From: mayshao <[email protected]>
Hi all:
We reply in PR104688 that ZHAOXIN guarantees that 16-byte VMOVDQA on
16-byte aligned address is atomic, if memory type of the address is WB. So
there is no need to clear bit_AVX on ZHAOXIN CPUs.
Bootstrapped /regtested X86_64.
Ok for trunk?
BR
Mayshao
libatomic/ChangeLog:
PR target/104688
* config/x86/init.c (__libat_feat1_init): Don't clear
bit_AVX on ZHAOXIN CPUs.
---
libatomic/config/x86/init.c | 14 --------------
1 file changed, 14 deletions(-)
diff --git a/libatomic/config/x86/init.c b/libatomic/config/x86/init.c
index a75be3f175c..3740c88a936 100644
--- a/libatomic/config/x86/init.c
+++ b/libatomic/config/x86/init.c
@@ -34,20 +34,6 @@ __libat_feat1_init (void)
unsigned int eax, ebx, ecx, edx;
FEAT1_REGISTER = 0;
__get_cpuid (1, &eax, &ebx, &ecx, &edx);
-#ifdef __x86_64__
- if ((FEAT1_REGISTER & (bit_AVX | bit_CMPXCHG16B))
- == (bit_AVX | bit_CMPXCHG16B))
- {
- /* Intel SDM guarantees that 16-byte VMOVDQA on 16-byte aligned address
- is atomic, and AMD is going to do something similar soon.
- We don't have a guarantee from vendors of other CPUs with AVX,
- like Zhaoxin and VIA. */
- unsigned int ecx2 = 0;
- __get_cpuid (0, &eax, &ebx, &ecx2, &edx);
- if (ecx2 != signature_INTEL_ecx && ecx2 != signature_AMD_ecx)
- FEAT1_REGISTER &= ~bit_AVX;
- }
-#endif
/* See the load in load_feat1. */
__atomic_store_n (&__libat_feat1, FEAT1_REGISTER, __ATOMIC_RELAXED);
return FEAT1_REGISTER;
--
2.27.0
