[clang] [compiler-rt] [llvm] [X86] Support APXF to enable __builtin_cpu_supports. (PR #80636)

[Freddy Ye via cfe-commits]

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@@ -1845,6 +1845,7 @@ bool sys::getHostCPUFeatures(StringMap<bool> &Features) {
   Features["prefetchi"]  = HasLeaf7Subleaf1 && ((EDX >> 14) & 1);
   Features["usermsr"]  = HasLeaf7Subleaf1 && ((EDX >> 15) & 1);
   Features["avx10.1-256"] = HasLeaf7Subleaf1 && ((EDX >> 19) & 1);
+  Features["apxf"] = HasLeaf7Subleaf1 && ((EDX >> 21) & 1);
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FreddyLeaf wrote:

Emm, I happened to find an issue with this patch.
```
$ clang -march=native foo.c -S -emit-llvm 
'-apxf' is not a recognized feature for this target (ignoring feature)
```
It turns out even not adding logics in X86TargetInfo::hasFeature it will still return false for "apxf". I also found "-egpr" is not generated. How did you handle this?

https://github.com/llvm/llvm-project/pull/80636