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[Bug target/59968] Unused BT patterns
- From: "hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 28 Jan 2014 17:59:35 +0000
- Subject: [Bug target/59968] Unused BT patterns
- Auto-submitted: auto-generated
- References: <bug-59968-4 at http dot gcc dot gnu dot org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59968
--- Comment #8 from H.J. Lu <hjl.tools at gmail dot com> ---
For
int bar1;
void
__attribute__((noinline))
foo1 (int y)
{
if (!(bar1 & (1 << y)))
bar1 |= 1 << y;
}
we generate
movl bar1(%rip), %eax
btl %edi, %eax
jc .L1
movl $1, %edx
movl %edi, %ecx
sall %cl, %edx
orl %edx, %eax
movl %eax, bar1(%rip)
.L1:
rep ret
I expect:
bts %edi, bar2(%rip)
ret