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reorg.c (fill_simple_delay_slots): If TARGET_FLAGS_REGNUM is valid...

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* reorg.c (fill_simple_delay_slots): If TARGET_FLAGS_REGNUM is valid,
	implement a more precise life analysis for it during backward scan.

From-SVN: r219800
This commit is contained in:
Eric Botcazou 2015-01-17 14:00:57 +00:00 • committed by Eric Botcazou
parent c6c1bfd99b
commit 33c2207d3f
2 changed files with 35 additions and 1 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2015-01-17 Eric Botcazou <ebotcazou@adacore.com>
* reorg.c (fill_simple_delay_slots): If TARGET_FLAGS_REGNUM is valid,
implement a more precise life analysis for it during backward scan.
2015-01-17 Jan Kratochvil <jan.kratochvil@redhat.com> 2015-01-17 Jan Kratochvil <jan.kratochvil@redhat.com>
* dwarf2out.c (gen_producer_string): Ignore also OPT_fpreprocessed. * dwarf2out.c (gen_producer_string): Ignore also OPT_fpreprocessed.

31
gcc/reorg.c
View file

@ -2072,9 +2072,24 @@ fill_simple_delay_slots (int non_jumps_p)
if (slots_filled < slots_to_fill) if (slots_filled < slots_to_fill)
{ {
/* If the flags register is dead after the insn, then we want to be
able to accept a candidate that clobbers it. For this purpose,
we need to filter the flags register during life analysis, so
that it doesn't create RAW and WAW dependencies, while still
creating the necessary WAR dependencies. */
bool filter_flags
= (slots_to_fill == 1
&& targetm.flags_regnum != INVALID_REGNUM
&& find_regno_note (insn, REG_DEAD, targetm.flags_regnum));
struct resources fset;
CLEAR_RESOURCE (&needed); CLEAR_RESOURCE (&needed);
CLEAR_RESOURCE (&set); CLEAR_RESOURCE (&set);
mark_set_resources (insn, &set, 0, MARK_SRC_DEST); mark_set_resources (insn, &set, 0, MARK_SRC_DEST);
if (filter_flags)
{
CLEAR_RESOURCE (&fset);
mark_set_resources (insn, &fset, 0, MARK_SRC_DEST);
}
mark_referenced_resources (insn, &needed, false); mark_referenced_resources (insn, &needed, false);
for (trial = prev_nonnote_insn (insn); ! stop_search_p (trial, 1); for (trial = prev_nonnote_insn (insn); ! stop_search_p (trial, 1);
@ -2092,7 +2107,9 @@ fill_simple_delay_slots (int non_jumps_p)
/* Check for resource conflict first, to avoid unnecessary /* Check for resource conflict first, to avoid unnecessary
splitting. */ splitting. */
if (! insn_references_resource_p (trial, &set, true) if (! insn_references_resource_p (trial, &set, true)
&& ! insn_sets_resource_p (trial, &set, true) && ! insn_sets_resource_p (trial,
filter_flags ? &fset : &set,
true)
&& ! insn_sets_resource_p (trial, &needed, true) && ! insn_sets_resource_p (trial, &needed, true)
#ifdef HAVE_cc0 #ifdef HAVE_cc0
/* Can't separate set of cc0 from its use. */ /* Can't separate set of cc0 from its use. */
@ -2121,6 +2138,18 @@ fill_simple_delay_slots (int non_jumps_p)
} }
mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL); mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL);
if (filter_flags)
{
mark_set_resources (trial, &fset, 0, MARK_SRC_DEST_CALL);
/* If the flags register is set, then it doesn't create RAW
dependencies any longer and it also doesn't create WAW
dependencies since it's dead after the original insn. */
if (TEST_HARD_REG_BIT (fset.regs, targetm.flags_regnum))
{
CLEAR_HARD_REG_BIT (needed.regs, targetm.flags_regnum);
CLEAR_HARD_REG_BIT (fset.regs, targetm.flags_regnum);
}
}
mark_referenced_resources (trial, &needed, true); mark_referenced_resources (trial, &needed, true);
} }
} }