jirayu_sri/stockfish
1
0
Fork 0
mirror of https://github.com/official-stockfish/Stockfish.git synced 2026-07-22 20:57:10 +00:00
Code Issues Packages Projects Releases Wiki Activity

Disable PEXT on AMD Excavator CPUs

Browse Source 
Excavator also supports BMI2, where it has the same microcoded performance implications as on Zen pre-3.

closes https://github.com/official-stockfish/Stockfish/pull/6868

No functional change
This commit is contained in:
Ciekce
2026-06-06 09:58:43 +02:00
committed by Joost VandeVondele
parent 91045b2ff6
commit 0c1001c93e
2 changed files with 12 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/universal/entry_x86.cpp
+4 -3
View File
@@ -67,16 +67,17 @@ DEFINE_BUILD(x86_64_avx512)
DEFINE_BUILD(x86_64_vnni512)
DEFINE_BUILD(x86_64_avx512icl)
// AMD Zen/Zen+/Zen2 (family 17h) implement pdep/pext via microcode.
// AMD Excavator (family 15h) and Zen/Zen+/Zen2 (family 17h) implement pdep/pext via microcode.
static bool has_slow_bmi2() {
return __builtin_cpu_is("amd") && (__builtin_cpu_is("znver1") || __builtin_cpu_is("znver2"));
return __builtin_cpu_is("amd")
&& (__builtin_cpu_is("bdver4") || __builtin_cpu_is("znver1") || __builtin_cpu_is("znver2"));
}
struct CpuFeatures {
bool sse41; // SSE4.1
bool popcnt; // POPCNT
bool avx2; // AVX2
bool bmi2; // BMI2 (may be slow on AMD Zen/Zen+/Zen2)
bool bmi2; // BMI2 (may be slow on AMD Excavator and Zen/Zen+/Zen2)
bool avx512f; // AVX-512 Foundation
bool avx512vl; // AVX-512 Vector Length extensions
bool avx512bw; // AVX-512 Byte and Word instructions