| /* 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 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, 59 Temple Place - Suite 330, Boston, MA |
| 02111-1307, USA. */ |
| |
| /* This is the pathetic reminder of old fame of the jump-optimization pass |
| of the compiler. Now it contains basically set of utility function 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" |
| |
| /* 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 redirect_exp (rtx, rtx, rtx); |
| static void invert_exp_1 (rtx); |
| static int invert_exp (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. |
| */ |
| void |
| 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); |
| } |
| } |
| } |
| |
| void |
| purge_line_number_notes (rtx f) |
| { |
| 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 = f; 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; |
| } |
| } |
| } |
| |
| /* 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 (VOIDmode, |
| 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, loop-beg, loop-cont, loop-vtop, loop-end, |
| 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 |
| || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG |
| || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)) |
| { |
| /* 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); |
| } |
| |
| /* 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: |
| abort (); |
| } |
| } |
| |
| /* 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: |
| abort (); |
| } |
| } |
| |
| /* 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: |
| abort (); |
| } |
| } |
| |
| /* 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: |
| abort (); |
| } |
| } |
| |
| /* 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: |
| abort (); |
| } |
| } |
| |
| /* 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 NOTE_INSN_LOOP_BEG or |
| 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++) |
| { |
| /* Don't chain through the insn that jumps into a loop |
| from outside the loop, |
| since that would create multiple loop entry jumps |
| and prevent loop optimization. */ |
| rtx tem; |
| if (!reload_completed) |
| for (tem = value; tem != insn; tem = NEXT_INSN (tem)) |
| if (NOTE_P (tem) |
| && (NOTE_LINE_NUMBER (tem) == NOTE_INSN_LOOP_BEG |
| /* ??? Optional. Disables some optimizations, but makes |
| gcov output more accurate with -O. */ |
| || (flag_test_coverage && 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; |
| |
| if (!LABEL_P (label)) |
| abort (); |
| |
| /* 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 (VOIDmode, nlabel); |
| else |
| n = gen_rtx_RETURN (VOIDmode); |
| |
| validate_change (insn, loc, n, 1); |
| return; |
| } |
| } |
| else if (code == RETURN && olabel == 0) |
| { |
| x = gen_rtx_LABEL_REF (VOIDmode, nlabel); |
| 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); |
| } |
| } |
| } |
| |
| /* Similar, but apply the change group and report success or failure. */ |
| |
| static int |
| redirect_exp (rtx olabel, rtx nlabel, rtx insn) |
| { |
| rtx *loc; |
| |
| if (GET_CODE (PATTERN (insn)) == PARALLEL) |
| loc = &XVECEXP (PATTERN (insn), 0, 0); |
| else |
| loc = &PATTERN (insn); |
| |
| redirect_exp_1 (loc, olabel, nlabel, insn); |
| if (num_validated_changes () == 0) |
| return 0; |
| |
| return apply_change_group (); |
| } |
| |
| /* 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); |
| rtx note; |
| |
| if (nlabel == olabel) |
| return 1; |
| |
| if (! redirect_exp (olabel, nlabel, jump)) |
| return 0; |
| |
| 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 && olabel) |
| { |
| rtx dest = XEXP (note, 0); |
| |
| if (GET_CODE (dest) == IF_THEN_ELSE) |
| { |
| if (GET_CODE (XEXP (dest, 1)) == LABEL_REF |
| && XEXP (XEXP (dest, 1), 0) == olabel) |
| XEXP (XEXP (dest, 1), 0) = nlabel; |
| if (GET_CODE (XEXP (dest, 2)) == LABEL_REF |
| && XEXP (XEXP (dest, 2), 0) == olabel) |
| XEXP (XEXP (dest, 2), 0) = nlabel; |
| } |
| else |
| remove_note (jump, note); |
| } |
| else |
| remove_note (jump, note); |
| } |
| |
| /* 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) |
| emit_note_after (NOTE_INSN_FUNCTION_END, nlabel); |
| |
| if (olabel && --LABEL_NUSES (olabel) == 0 && delete_unused |
| /* Undefined labels will remain outside the insn stream. */ |
| && INSN_UID (olabel)) |
| delete_related_insns (olabel); |
| |
| return 1; |
| } |
| |
| /* Invert the jump condition of rtx X contained in jump insn, INSN. |
| Accrue the modifications into the change group. */ |
| |
| static void |
| invert_exp_1 (rtx insn) |
| { |
| RTX_CODE code; |
| rtx x = pc_set (insn); |
| |
| if (!x) |
| abort (); |
| x = SET_SRC (x); |
| |
| 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; |
| } |
| |
| tem = XEXP (x, 1); |
| validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1); |
| validate_change (insn, &XEXP (x, 2), tem, 1); |
| } |
| else |
| abort (); |
| } |
| |
| /* Invert the jump condition of conditional jump insn, INSN. |
| |
| Return 1 if we can do so, 0 if we cannot find a way to do so that |
| matches a pattern. */ |
| |
| static int |
| invert_exp (rtx insn) |
| { |
| invert_exp_1 (insn); |
| if (num_validated_changes () == 0) |
| return 0; |
| |
| return apply_change_group (); |
| } |
| |
| /* 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) |
| { |
| int ochanges; |
| |
| ochanges = num_validated_changes (); |
| invert_exp_1 (jump); |
| if (num_validated_changes () == ochanges) |
| return 0; |
| |
| return 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) |
| { |
| /* We have to either invert the condition and change the label or |
| do neither. Either operation could fail. We first try to invert |
| the jump. If that succeeds, we try changing the label. If that fails, |
| we invert the jump back to what it was. */ |
| |
| if (! invert_exp (jump)) |
| return 0; |
| |
| if (redirect_jump (jump, nlabel, delete_unused)) |
| { |
| /* Remove REG_EQUAL note if we have one. */ |
| rtx note = find_reg_note (jump, REG_EQUAL, NULL_RTX); |
| if (note) |
| remove_note (jump, note); |
| |
| invert_br_probabilities (jump); |
| |
| return 1; |
| } |
| |
| if (! invert_exp (jump)) |
| /* This should just be putting it back the way it was. */ |
| abort (); |
| |
| 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. |
| |
| ??? Addition is not commutative on the PA due to the weird implicit |
| space register selection rules for memory addresses. Therefore, we |
| don't consider a + b == b + a. |
| |
| We could/should make this test a little tighter. Possibly only |
| disabling it on the PA via some backend macro or only disabling this |
| case when the PLUS is inside a MEM. */ |
| |
| 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: |
| 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); |
| |
| /* 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. |
| |
| ??? Don't consider PLUS a commutative operator; see comments above. */ |
| if (COMMUTATIVE_P (x) && code != PLUS) |
| 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: |
| abort (); |
| } |
| } |
| 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) |
| 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 (REG_P (reg)) |
| return REGNO (reg); |
| if (GET_CODE (reg) == SUBREG) |
| return REGNO (SUBREG_REG (reg)); |
| abort (); |
| } |