| commit | e94c31035739b693c3699b3c4cad0206631fbee7 | |
| author | H.J. Lu <hjl.tools@gmail.com> | |
| Tue, 27 Jun 2017 14:55:00 +0000 (27 07:55 -0700) | ||
| committer | H.J. Lu <hjl.tools@gmail.com> | |
| Tue, 27 Jun 2017 14:55:00 +0000 (27 07:55 -0700) | ||
| tree | b0666d325944a10e78d4dd6333c19c108c50d74c | treesnapshot (tar.gz zip) |
| parent | 6980be7cbf4f108a4936ac64242f58340d56c806 | commitdiff |
x86-64: Optimize memcmp-avx2-movbe.S for short difference
Check the first 32 bytes before checking size when size >= 32 bytes
to avoid unnecessary branch if the difference is in the first 32 bytes.
Replace vpmovmskb/subl/jnz with vptest/jnc.
On Haswell, the new version is as fast as the previous one. On Skylake,
the new version is a little bit faster.
* sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S (MEMCMP): Check
the first 32 bytes before checking size when size >= 32 bytes.
Replace vpmovmskb/subl/jnz with vptest/jnc.
Check the first 32 bytes before checking size when size >= 32 bytes
to avoid unnecessary branch if the difference is in the first 32 bytes.
Replace vpmovmskb/subl/jnz with vptest/jnc.
On Haswell, the new version is as fast as the previous one. On Skylake,
the new version is a little bit faster.
* sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S (MEMCMP): Check
the first 32 bytes before checking size when size >= 32 bytes.
Replace vpmovmskb/subl/jnz with vptest/jnc.
| ChangeLog | diffblobblamehistory | |
| sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S | diffblobblamehistory |