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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/jump.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/jump.c | 2023 |
1 files changed, 2023 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/jump.c b/gcc-4.2.1-5666.3/gcc/jump.c new file mode 100644 index 000000000..4a4ad40af --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/jump.c @@ -0,0 +1,2023 @@ +/* Optimize jump instructions, for GNU compiler. + Copyright (C) 1987, 1988, 1989, 1991, 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 is the pathetic reminder of old fame of the jump-optimization pass + of the compiler. Now it contains basically a set of utility functions to + operate with jumps. + + Each CODE_LABEL has a count of the times it is used + stored in the LABEL_NUSES internal field, and each JUMP_INSN + has one label that it refers to stored in the + JUMP_LABEL internal field. With this we can detect labels that + become unused because of the deletion of all the jumps that + formerly used them. The JUMP_LABEL info is sometimes looked + at by later passes. + + The subroutines redirect_jump and invert_jump are used + from other passes as well. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "rtl.h" +#include "tm_p.h" +#include "flags.h" +#include "hard-reg-set.h" +#include "regs.h" +#include "insn-config.h" +#include "insn-attr.h" +#include "recog.h" +#include "function.h" +#include "expr.h" +#include "real.h" +#include "except.h" +#include "diagnostic.h" +#include "toplev.h" +#include "reload.h" +#include "predict.h" +#include "timevar.h" +#include "tree-pass.h" +#include "target.h" + +/* Optimize jump y; x: ... y: jumpif... x? + Don't know if it is worth bothering with. */ +/* Optimize two cases of conditional jump to conditional jump? + This can never delete any instruction or make anything dead, + or even change what is live at any point. + So perhaps let combiner do it. */ + +static void init_label_info (rtx); +static void mark_all_labels (rtx); +static void delete_computation (rtx); +static void redirect_exp_1 (rtx *, rtx, rtx, rtx); +static int invert_exp_1 (rtx, rtx); +static int returnjump_p_1 (rtx *, void *); +static void delete_prior_computation (rtx, rtx); + +/* Alternate entry into the jump optimizer. This entry point only rebuilds + the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping + instructions. */ +void +rebuild_jump_labels (rtx f) +{ + rtx insn; + + timevar_push (TV_REBUILD_JUMP); + init_label_info (f); + mark_all_labels (f); + + /* Keep track of labels used from static data; we don't track them + closely enough to delete them here, so make sure their reference + count doesn't drop to zero. */ + + for (insn = forced_labels; insn; insn = XEXP (insn, 1)) + if (LABEL_P (XEXP (insn, 0))) + LABEL_NUSES (XEXP (insn, 0))++; + timevar_pop (TV_REBUILD_JUMP); +} + +/* Some old code expects exactly one BARRIER as the NEXT_INSN of a + non-fallthru insn. This is not generally true, as multiple barriers + may have crept in, or the BARRIER may be separated from the last + real insn by one or more NOTEs. + + This simple pass moves barriers and removes duplicates so that the + old code is happy. + */ +unsigned int +cleanup_barriers (void) +{ + rtx insn, next, prev; + for (insn = get_insns (); insn; insn = next) + { + next = NEXT_INSN (insn); + if (BARRIER_P (insn)) + { + prev = prev_nonnote_insn (insn); + if (BARRIER_P (prev)) + delete_insn (insn); + else if (prev != PREV_INSN (insn)) + reorder_insns (insn, insn, prev); + } + } + return 0; +} + +struct tree_opt_pass pass_cleanup_barriers = +{ + "barriers", /* name */ + NULL, /* gate */ + cleanup_barriers, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + 0, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + +unsigned int +purge_line_number_notes (void) +{ + rtx last_note = 0; + rtx insn; + /* Delete extraneous line number notes. + Note that two consecutive notes for different lines are not really + extraneous. There should be some indication where that line belonged, + even if it became empty. */ + + for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) + if (NOTE_P (insn)) + { + if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) + /* Any previous line note was for the prologue; gdb wants a new + note after the prologue even if it is for the same line. */ + last_note = NULL_RTX; + else if (NOTE_LINE_NUMBER (insn) >= 0) + { + /* Delete this note if it is identical to previous note. */ + if (last_note +#ifdef USE_MAPPED_LOCATION + && NOTE_SOURCE_LOCATION (insn) == NOTE_SOURCE_LOCATION (last_note) +#else + && NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note) + && NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note) +#endif +) + { + delete_related_insns (insn); + continue; + } + + last_note = insn; + } + } + return 0; +} + +struct tree_opt_pass pass_purge_lineno_notes = +{ + "elnotes", /* name */ + NULL, /* gate */ + purge_line_number_notes, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + 0, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + + +/* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL + notes whose labels don't occur in the insn any more. Returns the + largest INSN_UID found. */ +static void +init_label_info (rtx f) +{ + rtx insn; + + for (insn = f; insn; insn = NEXT_INSN (insn)) + if (LABEL_P (insn)) + LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0); + else if (JUMP_P (insn)) + JUMP_LABEL (insn) = 0; + else if (NONJUMP_INSN_P (insn) || CALL_P (insn)) + { + rtx note, next; + + for (note = REG_NOTES (insn); note; note = next) + { + next = XEXP (note, 1); + if (REG_NOTE_KIND (note) == REG_LABEL + && ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) + remove_note (insn, note); + } + } +} + +/* Mark the label each jump jumps to. + Combine consecutive labels, and count uses of labels. */ + +static void +mark_all_labels (rtx f) +{ + rtx insn; + + for (insn = f; insn; insn = NEXT_INSN (insn)) + if (INSN_P (insn)) + { + mark_jump_label (PATTERN (insn), insn, 0); + if (! INSN_DELETED_P (insn) && JUMP_P (insn)) + { + /* When we know the LABEL_REF contained in a REG used in + an indirect jump, we'll have a REG_LABEL note so that + flow can tell where it's going. */ + if (JUMP_LABEL (insn) == 0) + { + rtx label_note = find_reg_note (insn, REG_LABEL, NULL_RTX); + if (label_note) + { + /* But a LABEL_REF around the REG_LABEL note, so + that we can canonicalize it. */ + rtx label_ref = gen_rtx_LABEL_REF (Pmode, + XEXP (label_note, 0)); + + mark_jump_label (label_ref, insn, 0); + XEXP (label_note, 0) = XEXP (label_ref, 0); + JUMP_LABEL (insn) = XEXP (label_note, 0); + } + } + } + } +} + +/* Move all block-beg, block-end and loop-beg notes between START and END out + before START. START and END may be such notes. Returns the values of the + new starting and ending insns, which may be different if the original ones + were such notes. Return true if there were only such notes and no real + instructions. */ + +bool +squeeze_notes (rtx* startp, rtx* endp) +{ + rtx start = *startp; + rtx end = *endp; + + rtx insn; + rtx next; + rtx last = NULL; + rtx past_end = NEXT_INSN (end); + + for (insn = start; insn != past_end; insn = next) + { + next = NEXT_INSN (insn); + if (NOTE_P (insn) + && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END + || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)) + { + /* BLOCK_BEG or BLOCK_END notes only exist in the `final' pass. */ + gcc_assert (NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_BEG + && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_END); + + if (insn == start) + start = next; + else + { + rtx prev = PREV_INSN (insn); + PREV_INSN (insn) = PREV_INSN (start); + NEXT_INSN (insn) = start; + NEXT_INSN (PREV_INSN (insn)) = insn; + PREV_INSN (NEXT_INSN (insn)) = insn; + NEXT_INSN (prev) = next; + PREV_INSN (next) = prev; + } + } + else + last = insn; + } + + /* There were no real instructions. */ + if (start == past_end) + return true; + + end = last; + + *startp = start; + *endp = end; + return false; +} + +/* Return the label before INSN, or put a new label there. */ + +rtx +get_label_before (rtx insn) +{ + rtx label; + + /* Find an existing label at this point + or make a new one if there is none. */ + label = prev_nonnote_insn (insn); + + if (label == 0 || !LABEL_P (label)) + { + rtx prev = PREV_INSN (insn); + + label = gen_label_rtx (); + emit_label_after (label, prev); + LABEL_NUSES (label) = 0; + } + return label; +} + +/* Return the label after INSN, or put a new label there. */ + +rtx +get_label_after (rtx insn) +{ + rtx label; + + /* Find an existing label at this point + or make a new one if there is none. */ + label = next_nonnote_insn (insn); + + if (label == 0 || !LABEL_P (label)) + { + label = gen_label_rtx (); + emit_label_after (label, insn); + LABEL_NUSES (label) = 0; + } + return label; +} + +/* Given a comparison (CODE ARG0 ARG1), inside an insn, INSN, return a code + of reversed comparison if it is possible to do so. Otherwise return UNKNOWN. + UNKNOWN may be returned in case we are having CC_MODE compare and we don't + know whether it's source is floating point or integer comparison. Machine + description should define REVERSIBLE_CC_MODE and REVERSE_CONDITION macros + to help this function avoid overhead in these cases. */ +enum rtx_code +reversed_comparison_code_parts (enum rtx_code code, rtx arg0, rtx arg1, rtx insn) +{ + enum machine_mode mode; + + /* If this is not actually a comparison, we can't reverse it. */ + if (GET_RTX_CLASS (code) != RTX_COMPARE + && GET_RTX_CLASS (code) != RTX_COMM_COMPARE) + return UNKNOWN; + + mode = GET_MODE (arg0); + if (mode == VOIDmode) + mode = GET_MODE (arg1); + + /* First see if machine description supplies us way to reverse the + comparison. Give it priority over everything else to allow + machine description to do tricks. */ + if (GET_MODE_CLASS (mode) == MODE_CC + && REVERSIBLE_CC_MODE (mode)) + { +#ifdef REVERSE_CONDITION + return REVERSE_CONDITION (code, mode); +#endif + return reverse_condition (code); + } + + /* Try a few special cases based on the comparison code. */ + switch (code) + { + case GEU: + case GTU: + case LEU: + case LTU: + case NE: + case EQ: + /* It is always safe to reverse EQ and NE, even for the floating + point. Similarly the unsigned comparisons are never used for + floating point so we can reverse them in the default way. */ + return reverse_condition (code); + case ORDERED: + case UNORDERED: + case LTGT: + case UNEQ: + /* In case we already see unordered comparison, we can be sure to + be dealing with floating point so we don't need any more tests. */ + return reverse_condition_maybe_unordered (code); + case UNLT: + case UNLE: + case UNGT: + case UNGE: + /* We don't have safe way to reverse these yet. */ + return UNKNOWN; + default: + break; + } + + if (GET_MODE_CLASS (mode) == MODE_CC || CC0_P (arg0)) + { + rtx prev; + /* Try to search for the comparison to determine the real mode. + This code is expensive, but with sane machine description it + will be never used, since REVERSIBLE_CC_MODE will return true + in all cases. */ + if (! insn) + return UNKNOWN; + + for (prev = prev_nonnote_insn (insn); + prev != 0 && !LABEL_P (prev); + prev = prev_nonnote_insn (prev)) + { + rtx set = set_of (arg0, prev); + if (set && GET_CODE (set) == SET + && rtx_equal_p (SET_DEST (set), arg0)) + { + rtx src = SET_SRC (set); + + if (GET_CODE (src) == COMPARE) + { + rtx comparison = src; + arg0 = XEXP (src, 0); + mode = GET_MODE (arg0); + if (mode == VOIDmode) + mode = GET_MODE (XEXP (comparison, 1)); + break; + } + /* We can get past reg-reg moves. This may be useful for model + of i387 comparisons that first move flag registers around. */ + if (REG_P (src)) + { + arg0 = src; + continue; + } + } + /* If register is clobbered in some ununderstandable way, + give up. */ + if (set) + return UNKNOWN; + } + } + + /* Test for an integer condition, or a floating-point comparison + in which NaNs can be ignored. */ + if (GET_CODE (arg0) == CONST_INT + || (GET_MODE (arg0) != VOIDmode + && GET_MODE_CLASS (mode) != MODE_CC + && !HONOR_NANS (mode))) + return reverse_condition (code); + + return UNKNOWN; +} + +/* A wrapper around the previous function to take COMPARISON as rtx + expression. This simplifies many callers. */ +enum rtx_code +reversed_comparison_code (rtx comparison, rtx insn) +{ + if (!COMPARISON_P (comparison)) + return UNKNOWN; + return reversed_comparison_code_parts (GET_CODE (comparison), + XEXP (comparison, 0), + XEXP (comparison, 1), insn); +} + +/* Return comparison with reversed code of EXP. + Return NULL_RTX in case we fail to do the reversal. */ +rtx +reversed_comparison (rtx exp, enum machine_mode mode) +{ + enum rtx_code reversed_code = reversed_comparison_code (exp, NULL_RTX); + if (reversed_code == UNKNOWN) + return NULL_RTX; + else + return simplify_gen_relational (reversed_code, mode, VOIDmode, + XEXP (exp, 0), XEXP (exp, 1)); +} + + +/* Given an rtx-code for a comparison, return the code for the negated + comparison. If no such code exists, return UNKNOWN. + + WATCH OUT! reverse_condition is not safe to use on a jump that might + be acting on the results of an IEEE floating point comparison, because + of the special treatment of non-signaling nans in comparisons. + Use reversed_comparison_code instead. */ + +enum rtx_code +reverse_condition (enum rtx_code code) +{ + switch (code) + { + case EQ: + return NE; + case NE: + return EQ; + case GT: + return LE; + case GE: + return LT; + case LT: + return GE; + case LE: + return GT; + case GTU: + return LEU; + case GEU: + return LTU; + case LTU: + return GEU; + case LEU: + return GTU; + case UNORDERED: + return ORDERED; + case ORDERED: + return UNORDERED; + + case UNLT: + case UNLE: + case UNGT: + case UNGE: + case UNEQ: + case LTGT: + return UNKNOWN; + + default: + gcc_unreachable (); + } +} + +/* Similar, but we're allowed to generate unordered comparisons, which + makes it safe for IEEE floating-point. Of course, we have to recognize + that the target will support them too... */ + +enum rtx_code +reverse_condition_maybe_unordered (enum rtx_code code) +{ + switch (code) + { + case EQ: + return NE; + case NE: + return EQ; + case GT: + return UNLE; + case GE: + return UNLT; + case LT: + return UNGE; + case LE: + return UNGT; + case LTGT: + return UNEQ; + case UNORDERED: + return ORDERED; + case ORDERED: + return UNORDERED; + case UNLT: + return GE; + case UNLE: + return GT; + case UNGT: + return LE; + case UNGE: + return LT; + case UNEQ: + return LTGT; + + default: + gcc_unreachable (); + } +} + +/* Similar, but return the code when two operands of a comparison are swapped. + This IS safe for IEEE floating-point. */ + +enum rtx_code +swap_condition (enum rtx_code code) +{ + switch (code) + { + case EQ: + case NE: + case UNORDERED: + case ORDERED: + case UNEQ: + case LTGT: + return code; + + case GT: + return LT; + case GE: + return LE; + case LT: + return GT; + case LE: + return GE; + case GTU: + return LTU; + case GEU: + return LEU; + case LTU: + return GTU; + case LEU: + return GEU; + case UNLT: + return UNGT; + case UNLE: + return UNGE; + case UNGT: + return UNLT; + case UNGE: + return UNLE; + + default: + gcc_unreachable (); + } +} + +/* Given a comparison CODE, return the corresponding unsigned comparison. + If CODE is an equality comparison or already an unsigned comparison, + CODE is returned. */ + +enum rtx_code +unsigned_condition (enum rtx_code code) +{ + switch (code) + { + case EQ: + case NE: + case GTU: + case GEU: + case LTU: + case LEU: + return code; + + case GT: + return GTU; + case GE: + return GEU; + case LT: + return LTU; + case LE: + return LEU; + + default: + gcc_unreachable (); + } +} + +/* Similarly, return the signed version of a comparison. */ + +enum rtx_code +signed_condition (enum rtx_code code) +{ + switch (code) + { + case EQ: + case NE: + case GT: + case GE: + case LT: + case LE: + return code; + + case GTU: + return GT; + case GEU: + return GE; + case LTU: + return LT; + case LEU: + return LE; + + default: + gcc_unreachable (); + } +} + +/* Return nonzero if CODE1 is more strict than CODE2, i.e., if the + truth of CODE1 implies the truth of CODE2. */ + +int +comparison_dominates_p (enum rtx_code code1, enum rtx_code code2) +{ + /* UNKNOWN comparison codes can happen as a result of trying to revert + comparison codes. + They can't match anything, so we have to reject them here. */ + if (code1 == UNKNOWN || code2 == UNKNOWN) + return 0; + + if (code1 == code2) + return 1; + + switch (code1) + { + case UNEQ: + if (code2 == UNLE || code2 == UNGE) + return 1; + break; + + case EQ: + if (code2 == LE || code2 == LEU || code2 == GE || code2 == GEU + || code2 == ORDERED) + return 1; + break; + + case UNLT: + if (code2 == UNLE || code2 == NE) + return 1; + break; + + case LT: + if (code2 == LE || code2 == NE || code2 == ORDERED || code2 == LTGT) + return 1; + break; + + case UNGT: + if (code2 == UNGE || code2 == NE) + return 1; + break; + + case GT: + if (code2 == GE || code2 == NE || code2 == ORDERED || code2 == LTGT) + return 1; + break; + + case GE: + case LE: + if (code2 == ORDERED) + return 1; + break; + + case LTGT: + if (code2 == NE || code2 == ORDERED) + return 1; + break; + + case LTU: + if (code2 == LEU || code2 == NE) + return 1; + break; + + case GTU: + if (code2 == GEU || code2 == NE) + return 1; + break; + + case UNORDERED: + if (code2 == NE || code2 == UNEQ || code2 == UNLE || code2 == UNLT + || code2 == UNGE || code2 == UNGT) + return 1; + break; + + default: + break; + } + + return 0; +} + +/* Return 1 if INSN is an unconditional jump and nothing else. */ + +int +simplejump_p (rtx insn) +{ + return (JUMP_P (insn) + && GET_CODE (PATTERN (insn)) == SET + && GET_CODE (SET_DEST (PATTERN (insn))) == PC + && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF); +} + +/* Return nonzero if INSN is a (possibly) conditional jump + and nothing more. + + Use of this function is deprecated, since we need to support combined + branch and compare insns. Use any_condjump_p instead whenever possible. */ + +int +condjump_p (rtx insn) +{ + rtx x = PATTERN (insn); + + if (GET_CODE (x) != SET + || GET_CODE (SET_DEST (x)) != PC) + return 0; + + x = SET_SRC (x); + if (GET_CODE (x) == LABEL_REF) + return 1; + else + return (GET_CODE (x) == IF_THEN_ELSE + && ((GET_CODE (XEXP (x, 2)) == PC + && (GET_CODE (XEXP (x, 1)) == LABEL_REF + || GET_CODE (XEXP (x, 1)) == RETURN)) + || (GET_CODE (XEXP (x, 1)) == PC + && (GET_CODE (XEXP (x, 2)) == LABEL_REF + || GET_CODE (XEXP (x, 2)) == RETURN)))); +} + +/* Return nonzero if INSN is a (possibly) conditional jump inside a + PARALLEL. + + Use this function is deprecated, since we need to support combined + branch and compare insns. Use any_condjump_p instead whenever possible. */ + +int +condjump_in_parallel_p (rtx insn) +{ + rtx x = PATTERN (insn); + + if (GET_CODE (x) != PARALLEL) + return 0; + else + x = XVECEXP (x, 0, 0); + + if (GET_CODE (x) != SET) + return 0; + if (GET_CODE (SET_DEST (x)) != PC) + return 0; + if (GET_CODE (SET_SRC (x)) == LABEL_REF) + return 1; + if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) + return 0; + if (XEXP (SET_SRC (x), 2) == pc_rtx + && (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF + || GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN)) + return 1; + if (XEXP (SET_SRC (x), 1) == pc_rtx + && (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF + || GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN)) + return 1; + return 0; +} + +/* Return set of PC, otherwise NULL. */ + +rtx +pc_set (rtx insn) +{ + rtx pat; + if (!JUMP_P (insn)) + return NULL_RTX; + pat = PATTERN (insn); + + /* The set is allowed to appear either as the insn pattern or + the first set in a PARALLEL. */ + if (GET_CODE (pat) == PARALLEL) + pat = XVECEXP (pat, 0, 0); + if (GET_CODE (pat) == SET && GET_CODE (SET_DEST (pat)) == PC) + return pat; + + return NULL_RTX; +} + +/* Return true when insn is an unconditional direct jump, + possibly bundled inside a PARALLEL. */ + +int +any_uncondjump_p (rtx insn) +{ + rtx x = pc_set (insn); + if (!x) + return 0; + if (GET_CODE (SET_SRC (x)) != LABEL_REF) + return 0; + if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX)) + return 0; + return 1; +} + +/* Return true when insn is a conditional jump. This function works for + instructions containing PC sets in PARALLELs. The instruction may have + various other effects so before removing the jump you must verify + onlyjump_p. + + Note that unlike condjump_p it returns false for unconditional jumps. */ + +int +any_condjump_p (rtx insn) +{ + rtx x = pc_set (insn); + enum rtx_code a, b; + + if (!x) + return 0; + if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) + return 0; + + a = GET_CODE (XEXP (SET_SRC (x), 1)); + b = GET_CODE (XEXP (SET_SRC (x), 2)); + + return ((b == PC && (a == LABEL_REF || a == RETURN)) + || (a == PC && (b == LABEL_REF || b == RETURN))); +} + +/* Return the label of a conditional jump. */ + +rtx +condjump_label (rtx insn) +{ + rtx x = pc_set (insn); + + if (!x) + return NULL_RTX; + x = SET_SRC (x); + if (GET_CODE (x) == LABEL_REF) + return x; + if (GET_CODE (x) != IF_THEN_ELSE) + return NULL_RTX; + if (XEXP (x, 2) == pc_rtx && GET_CODE (XEXP (x, 1)) == LABEL_REF) + return XEXP (x, 1); + if (XEXP (x, 1) == pc_rtx && GET_CODE (XEXP (x, 2)) == LABEL_REF) + return XEXP (x, 2); + return NULL_RTX; +} + +/* Return true if INSN is a (possibly conditional) return insn. */ + +static int +returnjump_p_1 (rtx *loc, void *data ATTRIBUTE_UNUSED) +{ + rtx x = *loc; + + return x && (GET_CODE (x) == RETURN + || (GET_CODE (x) == SET && SET_IS_RETURN_P (x))); +} + +int +returnjump_p (rtx insn) +{ + if (!JUMP_P (insn)) + return 0; + return for_each_rtx (&PATTERN (insn), returnjump_p_1, NULL); +} + +/* Return true if INSN is a jump that only transfers control and + nothing more. */ + +int +onlyjump_p (rtx insn) +{ + rtx set; + + if (!JUMP_P (insn)) + return 0; + + set = single_set (insn); + if (set == NULL) + return 0; + if (GET_CODE (SET_DEST (set)) != PC) + return 0; + if (side_effects_p (SET_SRC (set))) + return 0; + + return 1; +} + +#ifdef HAVE_cc0 + +/* Return nonzero if X is an RTX that only sets the condition codes + and has no side effects. */ + +int +only_sets_cc0_p (rtx x) +{ + if (! x) + return 0; + + if (INSN_P (x)) + x = PATTERN (x); + + return sets_cc0_p (x) == 1 && ! side_effects_p (x); +} + +/* Return 1 if X is an RTX that does nothing but set the condition codes + and CLOBBER or USE registers. + Return -1 if X does explicitly set the condition codes, + but also does other things. */ + +int +sets_cc0_p (rtx x) +{ + if (! x) + return 0; + + if (INSN_P (x)) + x = PATTERN (x); + + if (GET_CODE (x) == SET && SET_DEST (x) == cc0_rtx) + return 1; + if (GET_CODE (x) == PARALLEL) + { + int i; + int sets_cc0 = 0; + int other_things = 0; + for (i = XVECLEN (x, 0) - 1; i >= 0; i--) + { + if (GET_CODE (XVECEXP (x, 0, i)) == SET + && SET_DEST (XVECEXP (x, 0, i)) == cc0_rtx) + sets_cc0 = 1; + else if (GET_CODE (XVECEXP (x, 0, i)) == SET) + other_things = 1; + } + return ! sets_cc0 ? 0 : other_things ? -1 : 1; + } + return 0; +} +#endif + +/* Follow any unconditional jump at LABEL; + return the ultimate label reached by any such chain of jumps. + Return null if the chain ultimately leads to a return instruction. + If LABEL is not followed by a jump, return LABEL. + If the chain loops or we can't find end, return LABEL, + since that tells caller to avoid changing the insn. + + If RELOAD_COMPLETED is 0, we do not chain across a USE or CLOBBER. */ + +rtx +follow_jumps (rtx label) +{ + rtx insn; + rtx next; + rtx value = label; + int depth; + + for (depth = 0; + (depth < 10 + && (insn = next_active_insn (value)) != 0 + && JUMP_P (insn) + && ((JUMP_LABEL (insn) != 0 && any_uncondjump_p (insn) + && onlyjump_p (insn)) + || GET_CODE (PATTERN (insn)) == RETURN) + && (next = NEXT_INSN (insn)) + && BARRIER_P (next)); + depth++) + { + rtx tem; + if (!reload_completed && flag_test_coverage) + { + /* ??? Optional. Disables some optimizations, but makes + gcov output more accurate with -O. */ + for (tem = value; tem != insn; tem = NEXT_INSN (tem)) + if (NOTE_P (tem) && NOTE_LINE_NUMBER (tem) > 0) + return value; + } + + /* If we have found a cycle, make the insn jump to itself. */ + if (JUMP_LABEL (insn) == label) + return label; + + tem = next_active_insn (JUMP_LABEL (insn)); + if (tem && (GET_CODE (PATTERN (tem)) == ADDR_VEC + || GET_CODE (PATTERN (tem)) == ADDR_DIFF_VEC)) + break; + + value = JUMP_LABEL (insn); + } + if (depth == 10) + return label; + return value; +} + + +/* Find all CODE_LABELs referred to in X, and increment their use counts. + If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced + in INSN, then store one of them in JUMP_LABEL (INSN). + If INSN is an INSN or a CALL_INSN and there is at least one CODE_LABEL + referenced in INSN, add a REG_LABEL note containing that label to INSN. + Also, when there are consecutive labels, canonicalize on the last of them. + + Note that two labels separated by a loop-beginning note + must be kept distinct if we have not yet done loop-optimization, + because the gap between them is where loop-optimize + will want to move invariant code to. CROSS_JUMP tells us + that loop-optimization is done with. */ + +void +mark_jump_label (rtx x, rtx insn, int in_mem) +{ + RTX_CODE code = GET_CODE (x); + int i; + const char *fmt; + + switch (code) + { + case PC: + case CC0: + case REG: + case CONST_INT: + case CONST_DOUBLE: + case CLOBBER: + case CALL: + return; + + case MEM: + in_mem = 1; + break; + + case SYMBOL_REF: + if (!in_mem) + return; + + /* If this is a constant-pool reference, see if it is a label. */ + if (CONSTANT_POOL_ADDRESS_P (x)) + mark_jump_label (get_pool_constant (x), insn, in_mem); + break; + + case LABEL_REF: + { + rtx label = XEXP (x, 0); + + /* Ignore remaining references to unreachable labels that + have been deleted. */ + if (NOTE_P (label) + && NOTE_LINE_NUMBER (label) == NOTE_INSN_DELETED_LABEL) + break; + + gcc_assert (LABEL_P (label)); + + /* Ignore references to labels of containing functions. */ + if (LABEL_REF_NONLOCAL_P (x)) + break; + + XEXP (x, 0) = label; + if (! insn || ! INSN_DELETED_P (insn)) + ++LABEL_NUSES (label); + + if (insn) + { + if (JUMP_P (insn)) + JUMP_LABEL (insn) = label; + else + { + /* Add a REG_LABEL note for LABEL unless there already + is one. All uses of a label, except for labels + that are the targets of jumps, must have a + REG_LABEL note. */ + if (! find_reg_note (insn, REG_LABEL, label)) + REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, label, + REG_NOTES (insn)); + } + } + return; + } + + /* Do walk the labels in a vector, but not the first operand of an + ADDR_DIFF_VEC. Don't set the JUMP_LABEL of a vector. */ + case ADDR_VEC: + case ADDR_DIFF_VEC: + if (! INSN_DELETED_P (insn)) + { + int eltnum = code == ADDR_DIFF_VEC ? 1 : 0; + + for (i = 0; i < XVECLEN (x, eltnum); i++) + mark_jump_label (XVECEXP (x, eltnum, i), NULL_RTX, in_mem); + } + return; + + default: + break; + } + + fmt = GET_RTX_FORMAT (code); + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + if (fmt[i] == 'e') + mark_jump_label (XEXP (x, i), insn, in_mem); + else if (fmt[i] == 'E') + { + int j; + for (j = 0; j < XVECLEN (x, i); j++) + mark_jump_label (XVECEXP (x, i, j), insn, in_mem); + } + } +} + +/* If all INSN does is set the pc, delete it, + and delete the insn that set the condition codes for it + if that's what the previous thing was. */ + +void +delete_jump (rtx insn) +{ + rtx set = single_set (insn); + + if (set && GET_CODE (SET_DEST (set)) == PC) + delete_computation (insn); +} + +/* Recursively delete prior insns that compute the value (used only by INSN + which the caller is deleting) stored in the register mentioned by NOTE + which is a REG_DEAD note associated with INSN. */ + +static void +delete_prior_computation (rtx note, rtx insn) +{ + rtx our_prev; + rtx reg = XEXP (note, 0); + + for (our_prev = prev_nonnote_insn (insn); + our_prev && (NONJUMP_INSN_P (our_prev) + || CALL_P (our_prev)); + our_prev = prev_nonnote_insn (our_prev)) + { + rtx pat = PATTERN (our_prev); + + /* If we reach a CALL which is not calling a const function + or the callee pops the arguments, then give up. */ + if (CALL_P (our_prev) + && (! CONST_OR_PURE_CALL_P (our_prev) + || GET_CODE (pat) != SET || GET_CODE (SET_SRC (pat)) != CALL)) + break; + + /* If we reach a SEQUENCE, it is too complex to try to + do anything with it, so give up. We can be run during + and after reorg, so SEQUENCE rtl can legitimately show + up here. */ + if (GET_CODE (pat) == SEQUENCE) + break; + + if (GET_CODE (pat) == USE + && NONJUMP_INSN_P (XEXP (pat, 0))) + /* reorg creates USEs that look like this. We leave them + alone because reorg needs them for its own purposes. */ + break; + + if (reg_set_p (reg, pat)) + { + if (side_effects_p (pat) && !CALL_P (our_prev)) + break; + + if (GET_CODE (pat) == PARALLEL) + { + /* If we find a SET of something else, we can't + delete the insn. */ + + int i; + + for (i = 0; i < XVECLEN (pat, 0); i++) + { + rtx part = XVECEXP (pat, 0, i); + + if (GET_CODE (part) == SET + && SET_DEST (part) != reg) + break; + } + + if (i == XVECLEN (pat, 0)) + delete_computation (our_prev); + } + else if (GET_CODE (pat) == SET + && REG_P (SET_DEST (pat))) + { + int dest_regno = REGNO (SET_DEST (pat)); + int dest_endregno + = (dest_regno + + (dest_regno < FIRST_PSEUDO_REGISTER + ? hard_regno_nregs[dest_regno] + [GET_MODE (SET_DEST (pat))] : 1)); + int regno = REGNO (reg); + int endregno + = (regno + + (regno < FIRST_PSEUDO_REGISTER + ? hard_regno_nregs[regno][GET_MODE (reg)] : 1)); + + if (dest_regno >= regno + && dest_endregno <= endregno) + delete_computation (our_prev); + + /* We may have a multi-word hard register and some, but not + all, of the words of the register are needed in subsequent + insns. Write REG_UNUSED notes for those parts that were not + needed. */ + else if (dest_regno <= regno + && dest_endregno >= endregno) + { + int i; + + REG_NOTES (our_prev) + = gen_rtx_EXPR_LIST (REG_UNUSED, reg, + REG_NOTES (our_prev)); + + for (i = dest_regno; i < dest_endregno; i++) + if (! find_regno_note (our_prev, REG_UNUSED, i)) + break; + + if (i == dest_endregno) + delete_computation (our_prev); + } + } + + break; + } + + /* If PAT references the register that dies here, it is an + additional use. Hence any prior SET isn't dead. However, this + insn becomes the new place for the REG_DEAD note. */ + if (reg_overlap_mentioned_p (reg, pat)) + { + XEXP (note, 1) = REG_NOTES (our_prev); + REG_NOTES (our_prev) = note; + break; + } + } +} + +/* Delete INSN and recursively delete insns that compute values used only + by INSN. This uses the REG_DEAD notes computed during flow analysis. + If we are running before flow.c, we need do nothing since flow.c will + delete dead code. We also can't know if the registers being used are + dead or not at this point. + + Otherwise, look at all our REG_DEAD notes. If a previous insn does + nothing other than set a register that dies in this insn, we can delete + that insn as well. + + On machines with CC0, if CC0 is used in this insn, we may be able to + delete the insn that set it. */ + +static void +delete_computation (rtx insn) +{ + rtx note, next; + +#ifdef HAVE_cc0 + if (reg_referenced_p (cc0_rtx, PATTERN (insn))) + { + rtx prev = prev_nonnote_insn (insn); + /* We assume that at this stage + CC's are always set explicitly + and always immediately before the jump that + will use them. So if the previous insn + exists to set the CC's, delete it + (unless it performs auto-increments, etc.). */ + if (prev && NONJUMP_INSN_P (prev) + && sets_cc0_p (PATTERN (prev))) + { + if (sets_cc0_p (PATTERN (prev)) > 0 + && ! side_effects_p (PATTERN (prev))) + delete_computation (prev); + else + /* Otherwise, show that cc0 won't be used. */ + REG_NOTES (prev) = gen_rtx_EXPR_LIST (REG_UNUSED, + cc0_rtx, REG_NOTES (prev)); + } + } +#endif + + for (note = REG_NOTES (insn); note; note = next) + { + next = XEXP (note, 1); + + if (REG_NOTE_KIND (note) != REG_DEAD + /* Verify that the REG_NOTE is legitimate. */ + || !REG_P (XEXP (note, 0))) + continue; + + delete_prior_computation (note, insn); + } + + delete_related_insns (insn); +} + +/* Delete insn INSN from the chain of insns and update label ref counts + and delete insns now unreachable. + + Returns the first insn after INSN that was not deleted. + + Usage of this instruction is deprecated. Use delete_insn instead and + subsequent cfg_cleanup pass to delete unreachable code if needed. */ + +rtx +delete_related_insns (rtx insn) +{ + int was_code_label = (LABEL_P (insn)); + rtx note; + rtx next = NEXT_INSN (insn), prev = PREV_INSN (insn); + + while (next && INSN_DELETED_P (next)) + next = NEXT_INSN (next); + + /* This insn is already deleted => return first following nondeleted. */ + if (INSN_DELETED_P (insn)) + return next; + + delete_insn (insn); + + /* If instruction is followed by a barrier, + delete the barrier too. */ + + if (next != 0 && BARRIER_P (next)) + delete_insn (next); + + /* If deleting a jump, decrement the count of the label, + and delete the label if it is now unused. */ + + if (JUMP_P (insn) && JUMP_LABEL (insn)) + { + rtx lab = JUMP_LABEL (insn), lab_next; + + if (LABEL_NUSES (lab) == 0) + { + /* This can delete NEXT or PREV, + either directly if NEXT is JUMP_LABEL (INSN), + or indirectly through more levels of jumps. */ + delete_related_insns (lab); + + /* I feel a little doubtful about this loop, + but I see no clean and sure alternative way + to find the first insn after INSN that is not now deleted. + I hope this works. */ + while (next && INSN_DELETED_P (next)) + next = NEXT_INSN (next); + return next; + } + else if (tablejump_p (insn, NULL, &lab_next)) + { + /* If we're deleting the tablejump, delete the dispatch table. + We may not be able to kill the label immediately preceding + just yet, as it might be referenced in code leading up to + the tablejump. */ + delete_related_insns (lab_next); + } + } + + /* Likewise if we're deleting a dispatch table. */ + + if (JUMP_P (insn) + && (GET_CODE (PATTERN (insn)) == ADDR_VEC + || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) + { + rtx pat = PATTERN (insn); + int i, diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; + int len = XVECLEN (pat, diff_vec_p); + + for (i = 0; i < len; i++) + if (LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0)) == 0) + delete_related_insns (XEXP (XVECEXP (pat, diff_vec_p, i), 0)); + while (next && INSN_DELETED_P (next)) + next = NEXT_INSN (next); + return next; + } + + /* Likewise for an ordinary INSN / CALL_INSN with a REG_LABEL note. */ + if (NONJUMP_INSN_P (insn) || CALL_P (insn)) + for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) + if (REG_NOTE_KIND (note) == REG_LABEL + /* This could also be a NOTE_INSN_DELETED_LABEL note. */ + && LABEL_P (XEXP (note, 0))) + if (LABEL_NUSES (XEXP (note, 0)) == 0) + delete_related_insns (XEXP (note, 0)); + + while (prev && (INSN_DELETED_P (prev) || NOTE_P (prev))) + prev = PREV_INSN (prev); + + /* If INSN was a label and a dispatch table follows it, + delete the dispatch table. The tablejump must have gone already. + It isn't useful to fall through into a table. */ + + if (was_code_label + && NEXT_INSN (insn) != 0 + && JUMP_P (NEXT_INSN (insn)) + && (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC + || GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC)) + next = delete_related_insns (NEXT_INSN (insn)); + + /* If INSN was a label, delete insns following it if now unreachable. */ + + if (was_code_label && prev && BARRIER_P (prev)) + { + enum rtx_code code; + while (next) + { + code = GET_CODE (next); + if (code == NOTE + && NOTE_LINE_NUMBER (next) != NOTE_INSN_FUNCTION_END) + next = NEXT_INSN (next); + /* Keep going past other deleted labels to delete what follows. */ + else if (code == CODE_LABEL && INSN_DELETED_P (next)) + next = NEXT_INSN (next); + else if (code == BARRIER || INSN_P (next)) + /* Note: if this deletes a jump, it can cause more + deletion of unreachable code, after a different label. + As long as the value from this recursive call is correct, + this invocation functions correctly. */ + next = delete_related_insns (next); + else + break; + } + } + + return next; +} + +/* Delete a range of insns from FROM to TO, inclusive. + This is for the sake of peephole optimization, so assume + that whatever these insns do will still be done by a new + peephole insn that will replace them. */ + +void +delete_for_peephole (rtx from, rtx to) +{ + rtx insn = from; + + while (1) + { + rtx next = NEXT_INSN (insn); + rtx prev = PREV_INSN (insn); + + if (!NOTE_P (insn)) + { + INSN_DELETED_P (insn) = 1; + + /* Patch this insn out of the chain. */ + /* We don't do this all at once, because we + must preserve all NOTEs. */ + if (prev) + NEXT_INSN (prev) = next; + + if (next) + PREV_INSN (next) = prev; + } + + if (insn == to) + break; + insn = next; + } + + /* Note that if TO is an unconditional jump + we *do not* delete the BARRIER that follows, + since the peephole that replaces this sequence + is also an unconditional jump in that case. */ +} + +/* Throughout LOC, redirect OLABEL to NLABEL. Treat null OLABEL or + NLABEL as a return. Accrue modifications into the change group. */ + +static void +redirect_exp_1 (rtx *loc, rtx olabel, rtx nlabel, rtx insn) +{ + rtx x = *loc; + RTX_CODE code = GET_CODE (x); + int i; + const char *fmt; + + if (code == LABEL_REF) + { + if (XEXP (x, 0) == olabel) + { + rtx n; + if (nlabel) + n = gen_rtx_LABEL_REF (Pmode, nlabel); + else + n = gen_rtx_RETURN (VOIDmode); + + validate_change (insn, loc, n, 1); + return; + } + } + else if (code == RETURN && olabel == 0) + { + if (nlabel) + x = gen_rtx_LABEL_REF (Pmode, nlabel); + else + x = gen_rtx_RETURN (VOIDmode); + if (loc == &PATTERN (insn)) + x = gen_rtx_SET (VOIDmode, pc_rtx, x); + validate_change (insn, loc, x, 1); + return; + } + + if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx + && GET_CODE (SET_SRC (x)) == LABEL_REF + && XEXP (SET_SRC (x), 0) == olabel) + { + validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 1); + return; + } + + fmt = GET_RTX_FORMAT (code); + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + if (fmt[i] == 'e') + redirect_exp_1 (&XEXP (x, i), olabel, nlabel, insn); + else if (fmt[i] == 'E') + { + int j; + for (j = 0; j < XVECLEN (x, i); j++) + redirect_exp_1 (&XVECEXP (x, i, j), olabel, nlabel, insn); + } + } +} + +/* Make JUMP go to NLABEL instead of where it jumps now. Accrue + the modifications into the change group. Return false if we did + not see how to do that. */ + +int +redirect_jump_1 (rtx jump, rtx nlabel) +{ + int ochanges = num_validated_changes (); + rtx *loc; + + if (GET_CODE (PATTERN (jump)) == PARALLEL) + loc = &XVECEXP (PATTERN (jump), 0, 0); + else + loc = &PATTERN (jump); + + redirect_exp_1 (loc, JUMP_LABEL (jump), nlabel, jump); + return num_validated_changes () > ochanges; +} + +/* Make JUMP go to NLABEL instead of where it jumps now. If the old + jump target label is unused as a result, it and the code following + it may be deleted. + + If NLABEL is zero, we are to turn the jump into a (possibly conditional) + RETURN insn. + + The return value will be 1 if the change was made, 0 if it wasn't + (this can only occur for NLABEL == 0). */ + +int +redirect_jump (rtx jump, rtx nlabel, int delete_unused) +{ + rtx olabel = JUMP_LABEL (jump); + + if (nlabel == olabel) + return 1; + + if (! redirect_jump_1 (jump, nlabel) || ! apply_change_group ()) + return 0; + + redirect_jump_2 (jump, olabel, nlabel, delete_unused, 0); + return 1; +} + +/* Fix up JUMP_LABEL and label ref counts after OLABEL has been replaced with + NLABEL in JUMP. If DELETE_UNUSED is non-negative, copy a + NOTE_INSN_FUNCTION_END found after OLABEL to the place after NLABEL. + If DELETE_UNUSED is positive, delete related insn to OLABEL if its ref + count has dropped to zero. */ +void +redirect_jump_2 (rtx jump, rtx olabel, rtx nlabel, int delete_unused, + int invert) +{ + rtx note; + + JUMP_LABEL (jump) = nlabel; + if (nlabel) + ++LABEL_NUSES (nlabel); + + /* Update labels in any REG_EQUAL note. */ + if ((note = find_reg_note (jump, REG_EQUAL, NULL_RTX)) != NULL_RTX) + { + if (!nlabel || (invert && !invert_exp_1 (XEXP (note, 0), jump))) + remove_note (jump, note); + else + { + redirect_exp_1 (&XEXP (note, 0), olabel, nlabel, jump); + confirm_change_group (); + } + } + + /* If we're eliding the jump over exception cleanups at the end of a + function, move the function end note so that -Wreturn-type works. */ + if (olabel && nlabel + && NEXT_INSN (olabel) + && NOTE_P (NEXT_INSN (olabel)) + && NOTE_LINE_NUMBER (NEXT_INSN (olabel)) == NOTE_INSN_FUNCTION_END + && delete_unused >= 0) + emit_note_after (NOTE_INSN_FUNCTION_END, nlabel); + + if (olabel && --LABEL_NUSES (olabel) == 0 && delete_unused > 0 + /* Undefined labels will remain outside the insn stream. */ + && INSN_UID (olabel)) + delete_related_insns (olabel); + if (invert) + invert_br_probabilities (jump); +} + +/* Invert the jump condition X contained in jump insn INSN. Accrue the + modifications into the change group. Return nonzero for success. */ +static int +invert_exp_1 (rtx x, rtx insn) +{ + RTX_CODE code = GET_CODE (x); + + if (code == IF_THEN_ELSE) + { + rtx comp = XEXP (x, 0); + rtx tem; + enum rtx_code reversed_code; + + /* We can do this in two ways: The preferable way, which can only + be done if this is not an integer comparison, is to reverse + the comparison code. Otherwise, swap the THEN-part and ELSE-part + of the IF_THEN_ELSE. If we can't do either, fail. */ + + reversed_code = reversed_comparison_code (comp, insn); + + if (reversed_code != UNKNOWN) + { + validate_change (insn, &XEXP (x, 0), + gen_rtx_fmt_ee (reversed_code, + GET_MODE (comp), XEXP (comp, 0), + XEXP (comp, 1)), + 1); + return 1; + } + + tem = XEXP (x, 1); + validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1); + validate_change (insn, &XEXP (x, 2), tem, 1); + return 1; + } + else + return 0; +} + +/* Invert the condition of the jump JUMP, and make it jump to label + NLABEL instead of where it jumps now. Accrue changes into the + change group. Return false if we didn't see how to perform the + inversion and redirection. */ + +int +invert_jump_1 (rtx jump, rtx nlabel) +{ + rtx x = pc_set (jump); + int ochanges; + int ok; + + ochanges = num_validated_changes (); + gcc_assert (x); + ok = invert_exp_1 (SET_SRC (x), jump); + gcc_assert (ok); + + if (num_validated_changes () == ochanges) + return 0; + + /* redirect_jump_1 will fail of nlabel == olabel, and the current use is + in Pmode, so checking this is not merely an optimization. */ + return nlabel == JUMP_LABEL (jump) || redirect_jump_1 (jump, nlabel); +} + +/* Invert the condition of the jump JUMP, and make it jump to label + NLABEL instead of where it jumps now. Return true if successful. */ + +int +invert_jump (rtx jump, rtx nlabel, int delete_unused) +{ + rtx olabel = JUMP_LABEL (jump); + + if (invert_jump_1 (jump, nlabel) && apply_change_group ()) + { + redirect_jump_2 (jump, olabel, nlabel, delete_unused, 1); + return 1; + } + cancel_changes (0); + return 0; +} + + +/* Like rtx_equal_p except that it considers two REGs as equal + if they renumber to the same value and considers two commutative + operations to be the same if the order of the operands has been + reversed. */ + +int +rtx_renumbered_equal_p (rtx x, rtx y) +{ + int i; + enum rtx_code code = GET_CODE (x); + const char *fmt; + + if (x == y) + return 1; + + if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x)))) + && (REG_P (y) || (GET_CODE (y) == SUBREG + && REG_P (SUBREG_REG (y))))) + { + int reg_x = -1, reg_y = -1; + int byte_x = 0, byte_y = 0; + + if (GET_MODE (x) != GET_MODE (y)) + return 0; + + /* If we haven't done any renumbering, don't + make any assumptions. */ + if (reg_renumber == 0) + return rtx_equal_p (x, y); + + if (code == SUBREG) + { + reg_x = REGNO (SUBREG_REG (x)); + byte_x = SUBREG_BYTE (x); + + if (reg_renumber[reg_x] >= 0) + { + reg_x = subreg_regno_offset (reg_renumber[reg_x], + GET_MODE (SUBREG_REG (x)), + byte_x, + GET_MODE (x)); + byte_x = 0; + } + } + else + { + reg_x = REGNO (x); + if (reg_renumber[reg_x] >= 0) + reg_x = reg_renumber[reg_x]; + } + + if (GET_CODE (y) == SUBREG) + { + reg_y = REGNO (SUBREG_REG (y)); + byte_y = SUBREG_BYTE (y); + + if (reg_renumber[reg_y] >= 0) + { + reg_y = subreg_regno_offset (reg_renumber[reg_y], + GET_MODE (SUBREG_REG (y)), + byte_y, + GET_MODE (y)); + byte_y = 0; + } + } + else + { + reg_y = REGNO (y); + if (reg_renumber[reg_y] >= 0) + reg_y = reg_renumber[reg_y]; + } + + return reg_x >= 0 && reg_x == reg_y && byte_x == byte_y; + } + + /* Now we have disposed of all the cases + in which different rtx codes can match. */ + if (code != GET_CODE (y)) + return 0; + + switch (code) + { + case PC: + case CC0: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case CONST_INT: + case CONST_DOUBLE: + return 0; + + case LABEL_REF: + /* We can't assume nonlocal labels have their following insns yet. */ + if (LABEL_REF_NONLOCAL_P (x) || LABEL_REF_NONLOCAL_P (y)) + return XEXP (x, 0) == XEXP (y, 0); + + /* APPLE LOCAL begin ARM pic support */ + /* ARM uses label_refs to contant pool entries in + pic_add_dot_plus_eight that must not compare equal, but, they + are not emitted into the function body, so, there is no + next_real_insn for them. Unfortunately, different labels + both return 0, leading to a false equality. Found on + libiberty build. */ + if (next_real_insn (XEXP (x, 0)) == 0) + return 0; + /* APPLE LOCAL end ARM pic support */ + + /* Two label-refs are equivalent if they point at labels + in the same position in the instruction stream. */ + return (next_real_insn (XEXP (x, 0)) + == next_real_insn (XEXP (y, 0))); + + case SYMBOL_REF: + return XSTR (x, 0) == XSTR (y, 0); + + case CODE_LABEL: + /* If we didn't match EQ equality above, they aren't the same. */ + return 0; + + default: + break; + } + + /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ + + if (GET_MODE (x) != GET_MODE (y)) + return 0; + + /* For commutative operations, the RTX match if the operand match in any + order. Also handle the simple binary and unary cases without a loop. */ + if (targetm.commutative_p (x, UNKNOWN)) + return ((rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) + && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))) + || (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 1)) + && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 0)))); + else if (NON_COMMUTATIVE_P (x)) + return (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) + && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))); + else if (UNARY_P (x)) + return rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)); + + /* Compare the elements. If any pair of corresponding elements + fail to match, return 0 for the whole things. */ + + fmt = GET_RTX_FORMAT (code); + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + int j; + switch (fmt[i]) + { + case 'w': + if (XWINT (x, i) != XWINT (y, i)) + return 0; + break; + + case 'i': + if (XINT (x, i) != XINT (y, i)) + return 0; + break; + + case 't': + if (XTREE (x, i) != XTREE (y, i)) + return 0; + break; + + case 's': + if (strcmp (XSTR (x, i), XSTR (y, i))) + return 0; + break; + + case 'e': + if (! rtx_renumbered_equal_p (XEXP (x, i), XEXP (y, i))) + return 0; + break; + + case 'u': + if (XEXP (x, i) != XEXP (y, i)) + return 0; + /* Fall through. */ + case '0': + break; + + case 'E': + if (XVECLEN (x, i) != XVECLEN (y, i)) + return 0; + for (j = XVECLEN (x, i) - 1; j >= 0; j--) + if (!rtx_renumbered_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j))) + return 0; + break; + + default: + gcc_unreachable (); + } + } + return 1; +} + +/* If X is a hard register or equivalent to one or a subregister of one, + return the hard register number. If X is a pseudo register that was not + assigned a hard register, return the pseudo register number. Otherwise, + return -1. Any rtx is valid for X. */ + +int +true_regnum (rtx x) +{ + if (REG_P (x)) + { + if (REGNO (x) >= FIRST_PSEUDO_REGISTER && reg_renumber[REGNO (x)] >= 0) + return reg_renumber[REGNO (x)]; + return REGNO (x); + } + if (GET_CODE (x) == SUBREG) + { + int base = true_regnum (SUBREG_REG (x)); + if (base >= 0 + && base < FIRST_PSEUDO_REGISTER + && subreg_offset_representable_p (REGNO (SUBREG_REG (x)), + GET_MODE (SUBREG_REG (x)), + SUBREG_BYTE (x), GET_MODE (x))) + return base + subreg_regno_offset (REGNO (SUBREG_REG (x)), + GET_MODE (SUBREG_REG (x)), + SUBREG_BYTE (x), GET_MODE (x)); + } + return -1; +} + +/* Return regno of the register REG and handle subregs too. */ +unsigned int +reg_or_subregno (rtx reg) +{ + if (GET_CODE (reg) == SUBREG) + reg = SUBREG_REG (reg); + gcc_assert (REG_P (reg)); + return REGNO (reg); +} |