https://github.com/Thibault-Monnier created https://github.com/llvm/llvm-project/pull/174946
Reverts llvm/llvm-project#171914 because of compilation failures reported. >From db088ceb6c23ab806ee8a2953099da1a5955f267 Mon Sep 17 00:00:00 2001 From: Thibault Monnier <[email protected]> Date: Thu, 8 Jan 2026 11:51:03 +0100 Subject: [PATCH] =?UTF-8?q?Revert=20"[Clang]=20[Lexer]=20Detect=20SSE4.2?= =?UTF-8?q?=20availability=20at=20runtime=20in=20fastParseASC=E2=80=A6"?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This reverts commit 961d52f3304700393b1b03a72c9ad5bb155e851b. --- clang/lib/Lex/Lexer.cpp | 40 ++++++++++------------------------------ 1 file changed, 10 insertions(+), 30 deletions(-) diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp index 5e8ed5f815c7b..afebef0974016 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 @@ -1920,21 +1919,10 @@ 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 a compiler that supports -// the 'target' attribute, which is used for runtime dispatch. Otherwise, we -// fall back to the scalar implementation. -#if (defined(__i386__) || defined(__x86_64__)) && defined(__has_attribute) && \ - __has_attribute(target) && !defined(_MSC_VER) -__attribute__((target("sse4.2"))) static const char * -fastParseASCIIIdentifierSSE42(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', }; @@ -1954,20 +1942,12 @@ fastParseASCIIIdentifierSSE42(const char *CurPtr, const char *BufferEnd) { continue; return CurPtr; } - - return fastParseASCIIIdentifierScalar(CurPtr); -} - -__attribute__((target("sse4.2"))) static const char * -fastParseASCIIIdentifier(const char *CurPtr, const char *BufferEnd) { - return fastParseASCIIIdentifierSSE42(CurPtr, BufferEnd); -} - -__attribute__((target("default"))) #endif -static const char *fastParseASCIIIdentifier(const char *CurPtr, - const char *BufferEnd) { - return fastParseASCIIIdentifierScalar(CurPtr); + + unsigned char C = *CurPtr; + while (isAsciiIdentifierContinue(C)) + C = *++CurPtr; + return CurPtr; } bool Lexer::LexIdentifierContinue(Token &Result, const char *CurPtr) { _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
