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authorH.J. Lu <hjl.tools@gmail.com>2021-02-26 05:36:59 -0800
committerH.J. Lu <hjl.tools@gmail.com>2021-03-29 07:40:17 -0700
commit1da50d4bda07f04135dca39f40e79fc9eabed1f8 (patch)
treebf3a3ffac8850fffcb22dfb889374349f66136b1 /sysdeps/x86_64/tst-avx512.c
parent934d88d862627a0ded8955985b43f5f12aa38046 (diff)
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x86: Set Prefer_No_VZEROUPPER and add Prefer_AVX2_STRCMP
1. Set Prefer_No_VZEROUPPER if RTM is usable to avoid RTM abort triggered
by VZEROUPPER inside a transactionally executing RTM region.
2. Since to compare 2 32-byte strings, 256-bit EVEX strcmp requires 2
loads, 3 VPCMPs and 2 KORDs while AVX2 strcmp requires 1 load, 2 VPCMPEQs,
1 VPMINU and 1 VPMOVMSKB, AVX2 strcmp is faster than EVEX strcmp.  Add
Prefer_AVX2_STRCMP to prefer AVX2 strcmp family functions.
Diffstat (limited to 'sysdeps/x86_64/tst-avx512.c')
0 files changed, 0 insertions, 0 deletions