This peephole transforms
lis a,HI ; ori a,a,LO
cmpw c,a,b ; beq c,...
to
xoris a,b,HI1
cmpwi c,a,LO1 ; beq c,...
when a and c are dead after this. But it forgets to check that a and b
are not the same reg, generating non-sensical code. This patch fixes that.
Tested etc.; is this okay for trunk?
(This peephole caused some FAILs in the testsuite after an unrelated change;
gone after this patch).
Segher
2015-05-08 Segher Boessenkool <seg...@kernel.crashing.org>
* config/rs6000/rs6000.md: Require operand inequality in one
of the peepholes.
---
gcc/config/rs6000/rs6000.md | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 0178bf4..463bd3c 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -11954,7 +11954,8 @@ (define_peephole2
(match_operand 7 "" "")
(match_operand 8 "" "")))]
"peep2_reg_dead_p (3, operands[0])
- && peep2_reg_dead_p (4, operands[4])"
+ && peep2_reg_dead_p (4, operands[4])
+ && REGNO (operands[0]) != REGNO (operands[5])"
[(set (match_dup 0) (xor:SI (match_dup 5) (match_dup 9)))
(set (match_dup 4) (compare:CC (match_dup 0) (match_dup 10)))
(set (pc) (if_then_else (match_dup 6) (match_dup 7) (match_dup 8)))]
--
1.8.1.4
