Paolo Bonzini - [PATCH] delete (almost) last use of LABEL_REFS (original) (raw)

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• From: Paolo Bonzini
• To: GCC Patches
• Date: Fri, 16 Feb 2007 17:38:39 +0100
• Subject: [PATCH] delete (almost) last use of LABEL_REFS

While it is not so beneficial to remove a field from CODE_LABEL, this still removes the last use of LABEL_REFS in non-backend code. Now the last user is SH, but I don't have time to look into it.The usage was introduced in http://gcc.gnu.org/ml/gcc-patches/1998-09/msg00050.html (nine years) and disabled pretty soon after its checkin (could not find the posting for this one).Just for extra safety, this does not affect SH as SH is not a CC0 target, and this patch is only for CC0 targets. Tested by building m68k-elf.Ok for mainline?Paolo

2007-02-17 Paolo Bonzini bonzini@gnu.org

* final.c (final): Remove code to set LABEL_REFS.
(final_scan_insn): Remove disabled code.

Index: gcc-test-df/base-gcc-src/gcc/final.c

--- gcc-test-df/base-gcc-src/gcc/final.c (revision 122035) +++ gcc-test-df/base-gcc-src/gcc/final.c (working copy) @@ -1573,22 +1573,8 @@ final (rtx first, FILE file, int optimi #endif for (insn = first; insn; insn = NEXT_INSN (insn)) - { - if (INSN_UID (insn) > max_uid) / Find largest UID. / - max_uid = INSN_UID (insn); -#ifdef HAVE_cc0 - / If CC tracking across branches is enabled, record the insn which - jumps to each branch only reached from one place. / - if (optimize && JUMP_P (insn)) - { - rtx lab = JUMP_LABEL (insn); - if (lab && LABEL_NUSES (lab) == 1) - { - LABEL_REFS (lab) = insn; - } - } -#endif - } + if (INSN_UID (insn) > max_uid) / Find largest UID. */ + max_uid = INSN_UID (insn); init_recog (); @@ -1859,30 +1845,6 @@ final_scan_insn (rtx insn, FILE file, i } #ifdef HAVE_cc0 CC_STATUS_INIT; - / If this label is reached from only one place, set the condition - codes from the instruction just before the branch. */

•  /* Disabled because some insns set cc_status in the C output code

• and NOTICE_UPDATE_CC alone can set incorrect status.  */

•  if (0 /* optimize && LABEL_NUSES (insn) == 1*/)

• {

•  rtx jump = LABEL_REFS (insn);

•  rtx barrier = prev_nonnote_insn (insn);

•  rtx prev;

•  /* If the LABEL_REFS field of this label has been set to point

•     at a branch, the predecessor of the branch is a regular

•     insn, and that branch is the only way to reach this label,

•     set the condition codes based on the branch and its

•     predecessor.  */

•  if (barrier && BARRIER_P (barrier)

•      && jump && JUMP_P (jump)

•      && (prev = prev_nonnote_insn (jump))

•      && NONJUMP_INSN_P (prev))

•    {

•      NOTICE_UPDATE_CC (PATTERN (prev), prev);

•      NOTICE_UPDATE_CC (PATTERN (jump), jump);

•    }

• } #endif

    if (LABEL_NAME (insn))