Rollup merge of #132552 - taiki-e:sparc-target-feature, r=workingjubilee

Add v9, v8plus, and leoncasa target feature to sparc and use v8plus in create_object_file

This adds the following three unstable target features:

- `v9`: SPARC-V9 instructions ([LLVM definition][sparc-v9])
  - Relevant to https://github.com/rust-lang/rust/pull/131222#issuecomment-2453310963
  - Relevant to https://github.com/rust-lang/rust/pull/132472#discussion_r1832606081
  - This is also needed to implement https://github.com/taiki-e/atomic-maybe-uninit/pull/31 (depends on inline assembly support) more robustly.
- `v8plus`: SPARC-V8+ ABI ([LLVM definition][sparc-v8plus])
  - This is added in LLVM 20. In LLVM 19 and older, it is emulated to work the same way as LLVM in each LLVM version.
  - See https://github.com/rust-lang/rust/issues/132585#issuecomment-2453926257 for more.
- `leoncasa`: CASA instruction[^1] of LEON3 and LEON4 processors ([LLVM definition][sparc-leoncasa], LLVM feature name: `hasleoncasa`)
  - This is needed to implement https://github.com/taiki-e/atomic-maybe-uninit/pull/31 (depends on inline assembly support) more robustly.

[^1]: Atomic CAS instruction

[sparc-v9]: f5e4ffaa49/llvm/lib/Target/Sparc/Sparc.td (L37-L39)
[sparc-v8plus]: f5e4ffaa49/llvm/lib/Target/Sparc/Sparc.td (L37-L39)
[sparc-leoncasa]: https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/Sparc/LeonFeatures.td#L32-L37

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -228,6 +228,8 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         "x86"
     } else if sess.target.arch == "arm64ec" {
         "aarch64"
+    } else if sess.target.arch == "sparc64" {
+        "sparc"
     } else {
         &*sess.target.arch
     };
@@ -280,6 +282,13 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         // Support for `wide-arithmetic` will first land in LLVM 20 as part of
         // llvm/llvm-project#111598
         ("wasm32" | "wasm64", "wide-arithmetic") if get_version() < (20, 0, 0) => None,
+        ("sparc", "leoncasa") => Some(LLVMFeature::new("hasleoncasa")),
+        // In LLVM 19, there is no `v8plus` feature and `v9` means "SPARC-V9 instruction available and SPARC-V8+ ABI used".
+        // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/Sparc/MCTargetDesc/SparcELFObjectWriter.cpp#L27-L28
+        // Before LLVM 19, there is no `v8plus` feature and `v9` means "SPARC-V9 instruction available".
+        // https://github.com/llvm/llvm-project/blob/llvmorg-18.1.0/llvm/lib/Target/Sparc/MCTargetDesc/SparcELFObjectWriter.cpp#L26
+        ("sparc", "v8plus") if get_version().0 == 19 => Some(LLVMFeature::new("v9")),
+        ("sparc", "v8plus") if get_version().0 < 19 => None,
         (_, s) => Some(LLVMFeature::new(s)),
     }
 }
@@ -619,6 +628,8 @@ pub(crate) fn global_llvm_features(
             .features
             .split(',')
             .filter(|v| !v.is_empty() && backend_feature_name(sess, v).is_some())
+            // Drop +v8plus feature introduced in LLVM 20.
+            .filter(|v| *v != "+v8plus" || get_version() >= (20, 0, 0))
             .map(String::from),
     );
 

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -212,7 +212,7 @@ pub(crate) fn create_object_file(sess: &Session) -> Option<write::Object<'static
         "riscv32" => (Architecture::Riscv32, None),
         "riscv64" => (Architecture::Riscv64, None),
         "sparc" => {
-            if sess.target.options.cpu == "v9" {
+            if sess.unstable_target_features.contains(&sym::v8plus) {
                 // Target uses V8+, aka EM_SPARC32PLUS, aka 64-bit V9 but in 32-bit mode
                 (Architecture::Sparc32Plus, None)
             } else {

compiler/rustc_feature/src/unstable.rs

@@ -336,6 +336,7 @@ pub fn internal(&self, feature: Symbol) -> bool {
     (unstable, riscv_target_feature, "1.45.0", Some(44839)),
     (unstable, rtm_target_feature, "1.35.0", Some(44839)),
     (unstable, s390x_target_feature, "1.82.0", Some(44839)),
+    (unstable, sparc_target_feature, "CURRENT_RUSTC_VERSION", Some(132783)),
     (unstable, sse4a_target_feature, "1.27.0", Some(44839)),
     (unstable, tbm_target_feature, "1.27.0", Some(44839)),
     (unstable, wasm_target_feature, "1.30.0", Some(44839)),

compiler/rustc_span/src/symbol.rs

@@ -1867,6 +1867,7 @@
         slice_patterns,
         slicing_syntax,
         soft,
+        sparc_target_feature,
         specialization,
         speed,
         spotlight,
@@ -2109,6 +2110,7 @@
         usize_legacy_fn_max_value,
         usize_legacy_fn_min_value,
         usize_legacy_mod,
+        v8plus,
         va_arg,
         va_copy,
         va_end,

compiler/rustc_target/src/spec/targets/sparc_unknown_linux_gnu.rs

@@ -14,6 +14,7 @@ pub(crate) fn target() -> Target {
         data_layout: "E-m:e-p:32:32-i64:64-i128:128-f128:64-n32-S64".into(),
         arch: "sparc".into(),
         options: TargetOptions {
+            features: "+v8plus".into(),
             cpu: "v9".into(),
             endian: Endian::Big,
             late_link_args: TargetOptions::link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &[

compiler/rustc_target/src/target_features.rs

@@ -545,6 +545,14 @@ pub fn is_supported(self) -> bool {
     // tidy-alphabetical-end
 ];
 
+const SPARC_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
+    // tidy-alphabetical-start
+    ("leoncasa", Unstable(sym::sparc_target_feature), &[]),
+    ("v8plus", Unstable(sym::sparc_target_feature), &[]),
+    ("v9", Unstable(sym::sparc_target_feature), &[]),
+    // tidy-alphabetical-end
+];
+
 /// When rustdoc is running, provide a list of all known features so that all their respective
 /// primitives may be documented.
 ///
@@ -563,6 +571,7 @@ pub fn all_rust_features() -> impl Iterator<Item = (&'static str, Stability)> {
         .chain(CSKY_FEATURES)
         .chain(LOONGARCH_FEATURES)
         .chain(IBMZ_FEATURES)
+        .chain(SPARC_FEATURES)
         .cloned()
         .map(|(f, s, _)| (f, s))
 }
@@ -582,6 +591,7 @@ pub fn rust_target_features(&self) -> &'static [(&'static str, Stability, Implie
             "csky" => CSKY_FEATURES,
             "loongarch64" => LOONGARCH_FEATURES,
             "s390x" => IBMZ_FEATURES,
+            "sparc" | "sparc64" => SPARC_FEATURES,
             _ => &[],
         }
     }

tests/ui/abi/sparcv8plus.rs

@@ -0,0 +1,43 @@
+//@ revisions: sparc sparcv8plus sparc_cpu_v9 sparc_feature_v8plus sparc_cpu_v9_feature_v8plus
+//@[sparc] compile-flags: --target sparc-unknown-none-elf
+//@[sparc] needs-llvm-components: sparc
+//@[sparcv8plus] compile-flags: --target sparc-unknown-linux-gnu
+//@[sparcv8plus] needs-llvm-components: sparc
+//@[sparc_cpu_v9] compile-flags: --target sparc-unknown-none-elf -C target-cpu=v9
+//@[sparc_cpu_v9] needs-llvm-components: sparc
+//@[sparc_feature_v8plus] compile-flags: --target sparc-unknown-none-elf -C target-feature=+v8plus
+//@[sparc_feature_v8plus] needs-llvm-components: sparc
+//@[sparc_cpu_v9_feature_v8plus] compile-flags: --target sparc-unknown-none-elf -C target-cpu=v9 -C target-feature=+v8plus
+//@[sparc_cpu_v9_feature_v8plus] needs-llvm-components: sparc
+//@ min-llvm-version: 19
+
+#![crate_type = "rlib"]
+#![feature(no_core, rustc_attrs, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+#[rustc_builtin_macro]
+macro_rules! compile_error {
+    () => {};
+}
+
+#[cfg(all(not(target_feature = "v8plus"), not(target_feature = "v9")))]
+compile_error!("-v8plus,-v9");
+//[sparc]~^ ERROR -v8plus,-v9
+
+// FIXME: sparc_cpu_v9 should be in "-v8plus,+v9" group (fixed in LLVM 20)
+#[cfg(all(target_feature = "v8plus", target_feature = "v9"))]
+compile_error!("+v8plus,+v9");
+//[sparcv8plus,sparc_cpu_v9_feature_v8plus,sparc_cpu_v9]~^ ERROR +v8plus,+v9
+
+// FIXME: should be rejected
+#[cfg(all(target_feature = "v8plus", not(target_feature = "v9")))]
+compile_error!("+v8plus,-v9 (FIXME)");
+//[sparc_feature_v8plus]~^ ERROR +v8plus,-v9 (FIXME)
+
+#[cfg(all(not(target_feature = "v8plus"), target_feature = "v9"))]
+compile_error!("-v8plus,+v9");

tests/ui/abi/sparcv8plus.sparc.stderr

@@ -0,0 +1,8 @@
+error: -v8plus,-v9
+  --> $DIR/sparcv8plus.rs:29:1
+   |
+LL | compile_error!("-v8plus,-v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/abi/sparcv8plus.sparc_cpu_v9.stderr

@@ -0,0 +1,8 @@
+error: +v8plus,+v9
+  --> $DIR/sparcv8plus.rs:34:1
+   |
+LL | compile_error!("+v8plus,+v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/abi/sparcv8plus.sparc_cpu_v9_feature_v8plus.stderr

@@ -0,0 +1,8 @@
+error: +v8plus,+v9
+  --> $DIR/sparcv8plus.rs:34:1
+   |
+LL | compile_error!("+v8plus,+v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/abi/sparcv8plus.sparc_feature_v8plus.stderr

@@ -0,0 +1,8 @@
+error: +v8plus,-v9 (FIXME)
+  --> $DIR/sparcv8plus.rs:39:1
+   |
+LL | compile_error!("+v8plus,-v9 (FIXME)");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/abi/sparcv8plus.sparcv8plus.stderr

@@ -0,0 +1,8 @@
+error: +v8plus,+v9
+  --> $DIR/sparcv8plus.rs:34:1
+   |
+LL | compile_error!("+v8plus,+v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/check-cfg/mix.stderr

@@ -251,7 +251,7 @@ warning: unexpected `cfg` condition value: `zebra`
 LL |     cfg!(target_feature = "zebra");
    |          ^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, and `avx512vpopcntdq` and 247 more
+   = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, and `avx512vpopcntdq` and 250 more
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
 
 warning: 27 warnings emitted

tests/ui/check-cfg/well-known-values.stderr

@@ -174,7 +174,7 @@ warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
 LL |     target_feature = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, `avx512vpopcntdq`, `avxifma`, `avxneconvert`, `avxvnni`, `avxvnniint16`, `avxvnniint8`, `backchain`, `bf16`, `bmi1`, `bmi2`, `bti`, `bulk-memory`, `c`, `cache`, `cmpxchg16b`, `crc`, `crt-static`, `cssc`, `d`, `d32`, `dit`, `doloop`, `dotprod`, `dpb`, `dpb2`, `dsp`, `dsp1e2`, `dspe60`, `e`, `e1`, `e2`, `ecv`, `edsp`, `elrw`, `ermsb`, `exception-handling`, `extended-const`, `f`, `f16c`, `f32mm`, `f64mm`, `faminmax`, `fcma`, `fdivdu`, `fhm`, `flagm`, `flagm2`, `float1e2`, `float1e3`, `float3e4`, `float7e60`, `floate1`, `fma`, `fp-armv8`, `fp16`, `fp64`, `fp8`, `fp8dot2`, `fp8dot4`, `fp8fma`, `fpuv2_df`, `fpuv2_sf`, `fpuv3_df`, `fpuv3_hf`, `fpuv3_hi`, `fpuv3_sf`, `frecipe`, `frintts`, `fxsr`, `gfni`, `hard-float`, `hard-float-abi`, `hard-tp`, `hbc`, `high-registers`, `hvx`, `hvx-length128b`, `hwdiv`, `i8mm`, `jsconv`, `lahfsahf`, `lasx`, `lbt`, `lor`, `lse`, `lse128`, `lse2`, `lsx`, `lut`, `lvz`, `lzcnt`, `m`, `mclass`, `mops`, `movbe`, `mp`, `mp1e2`, `msa`, `mte`, `multivalue`, `mutable-globals`, `neon`, `nontrapping-fptoint`, `nvic`, `paca`, `pacg`, `pan`, `partword-atomics`, `pauth-lr`, `pclmulqdq`, `pmuv3`, `popcnt`, `power10-vector`, `power8-altivec`, `power8-vector`, `power9-altivec`, `power9-vector`, `prfchw`, `quadword-atomics`, `rand`, `ras`, `rclass`, `rcpc`, `rcpc2`, `rcpc3`, `rdm`, `rdrand`, `rdseed`, `reference-types`, `relax`, `relaxed-simd`, `rtm`, `sb`, `sha`, `sha2`, `sha3`, `sha512`, `sign-ext`, `simd128`, `sm3`, `sm4`, `sme`, `sme-b16b16`, `sme-f16f16`, `sme-f64f64`, `sme-f8f16`, `sme-f8f32`, `sme-fa64`, `sme-i16i64`, `sme-lutv2`, `sme2`, `sme2p1`, `spe`, `ssbs`, `sse`, `sse2`, `sse3`, `sse4.1`, `sse4.2`, `sse4a`, `ssse3`, `ssve-fp8dot2`, `ssve-fp8dot4`, `ssve-fp8fma`, `sve`, `sve-b16b16`, `sve2`, `sve2-aes`, `sve2-bitperm`, `sve2-sha3`, `sve2-sm4`, `sve2p1`, `tbm`, `thumb-mode`, `thumb2`, `tme`, `trust`, `trustzone`, `ual`, `unaligned-scalar-mem`, `v`, `v5te`, `v6`, `v6k`, `v6t2`, `v7`, `v8`, `v8.1a`, `v8.2a`, `v8.3a`, `v8.4a`, `v8.5a`, `v8.6a`, `v8.7a`, `v8.8a`, `v8.9a`, `v9.1a`, `v9.2a`, `v9.3a`, `v9.4a`, `v9.5a`, `v9a`, `vaes`, `vdsp2e60f`, `vdspv1`, `vdspv2`, `vector`, `vfp2`, `vfp3`, `vfp4`, `vh`, `virt`, `virtualization`, `vpclmulqdq`, `vsx`, `wfxt`, `wide-arithmetic`, `xop`, `xsave`, `xsavec`, `xsaveopt`, `xsaves`, `zaamo`, `zabha`, `zalrsc`, `zba`, `zbb`, `zbc`, `zbkb`, `zbkc`, `zbkx`, `zbs`, `zdinx`, `zfh`, `zfhmin`, `zfinx`, `zhinx`, `zhinxmin`, `zk`, `zkn`, `zknd`, `zkne`, `zknh`, `zkr`, `zks`, `zksed`, `zksh`, and `zkt`
+   = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, `avx512vpopcntdq`, `avxifma`, `avxneconvert`, `avxvnni`, `avxvnniint16`, `avxvnniint8`, `backchain`, `bf16`, `bmi1`, `bmi2`, `bti`, `bulk-memory`, `c`, `cache`, `cmpxchg16b`, `crc`, `crt-static`, `cssc`, `d`, `d32`, `dit`, `doloop`, `dotprod`, `dpb`, `dpb2`, `dsp`, `dsp1e2`, `dspe60`, `e`, `e1`, `e2`, `ecv`, `edsp`, `elrw`, `ermsb`, `exception-handling`, `extended-const`, `f`, `f16c`, `f32mm`, `f64mm`, `faminmax`, `fcma`, `fdivdu`, `fhm`, `flagm`, `flagm2`, `float1e2`, `float1e3`, `float3e4`, `float7e60`, `floate1`, `fma`, `fp-armv8`, `fp16`, `fp64`, `fp8`, `fp8dot2`, `fp8dot4`, `fp8fma`, `fpuv2_df`, `fpuv2_sf`, `fpuv3_df`, `fpuv3_hf`, `fpuv3_hi`, `fpuv3_sf`, `frecipe`, `frintts`, `fxsr`, `gfni`, `hard-float`, `hard-float-abi`, `hard-tp`, `hbc`, `high-registers`, `hvx`, `hvx-length128b`, `hwdiv`, `i8mm`, `jsconv`, `lahfsahf`, `lasx`, `lbt`, `leoncasa`, `lor`, `lse`, `lse128`, `lse2`, `lsx`, `lut`, `lvz`, `lzcnt`, `m`, `mclass`, `mops`, `movbe`, `mp`, `mp1e2`, `msa`, `mte`, `multivalue`, `mutable-globals`, `neon`, `nontrapping-fptoint`, `nvic`, `paca`, `pacg`, `pan`, `partword-atomics`, `pauth-lr`, `pclmulqdq`, `pmuv3`, `popcnt`, `power10-vector`, `power8-altivec`, `power8-vector`, `power9-altivec`, `power9-vector`, `prfchw`, `quadword-atomics`, `rand`, `ras`, `rclass`, `rcpc`, `rcpc2`, `rcpc3`, `rdm`, `rdrand`, `rdseed`, `reference-types`, `relax`, `relaxed-simd`, `rtm`, `sb`, `sha`, `sha2`, `sha3`, `sha512`, `sign-ext`, `simd128`, `sm3`, `sm4`, `sme`, `sme-b16b16`, `sme-f16f16`, `sme-f64f64`, `sme-f8f16`, `sme-f8f32`, `sme-fa64`, `sme-i16i64`, `sme-lutv2`, `sme2`, `sme2p1`, `spe`, `ssbs`, `sse`, `sse2`, `sse3`, `sse4.1`, `sse4.2`, `sse4a`, `ssse3`, `ssve-fp8dot2`, `ssve-fp8dot4`, `ssve-fp8fma`, `sve`, `sve-b16b16`, `sve2`, `sve2-aes`, `sve2-bitperm`, `sve2-sha3`, `sve2-sm4`, `sve2p1`, `tbm`, `thumb-mode`, `thumb2`, `tme`, `trust`, `trustzone`, `ual`, `unaligned-scalar-mem`, `v`, `v5te`, `v6`, `v6k`, `v6t2`, `v7`, `v8`, `v8.1a`, `v8.2a`, `v8.3a`, `v8.4a`, `v8.5a`, `v8.6a`, `v8.7a`, `v8.8a`, `v8.9a`, `v8plus`, `v9`, `v9.1a`, `v9.2a`, `v9.3a`, `v9.4a`, `v9.5a`, `v9a`, `vaes`, `vdsp2e60f`, `vdspv1`, `vdspv2`, `vector`, `vfp2`, `vfp3`, `vfp4`, `vh`, `virt`, `virtualization`, `vpclmulqdq`, `vsx`, `wfxt`, `wide-arithmetic`, `xop`, `xsave`, `xsavec`, `xsaveopt`, `xsaves`, `zaamo`, `zabha`, `zalrsc`, `zba`, `zbb`, `zbc`, `zbkb`, `zbkc`, `zbkx`, `zbs`, `zdinx`, `zfh`, `zfhmin`, `zfinx`, `zhinx`, `zhinxmin`, `zk`, `zkn`, `zknd`, `zkne`, `zknh`, `zkr`, `zks`, `zksed`, `zksh`, and `zkt`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`

tests/ui/target-feature/gate.rs

@@ -23,6 +23,7 @@
 // gate-test-lahfsahf_target_feature
 // gate-test-prfchw_target_feature
 // gate-test-s390x_target_feature
+// gate-test-sparc_target_feature
 
 #[target_feature(enable = "avx512bw")]
 //~^ ERROR: currently unstable

tests/ui/target-feature/gate.stderr

@@ -1,5 +1,5 @@
 error[E0658]: the target feature `avx512bw` is currently unstable
-  --> $DIR/gate.rs:27:18
+  --> $DIR/gate.rs:28:18
    |
 LL | #[target_feature(enable = "avx512bw")]
    |                  ^^^^^^^^^^^^^^^^^^^