[clang] [llvm] [Driver,CodeGen] Report error when enabling 64-bit-only features on non-64-bit arch (PR #101151)

[Shengchen Kan via cfe-commits]

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@@ -248,6 +248,10 @@ void x86::getX86TargetFeatures(const Driver &D, const llvm::Triple &Triple,
     Features.push_back(Args.MakeArgString((IsNegative ? "-" : "+") + Name));
   }
 
+  llvm::StringSet<> SubFeaturesOfAPX = {"egpr", "push2pop2", "ppx", "ndd",
+                                        "ccmp", "nf",        "cf",  "zu"};
+  llvm::StringSet<> FeaturesIn64BitOnly = {"uintr"};
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KanRobert wrote:

https://github.com/llvm/llvm-project/pull/101151#issue-2437258242

It's to align with GCC. Compiler won't generate these instructions for `usermsr` and `cmpccxadd` except intrinsic.

For intrinsic, it's not visible in 32-bit mode b/c the macro like `__x86_64` is not defined.
 

https://github.com/llvm/llvm-project/pull/101151