http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51821
--- Comment #3 from Uros Bizjak <ubizjak at gmail dot com> 2012-01-11 12:33:59 UTC --- (In reply to comment #2) > I believe this is a target issue. We produce > > test: > .LFB0: > .cfi_startproc > movl 4(%esp), %ecx > movl $-1, %eax > xorl %edx, %edx > sall %cl, %eax > testb $32, %cl > cmovne %eax, %edx <-- wrong > cmovne %edx, %eax > ret > > but as this is a SHIFT_COUNT_TRUNCATED target the sall instruction does > nothing, so shifting DImode by 32 is not implemented correctly on i?86 > (ix86_split_ashl). There is one cmovne too much. -O2 -m32 -msse2 is needed to trigger this bug, without cmove we produce correct code.
