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Matthias Krüger
7d63382000
Stabilize s390x `vector` target feature and `is_s390x_feature_detected!` macro closes https://github.com/rust-lang/rust/issues/145649 closes https://github.com/rust-lang/rust/issues/135413 cc: https://github.com/rust-lang/rust/issues/130869 reference PR: https://github.com/rust-lang/reference/pull/1972 # Stabilization report ## Summary This PR stabilizes the following s390x target features: - `vector` - `vector-enhancements-1` - `vector-enhancements-2` - `vector-enhancements-3` - `vector-packed-decimal` - `vector-packed-decimal-enhancement` - `vector-packed-decimal-enhancement-2` - `vector-packed-decimal-enhancement-3` - `nnp-assist` - `miscellaneous-extensions-2` - `miscellaneous-extensions-3` - `miscellaneous-extensions-4` Additionally, it stabilizes the `std::arch::is_s390x_feature_detected!` macro itself and stably accepts the target features listed above. ## Tests & ABI details Only the `vector` target feature changes the ABI, much like e.g. `avx2` it will, depending on the ABI, pass vector types in vector registers. This behavior is tested extensively: - [tests/assembly-llvm/s390x-vector-abi.rs](https://github.com/rust-lang/rust/blob/22a86f8280becb12c34ee3efd952baf5cf086fa0/tests/assembly-llvm/s390x-vector-abi.rs) - [tests/codegen-llvm/s390x-simd.rs](https://github.com/rust-lang/rust/blob/22a86f8280becb12c34ee3efd952baf5cf086fa0/tests/assembly-llvm/s390x-vector-abi.rs) - [tests/ui/abi/simd-abi-checks-s390x.rs ](https://github.com/rust-lang/rust/blob/22a86f8280becb12c34ee3efd952baf5cf086fa0/tests/ui/abi/simd-abi-checks-s390x.rs ) The remaining features don't influence the ABI, they only influence instruction selection. In stdarch we test that the expected instructions are in fact generated when the target feature is enabled. ## Implementation history For `is_s390x_feature_detected!`: - https://github.com/rust-lang/stdarch/pull/1699 - https://github.com/rust-lang/rust/pull/138275 - https://github.com/rust-lang/stdarch/pull/1720 - https://github.com/rust-lang/stdarch/pull/1832 For `vector` and friends - https://github.com/rust-lang/rust/pull/127506 - https://github.com/rust-lang/rust/pull/135630 - https://github.com/rust-lang/rust/pull/141250 ## Unresolved questions There is a fixme in [tests/ui/abi/simd-abi-checks-s390x.rs](https://github.com/rust-lang/rust/blob/22a86f8280becb12c34ee3efd952baf5cf086fa0/tests/ui/abi/simd-abi-checks-s390x.rs): ``` // FIXME: +soft-float itself doesn't set -vector //`@[z13_soft_float]` compile-flags: --target s390x-unknown-linux-gnu -C target-cpu=z13 -C target-feature=-vector,+soft-float //`@[z13_soft_float]` needs-llvm-components: systemz ``` I'm not sure whether that blocks stabilization? --- The implementation first extracts the listed target features into their own `s390x_target_feature_vector` rust feature, and then stabilizes that. best reviewed commit-by-commit r? `@Amanieu` cc `@uweigand` `@taiki-e`