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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/reg-stack.c')
-rw-r--r-- | gcc-4.2.1-5666.3/gcc/reg-stack.c | 3211 |
1 files changed, 0 insertions, 3211 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/reg-stack.c b/gcc-4.2.1-5666.3/gcc/reg-stack.c deleted file mode 100644 index 2a05612de..000000000 --- a/gcc-4.2.1-5666.3/gcc/reg-stack.c +++ /dev/null @@ -1,3211 +0,0 @@ -/* Register to Stack convert for GNU compiler. - Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, - 2000, 2001, 2002, 2003, 2004, 2005 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. */ - -/* This pass converts stack-like registers from the "flat register - file" model that gcc uses, to a stack convention that the 387 uses. - - * The form of the input: - - On input, the function consists of insn that have had their - registers fully allocated to a set of "virtual" registers. Note that - the word "virtual" is used differently here than elsewhere in gcc: for - each virtual stack reg, there is a hard reg, but the mapping between - them is not known until this pass is run. On output, hard register - numbers have been substituted, and various pop and exchange insns have - been emitted. The hard register numbers and the virtual register - numbers completely overlap - before this pass, all stack register - numbers are virtual, and afterward they are all hard. - - The virtual registers can be manipulated normally by gcc, and their - semantics are the same as for normal registers. After the hard - register numbers are substituted, the semantics of an insn containing - stack-like regs are not the same as for an insn with normal regs: for - instance, it is not safe to delete an insn that appears to be a no-op - move. In general, no insn containing hard regs should be changed - after this pass is done. - - * The form of the output: - - After this pass, hard register numbers represent the distance from - the current top of stack to the desired register. A reference to - FIRST_STACK_REG references the top of stack, FIRST_STACK_REG + 1, - represents the register just below that, and so forth. Also, REG_DEAD - notes indicate whether or not a stack register should be popped. - - A "swap" insn looks like a parallel of two patterns, where each - pattern is a SET: one sets A to B, the other B to A. - - A "push" or "load" insn is a SET whose SET_DEST is FIRST_STACK_REG - and whose SET_DEST is REG or MEM. Any other SET_DEST, such as PLUS, - will replace the existing stack top, not push a new value. - - A store insn is a SET whose SET_DEST is FIRST_STACK_REG, and whose - SET_SRC is REG or MEM. - - The case where the SET_SRC and SET_DEST are both FIRST_STACK_REG - appears ambiguous. As a special case, the presence of a REG_DEAD note - for FIRST_STACK_REG differentiates between a load insn and a pop. - - If a REG_DEAD is present, the insn represents a "pop" that discards - the top of the register stack. If there is no REG_DEAD note, then the - insn represents a "dup" or a push of the current top of stack onto the - stack. - - * Methodology: - - Existing REG_DEAD and REG_UNUSED notes for stack registers are - deleted and recreated from scratch. REG_DEAD is never created for a - SET_DEST, only REG_UNUSED. - - * asm_operands: - - There are several rules on the usage of stack-like regs in - asm_operands insns. These rules apply only to the operands that are - stack-like regs: - - 1. Given a set of input regs that die in an asm_operands, it is - necessary to know which are implicitly popped by the asm, and - which must be explicitly popped by gcc. - - An input reg that is implicitly popped by the asm must be - explicitly clobbered, unless it is constrained to match an - output operand. - - 2. For any input reg that is implicitly popped by an asm, it is - necessary to know how to adjust the stack to compensate for the pop. - If any non-popped input is closer to the top of the reg-stack than - the implicitly popped reg, it would not be possible to know what the - stack looked like - it's not clear how the rest of the stack "slides - up". - - All implicitly popped input regs must be closer to the top of - the reg-stack than any input that is not implicitly popped. - - 3. It is possible that if an input dies in an insn, reload might - use the input reg for an output reload. Consider this example: - - asm ("foo" : "=t" (a) : "f" (b)); - - This asm says that input B is not popped by the asm, and that - the asm pushes a result onto the reg-stack, i.e., the stack is one - deeper after the asm than it was before. But, it is possible that - reload will think that it can use the same reg for both the input and - the output, if input B dies in this insn. - - If any input operand uses the "f" constraint, all output reg - constraints must use the "&" earlyclobber. - - The asm above would be written as - - asm ("foo" : "=&t" (a) : "f" (b)); - - 4. Some operands need to be in particular places on the stack. All - output operands fall in this category - there is no other way to - know which regs the outputs appear in unless the user indicates - this in the constraints. - - Output operands must specifically indicate which reg an output - appears in after an asm. "=f" is not allowed: the operand - constraints must select a class with a single reg. - - 5. Output operands may not be "inserted" between existing stack regs. - Since no 387 opcode uses a read/write operand, all output operands - are dead before the asm_operands, and are pushed by the asm_operands. - It makes no sense to push anywhere but the top of the reg-stack. - - Output operands must start at the top of the reg-stack: output - operands may not "skip" a reg. - - 6. Some asm statements may need extra stack space for internal - calculations. This can be guaranteed by clobbering stack registers - unrelated to the inputs and outputs. - - Here are a couple of reasonable asms to want to write. This asm - takes one input, which is internally popped, and produces two outputs. - - asm ("fsincos" : "=t" (cos), "=u" (sin) : "0" (inp)); - - This asm takes two inputs, which are popped by the fyl2xp1 opcode, - and replaces them with one output. The user must code the "st(1)" - clobber for reg-stack.c to know that fyl2xp1 pops both inputs. - - asm ("fyl2xp1" : "=t" (result) : "0" (x), "u" (y) : "st(1)"); - -*/ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "tree.h" -#include "rtl.h" -#include "tm_p.h" -#include "function.h" -#include "insn-config.h" -#include "regs.h" -#include "hard-reg-set.h" -#include "flags.h" -#include "toplev.h" -#include "recog.h" -#include "output.h" -#include "basic-block.h" -#include "varray.h" -#include "reload.h" -#include "ggc.h" -#include "timevar.h" -#include "tree-pass.h" -#include "target.h" -#include "vecprim.h" - -#ifdef STACK_REGS - -/* We use this array to cache info about insns, because otherwise we - spend too much time in stack_regs_mentioned_p. - - Indexed by insn UIDs. A value of zero is uninitialized, one indicates - the insn uses stack registers, two indicates the insn does not use - stack registers. */ -static VEC(char,heap) *stack_regs_mentioned_data; - -#define REG_STACK_SIZE (LAST_STACK_REG - FIRST_STACK_REG + 1) - -int regstack_completed = 0; - -/* This is the basic stack record. TOP is an index into REG[] such - that REG[TOP] is the top of stack. If TOP is -1 the stack is empty. - - If TOP is -2, REG[] is not yet initialized. Stack initialization - consists of placing each live reg in array `reg' and setting `top' - appropriately. - - REG_SET indicates which registers are live. */ - -typedef struct stack_def -{ - int top; /* index to top stack element */ - HARD_REG_SET reg_set; /* set of live registers */ - unsigned char reg[REG_STACK_SIZE];/* register - stack mapping */ -} *stack; - -/* This is used to carry information about basic blocks. It is - attached to the AUX field of the standard CFG block. */ - -typedef struct block_info_def -{ - struct stack_def stack_in; /* Input stack configuration. */ - struct stack_def stack_out; /* Output stack configuration. */ - HARD_REG_SET out_reg_set; /* Stack regs live on output. */ - int done; /* True if block already converted. */ - int predecessors; /* Number of predecessors that need - to be visited. */ -} *block_info; - -#define BLOCK_INFO(B) ((block_info) (B)->aux) - -/* Passed to change_stack to indicate where to emit insns. */ -enum emit_where -{ - EMIT_AFTER, - EMIT_BEFORE -}; - -/* The block we're currently working on. */ -static basic_block current_block; - -/* In the current_block, whether we're processing the first register - stack or call instruction, i.e. the regstack is currently the - same as BLOCK_INFO(current_block)->stack_in. */ -static bool starting_stack_p; - -/* This is the register file for all register after conversion. */ -static rtx - FP_mode_reg[LAST_STACK_REG+1-FIRST_STACK_REG][(int) MAX_MACHINE_MODE]; - -#define FP_MODE_REG(regno,mode) \ - (FP_mode_reg[(regno)-FIRST_STACK_REG][(int) (mode)]) - -/* Used to initialize uninitialized registers. */ -static rtx not_a_num; - -/* Forward declarations */ - -static int stack_regs_mentioned_p (rtx pat); -static void pop_stack (stack, int); -static rtx *get_true_reg (rtx *); - -static int check_asm_stack_operands (rtx); -static int get_asm_operand_n_inputs (rtx); -static rtx stack_result (tree); -static void replace_reg (rtx *, int); -static void remove_regno_note (rtx, enum reg_note, unsigned int); -static int get_hard_regnum (stack, rtx); -static rtx emit_pop_insn (rtx, stack, rtx, enum emit_where); -static void swap_to_top(rtx, stack, rtx, rtx); -static bool move_for_stack_reg (rtx, stack, rtx); -static bool move_nan_for_stack_reg (rtx, stack, rtx); -static int swap_rtx_condition_1 (rtx); -static int swap_rtx_condition (rtx); -static void compare_for_stack_reg (rtx, stack, rtx); -static bool subst_stack_regs_pat (rtx, stack, rtx); -static void subst_asm_stack_regs (rtx, stack); -static bool subst_stack_regs (rtx, stack); -static void change_stack (rtx, stack, stack, enum emit_where); -static void print_stack (FILE *, stack); -static rtx next_flags_user (rtx); - -/* Return nonzero if any stack register is mentioned somewhere within PAT. */ - -static int -stack_regs_mentioned_p (rtx pat) -{ - const char *fmt; - int i; - - if (STACK_REG_P (pat)) - return 1; - - fmt = GET_RTX_FORMAT (GET_CODE (pat)); - for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--) - { - if (fmt[i] == 'E') - { - int j; - - for (j = XVECLEN (pat, i) - 1; j >= 0; j--) - if (stack_regs_mentioned_p (XVECEXP (pat, i, j))) - return 1; - } - else if (fmt[i] == 'e' && stack_regs_mentioned_p (XEXP (pat, i))) - return 1; - } - - return 0; -} - -/* Return nonzero if INSN mentions stacked registers, else return zero. */ - -int -stack_regs_mentioned (rtx insn) -{ - unsigned int uid, max; - int test; - - if (! INSN_P (insn) || !stack_regs_mentioned_data) - return 0; - - uid = INSN_UID (insn); - max = VEC_length (char, stack_regs_mentioned_data); - if (uid >= max) - { - char *p; - unsigned int old_max = max; - - /* Allocate some extra size to avoid too many reallocs, but - do not grow too quickly. */ - max = uid + uid / 20 + 1; - VEC_safe_grow (char, heap, stack_regs_mentioned_data, max); - p = VEC_address (char, stack_regs_mentioned_data); - memset (&p[old_max], 0, - sizeof (char) * (max - old_max)); - } - - test = VEC_index (char, stack_regs_mentioned_data, uid); - if (test == 0) - { - /* This insn has yet to be examined. Do so now. */ - test = stack_regs_mentioned_p (PATTERN (insn)) ? 1 : 2; - VEC_replace (char, stack_regs_mentioned_data, uid, test); - } - - return test == 1; -} - -static rtx ix86_flags_rtx; - -static rtx -next_flags_user (rtx insn) -{ - /* Search forward looking for the first use of this value. - Stop at block boundaries. */ - - while (insn != BB_END (current_block)) - { - insn = NEXT_INSN (insn); - - if (INSN_P (insn) && reg_mentioned_p (ix86_flags_rtx, PATTERN (insn))) - return insn; - - if (CALL_P (insn)) - return NULL_RTX; - } - return NULL_RTX; -} - -/* Reorganize the stack into ascending numbers, before this insn. */ - -static void -straighten_stack (rtx insn, stack regstack) -{ - struct stack_def temp_stack; - int top; - - /* If there is only a single register on the stack, then the stack is - already in increasing order and no reorganization is needed. - - Similarly if the stack is empty. */ - if (regstack->top <= 0) - return; - - COPY_HARD_REG_SET (temp_stack.reg_set, regstack->reg_set); - - for (top = temp_stack.top = regstack->top; top >= 0; top--) - temp_stack.reg[top] = FIRST_STACK_REG + temp_stack.top - top; - - change_stack (insn, regstack, &temp_stack, EMIT_BEFORE); -} - -/* Pop a register from the stack. */ - -static void -pop_stack (stack regstack, int regno) -{ - int top = regstack->top; - - CLEAR_HARD_REG_BIT (regstack->reg_set, regno); - regstack->top--; - /* If regno was not at the top of stack then adjust stack. */ - if (regstack->reg [top] != regno) - { - int i; - for (i = regstack->top; i >= 0; i--) - if (regstack->reg [i] == regno) - { - int j; - for (j = i; j < top; j++) - regstack->reg [j] = regstack->reg [j + 1]; - break; - } - } -} - -/* Return a pointer to the REG expression within PAT. If PAT is not a - REG, possible enclosed by a conversion rtx, return the inner part of - PAT that stopped the search. */ - -static rtx * -get_true_reg (rtx *pat) -{ - for (;;) - switch (GET_CODE (*pat)) - { - case SUBREG: - /* Eliminate FP subregister accesses in favor of the - actual FP register in use. */ - { - rtx subreg; - if (FP_REG_P (subreg = SUBREG_REG (*pat))) - { - int regno_off = subreg_regno_offset (REGNO (subreg), - GET_MODE (subreg), - SUBREG_BYTE (*pat), - GET_MODE (*pat)); - *pat = FP_MODE_REG (REGNO (subreg) + regno_off, - GET_MODE (subreg)); - default: - return pat; - } - } - case FLOAT: - case FIX: - case FLOAT_EXTEND: - pat = & XEXP (*pat, 0); - break; - - case FLOAT_TRUNCATE: - if (!flag_unsafe_math_optimizations) - return pat; - pat = & XEXP (*pat, 0); - break; - } -} - -/* Set if we find any malformed asms in a block. */ -static bool any_malformed_asm; - -/* There are many rules that an asm statement for stack-like regs must - follow. Those rules are explained at the top of this file: the rule - numbers below refer to that explanation. */ - -static int -check_asm_stack_operands (rtx insn) -{ - int i; - int n_clobbers; - int malformed_asm = 0; - rtx body = PATTERN (insn); - - char reg_used_as_output[FIRST_PSEUDO_REGISTER]; - char implicitly_dies[FIRST_PSEUDO_REGISTER]; - int alt; - - rtx *clobber_reg = 0; - int n_inputs, n_outputs; - - /* Find out what the constraints require. If no constraint - alternative matches, this asm is malformed. */ - extract_insn (insn); - constrain_operands (1); - alt = which_alternative; - - preprocess_constraints (); - - n_inputs = get_asm_operand_n_inputs (body); - n_outputs = recog_data.n_operands - n_inputs; - - if (alt < 0) - { - malformed_asm = 1; - /* Avoid further trouble with this insn. */ - PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx); - return 0; - } - - /* Strip SUBREGs here to make the following code simpler. */ - for (i = 0; i < recog_data.n_operands; i++) - if (GET_CODE (recog_data.operand[i]) == SUBREG - && REG_P (SUBREG_REG (recog_data.operand[i]))) - recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]); - - /* Set up CLOBBER_REG. */ - - n_clobbers = 0; - - if (GET_CODE (body) == PARALLEL) - { - clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx)); - - for (i = 0; i < XVECLEN (body, 0); i++) - if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER) - { - rtx clobber = XVECEXP (body, 0, i); - rtx reg = XEXP (clobber, 0); - - if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg))) - reg = SUBREG_REG (reg); - - if (STACK_REG_P (reg)) - { - clobber_reg[n_clobbers] = reg; - n_clobbers++; - } - } - } - - /* Enforce rule #4: Output operands must specifically indicate which - reg an output appears in after an asm. "=f" is not allowed: the - operand constraints must select a class with a single reg. - - Also enforce rule #5: Output operands must start at the top of - the reg-stack: output operands may not "skip" a reg. */ - - memset (reg_used_as_output, 0, sizeof (reg_used_as_output)); - for (i = 0; i < n_outputs; i++) - if (STACK_REG_P (recog_data.operand[i])) - { - if (reg_class_size[(int) recog_op_alt[i][alt].cl] != 1) - { - error_for_asm (insn, "output constraint %d must specify a single register", i); - malformed_asm = 1; - } - else - { - int j; - - for (j = 0; j < n_clobbers; j++) - if (REGNO (recog_data.operand[i]) == REGNO (clobber_reg[j])) - { - error_for_asm (insn, "output constraint %d cannot be specified together with \"%s\" clobber", - i, reg_names [REGNO (clobber_reg[j])]); - malformed_asm = 1; - break; - } - if (j == n_clobbers) - reg_used_as_output[REGNO (recog_data.operand[i])] = 1; - } - } - - - /* Search for first non-popped reg. */ - for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++) - if (! reg_used_as_output[i]) - break; - - /* If there are any other popped regs, that's an error. */ - for (; i < LAST_STACK_REG + 1; i++) - if (reg_used_as_output[i]) - break; - - if (i != LAST_STACK_REG + 1) - { - error_for_asm (insn, "output regs must be grouped at top of stack"); - malformed_asm = 1; - } - - /* Enforce rule #2: All implicitly popped input regs must be closer - to the top of the reg-stack than any input that is not implicitly - popped. */ - - memset (implicitly_dies, 0, sizeof (implicitly_dies)); - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_data.operand[i])) - { - /* An input reg is implicitly popped if it is tied to an - output, or if there is a CLOBBER for it. */ - int j; - - for (j = 0; j < n_clobbers; j++) - if (operands_match_p (clobber_reg[j], recog_data.operand[i])) - break; - - if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0) - implicitly_dies[REGNO (recog_data.operand[i])] = 1; - } - - /* Search for first non-popped reg. */ - for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++) - if (! implicitly_dies[i]) - break; - - /* If there are any other popped regs, that's an error. */ - for (; i < LAST_STACK_REG + 1; i++) - if (implicitly_dies[i]) - break; - - if (i != LAST_STACK_REG + 1) - { - error_for_asm (insn, - "implicitly popped regs must be grouped at top of stack"); - malformed_asm = 1; - } - - /* Enforce rule #3: If any input operand uses the "f" constraint, all - output constraints must use the "&" earlyclobber. - - ??? Detect this more deterministically by having constrain_asm_operands - record any earlyclobber. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (recog_op_alt[i][alt].matches == -1) - { - int j; - - for (j = 0; j < n_outputs; j++) - if (operands_match_p (recog_data.operand[j], recog_data.operand[i])) - { - error_for_asm (insn, - "output operand %d must use %<&%> constraint", j); - malformed_asm = 1; - } - } - - if (malformed_asm) - { - /* Avoid further trouble with this insn. */ - PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx); - any_malformed_asm = true; - return 0; - } - - return 1; -} - -/* Calculate the number of inputs and outputs in BODY, an - asm_operands. N_OPERANDS is the total number of operands, and - N_INPUTS and N_OUTPUTS are pointers to ints into which the results are - placed. */ - -static int -get_asm_operand_n_inputs (rtx body) -{ - switch (GET_CODE (body)) - { - case SET: - gcc_assert (GET_CODE (SET_SRC (body)) == ASM_OPERANDS); - return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body)); - - case ASM_OPERANDS: - return ASM_OPERANDS_INPUT_LENGTH (body); - - case PARALLEL: - return get_asm_operand_n_inputs (XVECEXP (body, 0, 0)); - - default: - gcc_unreachable (); - } -} - -/* If current function returns its result in an fp stack register, - return the REG. Otherwise, return 0. */ - -static rtx -stack_result (tree decl) -{ - rtx result; - - /* If the value is supposed to be returned in memory, then clearly - it is not returned in a stack register. */ - if (aggregate_value_p (DECL_RESULT (decl), decl)) - return 0; - - result = DECL_RTL_IF_SET (DECL_RESULT (decl)); - if (result != 0) - result = targetm.calls.function_value (TREE_TYPE (DECL_RESULT (decl)), - decl, true); - - return result != 0 && STACK_REG_P (result) ? result : 0; -} - - -/* - * This section deals with stack register substitution, and forms the second - * pass over the RTL. - */ - -/* Replace REG, which is a pointer to a stack reg RTX, with an RTX for - the desired hard REGNO. */ - -static void -replace_reg (rtx *reg, int regno) -{ - gcc_assert (regno >= FIRST_STACK_REG); - gcc_assert (regno <= LAST_STACK_REG); - gcc_assert (STACK_REG_P (*reg)); - - gcc_assert (SCALAR_FLOAT_MODE_P (GET_MODE (*reg)) - || GET_MODE_CLASS (GET_MODE (*reg)) == MODE_COMPLEX_FLOAT); - - *reg = FP_MODE_REG (regno, GET_MODE (*reg)); -} - -/* Remove a note of type NOTE, which must be found, for register - number REGNO from INSN. Remove only one such note. */ - -static void -remove_regno_note (rtx insn, enum reg_note note, unsigned int regno) -{ - rtx *note_link, this; - - note_link = ®_NOTES (insn); - for (this = *note_link; this; this = XEXP (this, 1)) - if (REG_NOTE_KIND (this) == note - && REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno) - { - *note_link = XEXP (this, 1); - return; - } - else - note_link = &XEXP (this, 1); - - gcc_unreachable (); -} - -/* Find the hard register number of virtual register REG in REGSTACK. - The hard register number is relative to the top of the stack. -1 is - returned if the register is not found. */ - -static int -get_hard_regnum (stack regstack, rtx reg) -{ - int i; - - gcc_assert (STACK_REG_P (reg)); - - for (i = regstack->top; i >= 0; i--) - if (regstack->reg[i] == REGNO (reg)) - break; - - return i >= 0 ? (FIRST_STACK_REG + regstack->top - i) : -1; -} - -/* Emit an insn to pop virtual register REG before or after INSN. - REGSTACK is the stack state after INSN and is updated to reflect this - pop. WHEN is either emit_insn_before or emit_insn_after. A pop insn - is represented as a SET whose destination is the register to be popped - and source is the top of stack. A death note for the top of stack - cases the movdf pattern to pop. */ - -static rtx -emit_pop_insn (rtx insn, stack regstack, rtx reg, enum emit_where where) -{ - rtx pop_insn, pop_rtx; - int hard_regno; - - /* For complex types take care to pop both halves. These may survive in - CLOBBER and USE expressions. */ - if (COMPLEX_MODE_P (GET_MODE (reg))) - { - rtx reg1 = FP_MODE_REG (REGNO (reg), DFmode); - rtx reg2 = FP_MODE_REG (REGNO (reg) + 1, DFmode); - - pop_insn = NULL_RTX; - if (get_hard_regnum (regstack, reg1) >= 0) - pop_insn = emit_pop_insn (insn, regstack, reg1, where); - if (get_hard_regnum (regstack, reg2) >= 0) - pop_insn = emit_pop_insn (insn, regstack, reg2, where); - gcc_assert (pop_insn); - return pop_insn; - } - - hard_regno = get_hard_regnum (regstack, reg); - - gcc_assert (hard_regno >= FIRST_STACK_REG); - - pop_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG (hard_regno, DFmode), - FP_MODE_REG (FIRST_STACK_REG, DFmode)); - - if (where == EMIT_AFTER) - pop_insn = emit_insn_after (pop_rtx, insn); - else - pop_insn = emit_insn_before (pop_rtx, insn); - - REG_NOTES (pop_insn) - = gen_rtx_EXPR_LIST (REG_DEAD, FP_MODE_REG (FIRST_STACK_REG, DFmode), - REG_NOTES (pop_insn)); - - regstack->reg[regstack->top - (hard_regno - FIRST_STACK_REG)] - = regstack->reg[regstack->top]; - regstack->top -= 1; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (reg)); - - return pop_insn; -} - -/* Emit an insn before or after INSN to swap virtual register REG with - the top of stack. REGSTACK is the stack state before the swap, and - is updated to reflect the swap. A swap insn is represented as a - PARALLEL of two patterns: each pattern moves one reg to the other. - - If REG is already at the top of the stack, no insn is emitted. */ - -static void -emit_swap_insn (rtx insn, stack regstack, rtx reg) -{ - int hard_regno; - rtx swap_rtx; - int tmp, other_reg; /* swap regno temps */ - rtx i1; /* the stack-reg insn prior to INSN */ - rtx i1set = NULL_RTX; /* the SET rtx within I1 */ - - hard_regno = get_hard_regnum (regstack, reg); - - if (hard_regno == FIRST_STACK_REG) - return; - if (hard_regno == -1) - { - /* Something failed if the register wasn't on the stack. If we had - malformed asms, we zapped the instruction itself, but that didn't - produce the same pattern of register sets as before. To prevent - further failure, adjust REGSTACK to include REG at TOP. */ - gcc_assert (any_malformed_asm); - regstack->reg[++regstack->top] = REGNO (reg); - return; - } - gcc_assert (hard_regno >= FIRST_STACK_REG); - - other_reg = regstack->top - (hard_regno - FIRST_STACK_REG); - - tmp = regstack->reg[other_reg]; - regstack->reg[other_reg] = regstack->reg[regstack->top]; - regstack->reg[regstack->top] = tmp; - - /* Find the previous insn involving stack regs, but don't pass a - block boundary. */ - i1 = NULL; - if (current_block && insn != BB_HEAD (current_block)) - { - rtx tmp = PREV_INSN (insn); - rtx limit = PREV_INSN (BB_HEAD (current_block)); - while (tmp != limit) - { - if (LABEL_P (tmp) - || CALL_P (tmp) - || NOTE_INSN_BASIC_BLOCK_P (tmp) - || (NONJUMP_INSN_P (tmp) - && stack_regs_mentioned (tmp))) - { - i1 = tmp; - break; - } - tmp = PREV_INSN (tmp); - } - } - - if (i1 != NULL_RTX - && (i1set = single_set (i1)) != NULL_RTX) - { - rtx i1src = *get_true_reg (&SET_SRC (i1set)); - rtx i1dest = *get_true_reg (&SET_DEST (i1set)); - - /* If the previous register stack push was from the reg we are to - swap with, omit the swap. */ - - if (REG_P (i1dest) && REGNO (i1dest) == FIRST_STACK_REG - && REG_P (i1src) - && REGNO (i1src) == (unsigned) hard_regno - 1 - && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX) - return; - - /* If the previous insn wrote to the reg we are to swap with, - omit the swap. */ - - if (REG_P (i1dest) && REGNO (i1dest) == (unsigned) hard_regno - && REG_P (i1src) && REGNO (i1src) == FIRST_STACK_REG - && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX) - return; - } - - /* Avoid emitting the swap if this is the first register stack insn - of the current_block. Instead update the current_block's stack_in - and let compensate edges take care of this for us. */ - if (current_block && starting_stack_p) - { - BLOCK_INFO (current_block)->stack_in = *regstack; - starting_stack_p = false; - return; - } - - swap_rtx = gen_swapxf (FP_MODE_REG (hard_regno, XFmode), - FP_MODE_REG (FIRST_STACK_REG, XFmode)); - - if (i1) - emit_insn_after (swap_rtx, i1); - else if (current_block) - emit_insn_before (swap_rtx, BB_HEAD (current_block)); - else - emit_insn_before (swap_rtx, insn); -} - -/* Emit an insns before INSN to swap virtual register SRC1 with - the top of stack and virtual register SRC2 with second stack - slot. REGSTACK is the stack state before the swaps, and - is updated to reflect the swaps. A swap insn is represented as a - PARALLEL of two patterns: each pattern moves one reg to the other. - - If SRC1 and/or SRC2 are already at the right place, no swap insn - is emitted. */ - -static void -swap_to_top (rtx insn, stack regstack, rtx src1, rtx src2) -{ - struct stack_def temp_stack; - int regno, j, k, temp; - - temp_stack = *regstack; - - /* Place operand 1 at the top of stack. */ - regno = get_hard_regnum (&temp_stack, src1); - gcc_assert (regno >= 0); - if (regno != FIRST_STACK_REG) - { - k = temp_stack.top - (regno - FIRST_STACK_REG); - j = temp_stack.top; - - temp = temp_stack.reg[k]; - temp_stack.reg[k] = temp_stack.reg[j]; - temp_stack.reg[j] = temp; - } - - /* Place operand 2 next on the stack. */ - regno = get_hard_regnum (&temp_stack, src2); - gcc_assert (regno >= 0); - if (regno != FIRST_STACK_REG + 1) - { - k = temp_stack.top - (regno - FIRST_STACK_REG); - j = temp_stack.top - 1; - - temp = temp_stack.reg[k]; - temp_stack.reg[k] = temp_stack.reg[j]; - temp_stack.reg[j] = temp; - } - - change_stack (insn, regstack, &temp_stack, EMIT_BEFORE); -} - -/* Handle a move to or from a stack register in PAT, which is in INSN. - REGSTACK is the current stack. Return whether a control flow insn - was deleted in the process. */ - -static bool -move_for_stack_reg (rtx insn, stack regstack, rtx pat) -{ - rtx *psrc = get_true_reg (&SET_SRC (pat)); - rtx *pdest = get_true_reg (&SET_DEST (pat)); - rtx src, dest; - rtx note; - bool control_flow_insn_deleted = false; - - src = *psrc; dest = *pdest; - - if (STACK_REG_P (src) && STACK_REG_P (dest)) - { - /* Write from one stack reg to another. If SRC dies here, then - just change the register mapping and delete the insn. */ - - note = find_regno_note (insn, REG_DEAD, REGNO (src)); - if (note) - { - int i; - - /* If this is a no-op move, there must not be a REG_DEAD note. */ - gcc_assert (REGNO (src) != REGNO (dest)); - - for (i = regstack->top; i >= 0; i--) - if (regstack->reg[i] == REGNO (src)) - break; - - /* The destination must be dead, or life analysis is borked. */ - gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG); - - /* If the source is not live, this is yet another case of - uninitialized variables. Load up a NaN instead. */ - if (i < 0) - return move_nan_for_stack_reg (insn, regstack, dest); - - /* It is possible that the dest is unused after this insn. - If so, just pop the src. */ - - if (find_regno_note (insn, REG_UNUSED, REGNO (dest))) - emit_pop_insn (insn, regstack, src, EMIT_AFTER); - else - { - regstack->reg[i] = REGNO (dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest)); - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src)); - } - - control_flow_insn_deleted |= control_flow_insn_p (insn); - delete_insn (insn); - return control_flow_insn_deleted; - } - - /* The source reg does not die. */ - - /* If this appears to be a no-op move, delete it, or else it - will confuse the machine description output patterns. But if - it is REG_UNUSED, we must pop the reg now, as per-insn processing - for REG_UNUSED will not work for deleted insns. */ - - if (REGNO (src) == REGNO (dest)) - { - if (find_regno_note (insn, REG_UNUSED, REGNO (dest))) - emit_pop_insn (insn, regstack, dest, EMIT_AFTER); - - control_flow_insn_deleted |= control_flow_insn_p (insn); - delete_insn (insn); - return control_flow_insn_deleted; - } - - /* The destination ought to be dead. */ - gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG); - - replace_reg (psrc, get_hard_regnum (regstack, src)); - - regstack->reg[++regstack->top] = REGNO (dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest)); - replace_reg (pdest, FIRST_STACK_REG); - } - else if (STACK_REG_P (src)) - { - /* Save from a stack reg to MEM, or possibly integer reg. Since - only top of stack may be saved, emit an exchange first if - needs be. */ - - emit_swap_insn (insn, regstack, src); - - note = find_regno_note (insn, REG_DEAD, REGNO (src)); - if (note) - { - replace_reg (&XEXP (note, 0), FIRST_STACK_REG); - regstack->top--; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src)); - } - else if ((GET_MODE (src) == XFmode) - && regstack->top < REG_STACK_SIZE - 1) - { - /* A 387 cannot write an XFmode value to a MEM without - clobbering the source reg. The output code can handle - this by reading back the value from the MEM. - But it is more efficient to use a temp register if one is - available. Push the source value here if the register - stack is not full, and then write the value to memory via - a pop. */ - rtx push_rtx; - rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, GET_MODE (src)); - - push_rtx = gen_movxf (top_stack_reg, top_stack_reg); - emit_insn_before (push_rtx, insn); - REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, top_stack_reg, - REG_NOTES (insn)); - } - - replace_reg (psrc, FIRST_STACK_REG); - } - else - { - gcc_assert (STACK_REG_P (dest)); - - /* Load from MEM, or possibly integer REG or constant, into the - stack regs. The actual target is always the top of the - stack. The stack mapping is changed to reflect that DEST is - now at top of stack. */ - - /* The destination ought to be dead. */ - gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG); - - gcc_assert (regstack->top < REG_STACK_SIZE); - - regstack->reg[++regstack->top] = REGNO (dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest)); - replace_reg (pdest, FIRST_STACK_REG); - } - - return control_flow_insn_deleted; -} - -/* A helper function which replaces INSN with a pattern that loads up - a NaN into DEST, then invokes move_for_stack_reg. */ - -static bool -move_nan_for_stack_reg (rtx insn, stack regstack, rtx dest) -{ - rtx pat; - - dest = FP_MODE_REG (REGNO (dest), SFmode); - pat = gen_rtx_SET (VOIDmode, dest, not_a_num); - PATTERN (insn) = pat; - INSN_CODE (insn) = -1; - - return move_for_stack_reg (insn, regstack, pat); -} - -/* Swap the condition on a branch, if there is one. Return true if we - found a condition to swap. False if the condition was not used as - such. */ - -static int -swap_rtx_condition_1 (rtx pat) -{ - const char *fmt; - int i, r = 0; - - if (COMPARISON_P (pat)) - { - PUT_CODE (pat, swap_condition (GET_CODE (pat))); - r = 1; - } - else - { - fmt = GET_RTX_FORMAT (GET_CODE (pat)); - for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--) - { - if (fmt[i] == 'E') - { - int j; - - for (j = XVECLEN (pat, i) - 1; j >= 0; j--) - r |= swap_rtx_condition_1 (XVECEXP (pat, i, j)); - } - else if (fmt[i] == 'e') - r |= swap_rtx_condition_1 (XEXP (pat, i)); - } - } - - return r; -} - -static int -swap_rtx_condition (rtx insn) -{ - rtx pat = PATTERN (insn); - - /* We're looking for a single set to cc0 or an HImode temporary. */ - - if (GET_CODE (pat) == SET - && REG_P (SET_DEST (pat)) - && REGNO (SET_DEST (pat)) == FLAGS_REG) - { - insn = next_flags_user (insn); - if (insn == NULL_RTX) - return 0; - pat = PATTERN (insn); - } - - /* See if this is, or ends in, a fnstsw. If so, we're not doing anything - with the cc value right now. We may be able to search for one - though. */ - - if (GET_CODE (pat) == SET - && GET_CODE (SET_SRC (pat)) == UNSPEC - && XINT (SET_SRC (pat), 1) == UNSPEC_FNSTSW) - { - rtx dest = SET_DEST (pat); - - /* Search forward looking for the first use of this value. - Stop at block boundaries. */ - while (insn != BB_END (current_block)) - { - insn = NEXT_INSN (insn); - if (INSN_P (insn) && reg_mentioned_p (dest, insn)) - break; - if (CALL_P (insn)) - return 0; - } - - /* We haven't found it. */ - if (insn == BB_END (current_block)) - return 0; - - /* So we've found the insn using this value. If it is anything - other than sahf or the value does not die (meaning we'd have - to search further), then we must give up. */ - pat = PATTERN (insn); - if (GET_CODE (pat) != SET - || GET_CODE (SET_SRC (pat)) != UNSPEC - || XINT (SET_SRC (pat), 1) != UNSPEC_SAHF - || ! dead_or_set_p (insn, dest)) - return 0; - - /* Now we are prepared to handle this as a normal cc0 setter. */ - insn = next_flags_user (insn); - if (insn == NULL_RTX) - return 0; - pat = PATTERN (insn); - } - - if (swap_rtx_condition_1 (pat)) - { - int fail = 0; - INSN_CODE (insn) = -1; - if (recog_memoized (insn) == -1) - fail = 1; - /* In case the flags don't die here, recurse to try fix - following user too. */ - else if (! dead_or_set_p (insn, ix86_flags_rtx)) - { - insn = next_flags_user (insn); - if (!insn || !swap_rtx_condition (insn)) - fail = 1; - } - if (fail) - { - swap_rtx_condition_1 (pat); - return 0; - } - return 1; - } - return 0; -} - -/* Handle a comparison. Special care needs to be taken to avoid - causing comparisons that a 387 cannot do correctly, such as EQ. - - Also, a pop insn may need to be emitted. The 387 does have an - `fcompp' insn that can pop two regs, but it is sometimes too expensive - to do this - a `fcomp' followed by a `fstpl %st(0)' may be easier to - set up. */ - -static void -compare_for_stack_reg (rtx insn, stack regstack, rtx pat_src) -{ - rtx *src1, *src2; - rtx src1_note, src2_note; - - src1 = get_true_reg (&XEXP (pat_src, 0)); - src2 = get_true_reg (&XEXP (pat_src, 1)); - - /* ??? If fxch turns out to be cheaper than fstp, give priority to - registers that die in this insn - move those to stack top first. */ - if ((! STACK_REG_P (*src1) - || (STACK_REG_P (*src2) - && get_hard_regnum (regstack, *src2) == FIRST_STACK_REG)) - && swap_rtx_condition (insn)) - { - rtx temp; - temp = XEXP (pat_src, 0); - XEXP (pat_src, 0) = XEXP (pat_src, 1); - XEXP (pat_src, 1) = temp; - - src1 = get_true_reg (&XEXP (pat_src, 0)); - src2 = get_true_reg (&XEXP (pat_src, 1)); - - INSN_CODE (insn) = -1; - } - - /* We will fix any death note later. */ - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - - if (STACK_REG_P (*src2)) - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - else - src2_note = NULL_RTX; - - emit_swap_insn (insn, regstack, *src1); - - replace_reg (src1, FIRST_STACK_REG); - - if (STACK_REG_P (*src2)) - replace_reg (src2, get_hard_regnum (regstack, *src2)); - - if (src1_note) - { - pop_stack (regstack, REGNO (XEXP (src1_note, 0))); - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - } - - /* If the second operand dies, handle that. But if the operands are - the same stack register, don't bother, because only one death is - needed, and it was just handled. */ - - if (src2_note - && ! (STACK_REG_P (*src1) && STACK_REG_P (*src2) - && REGNO (*src1) == REGNO (*src2))) - { - /* As a special case, two regs may die in this insn if src2 is - next to top of stack and the top of stack also dies. Since - we have already popped src1, "next to top of stack" is really - at top (FIRST_STACK_REG) now. */ - - if (get_hard_regnum (regstack, XEXP (src2_note, 0)) == FIRST_STACK_REG - && src1_note) - { - pop_stack (regstack, REGNO (XEXP (src2_note, 0))); - replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1); - } - else - { - /* The 386 can only represent death of the first operand in - the case handled above. In all other cases, emit a separate - pop and remove the death note from here. */ - - /* link_cc0_insns (insn); */ - - remove_regno_note (insn, REG_DEAD, REGNO (XEXP (src2_note, 0))); - - emit_pop_insn (insn, regstack, XEXP (src2_note, 0), - EMIT_AFTER); - } - } -} - -/* Substitute new registers in PAT, which is part of INSN. REGSTACK - is the current register layout. Return whether a control flow insn - was deleted in the process. */ - -static bool -subst_stack_regs_pat (rtx insn, stack regstack, rtx pat) -{ - rtx *dest, *src; - bool control_flow_insn_deleted = false; - - switch (GET_CODE (pat)) - { - case USE: - /* Deaths in USE insns can happen in non optimizing compilation. - Handle them by popping the dying register. */ - src = get_true_reg (&XEXP (pat, 0)); - if (STACK_REG_P (*src) - && find_regno_note (insn, REG_DEAD, REGNO (*src))) - { - emit_pop_insn (insn, regstack, *src, EMIT_AFTER); - return control_flow_insn_deleted; - } - /* ??? Uninitialized USE should not happen. */ - else - gcc_assert (get_hard_regnum (regstack, *src) != -1); - break; - - case CLOBBER: - { - rtx note; - - dest = get_true_reg (&XEXP (pat, 0)); - if (STACK_REG_P (*dest)) - { - note = find_reg_note (insn, REG_DEAD, *dest); - - if (pat != PATTERN (insn)) - { - /* The fix_truncdi_1 pattern wants to be able to allocate - its own scratch register. It does this by clobbering - an fp reg so that it is assured of an empty reg-stack - register. If the register is live, kill it now. - Remove the DEAD/UNUSED note so we don't try to kill it - later too. */ - - if (note) - emit_pop_insn (insn, regstack, *dest, EMIT_BEFORE); - else - { - note = find_reg_note (insn, REG_UNUSED, *dest); - gcc_assert (note); - } - remove_note (insn, note); - replace_reg (dest, FIRST_STACK_REG + 1); - } - else - { - /* A top-level clobber with no REG_DEAD, and no hard-regnum - indicates an uninitialized value. Because reload removed - all other clobbers, this must be due to a function - returning without a value. Load up a NaN. */ - - if (!note) - { - rtx t = *dest; - if (COMPLEX_MODE_P (GET_MODE (t))) - { - rtx u = FP_MODE_REG (REGNO (t) + 1, SFmode); - if (get_hard_regnum (regstack, u) == -1) - { - rtx pat2 = gen_rtx_CLOBBER (VOIDmode, u); - rtx insn2 = emit_insn_before (pat2, insn); - control_flow_insn_deleted - |= move_nan_for_stack_reg (insn2, regstack, u); - } - } - if (get_hard_regnum (regstack, t) == -1) - control_flow_insn_deleted - |= move_nan_for_stack_reg (insn, regstack, t); - } - } - } - break; - } - - case SET: - { - rtx *src1 = (rtx *) 0, *src2; - rtx src1_note, src2_note; - rtx pat_src; - - dest = get_true_reg (&SET_DEST (pat)); - src = get_true_reg (&SET_SRC (pat)); - pat_src = SET_SRC (pat); - - /* See if this is a `movM' pattern, and handle elsewhere if so. */ - if (STACK_REG_P (*src) - || (STACK_REG_P (*dest) - && (REG_P (*src) || MEM_P (*src) - || GET_CODE (*src) == CONST_DOUBLE))) - { - control_flow_insn_deleted |= move_for_stack_reg (insn, regstack, pat); - break; - } - - switch (GET_CODE (pat_src)) - { - case COMPARE: - compare_for_stack_reg (insn, regstack, pat_src); - break; - - case CALL: - { - int count; - for (count = hard_regno_nregs[REGNO (*dest)][GET_MODE (*dest)]; - --count >= 0;) - { - regstack->reg[++regstack->top] = REGNO (*dest) + count; - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest) + count); - } - } - replace_reg (dest, FIRST_STACK_REG); - break; - - case REG: - /* This is a `tstM2' case. */ - gcc_assert (*dest == cc0_rtx); - src1 = src; - - /* Fall through. */ - - case FLOAT_TRUNCATE: - case SQRT: - case ABS: - case NEG: - /* These insns only operate on the top of the stack. DEST might - be cc0_rtx if we're processing a tstM pattern. Also, it's - possible that the tstM case results in a REG_DEAD note on the - source. */ - - if (src1 == 0) - src1 = get_true_reg (&XEXP (pat_src, 0)); - - emit_swap_insn (insn, regstack, *src1); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - - if (STACK_REG_P (*dest)) - replace_reg (dest, FIRST_STACK_REG); - - if (src1_note) - { - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - regstack->top--; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1)); - } - - replace_reg (src1, FIRST_STACK_REG); - break; - - case MINUS: - case DIV: - /* On i386, reversed forms of subM3 and divM3 exist for - MODE_FLOAT, so the same code that works for addM3 and mulM3 - can be used. */ - case MULT: - case PLUS: - /* These insns can accept the top of stack as a destination - from a stack reg or mem, or can use the top of stack as a - source and some other stack register (possibly top of stack) - as a destination. */ - - src1 = get_true_reg (&XEXP (pat_src, 0)); - src2 = get_true_reg (&XEXP (pat_src, 1)); - - /* We will fix any death note later. */ - - if (STACK_REG_P (*src1)) - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - else - src1_note = NULL_RTX; - if (STACK_REG_P (*src2)) - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - else - src2_note = NULL_RTX; - - /* If either operand is not a stack register, then the dest - must be top of stack. */ - - if (! STACK_REG_P (*src1) || ! STACK_REG_P (*src2)) - emit_swap_insn (insn, regstack, *dest); - else - { - /* Both operands are REG. If neither operand is already - at the top of stack, choose to make the one that is the dest - the new top of stack. */ - - int src1_hard_regnum, src2_hard_regnum; - - src1_hard_regnum = get_hard_regnum (regstack, *src1); - src2_hard_regnum = get_hard_regnum (regstack, *src2); - gcc_assert (src1_hard_regnum != -1); - gcc_assert (src2_hard_regnum != -1); - - if (src1_hard_regnum != FIRST_STACK_REG - && src2_hard_regnum != FIRST_STACK_REG) - emit_swap_insn (insn, regstack, *dest); - } - - if (STACK_REG_P (*src1)) - replace_reg (src1, get_hard_regnum (regstack, *src1)); - if (STACK_REG_P (*src2)) - replace_reg (src2, get_hard_regnum (regstack, *src2)); - - if (src1_note) - { - rtx src1_reg = XEXP (src1_note, 0); - - /* If the register that dies is at the top of stack, then - the destination is somewhere else - merely substitute it. - But if the reg that dies is not at top of stack, then - move the top of stack to the dead reg, as though we had - done the insn and then a store-with-pop. */ - - if (REGNO (src1_reg) == regstack->reg[regstack->top]) - { - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, get_hard_regnum (regstack, *dest)); - } - else - { - int regno = get_hard_regnum (regstack, src1_reg); - - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, regno); - - regstack->reg[regstack->top - (regno - FIRST_STACK_REG)] - = regstack->reg[regstack->top]; - } - - CLEAR_HARD_REG_BIT (regstack->reg_set, - REGNO (XEXP (src1_note, 0))); - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - regstack->top--; - } - else if (src2_note) - { - rtx src2_reg = XEXP (src2_note, 0); - if (REGNO (src2_reg) == regstack->reg[regstack->top]) - { - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, get_hard_regnum (regstack, *dest)); - } - else - { - int regno = get_hard_regnum (regstack, src2_reg); - - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, regno); - - regstack->reg[regstack->top - (regno - FIRST_STACK_REG)] - = regstack->reg[regstack->top]; - } - - CLEAR_HARD_REG_BIT (regstack->reg_set, - REGNO (XEXP (src2_note, 0))); - replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG); - regstack->top--; - } - else - { - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, get_hard_regnum (regstack, *dest)); - } - - /* Keep operand 1 matching with destination. */ - if (COMMUTATIVE_ARITH_P (pat_src) - && REG_P (*src1) && REG_P (*src2) - && REGNO (*src1) != REGNO (*dest)) - { - int tmp = REGNO (*src1); - replace_reg (src1, REGNO (*src2)); - replace_reg (src2, tmp); - } - break; - - case UNSPEC: - switch (XINT (pat_src, 1)) - { - case UNSPEC_FIST: - - case UNSPEC_FIST_FLOOR: - case UNSPEC_FIST_CEIL: - - /* These insns only operate on the top of the stack. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - emit_swap_insn (insn, regstack, *src1); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - - if (STACK_REG_P (*dest)) - replace_reg (dest, FIRST_STACK_REG); - - if (src1_note) - { - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - regstack->top--; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1)); - } - - replace_reg (src1, FIRST_STACK_REG); - break; - - case UNSPEC_SIN: - case UNSPEC_COS: - case UNSPEC_FRNDINT: - case UNSPEC_F2XM1: - - case UNSPEC_FRNDINT_FLOOR: - case UNSPEC_FRNDINT_CEIL: - case UNSPEC_FRNDINT_TRUNC: - case UNSPEC_FRNDINT_MASK_PM: - - /* These insns only operate on the top of the stack. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - - emit_swap_insn (insn, regstack, *src1); - - /* Input should never die, it is - replaced with output. */ - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - gcc_assert (!src1_note); - - if (STACK_REG_P (*dest)) - replace_reg (dest, FIRST_STACK_REG); - - replace_reg (src1, FIRST_STACK_REG); - break; - - case UNSPEC_FPATAN: - case UNSPEC_FYL2X: - case UNSPEC_FYL2XP1: - /* These insns operate on the top two stack slots. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - src2 = get_true_reg (&XVECEXP (pat_src, 0, 1)); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - - swap_to_top (insn, regstack, *src1, *src2); - - replace_reg (src1, FIRST_STACK_REG); - replace_reg (src2, FIRST_STACK_REG + 1); - - if (src1_note) - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - if (src2_note) - replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1); - - /* Pop both input operands from the stack. */ - CLEAR_HARD_REG_BIT (regstack->reg_set, - regstack->reg[regstack->top]); - CLEAR_HARD_REG_BIT (regstack->reg_set, - regstack->reg[regstack->top - 1]); - regstack->top -= 2; - - /* Push the result back onto the stack. */ - regstack->reg[++regstack->top] = REGNO (*dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG); - break; - - case UNSPEC_FSCALE_FRACT: - case UNSPEC_FPREM_F: - case UNSPEC_FPREM1_F: - /* These insns operate on the top two stack slots. - first part of double input, double output insn. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - src2 = get_true_reg (&XVECEXP (pat_src, 0, 1)); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - - /* Inputs should never die, they are - replaced with outputs. */ - gcc_assert (!src1_note); - gcc_assert (!src2_note); - - swap_to_top (insn, regstack, *src1, *src2); - - /* Push the result back onto stack. Empty stack slot - will be filled in second part of insn. */ - if (STACK_REG_P (*dest)) { - regstack->reg[regstack->top] = REGNO (*dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG); - } - - replace_reg (src1, FIRST_STACK_REG); - replace_reg (src2, FIRST_STACK_REG + 1); - break; - - case UNSPEC_FSCALE_EXP: - case UNSPEC_FPREM_U: - case UNSPEC_FPREM1_U: - /* These insns operate on the top two stack slots./ - second part of double input, double output insn. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - src2 = get_true_reg (&XVECEXP (pat_src, 0, 1)); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - - /* Inputs should never die, they are - replaced with outputs. */ - gcc_assert (!src1_note); - gcc_assert (!src2_note); - - swap_to_top (insn, regstack, *src1, *src2); - - /* Push the result back onto stack. Fill empty slot from - first part of insn and fix top of stack pointer. */ - if (STACK_REG_P (*dest)) { - regstack->reg[regstack->top - 1] = REGNO (*dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG + 1); - } - - replace_reg (src1, FIRST_STACK_REG); - replace_reg (src2, FIRST_STACK_REG + 1); - break; - - case UNSPEC_SINCOS_COS: - case UNSPEC_TAN_ONE: - case UNSPEC_XTRACT_FRACT: - /* These insns operate on the top two stack slots, - first part of one input, double output insn. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - - emit_swap_insn (insn, regstack, *src1); - - /* Input should never die, it is - replaced with output. */ - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - gcc_assert (!src1_note); - - /* Push the result back onto stack. Empty stack slot - will be filled in second part of insn. */ - if (STACK_REG_P (*dest)) { - regstack->reg[regstack->top + 1] = REGNO (*dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG); - } - - replace_reg (src1, FIRST_STACK_REG); - break; - - case UNSPEC_SINCOS_SIN: - case UNSPEC_TAN_TAN: - case UNSPEC_XTRACT_EXP: - /* These insns operate on the top two stack slots, - second part of one input, double output insn. */ - - src1 = get_true_reg (&XVECEXP (pat_src, 0, 0)); - - emit_swap_insn (insn, regstack, *src1); - - /* Input should never die, it is - replaced with output. */ - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - gcc_assert (!src1_note); - - /* Push the result back onto stack. Fill empty slot from - first part of insn and fix top of stack pointer. */ - if (STACK_REG_P (*dest)) { - regstack->reg[regstack->top] = REGNO (*dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG + 1); - - regstack->top++; - } - - replace_reg (src1, FIRST_STACK_REG); - break; - - case UNSPEC_SAHF: - /* (unspec [(unspec [(compare)] UNSPEC_FNSTSW)] UNSPEC_SAHF) - The combination matches the PPRO fcomi instruction. */ - - pat_src = XVECEXP (pat_src, 0, 0); - gcc_assert (GET_CODE (pat_src) == UNSPEC); - gcc_assert (XINT (pat_src, 1) == UNSPEC_FNSTSW); - /* Fall through. */ - - case UNSPEC_FNSTSW: - /* Combined fcomp+fnstsw generated for doing well with - CSE. When optimizing this would have been broken - up before now. */ - - pat_src = XVECEXP (pat_src, 0, 0); - gcc_assert (GET_CODE (pat_src) == COMPARE); - - compare_for_stack_reg (insn, regstack, pat_src); - break; - - default: - gcc_unreachable (); - } - break; - - case IF_THEN_ELSE: - /* This insn requires the top of stack to be the destination. */ - - src1 = get_true_reg (&XEXP (pat_src, 1)); - src2 = get_true_reg (&XEXP (pat_src, 2)); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - - /* If the comparison operator is an FP comparison operator, - it is handled correctly by compare_for_stack_reg () who - will move the destination to the top of stack. But if the - comparison operator is not an FP comparison operator, we - have to handle it here. */ - if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG - && REGNO (*dest) != regstack->reg[regstack->top]) - { - /* In case one of operands is the top of stack and the operands - dies, it is safe to make it the destination operand by - reversing the direction of cmove and avoid fxch. */ - if ((REGNO (*src1) == regstack->reg[regstack->top] - && src1_note) - || (REGNO (*src2) == regstack->reg[regstack->top] - && src2_note)) - { - int idx1 = (get_hard_regnum (regstack, *src1) - - FIRST_STACK_REG); - int idx2 = (get_hard_regnum (regstack, *src2) - - FIRST_STACK_REG); - - /* Make reg-stack believe that the operands are already - swapped on the stack */ - regstack->reg[regstack->top - idx1] = REGNO (*src2); - regstack->reg[regstack->top - idx2] = REGNO (*src1); - - /* Reverse condition to compensate the operand swap. - i386 do have comparison always reversible. */ - PUT_CODE (XEXP (pat_src, 0), - reversed_comparison_code (XEXP (pat_src, 0), insn)); - } - else - emit_swap_insn (insn, regstack, *dest); - } - - { - rtx src_note [3]; - int i; - - src_note[0] = 0; - src_note[1] = src1_note; - src_note[2] = src2_note; - - if (STACK_REG_P (*src1)) - replace_reg (src1, get_hard_regnum (regstack, *src1)); - if (STACK_REG_P (*src2)) - replace_reg (src2, get_hard_regnum (regstack, *src2)); - - for (i = 1; i <= 2; i++) - if (src_note [i]) - { - int regno = REGNO (XEXP (src_note[i], 0)); - - /* If the register that dies is not at the top of - stack, then move the top of stack to the dead reg. - Top of stack should never die, as it is the - destination. */ - gcc_assert (regno != regstack->reg[regstack->top]); - remove_regno_note (insn, REG_DEAD, regno); - emit_pop_insn (insn, regstack, XEXP (src_note[i], 0), - EMIT_AFTER); - } - } - - /* Make dest the top of stack. Add dest to regstack if - not present. */ - if (get_hard_regnum (regstack, *dest) < FIRST_STACK_REG) - regstack->reg[++regstack->top] = REGNO (*dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG); - break; - - default: - gcc_unreachable (); - } - break; - } - - default: - break; - } - - return control_flow_insn_deleted; -} - -/* Substitute hard regnums for any stack regs in INSN, which has - N_INPUTS inputs and N_OUTPUTS outputs. REGSTACK is the stack info - before the insn, and is updated with changes made here. - - There are several requirements and assumptions about the use of - stack-like regs in asm statements. These rules are enforced by - record_asm_stack_regs; see comments there for details. Any - asm_operands left in the RTL at this point may be assume to meet the - requirements, since record_asm_stack_regs removes any problem asm. */ - -static void -subst_asm_stack_regs (rtx insn, stack regstack) -{ - rtx body = PATTERN (insn); - int alt; - - rtx *note_reg; /* Array of note contents */ - rtx **note_loc; /* Address of REG field of each note */ - enum reg_note *note_kind; /* The type of each note */ - - rtx *clobber_reg = 0; - rtx **clobber_loc = 0; - - struct stack_def temp_stack; - int n_notes; - int n_clobbers; - rtx note; - int i; - int n_inputs, n_outputs; - - if (! check_asm_stack_operands (insn)) - return; - - /* Find out what the constraints required. If no constraint - alternative matches, that is a compiler bug: we should have caught - such an insn in check_asm_stack_operands. */ - extract_insn (insn); - constrain_operands (1); - alt = which_alternative; - - preprocess_constraints (); - - n_inputs = get_asm_operand_n_inputs (body); - n_outputs = recog_data.n_operands - n_inputs; - - gcc_assert (alt >= 0); - - /* Strip SUBREGs here to make the following code simpler. */ - for (i = 0; i < recog_data.n_operands; i++) - if (GET_CODE (recog_data.operand[i]) == SUBREG - && REG_P (SUBREG_REG (recog_data.operand[i]))) - { - recog_data.operand_loc[i] = & SUBREG_REG (recog_data.operand[i]); - recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]); - } - - /* Set up NOTE_REG, NOTE_LOC and NOTE_KIND. */ - - for (i = 0, note = REG_NOTES (insn); note; note = XEXP (note, 1)) - i++; - - note_reg = alloca (i * sizeof (rtx)); - note_loc = alloca (i * sizeof (rtx *)); - note_kind = alloca (i * sizeof (enum reg_note)); - - n_notes = 0; - for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) - { - rtx reg = XEXP (note, 0); - rtx *loc = & XEXP (note, 0); - - if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg))) - { - loc = & SUBREG_REG (reg); - reg = SUBREG_REG (reg); - } - - if (STACK_REG_P (reg) - && (REG_NOTE_KIND (note) == REG_DEAD - || REG_NOTE_KIND (note) == REG_UNUSED)) - { - note_reg[n_notes] = reg; - note_loc[n_notes] = loc; - note_kind[n_notes] = REG_NOTE_KIND (note); - n_notes++; - } - } - - /* Set up CLOBBER_REG and CLOBBER_LOC. */ - - n_clobbers = 0; - - if (GET_CODE (body) == PARALLEL) - { - clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx)); - clobber_loc = alloca (XVECLEN (body, 0) * sizeof (rtx *)); - - for (i = 0; i < XVECLEN (body, 0); i++) - if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER) - { - rtx clobber = XVECEXP (body, 0, i); - rtx reg = XEXP (clobber, 0); - rtx *loc = & XEXP (clobber, 0); - - if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg))) - { - loc = & SUBREG_REG (reg); - reg = SUBREG_REG (reg); - } - - if (STACK_REG_P (reg)) - { - clobber_reg[n_clobbers] = reg; - clobber_loc[n_clobbers] = loc; - n_clobbers++; - } - } - } - - temp_stack = *regstack; - - /* Put the input regs into the desired place in TEMP_STACK. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_data.operand[i]) - && reg_class_subset_p (recog_op_alt[i][alt].cl, - FLOAT_REGS) - && recog_op_alt[i][alt].cl != FLOAT_REGS) - { - /* If an operand needs to be in a particular reg in - FLOAT_REGS, the constraint was either 't' or 'u'. Since - these constraints are for single register classes, and - reload guaranteed that operand[i] is already in that class, - we can just use REGNO (recog_data.operand[i]) to know which - actual reg this operand needs to be in. */ - - int regno = get_hard_regnum (&temp_stack, recog_data.operand[i]); - - gcc_assert (regno >= 0); - - if ((unsigned int) regno != REGNO (recog_data.operand[i])) - { - /* recog_data.operand[i] is not in the right place. Find - it and swap it with whatever is already in I's place. - K is where recog_data.operand[i] is now. J is where it - should be. */ - int j, k, temp; - - k = temp_stack.top - (regno - FIRST_STACK_REG); - j = (temp_stack.top - - (REGNO (recog_data.operand[i]) - FIRST_STACK_REG)); - - temp = temp_stack.reg[k]; - temp_stack.reg[k] = temp_stack.reg[j]; - temp_stack.reg[j] = temp; - } - } - - /* Emit insns before INSN to make sure the reg-stack is in the right - order. */ - - change_stack (insn, regstack, &temp_stack, EMIT_BEFORE); - - /* Make the needed input register substitutions. Do death notes and - clobbers too, because these are for inputs, not outputs. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_data.operand[i])) - { - int regnum = get_hard_regnum (regstack, recog_data.operand[i]); - - gcc_assert (regnum >= 0); - - replace_reg (recog_data.operand_loc[i], regnum); - } - - for (i = 0; i < n_notes; i++) - if (note_kind[i] == REG_DEAD) - { - int regnum = get_hard_regnum (regstack, note_reg[i]); - - gcc_assert (regnum >= 0); - - replace_reg (note_loc[i], regnum); - } - - for (i = 0; i < n_clobbers; i++) - { - /* It's OK for a CLOBBER to reference a reg that is not live. - Don't try to replace it in that case. */ - int regnum = get_hard_regnum (regstack, clobber_reg[i]); - - if (regnum >= 0) - { - /* Sigh - clobbers always have QImode. But replace_reg knows - that these regs can't be MODE_INT and will assert. Just put - the right reg there without calling replace_reg. */ - - *clobber_loc[i] = FP_MODE_REG (regnum, DFmode); - } - } - - /* Now remove from REGSTACK any inputs that the asm implicitly popped. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_data.operand[i])) - { - /* An input reg is implicitly popped if it is tied to an - output, or if there is a CLOBBER for it. */ - int j; - - for (j = 0; j < n_clobbers; j++) - if (operands_match_p (clobber_reg[j], recog_data.operand[i])) - break; - - if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0) - { - /* recog_data.operand[i] might not be at the top of stack. - But that's OK, because all we need to do is pop the - right number of regs off of the top of the reg-stack. - record_asm_stack_regs guaranteed that all implicitly - popped regs were grouped at the top of the reg-stack. */ - - CLEAR_HARD_REG_BIT (regstack->reg_set, - regstack->reg[regstack->top]); - regstack->top--; - } - } - - /* Now add to REGSTACK any outputs that the asm implicitly pushed. - Note that there isn't any need to substitute register numbers. - ??? Explain why this is true. */ - - for (i = LAST_STACK_REG; i >= FIRST_STACK_REG; i--) - { - /* See if there is an output for this hard reg. */ - int j; - - for (j = 0; j < n_outputs; j++) - if (STACK_REG_P (recog_data.operand[j]) - && REGNO (recog_data.operand[j]) == (unsigned) i) - { - regstack->reg[++regstack->top] = i; - SET_HARD_REG_BIT (regstack->reg_set, i); - break; - } - } - - /* Now emit a pop insn for any REG_UNUSED output, or any REG_DEAD - input that the asm didn't implicitly pop. If the asm didn't - implicitly pop an input reg, that reg will still be live. - - Note that we can't use find_regno_note here: the register numbers - in the death notes have already been substituted. */ - - for (i = 0; i < n_outputs; i++) - if (STACK_REG_P (recog_data.operand[i])) - { - int j; - - for (j = 0; j < n_notes; j++) - if (REGNO (recog_data.operand[i]) == REGNO (note_reg[j]) - && note_kind[j] == REG_UNUSED) - { - insn = emit_pop_insn (insn, regstack, recog_data.operand[i], - EMIT_AFTER); - break; - } - } - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_data.operand[i])) - { - int j; - - for (j = 0; j < n_notes; j++) - if (REGNO (recog_data.operand[i]) == REGNO (note_reg[j]) - && note_kind[j] == REG_DEAD - && TEST_HARD_REG_BIT (regstack->reg_set, - REGNO (recog_data.operand[i]))) - { - insn = emit_pop_insn (insn, regstack, recog_data.operand[i], - EMIT_AFTER); - break; - } - } -} - -/* Substitute stack hard reg numbers for stack virtual registers in - INSN. Non-stack register numbers are not changed. REGSTACK is the - current stack content. Insns may be emitted as needed to arrange the - stack for the 387 based on the contents of the insn. Return whether - a control flow insn was deleted in the process. */ - -static bool -subst_stack_regs (rtx insn, stack regstack) -{ - rtx *note_link, note; - bool control_flow_insn_deleted = false; - int i; - - if (CALL_P (insn)) - { - int top = regstack->top; - - /* If there are any floating point parameters to be passed in - registers for this call, make sure they are in the right - order. */ - - if (top >= 0) - { - straighten_stack (insn, regstack); - - /* Now mark the arguments as dead after the call. */ - - while (regstack->top >= 0) - { - CLEAR_HARD_REG_BIT (regstack->reg_set, FIRST_STACK_REG + regstack->top); - regstack->top--; - } - } - } - - /* Do the actual substitution if any stack regs are mentioned. - Since we only record whether entire insn mentions stack regs, and - subst_stack_regs_pat only works for patterns that contain stack regs, - we must check each pattern in a parallel here. A call_value_pop could - fail otherwise. */ - - if (stack_regs_mentioned (insn)) - { - int n_operands = asm_noperands (PATTERN (insn)); - if (n_operands >= 0) - { - /* This insn is an `asm' with operands. Decode the operands, - decide how many are inputs, and do register substitution. - Any REG_UNUSED notes will be handled by subst_asm_stack_regs. */ - - subst_asm_stack_regs (insn, regstack); - return control_flow_insn_deleted; - } - - if (GET_CODE (PATTERN (insn)) == PARALLEL) - for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++) - { - if (stack_regs_mentioned_p (XVECEXP (PATTERN (insn), 0, i))) - { - if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == CLOBBER) - XVECEXP (PATTERN (insn), 0, i) - = shallow_copy_rtx (XVECEXP (PATTERN (insn), 0, i)); - control_flow_insn_deleted - |= subst_stack_regs_pat (insn, regstack, - XVECEXP (PATTERN (insn), 0, i)); - } - } - else - control_flow_insn_deleted - |= subst_stack_regs_pat (insn, regstack, PATTERN (insn)); - } - - /* subst_stack_regs_pat may have deleted a no-op insn. If so, any - REG_UNUSED will already have been dealt with, so just return. */ - - if (NOTE_P (insn) || INSN_DELETED_P (insn)) - return control_flow_insn_deleted; - - /* If this a noreturn call, we can't insert pop insns after it. - Instead, reset the stack state to empty. */ - if (CALL_P (insn) - && find_reg_note (insn, REG_NORETURN, NULL)) - { - regstack->top = -1; - CLEAR_HARD_REG_SET (regstack->reg_set); - return control_flow_insn_deleted; - } - - /* If there is a REG_UNUSED note on a stack register on this insn, - the indicated reg must be popped. The REG_UNUSED note is removed, - since the form of the newly emitted pop insn references the reg, - making it no longer `unset'. */ - - note_link = ®_NOTES (insn); - for (note = *note_link; note; note = XEXP (note, 1)) - if (REG_NOTE_KIND (note) == REG_UNUSED && STACK_REG_P (XEXP (note, 0))) - { - *note_link = XEXP (note, 1); - insn = emit_pop_insn (insn, regstack, XEXP (note, 0), EMIT_AFTER); - } - else - note_link = &XEXP (note, 1); - - return control_flow_insn_deleted; -} - -/* Change the organization of the stack so that it fits a new basic - block. Some registers might have to be popped, but there can never be - a register live in the new block that is not now live. - - Insert any needed insns before or after INSN, as indicated by - WHERE. OLD is the original stack layout, and NEW is the desired - form. OLD is updated to reflect the code emitted, i.e., it will be - the same as NEW upon return. - - This function will not preserve block_end[]. But that information - is no longer needed once this has executed. */ - -static void -change_stack (rtx insn, stack old, stack new, enum emit_where where) -{ - int reg; - int update_end = 0; - - /* Stack adjustments for the first insn in a block update the - current_block's stack_in instead of inserting insns directly. - compensate_edges will add the necessary code later. */ - if (current_block - && starting_stack_p - && where == EMIT_BEFORE) - { - BLOCK_INFO (current_block)->stack_in = *new; - starting_stack_p = false; - *old = *new; - return; - } - - /* We will be inserting new insns "backwards". If we are to insert - after INSN, find the next insn, and insert before it. */ - - if (where == EMIT_AFTER) - { - if (current_block && BB_END (current_block) == insn) - update_end = 1; - insn = NEXT_INSN (insn); - } - - /* Pop any registers that are not needed in the new block. */ - - /* If the destination block's stack already has a specified layout - and contains two or more registers, use a more intelligent algorithm - to pop registers that minimizes the number number of fxchs below. */ - if (new->top > 0) - { - bool slots[REG_STACK_SIZE]; - int pops[REG_STACK_SIZE]; - int next, dest, topsrc; - - /* First pass to determine the free slots. */ - for (reg = 0; reg <= new->top; reg++) - slots[reg] = TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]); - - /* Second pass to allocate preferred slots. */ - topsrc = -1; - for (reg = old->top; reg > new->top; reg--) - if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg])) - { - dest = -1; - for (next = 0; next <= new->top; next++) - if (!slots[next] && new->reg[next] == old->reg[reg]) - { - /* If this is a preference for the new top of stack, record - the fact by remembering it's old->reg in topsrc. */ - if (next == new->top) - topsrc = reg; - slots[next] = true; - dest = next; - break; - } - pops[reg] = dest; - } - else - pops[reg] = reg; - - /* Intentionally, avoid placing the top of stack in it's correct - location, if we still need to permute the stack below and we - can usefully place it somewhere else. This is the case if any - slot is still unallocated, in which case we should place the - top of stack there. */ - if (topsrc != -1) - for (reg = 0; reg < new->top; reg++) - if (!slots[reg]) - { - pops[topsrc] = reg; - slots[new->top] = false; - slots[reg] = true; - break; - } - - /* Third pass allocates remaining slots and emits pop insns. */ - next = new->top; - for (reg = old->top; reg > new->top; reg--) - { - dest = pops[reg]; - if (dest == -1) - { - /* Find next free slot. */ - while (slots[next]) - next--; - dest = next--; - } - emit_pop_insn (insn, old, FP_MODE_REG (old->reg[dest], DFmode), - EMIT_BEFORE); - } - } - else - { - /* The following loop attempts to maximize the number of times we - pop the top of the stack, as this permits the use of the faster - ffreep instruction on platforms that support it. */ - int live, next; - - live = 0; - for (reg = 0; reg <= old->top; reg++) - if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg])) - live++; - - next = live; - while (old->top >= live) - if (TEST_HARD_REG_BIT (new->reg_set, old->reg[old->top])) - { - while (TEST_HARD_REG_BIT (new->reg_set, old->reg[next])) - next--; - emit_pop_insn (insn, old, FP_MODE_REG (old->reg[next], DFmode), - EMIT_BEFORE); - } - else - emit_pop_insn (insn, old, FP_MODE_REG (old->reg[old->top], DFmode), - EMIT_BEFORE); - } - - if (new->top == -2) - { - /* If the new block has never been processed, then it can inherit - the old stack order. */ - - new->top = old->top; - memcpy (new->reg, old->reg, sizeof (new->reg)); - } - else - { - /* This block has been entered before, and we must match the - previously selected stack order. */ - - /* By now, the only difference should be the order of the stack, - not their depth or liveliness. */ - - GO_IF_HARD_REG_EQUAL (old->reg_set, new->reg_set, win); - gcc_unreachable (); - win: - gcc_assert (old->top == new->top); - - /* If the stack is not empty (new->top != -1), loop here emitting - swaps until the stack is correct. - - The worst case number of swaps emitted is N + 2, where N is the - depth of the stack. In some cases, the reg at the top of - stack may be correct, but swapped anyway in order to fix - other regs. But since we never swap any other reg away from - its correct slot, this algorithm will converge. */ - - if (new->top != -1) - do - { - /* Swap the reg at top of stack into the position it is - supposed to be in, until the correct top of stack appears. */ - - while (old->reg[old->top] != new->reg[new->top]) - { - for (reg = new->top; reg >= 0; reg--) - if (new->reg[reg] == old->reg[old->top]) - break; - - gcc_assert (reg != -1); - - emit_swap_insn (insn, old, - FP_MODE_REG (old->reg[reg], DFmode)); - } - - /* See if any regs remain incorrect. If so, bring an - incorrect reg to the top of stack, and let the while loop - above fix it. */ - - for (reg = new->top; reg >= 0; reg--) - if (new->reg[reg] != old->reg[reg]) - { - emit_swap_insn (insn, old, - FP_MODE_REG (old->reg[reg], DFmode)); - break; - } - } while (reg >= 0); - - /* At this point there must be no differences. */ - - for (reg = old->top; reg >= 0; reg--) - gcc_assert (old->reg[reg] == new->reg[reg]); - } - - if (update_end) - BB_END (current_block) = PREV_INSN (insn); -} - -/* Print stack configuration. */ - -static void -print_stack (FILE *file, stack s) -{ - if (! file) - return; - - if (s->top == -2) - fprintf (file, "uninitialized\n"); - else if (s->top == -1) - fprintf (file, "empty\n"); - else - { - int i; - fputs ("[ ", file); - for (i = 0; i <= s->top; ++i) - fprintf (file, "%d ", s->reg[i]); - fputs ("]\n", file); - } -} - -/* This function was doing life analysis. We now let the regular live - code do it's job, so we only need to check some extra invariants - that reg-stack expects. Primary among these being that all registers - are initialized before use. - - The function returns true when code was emitted to CFG edges and - commit_edge_insertions needs to be called. */ - -static int -convert_regs_entry (void) -{ - int inserted = 0; - edge e; - edge_iterator ei; - - /* Load something into each stack register live at function entry. - Such live registers can be caused by uninitialized variables or - functions not returning values on all paths. In order to keep - the push/pop code happy, and to not scrog the register stack, we - must put something in these registers. Use a QNaN. - - Note that we are inserting converted code here. This code is - never seen by the convert_regs pass. */ - - FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) - { - basic_block block = e->dest; - block_info bi = BLOCK_INFO (block); - int reg, top = -1; - - for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg) - if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg)) - { - rtx init; - - bi->stack_in.reg[++top] = reg; - - init = gen_rtx_SET (VOIDmode, - FP_MODE_REG (FIRST_STACK_REG, SFmode), - not_a_num); - insert_insn_on_edge (init, e); - inserted = 1; - } - - bi->stack_in.top = top; - } - - return inserted; -} - -/* Construct the desired stack for function exit. This will either - be `empty', or the function return value at top-of-stack. */ - -static void -convert_regs_exit (void) -{ - int value_reg_low, value_reg_high; - stack output_stack; - rtx retvalue; - - retvalue = stack_result (current_function_decl); - value_reg_low = value_reg_high = -1; - if (retvalue) - { - value_reg_low = REGNO (retvalue); - value_reg_high = value_reg_low - + hard_regno_nregs[value_reg_low][GET_MODE (retvalue)] - 1; - } - - output_stack = &BLOCK_INFO (EXIT_BLOCK_PTR)->stack_in; - if (value_reg_low == -1) - output_stack->top = -1; - else - { - int reg; - - output_stack->top = value_reg_high - value_reg_low; - for (reg = value_reg_low; reg <= value_reg_high; ++reg) - { - output_stack->reg[value_reg_high - reg] = reg; - SET_HARD_REG_BIT (output_stack->reg_set, reg); - } - } -} - -/* Copy the stack info from the end of edge E's source block to the - start of E's destination block. */ - -static void -propagate_stack (edge e) -{ - stack src_stack = &BLOCK_INFO (e->src)->stack_out; - stack dest_stack = &BLOCK_INFO (e->dest)->stack_in; - int reg; - - /* Preserve the order of the original stack, but check whether - any pops are needed. */ - dest_stack->top = -1; - for (reg = 0; reg <= src_stack->top; ++reg) - if (TEST_HARD_REG_BIT (dest_stack->reg_set, src_stack->reg[reg])) - dest_stack->reg[++dest_stack->top] = src_stack->reg[reg]; -} - - -/* Adjust the stack of edge E's source block on exit to match the stack - of it's target block upon input. The stack layouts of both blocks - should have been defined by now. */ - -static bool -compensate_edge (edge e) -{ - basic_block source = e->src, target = e->dest; - stack target_stack = &BLOCK_INFO (target)->stack_in; - stack source_stack = &BLOCK_INFO (source)->stack_out; - struct stack_def regstack; - int reg; - - if (dump_file) - fprintf (dump_file, "Edge %d->%d: ", source->index, target->index); - - gcc_assert (target_stack->top != -2); - - /* Check whether stacks are identical. */ - if (target_stack->top == source_stack->top) - { - for (reg = target_stack->top; reg >= 0; --reg) - if (target_stack->reg[reg] != source_stack->reg[reg]) - break; - - if (reg == -1) - { - if (dump_file) - fprintf (dump_file, "no changes needed\n"); - return false; - } - } - - if (dump_file) - { - fprintf (dump_file, "correcting stack to "); - print_stack (dump_file, target_stack); - } - - /* Abnormal calls may appear to have values live in st(0), but the - abnormal return path will not have actually loaded the values. */ - if (e->flags & EDGE_ABNORMAL_CALL) - { - /* Assert that the lifetimes are as we expect -- one value - live at st(0) on the end of the source block, and no - values live at the beginning of the destination block. - For complex return values, we may have st(1) live as well. */ - gcc_assert (source_stack->top == 0 || source_stack->top == 1); - gcc_assert (target_stack->top == -1); - return false; - } - - /* Handle non-call EH edges specially. The normal return path have - values in registers. These will be popped en masse by the unwind - library. */ - if (e->flags & EDGE_EH) - { - gcc_assert (target_stack->top == -1); - return false; - } - - /* We don't support abnormal edges. Global takes care to - avoid any live register across them, so we should never - have to insert instructions on such edges. */ - gcc_assert (! (e->flags & EDGE_ABNORMAL)); - - /* Make a copy of source_stack as change_stack is destructive. */ - regstack = *source_stack; - - /* It is better to output directly to the end of the block - instead of to the edge, because emit_swap can do minimal - insn scheduling. We can do this when there is only one - edge out, and it is not abnormal. */ - if (EDGE_COUNT (source->succs) == 1) - { - current_block = source; - change_stack (BB_END (source), ®stack, target_stack, - (JUMP_P (BB_END (source)) ? EMIT_BEFORE : EMIT_AFTER)); - } - else - { - rtx seq, after; - - current_block = NULL; - start_sequence (); - - /* ??? change_stack needs some point to emit insns after. */ - after = emit_note (NOTE_INSN_DELETED); - - change_stack (after, ®stack, target_stack, EMIT_BEFORE); - - seq = get_insns (); - end_sequence (); - - insert_insn_on_edge (seq, e); - return true; - } - return false; -} - -/* Traverse all non-entry edges in the CFG, and emit the necessary - edge compensation code to change the stack from stack_out of the - source block to the stack_in of the destination block. */ - -static bool -compensate_edges (void) -{ - bool inserted = false; - basic_block bb; - - starting_stack_p = false; - - FOR_EACH_BB (bb) - if (bb != ENTRY_BLOCK_PTR) - { - edge e; - edge_iterator ei; - - FOR_EACH_EDGE (e, ei, bb->succs) - inserted |= compensate_edge (e); - } - return inserted; -} - -/* Select the better of two edges E1 and E2 to use to determine the - stack layout for their shared destination basic block. This is - typically the more frequently executed. The edge E1 may be NULL - (in which case E2 is returned), but E2 is always non-NULL. */ - -static edge -better_edge (edge e1, edge e2) -{ - if (!e1) - return e2; - - if (EDGE_FREQUENCY (e1) > EDGE_FREQUENCY (e2)) - return e1; - if (EDGE_FREQUENCY (e1) < EDGE_FREQUENCY (e2)) - return e2; - - if (e1->count > e2->count) - return e1; - if (e1->count < e2->count) - return e2; - - /* Prefer critical edges to minimize inserting compensation code on - critical edges. */ - - if (EDGE_CRITICAL_P (e1) != EDGE_CRITICAL_P (e2)) - return EDGE_CRITICAL_P (e1) ? e1 : e2; - - /* Avoid non-deterministic behavior. */ - return (e1->src->index < e2->src->index) ? e1 : e2; -} - -/* Convert stack register references in one block. */ - -static void -convert_regs_1 (basic_block block) -{ - struct stack_def regstack; - block_info bi = BLOCK_INFO (block); - int reg; - rtx insn, next; - bool control_flow_insn_deleted = false; - - any_malformed_asm = false; - - /* Choose an initial stack layout, if one hasn't already been chosen. */ - if (bi->stack_in.top == -2) - { - edge e, beste = NULL; - edge_iterator ei; - - /* Select the best incoming edge (typically the most frequent) to - use as a template for this basic block. */ - FOR_EACH_EDGE (e, ei, block->preds) - if (BLOCK_INFO (e->src)->done) - beste = better_edge (beste, e); - - if (beste) - propagate_stack (beste); - else - { - /* No predecessors. Create an arbitrary input stack. */ - bi->stack_in.top = -1; - for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg) - if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg)) - bi->stack_in.reg[++bi->stack_in.top] = reg; - } - } - - if (dump_file) - { - fprintf (dump_file, "\nBasic block %d\nInput stack: ", block->index); - print_stack (dump_file, &bi->stack_in); - } - - /* Process all insns in this block. Keep track of NEXT so that we - don't process insns emitted while substituting in INSN. */ - current_block = block; - next = BB_HEAD (block); - regstack = bi->stack_in; - starting_stack_p = true; - - do - { - insn = next; - next = NEXT_INSN (insn); - - /* Ensure we have not missed a block boundary. */ - gcc_assert (next); - if (insn == BB_END (block)) - next = NULL; - - /* Don't bother processing unless there is a stack reg - mentioned or if it's a CALL_INSN. */ - if (stack_regs_mentioned (insn) - || CALL_P (insn)) - { - if (dump_file) - { - fprintf (dump_file, " insn %d input stack: ", - INSN_UID (insn)); - print_stack (dump_file, ®stack); - } - control_flow_insn_deleted |= subst_stack_regs (insn, ®stack); - starting_stack_p = false; - } - } - while (next); - - if (dump_file) - { - fprintf (dump_file, "Expected live registers ["); - for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; ++reg) - if (TEST_HARD_REG_BIT (bi->out_reg_set, reg)) - fprintf (dump_file, " %d", reg); - fprintf (dump_file, " ]\nOutput stack: "); - print_stack (dump_file, ®stack); - } - - insn = BB_END (block); - if (JUMP_P (insn)) - insn = PREV_INSN (insn); - - /* If the function is declared to return a value, but it returns one - in only some cases, some registers might come live here. Emit - necessary moves for them. */ - - for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; ++reg) - { - if (TEST_HARD_REG_BIT (bi->out_reg_set, reg) - && ! TEST_HARD_REG_BIT (regstack.reg_set, reg)) - { - rtx set; - - if (dump_file) - fprintf (dump_file, "Emitting insn initializing reg %d\n", reg); - - set = gen_rtx_SET (VOIDmode, FP_MODE_REG (reg, SFmode), not_a_num); - insn = emit_insn_after (set, insn); - control_flow_insn_deleted |= subst_stack_regs (insn, ®stack); - } - } - - /* Amongst the insns possibly deleted during the substitution process above, - might have been the only trapping insn in the block. We purge the now - possibly dead EH edges here to avoid an ICE from fixup_abnormal_edges, - called at the end of convert_regs. The order in which we process the - blocks ensures that we never delete an already processed edge. - - Note that, at this point, the CFG may have been damaged by the emission - of instructions after an abnormal call, which moves the basic block end - (and is the reason why we call fixup_abnormal_edges later). So we must - be sure that the trapping insn has been deleted before trying to purge - dead edges, otherwise we risk purging valid edges. - - ??? We are normally supposed not to delete trapping insns, so we pretend - that the insns deleted above don't actually trap. It would have been - better to detect this earlier and avoid creating the EH edge in the first - place, still, but we don't have enough information at that time. */ - - if (control_flow_insn_deleted) - purge_dead_edges (block); - - /* Something failed if the stack lives don't match. If we had malformed - asms, we zapped the instruction itself, but that didn't produce the - same pattern of register kills as before. */ - GO_IF_HARD_REG_EQUAL (regstack.reg_set, bi->out_reg_set, win); - gcc_assert (any_malformed_asm); - win: - bi->stack_out = regstack; - bi->done = true; -} - -/* Convert registers in all blocks reachable from BLOCK. */ - -static void -convert_regs_2 (basic_block block) -{ - basic_block *stack, *sp; - - /* We process the blocks in a top-down manner, in a way such that one block - is only processed after all its predecessors. The number of predecessors - of every block has already been computed. */ - - stack = XNEWVEC (basic_block, n_basic_blocks); - sp = stack; - - *sp++ = block; - - do - { - edge e; - edge_iterator ei; - - block = *--sp; - - /* Processing BLOCK is achieved by convert_regs_1, which may purge - some dead EH outgoing edge after the deletion of the trapping - insn inside the block. Since the number of predecessors of - BLOCK's successors was computed based on the initial edge set, - we check the necessity to process some of these successors - before such an edge deletion may happen. However, there is - a pitfall: if BLOCK is the only predecessor of a successor and - the edge between them happens to be deleted, the successor - becomes unreachable and should not be processed. The problem - is that there is no way to preventively detect this case so we - stack the successor in all cases and hand over the task of - fixing up the discrepancy to convert_regs_1. */ - - FOR_EACH_EDGE (e, ei, block->succs) - if (! (e->flags & EDGE_DFS_BACK)) - { - BLOCK_INFO (e->dest)->predecessors--; - if (!BLOCK_INFO (e->dest)->predecessors) - *sp++ = e->dest; - } - - convert_regs_1 (block); - } - while (sp != stack); - - free (stack); -} - -/* Traverse all basic blocks in a function, converting the register - references in each insn from the "flat" register file that gcc uses, - to the stack-like registers the 387 uses. */ - -static void -convert_regs (void) -{ - int inserted; - basic_block b; - edge e; - edge_iterator ei; - - /* Initialize uninitialized registers on function entry. */ - inserted = convert_regs_entry (); - - /* Construct the desired stack for function exit. */ - convert_regs_exit (); - BLOCK_INFO (EXIT_BLOCK_PTR)->done = 1; - - /* ??? Future: process inner loops first, and give them arbitrary - initial stacks which emit_swap_insn can modify. This ought to - prevent double fxch that often appears at the head of a loop. */ - - /* Process all blocks reachable from all entry points. */ - FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) - convert_regs_2 (e->dest); - - /* ??? Process all unreachable blocks. Though there's no excuse - for keeping these even when not optimizing. */ - FOR_EACH_BB (b) - { - block_info bi = BLOCK_INFO (b); - - if (! bi->done) - convert_regs_2 (b); - } - - inserted |= compensate_edges (); - - clear_aux_for_blocks (); - - fixup_abnormal_edges (); - if (inserted) - commit_edge_insertions (); - - if (dump_file) - fputc ('\n', dump_file); -} - -/* Convert register usage from "flat" register file usage to a "stack - register file. FILE is the dump file, if used. - - Construct a CFG and run life analysis. Then convert each insn one - by one. Run a last cleanup_cfg pass, if optimizing, to eliminate - code duplication created when the converter inserts pop insns on - the edges. */ - -static bool -reg_to_stack (void) -{ - basic_block bb; - int i; - int max_uid; - - /* Clean up previous run. */ - if (stack_regs_mentioned_data != NULL) - VEC_free (char, heap, stack_regs_mentioned_data); - - /* See if there is something to do. Flow analysis is quite - expensive so we might save some compilation time. */ - for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++) - if (regs_ever_live[i]) - break; - if (i > LAST_STACK_REG) - return false; - - /* Ok, floating point instructions exist. If not optimizing, - build the CFG and run life analysis. - Also need to rebuild life when superblock scheduling is done - as it don't update liveness yet. */ - if (!optimize - || ((flag_sched2_use_superblocks || flag_sched2_use_traces) - && flag_schedule_insns_after_reload)) - { - count_or_remove_death_notes (NULL, 1); - life_analysis (PROP_DEATH_NOTES); - } - mark_dfs_back_edges (); - - /* Set up block info for each basic block. */ - alloc_aux_for_blocks (sizeof (struct block_info_def)); - FOR_EACH_BB (bb) - { - block_info bi = BLOCK_INFO (bb); - edge_iterator ei; - edge e; - int reg; - - FOR_EACH_EDGE (e, ei, bb->preds) - if (!(e->flags & EDGE_DFS_BACK) - && e->src != ENTRY_BLOCK_PTR) - bi->predecessors++; - - /* Set current register status at last instruction `uninitialized'. */ - bi->stack_in.top = -2; - - /* Copy live_at_end and live_at_start into temporaries. */ - for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; reg++) - { - if (REGNO_REG_SET_P (bb->il.rtl->global_live_at_end, reg)) - SET_HARD_REG_BIT (bi->out_reg_set, reg); - if (REGNO_REG_SET_P (bb->il.rtl->global_live_at_start, reg)) - SET_HARD_REG_BIT (bi->stack_in.reg_set, reg); - } - } - - /* Create the replacement registers up front. */ - for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++) - { - enum machine_mode mode; - for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); - mode != VOIDmode; - mode = GET_MODE_WIDER_MODE (mode)) - FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i); - for (mode = GET_CLASS_NARROWEST_MODE (MODE_COMPLEX_FLOAT); - mode != VOIDmode; - mode = GET_MODE_WIDER_MODE (mode)) - FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i); - } - - ix86_flags_rtx = gen_rtx_REG (CCmode, FLAGS_REG); - - /* A QNaN for initializing uninitialized variables. - - ??? We can't load from constant memory in PIC mode, because - we're inserting these instructions before the prologue and - the PIC register hasn't been set up. In that case, fall back - on zero, which we can get from `ldz'. */ - - if (flag_pic) - not_a_num = CONST0_RTX (SFmode); - else - { - not_a_num = gen_lowpart (SFmode, GEN_INT (0x7fc00000)); - not_a_num = force_const_mem (SFmode, not_a_num); - } - - /* Allocate a cache for stack_regs_mentioned. */ - max_uid = get_max_uid (); - stack_regs_mentioned_data = VEC_alloc (char, heap, max_uid + 1); - memset (VEC_address (char, stack_regs_mentioned_data), - 0, sizeof (char) * max_uid + 1); - - convert_regs (); - - free_aux_for_blocks (); - return true; -} -#endif /* STACK_REGS */ - -static bool -gate_handle_stack_regs (void) -{ -#ifdef STACK_REGS - return 1; -#else - return 0; -#endif -} - -/* Convert register usage from flat register file usage to a stack - register file. */ -static unsigned int -rest_of_handle_stack_regs (void) -{ -#ifdef STACK_REGS - if (reg_to_stack () && optimize) - { - regstack_completed = 1; - if (cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_POST_REGSTACK - | (flag_crossjumping ? CLEANUP_CROSSJUMP : 0)) - && (flag_reorder_blocks || flag_reorder_blocks_and_partition)) - { - reorder_basic_blocks (0); - cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_POST_REGSTACK); - } - } - else - regstack_completed = 1; -#endif - return 0; -} - -struct tree_opt_pass pass_stack_regs = -{ - "stack", /* name */ - gate_handle_stack_regs, /* gate */ - rest_of_handle_stack_regs, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - TV_REG_STACK, /* tv_id */ - 0, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_dump_func | - TODO_ggc_collect, /* todo_flags_finish */ - 'k' /* letter */ -}; |