https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94795
Bug ID: 94795
Summary: Failure to use fast sbb method on x86 for spreading
any set bit to all bits
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: gabravier at gmail dot com
Target Milestone: ---
int isNonzero(int x)
{
if (x == 0)
return 0x00000000;
else
return 0xFFFFFFFF;
}
On x86, this can be simplified to a `neg`+`sbb`. LLVM does this transformation,
but GCC doesn't
Comparison here : https://godbolt.org/z/QFz9to
