As it happens the patch I did over a year ago for PR64682 isn't quite
correct. This is PR69567. This fixes it.
Tested on the separate testcases; also did bootstrap + testsuite on
powerpc64-linux and x86_64-linux. I'll commit this tomorrow or so if
no one sees something wrong with it.
Segher
2016-02-02 Segher Boessenkool <seg...@kernel.crashing.org>
PR rtl-optimization/64682
PR rtl-optimization/69567
* combine.c (distribute_notes) <REG_DEAD>: Place the death note
before I2 only if the register is both used and set in I2.
---
gcc/combine.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/gcc/combine.c b/gcc/combine.c
index ad79c44..7251078 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -13888,6 +13888,7 @@ distribute_notes (rtx notes, rtx_insn *from_insn,
rtx_insn *i3, rtx_insn *i2,
tem_insn = from_insn;
else
{
+ tem_insn = i3;
if (from_insn
&& CALL_P (from_insn)
&& find_reg_fusage (from_insn, USE, XEXP (note, 0)))
@@ -13896,7 +13897,14 @@ distribute_notes (rtx notes, rtx_insn *from_insn,
rtx_insn *i3, rtx_insn *i2,
place = i3;
else if (i2 != 0 && next_nonnote_nondebug_insn (i2) == i3
&& reg_referenced_p (XEXP (note, 0), PATTERN (i2)))
- place = i2;
+ {
+ place = i2;
+ /* If the new I2 sets the same register that is marked dead
+ in the note, the note now should not be put on I2, as the
+ note refers to a previous incarnation of the reg. */
+ if (reg_set_p (XEXP (note, 0), PATTERN (i2)))
+ tem_insn = i2;
+ }
else if ((rtx_equal_p (XEXP (note, 0), elim_i2)
&& !(i2mod
&& reg_overlap_mentioned_p (XEXP (note, 0),
@@ -13904,12 +13912,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn,
rtx_insn *i3, rtx_insn *i2,
|| rtx_equal_p (XEXP (note, 0), elim_i1)
|| rtx_equal_p (XEXP (note, 0), elim_i0))
break;
- tem_insn = i3;
- /* If the new I2 sets the same register that is marked dead
- in the note, the note now should not be put on I2, as the
- note refers to a previous incarnation of the reg. */
- if (i2 != 0 && reg_set_p (XEXP (note, 0), PATTERN (i2)))
- tem_insn = i2;
}
if (place == 0)
--
1.9.3
