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Rollup merge of #140389 - sayantn:avx512fp16, r=Amanieu

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Remove `avx512dq` and `avx512vl` implication for `avx512fp16`

According to Intel, `avx512fp16` requires only `avx512bw`, but LLVM also enables `avx512vl` and `avx512dq` when `avx512fp16` is active. This is relic code, and will be fixed in LLVM soon. We should remove this from Rust too asap, especially before the stabilization of AVX512

Related:
 - llvm/llvm-project#136209
 - #138940
 - rust-lang/stdarch#1781
 - #111137

``@rustbot`` label O-x86_64 O-x86_32 A-SIMD A-target-feature T-compiler -T-libs
r? ``@Amanieu``

**Update: the LLVM fix has been merged**

cc ``@rust-lang/wg-llvm`` will it be possible to update the rustc llvm version to something after llvm/llvm-project#137450
This commit is contained in:
Stuart Cook
2025-05-02 22:17:02 +10:00
committed by GitHub
parent 30e556e772 7443d039a5
commit 27d419a6b5
6 changed files with 3 additions and 6 deletions
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2
compiler/rustc_target/src/target_features.rs
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@@ -401,7 +401,7 @@ static X86_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
("avx512cd", Unstable(sym::avx512_target_feature), &["avx512f"]),
("avx512dq", Unstable(sym::avx512_target_feature), &["avx512f"]),
("avx512f", Unstable(sym::avx512_target_feature), &["avx2", "fma", "f16c"]),
("avx512fp16", Unstable(sym::avx512_target_feature), &["avx512bw", "avx512vl", "avx512dq"]),
("avx512fp16", Unstable(sym::avx512_target_feature), &["avx512bw"]),
("avx512ifma", Unstable(sym::avx512_target_feature), &["avx512f"]),
("avx512vbmi", Unstable(sym::avx512_target_feature), &["avx512bw"]),
("avx512vbmi2", Unstable(sym::avx512_target_feature), &["avx512bw"]),