[clang] [Clang] [Lexer] Detect SSE4.2 availability at runtime in fastParseASCIIIdentifier (PR #171914)

[Thibault Monnier via cfe-commits]

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@@ -1943,12 +1955,20 @@ fastParseASCIIIdentifier(const char *CurPtr,
       continue;
     return CurPtr;
   }
-#endif
 
-  unsigned char C = *CurPtr;
-  while (isAsciiIdentifierContinue(C))
-    C = *++CurPtr;
-  return CurPtr;
+  return fastParseASCIIIdentifierScalar(CurPtr);
+}
+
+__attribute__((target("sse4.2"))) static const char *
+fastParseASCIIIdentifier(const char *CurPtr, const char *BufferEnd) {
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Thibault-Monnier wrote:

I am still unable to reproduce. Are you able to reproduce on godbolt? Sorry for the inconvenience.

https://github.com/llvm/llvm-project/pull/171914