H.J. Lu 1da50d4bda 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.

2021-03-29 07:40:17 -07:00

..

cpu-features-preferred_feature_index_1.def

x86: Set Prefer_No_VZEROUPPER and add Prefer_AVX2_STRCMP

2021-03-29 07:40:17 -07:00

cpu-features.h

x86: Handle _SC_LEVEL1_ICACHE_LINESIZE [BZ #27444]

2021-03-15 05:43:26 -07:00