https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98961
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
Please note that LZCNT insn has it own set of problems (e.g.
TARGET_AVOID_FALSE_DEP_FOR_BMI), so I'm not convinced that even:
int z (int i)
{
return i == 0;
}
benefits from using LZCNT:
0: 31 c0 xor %eax,%eax
2: f3 0f bd c7 lzcnt %edi,%eax
6: c1 e8 05 shr $0x5,%eax
9: c3 retq
vs:
0: 31 c0 xor %eax,%eax
2: 85 ff test %edi,%edi
4: 0f 94 c0 sete %al
7: c3 retq
