Add fused multiply-add vector intrinsics #32066
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This defines the following intrinsics for 128 and 256 bit vectors of f32 and f64: * `fmadd` * `fmaddsub` * `fmsub` * `fmsubadd` * `fnmadd` * `fnmsub` The `_sd` and `_ss` variants are not included yet. Intel intrinsic reference: https://software.intel.com/en-us/node/523929 The intrinsics there are listed under AVX2, but in the Intel Intrinsic Guide they are part of the "FMA" technology, and LLVM puts them under FMA, not AVX2.
The file it generates had been modified, but instead the generator should have been modified, and the file regenerated. This merges the modifications into the template in the generator.
The exact command used was:
$ cd src/etc/platform-intrinsics/x86
$ python2 ../generator.py --format compiler-defs -i info.json \
sse.json sse2.json sse3.json ssse3.json sse41.json sse42.json \
avx.json avx2.json fma.json \
> ../../../librustc_platform_intrinsics/x86.rs
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cc @huonw, you wrote most of the other intrinsics and SIMD support, can you please have a look if you have the time? |
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This adds support for fused multiply-add and multiply-subtract vector intrinsics for 128 and 256-bit vectors of `f32` and `f64`. These correspond to the intrinsics [listed here](https://software.intel.com/en-us/node/523929) except for the `_ss` and `_sd` variants. The intrinsics added are: * `fmadd` * `fmaddsub` * `fmsub` * `fmsubadd` * `fnmadd` * `fnmsub` The “fma” target feature must be enabled by passing `-C target-feature=+fma` to rustc when using these, otherwise LLVM will complain. I verified locally that the `x86_mm256_fmadd_ps` and `x86_mm256_fmsub_ps` work.
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Is there a reason why fma 512 wasn't included? IIRC llvm also has support for these. |
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512-bit FMA instructions are part of AVX-512, not of the FMA instructions. I don’t have a CPU that supports AVX-512. |
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This adds support for fused multiply-add and multiply-subtract vector intrinsics for 128 and 256-bit vectors of
f32andf64. These correspond to the intrinsics listed here except for the_ssand_sdvariants. The intrinsics added are:fmaddfmaddsubfmsubfmsubaddfnmaddfnmsubThe “fma” target feature must be enabled by passing
-C target-feature=+fmato rustc when using these, otherwise LLVM will complain.I verified locally that the
x86_mm256_fmadd_psandx86_mm256_fmsub_pswork.