------- Comment #6 from mikpe at it dot uu dot se 2010-07-25 10:56 -------
My bisection identified r114057 as the cause or trigger for this bug:
http://gcc.gnu.org/ml/gcc-cvs/2006-05/msg00661.html
The assembly code diff for the test case with r114056 and r114057 is:
--- char-neg.s-r114056 2010-07-25 12:22:25.000000000 +0200
+++ char-neg.s-r114057 2010-07-25 12:22:31.000000000 +0200
@@ -57,9 +57,10 @@
movl %edi, %eax
xorl %ebx, %ebx
cmpb $-128, %al
+ movl %edi, %eax
sete %bl
negl %eax
- movsbl %al,%eax
+ subl $256, %eax
movl %ebx, 8(%esp)
movl %eax, 4(%esp)
movl %edi, (%esp)
which looks completely broken. (This is the inlined code for foo() in the loop
in test_neg().)
r114057 was backported to 4.1.2, but for some reason the bug doesn't trigger
there.
--
mikpe at it dot uu dot se changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rakdver at gcc dot gnu dot
| |org
Known to fail|4.3.2 |4.3.2 4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45034
