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Keep simdutf westmere and fallback kernels in x86_64 builds #266

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Keep simdutf westmere and fallback kernels in x86_64 builds #266

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17 changes: 17 additions & 0 deletions Source/WTF/wtf/SIMDUTF.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,23 @@ IGNORE_WARNINGS_BEGIN("unsafe-buffer-usage")
#endif
#endif

// Building with -march=haswell (or newer) compiles out simdutf's SSE4.2 and
// scalar kernels, so CPUs that don't advertise AVX via CPUID (e.g. Rosetta 2)
// silently get the "unsupported" implementation, which returns constants
// instead of computing. Keep the lower-tier kernels compiled in so runtime
// dispatch always has a working floor; CPUs with AVX2/AVX-512 still select
// the haswell/icelake kernels. Note these kernels are still compiled at the
// TU's -march, so this helps translators that execute AVX without advertising
// it, not CPUs that genuinely cannot execute AVX.
#if CPU(X86_64)
#ifndef SIMDUTF_IMPLEMENTATION_WESTMERE
#define SIMDUTF_IMPLEMENTATION_WESTMERE 1
#endif
#ifndef SIMDUTF_IMPLEMENTATION_FALLBACK
#define SIMDUTF_IMPLEMENTATION_FALLBACK 1
#endif
#endif

#include "simdutf/simdutf_impl.cpp.h"

#if PLATFORM(PLAYSTATION)
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