stabilize s390x vector registers#2215
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| | s390x | `vreg` | `v[0-31]` | Only clobbers | | ||
| | s390x | `vreg` | `v[0-31]` | `v` | |
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| > [!NOTE] | ||
| > If the value's type is smaller than the register, the value of the upper bits is platform-specific. Some targets zero out the upper bits, while others leave them untouched. |
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This came up in the stabilization PR. Amanieu mentions that aarch64 zeros the upper bits, while s390x does not touch them.
This might need some re-phrasing, but I think it's useful to include to prevent future confusion.
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…registers, r=Amanieu stabilize s390x vector registers tracking issue: rust-lang#133416 reference PR: rust-lang/reference#2215 Stabilizes s390x vector registers, e.g. ```rust unsafe fn vreg_128(x: i128) -> i128 { let y; asm!("vlr {}, {}", out(vreg) y, in(vreg) x); y } ``` The types that are accepted for vreg registers are - all float types `f16`, `f32`, `f64`, `f128` - integer types `i32`, `i64` and `i128` and their unsigned counterparts - integer vector types `i8x16`, `i16x8`, `i32x4`, `i64x2` and their unsigned counterparts - float vector types `f16x8`, `f32x4` and `f64x2` Support for all of these is tested in https://github.com/rust-lang/rust/blob/main/tests/assembly-llvm/asm/s390x-types.rs, and the types correspond with the LLVM definition in https://github.com/llvm/llvm-project/blob/df9eb79970c012990e829d174d181d575d414efe/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L312-L339 The `f16`, `f16x8` and `f128` types are unstable, and so can't be used on stable in practice. They do show up in some error messages though. `vreg` was previously only accepted as a clobber. --- Currently the vector types in `core::arch::s390x` are still unstable. Separately stabilizing `vreg` is still useful because scalar types can also be put into `vreg`s. ## Implementation history - rust-lang#131664 - rust-lang#150826 cc @uweigand @taiki-e r? @Amanieu
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Rollup merge of #154184 - folkertdev:stabilize-s390x-vector-registers, r=Amanieu stabilize s390x vector registers tracking issue: #133416 reference PR: rust-lang/reference#2215 Stabilizes s390x vector registers, e.g. ```rust unsafe fn vreg_128(x: i128) -> i128 { let y; asm!("vlr {}, {}", out(vreg) y, in(vreg) x); y } ``` The types that are accepted for vreg registers are - all float types `f16`, `f32`, `f64`, `f128` - integer types `i32`, `i64` and `i128` and their unsigned counterparts - integer vector types `i8x16`, `i16x8`, `i32x4`, `i64x2` and their unsigned counterparts - float vector types `f16x8`, `f32x4` and `f64x2` Support for all of these is tested in https://github.com/rust-lang/rust/blob/main/tests/assembly-llvm/asm/s390x-types.rs, and the types correspond with the LLVM definition in https://github.com/llvm/llvm-project/blob/df9eb79970c012990e829d174d181d575d414efe/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L312-L339 The `f16`, `f16x8` and `f128` types are unstable, and so can't be used on stable in practice. They do show up in some error messages though. `vreg` was previously only accepted as a clobber. --- Currently the vector types in `core::arch::s390x` are still unstable. Separately stabilizing `vreg` is still useful because scalar types can also be put into `vreg`s. ## Implementation history - #131664 - #150826 cc @uweigand @taiki-e r? @Amanieu
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cc rust-lang/rust#154184