Add support for x86 FMA intrinsics#27183
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Implement all 32 FMA intrinsics in a new <fmaintrin.h>, wired into <immintrin.h> and gated on __FMA__. Pass -msimd128 -mfma to enable. Each intrinsic has a dual implementation: - With -mrelaxed-simd, it lowers to Wasm relaxed SIMD fused multiply-add (relaxed_madd / relaxed_nmadd). - With -msimd128 only, it is emulated with separate multiply and add/subtract. The 256-bit AVX variants are emulated by applying the 128-bit operation to each half of the vector. Compiler wiring adds -mfma to the SIMD Intel feature tower and defines __FMA__ accordingly. Documentation is added to the SIMD porting guide and ChangeLog. Tests: - test/sse/test_fma.cpp: self-contained correctness checks covering all 32 intrinsics, run with the emulated path. - test/sse/test_fma_relaxed.cpp: exhaustive comparison against native x86, run with relaxed SIMD.
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This change follows #23035. It adds support for compiling x86 FMA intrinsics to WebAssembly. All 32 FMA intrinsics are implemented in a new <fmaintrin.h>, wired into <immintrin.h> and gated on
__FMA__. Enable with -msimd128 -mfma.Each intrinsic has a dual implementation:
The 256-bit AVX variants are emulated by applying the 128-bit operation to each half of the vector. Compiler wiring adds -mfma to the SIMD Intel feature tower and defines
__FMA__.Tests: