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PR70890, stage2 miscompilation

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PR rtl-optimization/70890
	* ira.c (combine_and_move_insns): When moving def_insn, remove
	equivs on use_insn.

From-SVN: r235825
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Alan Modra 2016-05-04 00:13:35 +09:30 • committed by Alan Modra
parent f3d9004571
commit fcc861d975
2 changed files with 22 additions and 0 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2016-05-03 Alan Modra <amodra@gmail.com>
PR rtl-optimization/70890
* ira.c (combine_and_move_insns): When moving def_insn, remove
equivs on use_insn.
2016-05-03 Dominik Vogt <vogt@linux.vnet.ibm.com>
* config/s390/s390.md ("*r<noxa>sbg_<mode>_sll")

16
gcc/ira.c
View file

@ -3742,6 +3742,22 @@ combine_and_move_insns (void)
if (use_insn == BB_HEAD (use_bb))
BB_HEAD (use_bb) = new_insn;
/* We know regno dies in use_insn, but inside a loop
REG_DEAD notes might be missing when def_insn was in
another basic block. However, when we move def_insn into
this bb we'll definitely get a REG_DEAD note and reload
will see the death. It's possible that update_equiv_regs
set up an equivalence referencing regno for a reg set by
use_insn, when regno was seen as non-local. Now that
regno is local to this block, and dies, such an
equivalence is invalid. */
if (find_reg_note (use_insn, REG_EQUIV, NULL_RTX))
{
rtx set = single_set (use_insn);
if (set && REG_P (SET_DEST (set)))
no_equiv (SET_DEST (set), set, NULL);
}
ira_reg_equiv[regno].init_insns
= gen_rtx_INSN_LIST (VOIDmode, new_insn, NULL_RTX);
bitmap_set_bit (cleared_regs, regno);