Author: Thibault Monnier Date: 2026-01-22T09:58:47+01:00 New Revision: 0e23e6337e73234822f93b40880a0696a8c4adfe
URL: https://github.com/llvm/llvm-project/commit/0e23e6337e73234822f93b40880a0696a8c4adfe DIFF: https://github.com/llvm/llvm-project/commit/0e23e6337e73234822f93b40880a0696a8c4adfe.diff LOG: Revert "[Clang][Lexer] Reland "Detect SSE4.2 availability at runtime in fastP…" This reverts commit 146a919360eb0e4f0ac012050ccc7c0f4593345e. Added: Modified: clang/lib/Lex/Lexer.cpp llvm/include/llvm/Support/Compiler.h Removed: ################################################################################ diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp index 2c4ba70551fab..5e9d2743ba53f 100644 --- a/clang/lib/Lex/Lexer.cpp +++ b/clang/lib/Lex/Lexer.cpp @@ -36,7 +36,6 @@ #include "llvm/Support/NativeFormatting.h" #include "llvm/Support/Unicode.h" #include "llvm/Support/UnicodeCharRanges.h" - #include <algorithm> #include <cassert> #include <cstddef> @@ -46,7 +45,7 @@ #include <optional> #include <string> -#if defined(__i386__) || defined(__x86_64__) +#ifdef __SSE4_2__ #include <nmmintrin.h> #endif @@ -1931,21 +1930,10 @@ bool Lexer::LexUnicodeIdentifierStart(Token &Result, uint32_t C, return true; } -static const char *fastParseASCIIIdentifierScalar(const char *CurPtr) { - unsigned char C = *CurPtr; - while (isAsciiIdentifierContinue(C)) - C = *++CurPtr; - return CurPtr; -} - -// Fast path for lexing ASCII identifiers using SSE4.2 instructions. -// Only enabled on x86/x86_64 when building with __SSE4_2__ enabled, or with a -// compiler and platform that support runtime dispatch. -#if defined(__SSE4_2__) || LLVM_SUPPORTS_RUNTIME_SSE42_CHECK -// LLVM_ATTRIBUTE_USED is a hack to suppress a false-positive warning due to a -// bug in clang-18 and less. See PR175452. -LLVM_ATTRIBUTE_USED LLVM_TARGET_SSE42 static const char * -fastParseASCIIIdentifier(const char *CurPtr, const char *BufferEnd) { +static const char * +fastParseASCIIIdentifier(const char *CurPtr, + [[maybe_unused]] const char *BufferEnd) { +#ifdef __SSE4_2__ alignas(16) static constexpr char AsciiIdentifierRange[16] = { '_', '_', 'A', 'Z', 'a', 'z', '0', '9', }; @@ -1965,19 +1953,13 @@ fastParseASCIIIdentifier(const char *CurPtr, const char *BufferEnd) { continue; return CurPtr; } - - return fastParseASCIIIdentifierScalar(CurPtr); -} #endif -#ifndef __SSE4_2__ -#if LLVM_SUPPORTS_RUNTIME_SSE42_CHECK -LLVM_TARGET_DEFAULT -#endif -static const char *fastParseASCIIIdentifier(const char *CurPtr, const char *) { - return fastParseASCIIIdentifierScalar(CurPtr); + unsigned char C = *CurPtr; + while (isAsciiIdentifierContinue(C)) + C = *++CurPtr; + return CurPtr; } -#endif bool Lexer::LexIdentifierContinue(Token &Result, const char *CurPtr) { // Match [_A-Za-z0-9]*, we have already matched an identifier start. diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h index 4115c3d6060e3..f4bd894021097 100644 --- a/llvm/include/llvm/Support/Compiler.h +++ b/llvm/include/llvm/Support/Compiler.h @@ -762,30 +762,4 @@ void AnnotateIgnoreWritesEnd(const char *file, int line); #endif // clang-format on -/// \macro LLVM_SUPPORTS_RUNTIME_SSE42_CHECK -/// Expands to true if runtime detection of SSE4.2 is supported. -/// This can be used to guard runtime checks for SSE4.2 support. -#if ((defined(__i386__) || defined(__x86_64__)) && defined(__has_attribute) && \ - __has_attribute(target) && !defined(_WIN32)) -#define LLVM_SUPPORTS_RUNTIME_SSE42_CHECK 1 -#else -#define LLVM_SUPPORTS_RUNTIME_SSE42_CHECK 0 -#endif - -/// \macro LLVM_TARGET_DEFAULT -/// Function attribute to compile a function with default target features. -#if defined(__has_attribute) && __has_attribute(target) -#define LLVM_TARGET_DEFAULT __attribute__((target("default"))) -#else -#define LLVM_TARGET_DEFAULT -#endif - -/// \macro LLVM_TARGET_SSE42 -/// Function attribute to compile a function with SSE4.2 enabled. -#if defined(__has_attribute) && __has_attribute(target) -#define LLVM_TARGET_SSE42 __attribute__((target("sse4.2"))) -#else -#define LLVM_TARGET_SSE42 -#endif - #endif _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
