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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](22a86f8280/tests/assembly-llvm/s390x-vector-abi.rs) - [tests/codegen-llvm/s390x-simd.rs](22a86f8280/tests/assembly-llvm/s390x-vector-abi.rs) - [tests/ui/abi/simd-abi-checks-s390x.rs ](22a86f8280/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](22a86f8280/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`
The files here use the LLVM FileCheck framework, documented at https://llvm.org/docs/CommandGuide/FileCheck.html.
One extension worth noting is the use of revisions as custom prefixes for FileCheck. If your codegen test has different behavior based on the chosen target or different compiler flags that you want to exercise, you can use a revisions annotation, like so:
// revisions: aaa bbb
// [bbb] compile-flags: --flags-for-bbb
After specifying those variations, you can write different expected, or
explicitly unexpected output by using <prefix>-SAME: and <prefix>-NOT:,
like so:
// CHECK: expected code
// aaa-SAME: emitted-only-for-aaa
// aaa-NOT: emitted-only-for-bbb
// bbb-NOT: emitted-only-for-aaa
// bbb-SAME: emitted-only-for-bbb