[PATCH] D97504: [llvm-exegesis] Disable the LBR check on AMD

Tue Mar 9 23:46:49 PST 2021

oontvoo added inline comments.

================
Comment at: llvm/lib/Support/Host.cpp:514-519
+  // "Genu ineI ntel"
+  if (EBX == 0x756e6547 && ECX == 0x6c65746e && EDX == 0x49656e69)
+    return VendorSignatures::GENUINE_INTEL;
+
+  // "Auth enti cAMD"
+  if (EBX == 0x68747541 && ECX == 0x69746e65 && EDX == 0x444d4163)
----------------
ppenzin wrote:
> I think you have ECX and EDX flipped around, vendor string supposed to be read from EBX, EDX, ECX (in order): https://en.wikipedia.org/wiki/CPUID#EAX=0:_Highest_Function_Parameter_and_Manufacturer_ID
> 
> I can observe this patch returning `UNKNOWN` instead of `AUTHENTIC_AMD` on AMD A10 running FreeBSD.
> 
> 
Thanks! The Intel case was correct. ( ECX went first, but its expected value is 0x6c65746e, which is `ntel`)
I've sent to correct the AMD case.https://reviews.llvm.org/D98322

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D97504/new/

https://reviews.llvm.org/D97504