_rtx_MINUS (compute_mode, t1, nsign), + NULL_RTX); + t4 = expand_divmod (0, TRUNC_DIV_EXPR, compute_mode, t3, op1, + NULL_RTX, 0); + if (t4) + { + rtx t5; + t5 = expand_unop (compute_mode, one_cmpl_optab, nsign, + NULL_RTX, 0); + quotient = force_operand (gen_rtx_PLUS (compute_mode, + t4, t5), + tquotient); + } + } + } + + if (quotient != 0) + break; + delete_insns_since (last); + + /* Try using an instruction that produces both the quotient and + remainder, using truncation. We can easily compensate the quotient + or remainder to get floor rounding, once we have the remainder. + Notice that we compute also the final remainder value here, + and return the result right away. */ + if (target == 0 || GET_MODE (target) != compute_mode) + target = gen_reg_rtx (compute_mode); + + if (rem_flag) + { + remainder + = REG_P (target) ? target : gen_reg_rtx (compute_mode); + quotient = gen_reg_rtx (compute_mode); + } + else + { + quotient + = REG_P (target) ? target : gen_reg_rtx (compute_mode); + remainder = gen_reg_rtx (compute_mode); + } + + if (expand_twoval_binop (sdivmod_optab, op0, op1, + quotient, remainder, 0)) + { + /* This could be computed with a branch-less sequence. + Save that for later. */ + rtx tem; + rtx label = gen_label_rtx (); + do_cmp_and_jump (remainder, const0_rtx, EQ, compute_mode, label); + tem = expand_binop (compute_mode, xor_optab, op0, op1, + NULL_RTX, 0, OPTAB_WIDEN); + do_cmp_and_jump (tem, const0_rtx, GE, compute_mode, label); + expand_dec (quotient, const1_rtx); + expand_inc (remainder, op1); + emit_label (label); + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + /* No luck with division elimination or divmod. Have to do it + by conditionally adjusting op0 *and* the result. */ + { + rtx label1, label2, label3, label4, label5; + rtx adjusted_op0; + rtx tem; + + quotient = gen_reg_rtx (compute_mode); + adjusted_op0 = copy_to_mode_reg (compute_mode, op0); + label1 = gen_label_rtx (); + label2 = gen_label_rtx (); + label3 = gen_label_rtx (); + label4 = gen_label_rtx (); + label5 = gen_label_rtx (); + do_cmp_and_jump (op1, const0_rtx, LT, compute_mode, label2); + do_cmp_and_jump (adjusted_op0, const0_rtx, LT, compute_mode, label1); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label1); + expand_inc (adjusted_op0, const1_rtx); + emit_jump_insn (gen_jump (label4)); + emit_barrier (); + emit_label (label2); + do_cmp_and_jump (adjusted_op0, const0_rtx, GT, compute_mode, label3); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label3); + expand_dec (adjusted_op0, const1_rtx); + emit_label (label4); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + expand_dec (quotient, const1_rtx); + emit_label (label5); + } + break; + + case CEIL_DIV_EXPR: + case CEIL_MOD_EXPR: + if (unsignedp) + { + if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1))) + { + rtx t1, t2, t3; + unsigned HOST_WIDE_INT d = INTVAL (op1); + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, floor_log2 (d)), + tquotient, 1); + t2 = expand_binop (compute_mode, and_optab, op0, + GEN_INT (d - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + t3 = gen_reg_rtx (compute_mode); + t3 = emit_store_flag (t3, NE, t2, const0_rtx, + compute_mode, 1, 1); + if (t3 == 0) + { + rtx lab; + lab = gen_label_rtx (); + do_cmp_and_jump (t2, const0_rtx, EQ, compute_mode, lab); + expand_inc (t1, const1_rtx); + emit_label (lab); + quotient = t1; + } + else + quotient = force_operand (gen_rtx_PLUS (compute_mode, + t1, t3), + tquotient); + break; + } + + /* Try using an instruction that produces both the quotient and + remainder, using truncation. We can easily compensate the + quotient or remainder to get ceiling rounding, once we have the + remainder. Notice that we compute also the final remainder + value here, and return the result right away. */ + if (target == 0 || GET_MODE (target) != compute_mode) + target = gen_reg_rtx (compute_mode); + + if (rem_flag) + { + remainder = (REG_P (target) + ? target : gen_reg_rtx (compute_mode)); + quotient = gen_reg_rtx (compute_mode); + } + else + { + quotient = (REG_P (target) + ? target : gen_reg_rtx (compute_mode)); + remainder = gen_reg_rtx (compute_mode); + } + + if (expand_twoval_binop (udivmod_optab, op0, op1, quotient, + remainder, 1)) + { + /* This could be computed with a branch-less sequence. + Save that for later. */ + rtx label = gen_label_rtx (); + do_cmp_and_jump (remainder, const0_rtx, EQ, + compute_mode, label); + expand_inc (quotient, const1_rtx); + expand_dec (remainder, op1); + emit_label (label); + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + /* No luck with division elimination or divmod. Have to do it + by conditionally adjusting op0 *and* the result. */ + { + rtx label1, label2; + rtx adjusted_op0, tem; + + quotient = gen_reg_rtx (compute_mode); + adjusted_op0 = copy_to_mode_reg (compute_mode, op0); + label1 = gen_label_rtx (); + label2 = gen_label_rtx (); + do_cmp_and_jump (adjusted_op0, const0_rtx, NE, + compute_mode, label1); + emit_move_insn (quotient, const0_rtx); + emit_jump_insn (gen_jump (label2)); + emit_barrier (); + emit_label (label1); + expand_dec (adjusted_op0, const1_rtx); + tem = expand_binop (compute_mode, udiv_optab, adjusted_op0, op1, + quotient, 1, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + expand_inc (quotient, const1_rtx); + emit_label (label2); + } + } + else /* signed */ + { + if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)) + && INTVAL (op1) >= 0) + { + /* This is extremely similar to the code for the unsigned case + above. For 2.7 we should merge these variants, but for + 2.6.1 I don't want to touch the code for unsigned since that + get used in C. The signed case will only be used by other + languages (Ada). */ + + rtx t1, t2, t3; + unsigned HOST_WIDE_INT d = INTVAL (op1); + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, floor_log2 (d)), + tquotient, 0); + t2 = expand_binop (compute_mode, and_optab, op0, + GEN_INT (d - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + t3 = gen_reg_rtx (compute_mode); + t3 = emit_store_flag (t3, NE, t2, const0_rtx, + compute_mode, 1, 1); + if (t3 == 0) + { + rtx lab; + lab = gen_label_rtx (); + do_cmp_and_jump (t2, const0_rtx, EQ, compute_mode, lab); + expand_inc (t1, const1_rtx); + emit_label (lab); + quotient = t1; + } + else + quotient = force_operand (gen_rtx_PLUS (compute_mode, + t1, t3), + tquotient); + break; + } + + /* Try using an instruction that produces both the quotient and + remainder, using truncation. We can easily compensate the + quotient or remainder to get ceiling rounding, once we have the + remainder. Notice that we compute also the final remainder + value here, and return the result right away. */ + if (target == 0 || GET_MODE (target) != compute_mode) + target = gen_reg_rtx (compute_mode); + if (rem_flag) + { + remainder= (REG_P (target) + ? target : gen_reg_rtx (compute_mode)); + quotient = gen_reg_rtx (compute_mode); + } + else + { + quotient = (REG_P (target) + ? target : gen_reg_rtx (compute_mode)); + remainder = gen_reg_rtx (compute_mode); + } + + if (expand_twoval_binop (sdivmod_optab, op0, op1, quotient, + remainder, 0)) + { + /* This could be computed with a branch-less sequence. + Save that for later. */ + rtx tem; + rtx label = gen_label_rtx (); + do_cmp_and_jump (remainder, const0_rtx, EQ, + compute_mode, label); + tem = expand_binop (compute_mode, xor_optab, op0, op1, + NULL_RTX, 0, OPTAB_WIDEN); + do_cmp_and_jump (tem, const0_rtx, LT, compute_mode, label); + expand_inc (quotient, const1_rtx); + expand_dec (remainder, op1); + emit_label (label); + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + /* No luck with division elimination or divmod. Have to do it + by conditionally adjusting op0 *and* the result. */ + { + rtx label1, label2, label3, label4, label5; + rtx adjusted_op0; + rtx tem; + + quotient = gen_reg_rtx (compute_mode); + adjusted_op0 = copy_to_mode_reg (compute_mode, op0); + label1 = gen_label_rtx (); + label2 = gen_label_rtx (); + label3 = gen_label_rtx (); + label4 = gen_label_rtx (); + label5 = gen_label_rtx (); + do_cmp_and_jump (op1, const0_rtx, LT, compute_mode, label2); + do_cmp_and_jump (adjusted_op0, const0_rtx, GT, + compute_mode, label1); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label1); + expand_dec (adjusted_op0, const1_rtx); + emit_jump_insn (gen_jump (label4)); + emit_barrier (); + emit_label (label2); + do_cmp_and_jump (adjusted_op0, const0_rtx, LT, + compute_mode, label3); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label3); + expand_inc (adjusted_op0, const1_rtx); + emit_label (label4); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + expand_inc (quotient, const1_rtx); + emit_label (label5); + } + } + break; + + case EXACT_DIV_EXPR: + if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size) + { + HOST_WIDE_INT d = INTVAL (op1); + unsigned HOST_WIDE_INT ml; + int pre_shift; + rtx t1; + + pre_shift = floor_log2 (d & -d); + ml = invert_mod2n (d >> pre_shift, size); + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_cst (NULL_TREE, pre_shift), + NULL_RTX, unsignedp); + quotient = expand_mult (compute_mode, t1, + gen_int_mode (ml, compute_mode), + NULL_RTX, 1); + + insn = get_last_insn (); + set_unique_reg_note (insn, + REG_EQUAL, + gen_rtx_fmt_ee (unsignedp ? UDIV : DIV, + compute_mode, + op0, op1)); + } + break; + + case ROUND_DIV_EXPR: + case ROUND_MOD_EXPR: + if (unsignedp) + { + rtx tem; + rtx label; + label = gen_label_rtx (); + quotient = gen_reg_rtx (compute_mode); + remainder = gen_reg_rtx (compute_mode); + if (expand_twoval_binop (udivmod_optab, op0, op1, quotient, remainder, 1) == 0) + { + rtx tem; + quotient = expand_binop (compute_mode, udiv_optab, op0, op1, + quotient, 1, OPTAB_LIB_WIDEN); + tem = expand_mult (compute_mode, quotient, op1, NULL_RTX, 1); + remainder = expand_binop (compute_mode, sub_optab, op0, tem, + remainder, 1, OPTAB_LIB_WIDEN); + } + tem = plus_constant (op1, -1); + tem = expand_shift (RSHIFT_EXPR, compute_mode, tem, + build_int_cst (NULL_TREE, 1), + NULL_RTX, 1); + do_cmp_and_jump (remainder, tem, LEU, compute_mode, label); + expand_inc (quotient, const1_rtx); + expand_dec (remainder, op1); + emit_label (label); + } + else + { + rtx abs_rem, abs_op1, tem, mask; + rtx label; + label = gen_label_rtx (); + quotient = gen_reg_rtx (compute_mode); + remainder = gen_reg_rtx (compute_mode); + if (expand_twoval_binop (sdivmod_optab, op0, op1, quotient, remainder, 0) == 0) + { + rtx tem; + quotient = expand_binop (compute_mode, sdiv_optab, op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + tem = expand_mult (compute_mode, quotient, op1, NULL_RTX, 0); + remainder = expand_binop (compute_mode, sub_optab, op0, tem, + remainder, 0, OPTAB_LIB_WIDEN); + } + abs_rem = expand_abs (compute_mode, remainder, NULL_RTX, 1, 0); + abs_op1 = expand_abs (compute_mode, op1, NULL_RTX, 1, 0); + tem = expand_shift (LSHIFT_EXPR, compute_mode, abs_rem, + build_int_cst (NULL_TREE, 1), + NULL_RTX, 1); + do_cmp_and_jump (tem, abs_op1, LTU, compute_mode, label); + tem = expand_binop (compute_mode, xor_optab, op0, op1, + NULL_RTX, 0, OPTAB_WIDEN); + mask = expand_shift (RSHIFT_EXPR, compute_mode, tem, + build_int_cst (NULL_TREE, size - 1), + NULL_RTX, 0); + tem = expand_binop (compute_mode, xor_optab, mask, const1_rtx, + NULL_RTX, 0, OPTAB_WIDEN); + tem = expand_binop (compute_mode, sub_optab, tem, mask, + NULL_RTX, 0, OPTAB_WIDEN); + expand_inc (quotient, tem); + tem = expand_binop (compute_mode, xor_optab, mask, op1, + NULL_RTX, 0, OPTAB_WIDEN); + tem = expand_binop (compute_mode, sub_optab, tem, mask, + NULL_RTX, 0, OPTAB_WIDEN); + expand_dec (remainder, tem); + emit_label (label); + } + return gen_lowpart (mode, rem_flag ? remainder : quotient); + + default: + gcc_unreachable (); + } + + if (quotient == 0) + { + if (target && GET_MODE (target) != compute_mode) + target = 0; + + if (rem_flag) + { + /* Try to produce the remainder without producing the quotient. + If we seem to have a divmod pattern that does not require widening, + don't try widening here. We should really have a WIDEN argument + to expand_twoval_binop, since what we'd really like to do here is + 1) try a mod insn in compute_mode + 2) try a divmod insn in compute_mode + 3) try a div insn in compute_mode and multiply-subtract to get + remainder + 4) try the same things with widening allowed. */ + remainder + = sign_expand_binop (compute_mode, umod_optab, smod_optab, + op0, op1, target, + unsignedp, + ((optab2->handlers[compute_mode].insn_code + != CODE_FOR_nothing) + ? OPTAB_DIRECT : OPTAB_WIDEN)); + if (remainder == 0) + { + /* No luck there. Can we do remainder and divide at once + without a library call? */ + remainder = gen_reg_rtx (compute_mode); + if (! expand_twoval_binop ((unsignedp + ? udivmod_optab + : sdivmod_optab), + op0, op1, + NULL_RTX, remainder, unsignedp)) + remainder = 0; + } + + if (remainder) + return gen_lowpart (mode, remainder); + } + + /* Produce the quotient. Try a quotient insn, but not a library call. + If we have a divmod in this mode, use it in preference to widening + the div (for this test we assume it will not fail). Note that optab2 + is set to the one of the two optabs that the call below will use. */ + quotient + = sign_expand_binop (compute_mode, udiv_optab, sdiv_optab, + op0, op1, rem_flag ? NULL_RTX : target, + unsignedp, + ((optab2->handlers[compute_mode].insn_code + != CODE_FOR_nothing) + ? OPTAB_DIRECT : OPTAB_WIDEN)); + + if (quotient == 0) + { + /* No luck there. Try a quotient-and-remainder insn, + keeping the quotient alone. */ + quotient = gen_reg_rtx (compute_mode); + if (! expand_twoval_binop (unsignedp ? udivmod_optab : sdivmod_optab, + op0, op1, + quotient, NULL_RTX, unsignedp)) + { + quotient = 0; + if (! rem_flag) + /* Still no luck. If we are not computing the remainder, + use a library call for the quotient. */ + quotient = sign_expand_binop (compute_mode, + udiv_optab, sdiv_optab, + op0, op1, target, + unsignedp, OPTAB_LIB_WIDEN); + } + } + } + + if (rem_flag) + { + if (target && GET_MODE (target) != compute_mode) + target = 0; + + if (quotient == 0) + { + /* No divide instruction either. Use library for remainder. */ + remainder = sign_expand_binop (compute_mode, umod_optab, smod_optab, + op0, op1, target, + unsignedp, OPTAB_LIB_WIDEN); + /* No remainder function. Try a quotient-and-remainder + function, keeping the remainder. */ + if (!remainder) + { + remainder = gen_reg_rtx (compute_mode); + if (!expand_twoval_binop_libfunc + (unsignedp ? udivmod_optab : sdivmod_optab, + op0, op1, + NULL_RTX, remainder, + unsignedp ? UMOD : MOD)) + remainder = NULL_RTX; + } + } + else + { + /* We divided. Now finish doing X - Y * (X / Y). */ + remainder = expand_mult (compute_mode, quotient, op1, + NULL_RTX, unsignedp); + remainder = expand_binop (compute_mode, sub_optab, op0, + remainder, target, unsignedp, + OPTAB_LIB_WIDEN); + } + } + + return gen_lowpart (mode, rem_flag ? remainder : quotient); +} + +/* Return a tree node with data type TYPE, describing the value of X. + Usually this is an VAR_DECL, if there is no obvious better choice. + X may be an expression, however we only support those expressions + generated by loop.c. */ + +tree +make_tree (tree type, rtx x) +{ + tree t; + + switch (GET_CODE (x)) + { + case CONST_INT: + { + HOST_WIDE_INT hi = 0; + + if (INTVAL (x) < 0 + && !(TYPE_UNSIGNED (type) + && (GET_MODE_BITSIZE (TYPE_MODE (type)) + < HOST_BITS_PER_WIDE_INT))) + hi = -1; + + t = build_int_cst_wide (type, INTVAL (x), hi); + + return t; + } + + case CONST_DOUBLE: + if (GET_MODE (x) == VOIDmode) + t = build_int_cst_wide (type, + CONST_DOUBLE_LOW (x), CONST_DOUBLE_HIGH (x)); + else + { + REAL_VALUE_TYPE d; + + REAL_VALUE_FROM_CONST_DOUBLE (d, x); + t = build_real (type, d); + } + + return t; + + case CONST_VECTOR: + { + int units = CONST_VECTOR_NUNITS (x); + tree itype = TREE_TYPE (type); + tree t = NULL_TREE; + int i; + + + /* Build a tree with vector elements. */ + for (i = units - 1; i >= 0; --i) + { + rtx elt = CONST_VECTOR_ELT (x, i); + t = tree_cons (NULL_TREE, make_tree (itype, elt), t); + } + + return build_vector (type, t); + } + + case PLUS: + return fold_build2 (PLUS_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1))); + + case MINUS: + return fold_build2 (MINUS_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1))); + + case NEG: + return fold_build1 (NEGATE_EXPR, type, make_tree (type, XEXP (x, 0))); + + case MULT: + return fold_build2 (MULT_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1))); + + case ASHIFT: + return fold_build2 (LSHIFT_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1))); + + case LSHIFTRT: + t = lang_hooks.types.unsigned_type (type); + return fold_convert (type, build2 (RSHIFT_EXPR, t, + make_tree (t, XEXP (x, 0)), + make_tree (type, XEXP (x, 1)))); + + case ASHIFTRT: + t = lang_hooks.types.signed_type (type); + return fold_convert (type, build2 (RSHIFT_EXPR, t, + make_tree (t, XEXP (x, 0)), + make_tree (type, XEXP (x, 1)))); + + case DIV: + if (TREE_CODE (type) != REAL_TYPE) + t = lang_hooks.types.signed_type (type); + else + t = type; + + return fold_convert (type, build2 (TRUNC_DIV_EXPR, t, + make_tree (t, XEXP (x, 0)), + make_tree (t, XEXP (x, 1)))); + case UDIV: + t = lang_hooks.types.unsigned_type (type); + return fold_convert (type, build2 (TRUNC_DIV_EXPR, t, + make_tree (t, XEXP (x, 0)), + make_tree (t, XEXP (x, 1)))); + + case SIGN_EXTEND: + case ZERO_EXTEND: + t = lang_hooks.types.type_for_mode (GET_MODE (XEXP (x, 0)), + GET_CODE (x) == ZERO_EXTEND); + return fold_convert (type, make_tree (t, XEXP (x, 0))); + + case CONST: + return make_tree (type, XEXP (x, 0)); + + case SYMBOL_REF: + t = SYMBOL_REF_DECL (x); + if (t) + return fold_convert (type, build_fold_addr_expr (t)); + /* else fall through. */ + + default: + t = build_decl (VAR_DECL, NULL_TREE, type); + + /* If TYPE is a POINTER_TYPE, X might be Pmode with TYPE_MODE being + ptr_mode. So convert. */ + if (POINTER_TYPE_P (type)) + x = convert_memory_address (TYPE_MODE (type), x); + + /* Note that we do *not* use SET_DECL_RTL here, because we do not + want set_decl_rtl to go adjusting REG_ATTRS for this temporary. */ + t->decl_with_rtl.rtl = x; + + return t; + } +} + +/* Compute the logical-and of OP0 and OP1, storing it in TARGET + and returning TARGET. + + If TARGET is 0, a pseudo-register or constant is returned. */ + +rtx +expand_and (enum machine_mode mode, rtx op0, rtx op1, rtx target) +{ + rtx tem = 0; + + if (GET_MODE (op0) == VOIDmode && GET_MODE (op1) == VOIDmode) + tem = simplify_binary_operation (AND, mode, op0, op1); + if (tem == 0) + tem = expand_binop (mode, and_optab, op0, op1, target, 0, OPTAB_LIB_WIDEN); + + if (target == 0) + target = tem; + else if (tem != target) + emit_move_insn (target, tem); + return target; +} + +/* Emit a store-flags instruction for comparison CODE on OP0 and OP1 + and storing in TARGET. Normally return TARGET. + Return 0 if that cannot be done. + + MODE is the mode to use for OP0 and OP1 should they be CONST_INTs. If + it is VOIDmode, they cannot both be CONST_INT. + + UNSIGNEDP is for the case where we have to widen the operands + to perform the operation. It says to use zero-extension. + + NORMALIZEP is 1 if we should convert the result to be either zero + or one. Normalize is -1 if we should convert the result to be + either zero or -1. If NORMALIZEP is zero, the result will be left + "raw" out of the scc insn. */ + +rtx +emit_store_flag (rtx target, enum rtx_code code, rtx op0, rtx op1, + enum machine_mode mode, int unsignedp, int normalizep) +{ + rtx subtarget; + enum insn_code icode; + enum machine_mode compare_mode; + enum machine_mode target_mode = GET_MODE (target); + rtx tem; + rtx last = get_last_insn (); + rtx pattern, comparison; + + if (unsignedp) + code = unsigned_condition (code); + + /* If one operand is constant, make it the second one. Only do this + if the other operand is not constant as well. */ + + if (swap_commutative_operands_p (op0, op1)) + { + tem = op0; + op0 = op1; + op1 = tem; + code = swap_condition (code); + } + + if (mode == VOIDmode) + mode = GET_MODE (op0); + + /* For some comparisons with 1 and -1, we can convert this to + comparisons with zero. This will often produce more opportunities for + store-flag insns. */ + + switch (code) + { + case LT: + if (op1 == const1_rtx) + op1 = const0_rtx, code = LE; + break; + case LE: + if (op1 == constm1_rtx) + op1 = const0_rtx, code = LT; + break; + case GE: + if (op1 == const1_rtx) + op1 = const0_rtx, code = GT; + break; + case GT: + if (op1 == constm1_rtx) + op1 = const0_rtx, code = GE; + break; + case GEU: + if (op1 == const1_rtx) + op1 = const0_rtx, code = NE; + break; + case LTU: + if (op1 == const1_rtx) + op1 = const0_rtx, code = EQ; + break; + default: + break; + } + + /* If we are comparing a double-word integer with zero or -1, we can + convert the comparison into one involving a single word. */ + if (GET_MODE_BITSIZE (mode) == BITS_PER_WORD * 2 + && GET_MODE_CLASS (mode) == MODE_INT + && (!MEM_P (op0) || ! MEM_VOLATILE_P (op0))) + { + if ((code == EQ || code == NE) + && (op1 == const0_rtx || op1 == constm1_rtx)) + { + rtx op00, op01, op0both; + + /* Do a logical OR or AND of the two words and compare the result. */ + op00 = simplify_gen_subreg (word_mode, op0, mode, 0); + op01 = simplify_gen_subreg (word_mode, op0, mode, UNITS_PER_WORD); + op0both = expand_binop (word_mode, + op1 == const0_rtx ? ior_optab : and_optab, + op00, op01, NULL_RTX, unsignedp, OPTAB_DIRECT); + + if (op0both != 0) + return emit_store_flag (target, code, op0both, op1, word_mode, + unsignedp, normalizep); + } + else if ((code == LT || code == GE) && op1 == const0_rtx) + { + rtx op0h; + + /* If testing the sign bit, can just test on high word. */ + op0h = simplify_gen_subreg (word_mode, op0, mode, + subreg_highpart_offset (word_mode, mode)); + return emit_store_flag (target, code, op0h, op1, word_mode, + unsignedp, normalizep); + } + } + + /* From now on, we won't change CODE, so set ICODE now. */ + icode = setcc_gen_code[(int) code]; + + /* If this is A < 0 or A >= 0, we can do this by taking the ones + complement of A (for GE) and shifting the sign bit to the low bit. */ + if (op1 == const0_rtx && (code == LT || code == GE) + && GET_MODE_CLASS (mode) == MODE_INT + && (normalizep || STORE_FLAG_VALUE == 1 + || (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT + && ((STORE_FLAG_VALUE & GET_MODE_MASK (mode)) + == (unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))))) + { + subtarget = target; + + /* If the result is to be wider than OP0, it is best to convert it + first. If it is to be narrower, it is *incorrect* to convert it + first. */ + if (GET_MODE_SIZE (target_mode) > GET_MODE_SIZE (mode)) + { + op0 = convert_modes (target_mode, mode, op0, 0); + mode = target_mode; + } + + if (target_mode != mode) + subtarget = 0; + + if (code == GE) + op0 = expand_unop (mode, one_cmpl_optab, op0, + ((STORE_FLAG_VALUE == 1 || normalizep) + ? 0 : subtarget), 0); + + if (STORE_FLAG_VALUE == 1 || normalizep) + /* If we are supposed to produce a 0/1 value, we want to do + a logical shift from the sign bit to the low-order bit; for + a -1/0 value, we do an arithmetic shift. */ + op0 = expand_shift (RSHIFT_EXPR, mode, op0, + size_int (GET_MODE_BITSIZE (mode) - 1), + subtarget, normalizep != -1); + + if (mode != target_mode) + op0 = convert_modes (target_mode, mode, op0, 0); + + return op0; + } + + if (icode != CODE_FOR_nothing) + { + insn_operand_predicate_fn pred; + + /* We think we may be able to do this with a scc insn. Emit the + comparison and then the scc insn. */ + + do_pending_stack_adjust (); + last = get_last_insn (); + + comparison + = compare_from_rtx (op0, op1, code, unsignedp, mode, NULL_RTX); + if (CONSTANT_P (comparison)) + { + switch (GET_CODE (comparison)) + { + case CONST_INT: + if (comparison == const0_rtx) + return const0_rtx; + break; + +#ifdef FLOAT_STORE_FLAG_VALUE + case CONST_DOUBLE: + if (comparison == CONST0_RTX (GET_MODE (comparison))) + return const0_rtx; + break; +#endif + default: + gcc_unreachable (); + } + + if (normalizep == 1) + return const1_rtx; + if (normalizep == -1) + return constm1_rtx; + return const_true_rtx; + } + + /* The code of COMPARISON may not match CODE if compare_from_rtx + decided to swap its operands and reverse the original code. + + We know that compare_from_rtx returns either a CONST_INT or + a new comparison code, so it is safe to just extract the + code from COMPARISON. */ + code = GET_CODE (comparison); + + /* Get a reference to the target in the proper mode for this insn. */ + compare_mode = insn_data[(int) icode].operand[0].mode; + subtarget = target; + pred = insn_data[(int) icode].operand[0].predicate; + if (optimize || ! (*pred) (subtarget, compare_mode)) + subtarget = gen_reg_rtx (compare_mode); + + pattern = GEN_FCN (icode) (subtarget); + if (pattern) + { + emit_insn (pattern); + + /* If we are converting to a wider mode, first convert to + TARGET_MODE, then normalize. This produces better combining + opportunities on machines that have a SIGN_EXTRACT when we are + testing a single bit. This mostly benefits the 68k. + + If STORE_FLAG_VALUE does not have the sign bit set when + interpreted in COMPARE_MODE, we can do this conversion as + unsigned, which is usually more efficient. */ + if (GET_MODE_SIZE (target_mode) > GET_MODE_SIZE (compare_mode)) + { + convert_move (target, subtarget, + (GET_MODE_BITSIZE (compare_mode) + <= HOST_BITS_PER_WIDE_INT) + && 0 == (STORE_FLAG_VALUE + & ((HOST_WIDE_INT) 1 + << (GET_MODE_BITSIZE (compare_mode) -1)))); + op0 = target; + compare_mode = target_mode; + } + else + op0 = subtarget; + + /* If we want to keep subexpressions around, don't reuse our + last target. */ + + if (optimize) + subtarget = 0; + + /* Now normalize to the proper value in COMPARE_MODE. Sometimes + we don't have to do anything. */ + if (normalizep == 0 || normalizep == STORE_FLAG_VALUE) + ; + /* STORE_FLAG_VALUE might be the most negative number, so write + the comparison this way to avoid a compiler-time warning. */ + else if (- normalizep == STORE_FLAG_VALUE) + op0 = expand_unop (compare_mode, neg_optab, op0, subtarget, 0); + + /* We don't want to use STORE_FLAG_VALUE < 0 below since this + makes it hard to use a value of just the sign bit due to + ANSI integer constant typing rules. */ + else if (GET_MODE_BITSIZE (compare_mode) <= HOST_BITS_PER_WIDE_INT + && (STORE_FLAG_VALUE + & ((HOST_WIDE_INT) 1 + << (GET_MODE_BITSIZE (compare_mode) - 1)))) + op0 = expand_shift (RSHIFT_EXPR, compare_mode, op0, + size_int (GET_MODE_BITSIZE (compare_mode) - 1), + subtarget, normalizep == 1); + else + { + gcc_assert (STORE_FLAG_VALUE & 1); + + op0 = expand_and (compare_mode, op0, const1_rtx, subtarget); + if (normalizep == -1) + op0 = expand_unop (compare_mode, neg_optab, op0, op0, 0); + } + + /* If we were converting to a smaller mode, do the + conversion now. */ + if (target_mode != compare_mode) + { + convert_move (target, op0, 0); + return target; + } + else + return op0; + } + } + + delete_insns_since (last); + + /* If optimizing, use different pseudo registers for each insn, instead + of reusing the same pseudo. This leads to better CSE, but slows + down the compiler, since there are more pseudos */ + subtarget = (!optimize + && (target_mode == mode)) ? target : NULL_RTX; + + /* If we reached here, we can't do this with a scc insn. However, there + are some comparisons that can be done directly. For example, if + this is an equality comparison of integers, we can try to exclusive-or + (or subtract) the two operands and use a recursive call to try the + comparison with zero. Don't do any of these cases if branches are + very cheap. */ + + if (BRANCH_COST > 0 + && GET_MODE_CLASS (mode) == MODE_INT && (code == EQ || code == NE) + && op1 != const0_rtx) + { + tem = expand_binop (mode, xor_optab, op0, op1, subtarget, 1, + OPTAB_WIDEN); + + if (tem == 0) + tem = expand_binop (mode, sub_optab, op0, op1, subtarget, 1, + OPTAB_WIDEN); + if (tem != 0) + tem = emit_store_flag (target, code, tem, const0_rtx, + mode, unsignedp, normalizep); + if (tem == 0) + delete_insns_since (last); + return tem; + } + + /* Some other cases we can do are EQ, NE, LE, and GT comparisons with + the constant zero. Reject all other comparisons at this point. Only + do LE and GT if branches are expensive since they are expensive on + 2-operand machines. */ + + if (BRANCH_COST == 0 + || GET_MODE_CLASS (mode) != MODE_INT || op1 != const0_rtx + || (code != EQ && code != NE + && (BRANCH_COST <= 1 || (code != LE && code != GT)))) + return 0; + + /* See what we need to return. We can only return a 1, -1, or the + sign bit. */ + + if (normalizep == 0) + { + if (STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1) + normalizep = STORE_FLAG_VALUE; + + else if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT + && ((STORE_FLAG_VALUE & GET_MODE_MASK (mode)) + == (unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))) + ; + else + return 0; + } + + /* Try to put the result of the comparison in the sign bit. Assume we can't + do the necessary operation below. */ + + tem = 0; + + /* To see if A <= 0, compute (A | (A - 1)). A <= 0 iff that result has + the sign bit set. */ + + if (code == LE) + { + /* This is destructive, so SUBTARGET can't be OP0. */ + if (rtx_equal_p (subtarget, op0)) + subtarget = 0; + + tem = expand_binop (mode, sub_optab, op0, const1_rtx, subtarget, 0, + OPTAB_WIDEN); + if (tem) + tem = expand_binop (mode, ior_optab, op0, tem, subtarget, 0, + OPTAB_WIDEN); + } + + /* To see if A > 0, compute (((signed) A) << BITS) - A, where BITS is the + number of bits in the mode of OP0, minus one. */ + + if (code == GT) + { + if (rtx_equal_p (subtarget, op0)) + subtarget = 0; + + tem = expand_shift (RSHIFT_EXPR, mode, op0, + size_int (GET_MODE_BITSIZE (mode) - 1), + subtarget, 0); + tem = expand_binop (mode, sub_optab, tem, op0, subtarget, 0, + OPTAB_WIDEN); + } + + if (code == EQ || code == NE) + { + /* For EQ or NE, one way to do the comparison is to apply an operation + that converts the operand into a positive number if it is nonzero + or zero if it was originally zero. Then, for EQ, we subtract 1 and + for NE we negate. This puts the result in the sign bit. Then we + normalize with a shift, if needed. + + Two operations that can do the above actions are ABS and FFS, so try + them. If that doesn't work, and MODE is smaller than a full word, + we can use zero-extension to the wider mode (an unsigned conversion) + as the operation. */ + + /* Note that ABS doesn't yield a positive number for INT_MIN, but + that is compensated by the subsequent overflow when subtracting + one / negating. */ + + if (abs_optab->handlers[mode].insn_code != CODE_FOR_nothing) + tem = expand_unop (mode, abs_optab, op0, subtarget, 1); + else if (ffs_optab->handlers[mode].insn_code != CODE_FOR_nothing) + tem = expand_unop (mode, ffs_optab, op0, subtarget, 1); + else if (GET_MODE_SIZE (mode) < UNITS_PER_WORD) + { + tem = convert_modes (word_mode, mode, op0, 1); + mode = word_mode; + } + + if (tem != 0) + { + if (code == EQ) + tem = expand_binop (mode, sub_optab, tem, const1_rtx, subtarget, + 0, OPTAB_WIDEN); + else + tem = expand_unop (mode, neg_optab, tem, subtarget, 0); + } + + /* If we couldn't do it that way, for NE we can "or" the two's complement + of the value with itself. For EQ, we take the one's complement of + that "or", which is an extra insn, so we only handle EQ if branches + are expensive. */ + + if (tem == 0 && (code == NE || BRANCH_COST > 1)) + { + if (rtx_equal_p (subtarget, op0)) + subtarget = 0; + + tem = expand_unop (mode, neg_optab, op0, subtarget, 0); + tem = expand_binop (mode, ior_optab, tem, op0, subtarget, 0, + OPTAB_WIDEN); + + if (tem && code == EQ) + tem = expand_unop (mode, one_cmpl_optab, tem, subtarget, 0); + } + } + + if (tem && normalizep) + tem = expand_shift (RSHIFT_EXPR, mode, tem, + size_int (GET_MODE_BITSIZE (mode) - 1), + subtarget, normalizep == 1); + + if (tem) + { + if (GET_MODE (tem) != target_mode) + { + convert_move (target, tem, 0); + tem = target; + } + else if (!subtarget) + { + emit_move_insn (target, tem); + tem = target; + } + } + else + delete_insns_since (last); + + return tem; +} + +/* Like emit_store_flag, but always succeeds. */ + +rtx +emit_store_flag_force (rtx target, enum rtx_code code, rtx op0, rtx op1, + enum machine_mode mode, int unsignedp, int normalizep) +{ + rtx tem, label; + + /* First see if emit_store_flag can do the job. */ + tem = emit_store_flag (target, code, op0, op1, mode, unsignedp, normalizep); + if (tem != 0) + return tem; + + if (normalizep == 0) + normalizep = 1; + + /* If this failed, we have to do this with set/compare/jump/set code. */ + + if (!REG_P (target) + || reg_mentioned_p (target, op0) || reg_mentioned_p (target, op1)) + target = gen_reg_rtx (GET_MODE (target)); + + emit_move_insn (target, const1_rtx); + label = gen_label_rtx (); + do_compare_rtx_and_jump (op0, op1, code, unsignedp, mode, NULL_RTX, + NULL_RTX, label); + + emit_move_insn (target, const0_rtx); + emit_label (label); + + return target; +} + +/* Perform possibly multi-word comparison and conditional jump to LABEL + if ARG1 OP ARG2 true where ARG1 and ARG2 are of mode MODE. This is + now a thin wrapper around do_compare_rtx_and_jump. */ + +static void +do_cmp_and_jump (rtx arg1, rtx arg2, enum rtx_code op, enum machine_mode mode, + rtx label) +{ + int unsignedp = (op == LTU || op == LEU || op == GTU || op == GEU); + do_compare_rtx_and_jump (arg1, arg2, op, unsignedp, mode, + NULL_RTX, NULL_RTX, label); +} |