craig.topper added inline comments.
================
Comment at: compiler-rt/lib/scudo/scudo_utils.cpp:85
+ (Ecx == signature_HYGON_ecx);
+ if (!IsIntel && !IsAMD && !IsHygon)
return false;
----------------
fanjinke wrote:
> craig.topper wrote:
> > What's the rationale for the vendor check here anyway? Why isn't the bit in
> > ecx sufficient?
> Using the cpuid instruction to get the vendor id will return the ASCII code
> of the vendor id, which is stored in the ebx,ecx,edx registers.
> The ASCII code in the Hygon CPU is "HygonGenuine", the ecx = "eniu".
> For better differentiation from other cpus in the future, by following
> AMD/Intel way, we use full ASCII code to identify Hygon CPU.
>
Sorry, my question was about why this was restricted to Intel/AMD in the first
place. Why should this code need to be updated every time a new vendor comes
along? Why isn’t checking for sse4.2 regardless of vendor sufficient.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D62368/new/
https://reviews.llvm.org/D62368
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
