From 74653b61a67ae7db9f77ea1e09e65e40686c9058 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Fri, 26 Jul 2024 00:05:20 -0400
Subject: Add implied target features to target_feature attribute

---
 compiler/rustc_codegen_llvm/src/llvm_util.rs | 16 ----------------
 1 file changed, 16 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index af8a9be1ccb..dc21b92a95f 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -646,22 +646,6 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
         }
     }
 
-    // This is a workaround for a LLVM bug that doesn't implicitly enable
-    // `simd128` when `relaxed-simd` is.
-    // See <https://github.com/llvm/llvm-project/pull/99803>, which didn't make
-    // it into a released version of LLVM yet.
-    //
-    // This doesn't use the "implicit target feature" system because it is only
-    // used for function attributes in other targets, which fixes this bug as
-    // well on the function attribute level.
-    if sess.target.families.contains(&"wasm".into()) {
-        if features.iter().any(|f| f == "+relaxed-simd")
-            && !features.iter().any(|f| f == "+simd128")
-        {
-            features.push("+simd128".into());
-        }
-    }
-
     if diagnostics && let Some(f) = check_tied_features(sess, &featsmap) {
         sess.dcx().emit_err(TargetFeatureDisableOrEnable {
             features: f,
-- 
cgit 1.4.1-3-g733a5


From fbd618d4aa8f3a6c998b81aa83a543d4c09d9bb3 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Fri, 2 Aug 2024 00:20:49 -0400
Subject: Refactor and fill out target feature lists

---
 compiler/rustc_codegen_gcc/src/gcc_util.rs        |   4 +-
 compiler/rustc_codegen_gcc/src/lib.rs             |   2 +-
 compiler/rustc_codegen_llvm/src/llvm_util.rs      |  28 +-
 compiler/rustc_codegen_ssa/src/target_features.rs |   6 +-
 compiler/rustc_target/src/target_features.rs      | 613 ++++++++++------------
 5 files changed, 293 insertions(+), 360 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_gcc/src/gcc_util.rs b/compiler/rustc_codegen_gcc/src/gcc_util.rs
index 8bb90efe6fb..5308ccdb614 100644
--- a/compiler/rustc_codegen_gcc/src/gcc_util.rs
+++ b/compiler/rustc_codegen_gcc/src/gcc_util.rs
@@ -65,8 +65,8 @@ pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<Stri
 
             let feature = backend_feature_name(s)?;
             // Warn against use of GCC specific feature names on the CLI.
-            if diagnostics && !supported_features.iter().any(|&(v, _)| v == feature) {
-                let rust_feature = supported_features.iter().find_map(|&(rust_feature, _)| {
+            if diagnostics && !supported_features.iter().any(|&(v, _, _)| v == feature) {
+                let rust_feature = supported_features.iter().find_map(|&(rust_feature, _, _)| {
                     let gcc_features = to_gcc_features(sess, rust_feature);
                     if gcc_features.contains(&feature) && !gcc_features.contains(&rust_feature) {
                         Some(rust_feature)
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index cd63a405b67..94f016234f9 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -486,7 +486,7 @@ pub fn target_features(
     sess.target
         .supported_target_features()
         .iter()
-        .filter_map(|&(feature, gate)| {
+        .filter_map(|&(feature, gate, _)| {
             if sess.is_nightly_build() || allow_unstable || gate.is_stable() {
                 Some(feature)
             } else {
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index dc21b92a95f..c70f6dd8180 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -312,7 +312,7 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
     sess.target
         .supported_target_features()
         .iter()
-        .filter_map(|&(feature, gate)| {
+        .filter_map(|&(feature, gate, _)| {
             if sess.is_nightly_build() || allow_unstable || gate.is_stable() {
                 Some(feature)
             } else {
@@ -386,7 +386,7 @@ fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMach
         .target
         .supported_target_features()
         .iter()
-        .map(|(feature, _gate)| {
+        .map(|(feature, _gate, _implied)| {
             // LLVM asserts that these are sorted. LLVM and Rust both use byte comparison for these strings.
             let llvm_feature = to_llvm_features(sess, *feature).llvm_feature_name;
             let desc =
@@ -571,17 +571,19 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
             let feature = backend_feature_name(sess, s)?;
             // Warn against use of LLVM specific feature names and unstable features on the CLI.
             if diagnostics {
-                let feature_state = supported_features.iter().find(|&&(v, _)| v == feature);
+                let feature_state = supported_features.iter().find(|&&(v, _, _)| v == feature);
                 if feature_state.is_none() {
-                    let rust_feature = supported_features.iter().find_map(|&(rust_feature, _)| {
-                        let llvm_features = to_llvm_features(sess, rust_feature);
-                        if llvm_features.contains(feature) && !llvm_features.contains(rust_feature)
-                        {
-                            Some(rust_feature)
-                        } else {
-                            None
-                        }
-                    });
+                    let rust_feature =
+                        supported_features.iter().find_map(|&(rust_feature, _, _)| {
+                            let llvm_features = to_llvm_features(sess, rust_feature);
+                            if llvm_features.contains(feature)
+                                && !llvm_features.contains(rust_feature)
+                            {
+                                Some(rust_feature)
+                            } else {
+                                None
+                            }
+                        });
                     let unknown_feature = if let Some(rust_feature) = rust_feature {
                         UnknownCTargetFeature {
                             feature,
@@ -592,7 +594,7 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
                     };
                     sess.dcx().emit_warn(unknown_feature);
                 } else if feature_state
-                    .is_some_and(|(_name, feature_gate)| !feature_gate.is_stable())
+                    .is_some_and(|(_name, feature_gate, _implied)| !feature_gate.is_stable())
                 {
                     // An unstable feature. Warn about using it.
                     sess.dcx().emit_warn(UnstableCTargetFeature { feature });
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index 24b2c9c51c6..536f39375bb 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -160,7 +160,7 @@ pub(crate) fn provide(providers: &mut Providers) {
                     .target
                     .supported_target_features()
                     .iter()
-                    .map(|&(a, b)| (a.to_string(), b.as_feature_name()))
+                    .map(|&(a, b, _)| (a.to_string(), b.as_feature_name()))
                     .collect()
             }
         },
@@ -168,9 +168,9 @@ pub(crate) fn provide(providers: &mut Providers) {
             let implied_features = tcx
                 .sess
                 .target
-                .implied_target_features()
+                .supported_target_features()
                 .iter()
-                .map(|(f, i)| (Symbol::intern(f), i))
+                .map(|(f, _, i)| (Symbol::intern(f), i))
                 .collect::<FxHashMap<_, _>>();
 
             // implied target features have their own implied target features, so we traverse the
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
index 64f966d7a30..f408db1dcba 100644
--- a/compiler/rustc_target/src/target_features.rs
+++ b/compiler/rustc_target/src/target_features.rs
@@ -53,136 +53,146 @@ impl Stability {
 //
 // Stabilizing a target feature requires t-lang approval.
 
-const ARM_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+type ImpliedFeatures = &'static [&'static str];
+
+const ARM_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("aclass", Unstable(sym::arm_target_feature)),
-    ("aes", Unstable(sym::arm_target_feature)),
-    ("crc", Unstable(sym::arm_target_feature)),
-    ("d32", Unstable(sym::arm_target_feature)),
-    ("dotprod", Unstable(sym::arm_target_feature)),
-    ("dsp", Unstable(sym::arm_target_feature)),
-    ("fp-armv8", Unstable(sym::arm_target_feature)),
-    ("i8mm", Unstable(sym::arm_target_feature)),
-    ("mclass", Unstable(sym::arm_target_feature)),
-    ("neon", Unstable(sym::arm_target_feature)),
-    ("rclass", Unstable(sym::arm_target_feature)),
-    ("sha2", Unstable(sym::arm_target_feature)),
+    ("aclass", Unstable(sym::arm_target_feature), &[]),
+    ("aes", Unstable(sym::arm_target_feature), &["neon"]),
+    ("crc", Unstable(sym::arm_target_feature), &[]),
+    ("d32", Unstable(sym::arm_target_feature), &[]),
+    ("dotprod", Unstable(sym::arm_target_feature), &["neon"]),
+    ("dsp", Unstable(sym::arm_target_feature), &[]),
+    ("fp-armv8", Unstable(sym::arm_target_feature), &["vfp4"]),
+    ("i8mm", Unstable(sym::arm_target_feature), &["neon"]),
+    ("mclass", Unstable(sym::arm_target_feature), &[]),
+    ("neon", Unstable(sym::arm_target_feature), &["vfp3"]),
+    ("rclass", Unstable(sym::arm_target_feature), &[]),
+    ("sha2", Unstable(sym::arm_target_feature), &["neon"]),
     // This is needed for inline assembly, but shouldn't be stabilized as-is
     // since it should be enabled per-function using #[instruction_set], not
     // #[target_feature].
-    ("thumb-mode", Unstable(sym::arm_target_feature)),
-    ("thumb2", Unstable(sym::arm_target_feature)),
-    ("trustzone", Unstable(sym::arm_target_feature)),
-    ("v5te", Unstable(sym::arm_target_feature)),
-    ("v6", Unstable(sym::arm_target_feature)),
-    ("v6k", Unstable(sym::arm_target_feature)),
-    ("v6t2", Unstable(sym::arm_target_feature)),
-    ("v7", Unstable(sym::arm_target_feature)),
-    ("v8", Unstable(sym::arm_target_feature)),
-    ("vfp2", Unstable(sym::arm_target_feature)),
-    ("vfp3", Unstable(sym::arm_target_feature)),
-    ("vfp4", Unstable(sym::arm_target_feature)),
-    ("virtualization", Unstable(sym::arm_target_feature)),
+    ("thumb-mode", Unstable(sym::arm_target_feature), &[]),
+    ("thumb2", Unstable(sym::arm_target_feature), &[]),
+    ("trustzone", Unstable(sym::arm_target_feature), &[]),
+    ("v5te", Unstable(sym::arm_target_feature), &[]),
+    ("v6", Unstable(sym::arm_target_feature), &["v5te"]),
+    ("v6k", Unstable(sym::arm_target_feature), &["v6"]),
+    ("v6t2", Unstable(sym::arm_target_feature), &["v6k", "thumb2"]),
+    ("v7", Unstable(sym::arm_target_feature), &["v6t2"]),
+    ("v8", Unstable(sym::arm_target_feature), &["v7"]),
+    ("vfp2", Unstable(sym::arm_target_feature), &[]),
+    ("vfp3", Unstable(sym::arm_target_feature), &["vfp2", "d32"]),
+    ("vfp4", Unstable(sym::arm_target_feature), &["vfp3"]),
+    ("virtualization", Unstable(sym::arm_target_feature), &[]),
     // tidy-alphabetical-end
 ];
 
-const AARCH64_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
     // FEAT_AES & FEAT_PMULL
-    ("aes", Stable),
+    ("aes", Stable, &["neon"]),
     // FEAT_BF16
-    ("bf16", Stable),
+    ("bf16", Stable, &[]),
     // FEAT_BTI
-    ("bti", Stable),
+    ("bti", Stable, &[]),
     // FEAT_CRC
-    ("crc", Stable),
+    ("crc", Stable, &[]),
     // FEAT_DIT
-    ("dit", Stable),
+    ("dit", Stable, &[]),
     // FEAT_DotProd
-    ("dotprod", Stable),
+    ("dotprod", Stable, &["neon"]),
     // FEAT_DPB
-    ("dpb", Stable),
+    ("dpb", Stable, &[]),
     // FEAT_DPB2
-    ("dpb2", Stable),
+    ("dpb2", Stable, &["dpb"]),
     // FEAT_F32MM
-    ("f32mm", Stable),
+    ("f32mm", Stable, &["sve"]),
     // FEAT_F64MM
-    ("f64mm", Stable),
+    ("f64mm", Stable, &["sve"]),
     // FEAT_FCMA
-    ("fcma", Stable),
+    ("fcma", Stable, &["neon"]),
     // FEAT_FHM
-    ("fhm", Stable),
+    ("fhm", Stable, &["fp16"]),
     // FEAT_FLAGM
-    ("flagm", Stable),
+    ("flagm", Stable, &[]),
     // FEAT_FP16
-    ("fp16", Stable),
+    ("fp16", Stable, &[]),
     // FEAT_FRINTTS
-    ("frintts", Stable),
+    ("frintts", Stable, &[]),
     // FEAT_I8MM
-    ("i8mm", Stable),
+    ("i8mm", Stable, &[]),
     // FEAT_JSCVT
-    ("jsconv", Stable),
+    ("jsconv", Stable, &[]),
     // FEAT_LOR
-    ("lor", Stable),
+    ("lor", Stable, &[]),
     // FEAT_LSE
-    ("lse", Stable),
+    ("lse", Stable, &[]),
     // FEAT_MTE & FEAT_MTE2
-    ("mte", Stable),
+    ("mte", Stable, &[]),
     // FEAT_AdvSimd & FEAT_FP
-    ("neon", Stable),
+    ("neon", Stable, &[]),
     // FEAT_PAUTH (address authentication)
-    ("paca", Stable),
+    ("paca", Stable, &[]),
     // FEAT_PAUTH (generic authentication)
-    ("pacg", Stable),
+    ("pacg", Stable, &[]),
     // FEAT_PAN
-    ("pan", Stable),
+    ("pan", Stable, &[]),
     // FEAT_PMUv3
-    ("pmuv3", Stable),
+    ("pmuv3", Stable, &[]),
     // FEAT_RAND
-    ("rand", Stable),
+    ("rand", Stable, &[]),
     // FEAT_RAS & FEAT_RASv1p1
-    ("ras", Stable),
+    ("ras", Stable, &[]),
     // FEAT_RCPC
-    ("rcpc", Stable),
+    ("rcpc", Stable, &[]),
     // FEAT_RCPC2
-    ("rcpc2", Stable),
+    ("rcpc2", Stable, &["rcpc"]),
     // FEAT_RDM
-    ("rdm", Stable),
+    ("rdm", Stable, &["neon"]),
     // FEAT_SB
-    ("sb", Stable),
+    ("sb", Stable, &[]),
     // FEAT_SHA1 & FEAT_SHA256
-    ("sha2", Stable),
+    ("sha2", Stable, &["neon"]),
     // FEAT_SHA512 & FEAT_SHA3
-    ("sha3", Stable),
+    ("sha3", Stable, &["sha2"]),
     // FEAT_SM3 & FEAT_SM4
-    ("sm4", Stable),
+    ("sm4", Stable, &["neon"]),
     // FEAT_SPE
-    ("spe", Stable),
+    ("spe", Stable, &[]),
     // FEAT_SSBS & FEAT_SSBS2
-    ("ssbs", Stable),
+    ("ssbs", Stable, &[]),
     // FEAT_SVE
-    ("sve", Stable),
+    ("sve", Stable, &[]),
     // FEAT_SVE2
-    ("sve2", Stable),
+    ("sve2", Stable, &["sve"]),
     // FEAT_SVE2_AES
-    ("sve2-aes", Stable),
+    ("sve2-aes", Stable, &["sve2", "aes"]),
     // FEAT_SVE2_BitPerm
-    ("sve2-bitperm", Stable),
+    ("sve2-bitperm", Stable, &["sve2"]),
     // FEAT_SVE2_SHA3
-    ("sve2-sha3", Stable),
+    ("sve2-sha3", Stable, &["sve2", "sha3"]),
     // FEAT_SVE2_SM4
-    ("sve2-sm4", Stable),
+    ("sve2-sm4", Stable, &["sve2", "sm4"]),
     // FEAT_TME
-    ("tme", Stable),
-    ("v8.1a", Unstable(sym::aarch64_ver_target_feature)),
-    ("v8.2a", Unstable(sym::aarch64_ver_target_feature)),
-    ("v8.3a", Unstable(sym::aarch64_ver_target_feature)),
-    ("v8.4a", Unstable(sym::aarch64_ver_target_feature)),
-    ("v8.5a", Unstable(sym::aarch64_ver_target_feature)),
-    ("v8.6a", Unstable(sym::aarch64_ver_target_feature)),
-    ("v8.7a", Unstable(sym::aarch64_ver_target_feature)),
+    ("tme", Stable, &[]),
+    (
+        "v8.1a",
+        Unstable(sym::aarch64_ver_target_feature),
+        &["crc", "lse", "rdm", "pan", "lor", "vh"],
+    ),
+    ("v8.2a", Unstable(sym::aarch64_ver_target_feature), &["v8.1a", "ras", "dpb"]),
+    (
+        "v8.3a",
+        Unstable(sym::aarch64_ver_target_feature),
+        &["v8.2a", "rcpc", "paca", "pacg", "jsconv"],
+    ),
+    ("v8.4a", Unstable(sym::aarch64_ver_target_feature), &["v8.3a", "dotprod", "dit", "flagm"]),
+    ("v8.5a", Unstable(sym::aarch64_ver_target_feature), &["v8.4a", "ssbs", "sb", "dpb2", "bti"]),
+    ("v8.6a", Unstable(sym::aarch64_ver_target_feature), &["v8.5a", "bf16", "i8mm"]),
+    ("v8.7a", Unstable(sym::aarch64_ver_target_feature), &[]),
     // FEAT_VHE
-    ("vh", Stable),
+    ("vh", Stable, &[]),
     // tidy-alphabetical-end
 ];
 
@@ -190,295 +200,223 @@ const AARCH64_TIED_FEATURES: &[&[&str]] = &[
     &["paca", "pacg"], // Together these represent `pauth` in LLVM
 ];
 
-const X86_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const X86_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("adx", Stable),
-    ("aes", Stable),
-    ("amx-bf16", Unstable(sym::x86_amx_intrinsics)),
-    ("amx-complex", Unstable(sym::x86_amx_intrinsics)),
-    ("amx-fp16", Unstable(sym::x86_amx_intrinsics)),
-    ("amx-int8", Unstable(sym::x86_amx_intrinsics)),
-    ("amx-tile", Unstable(sym::x86_amx_intrinsics)),
-    ("avx", Stable),
-    ("avx2", Stable),
-    ("avx512bf16", Unstable(sym::avx512_target_feature)),
-    ("avx512bitalg", Unstable(sym::avx512_target_feature)),
-    ("avx512bw", Unstable(sym::avx512_target_feature)),
-    ("avx512cd", Unstable(sym::avx512_target_feature)),
-    ("avx512dq", Unstable(sym::avx512_target_feature)),
-    ("avx512f", Unstable(sym::avx512_target_feature)),
-    ("avx512fp16", Unstable(sym::avx512_target_feature)),
-    ("avx512ifma", Unstable(sym::avx512_target_feature)),
-    ("avx512vbmi", Unstable(sym::avx512_target_feature)),
-    ("avx512vbmi2", Unstable(sym::avx512_target_feature)),
-    ("avx512vl", Unstable(sym::avx512_target_feature)),
-    ("avx512vnni", Unstable(sym::avx512_target_feature)),
-    ("avx512vp2intersect", Unstable(sym::avx512_target_feature)),
-    ("avx512vpopcntdq", Unstable(sym::avx512_target_feature)),
-    ("avxifma", Unstable(sym::avx512_target_feature)),
-    ("avxneconvert", Unstable(sym::avx512_target_feature)),
-    ("avxvnni", Unstable(sym::avx512_target_feature)),
-    ("avxvnniint16", Unstable(sym::avx512_target_feature)),
-    ("avxvnniint8", Unstable(sym::avx512_target_feature)),
-    ("bmi1", Stable),
-    ("bmi2", Stable),
-    ("cmpxchg16b", Stable),
-    ("ermsb", Unstable(sym::ermsb_target_feature)),
-    ("f16c", Stable),
-    ("fma", Stable),
-    ("fxsr", Stable),
-    ("gfni", Unstable(sym::avx512_target_feature)),
-    ("lahfsahf", Unstable(sym::lahfsahf_target_feature)),
-    ("lzcnt", Stable),
-    ("movbe", Stable),
-    ("pclmulqdq", Stable),
-    ("popcnt", Stable),
-    ("prfchw", Unstable(sym::prfchw_target_feature)),
-    ("rdrand", Stable),
-    ("rdseed", Stable),
-    ("rtm", Unstable(sym::rtm_target_feature)),
-    ("sha", Stable),
-    ("sha512", Unstable(sym::sha512_sm_x86)),
-    ("sm3", Unstable(sym::sha512_sm_x86)),
-    ("sm4", Unstable(sym::sha512_sm_x86)),
-    ("sse", Stable),
-    ("sse2", Stable),
-    ("sse3", Stable),
-    ("sse4.1", Stable),
-    ("sse4.2", Stable),
-    ("sse4a", Unstable(sym::sse4a_target_feature)),
-    ("ssse3", Stable),
-    ("tbm", Unstable(sym::tbm_target_feature)),
-    ("vaes", Unstable(sym::avx512_target_feature)),
-    ("vpclmulqdq", Unstable(sym::avx512_target_feature)),
-    ("xop", Unstable(sym::xop_target_feature)),
-    ("xsave", Stable),
-    ("xsavec", Stable),
-    ("xsaveopt", Stable),
-    ("xsaves", Stable),
+    ("adx", Stable, &[]),
+    ("aes", Stable, &["sse2"]),
+    ("amx-bf16", Unstable(sym::x86_amx_intrinsics), &["amx-tile"]),
+    ("amx-complex", Unstable(sym::x86_amx_intrinsics), &["amx-tile"]),
+    ("amx-fp16", Unstable(sym::x86_amx_intrinsics), &["amx-tile"]),
+    ("amx-int8", Unstable(sym::x86_amx_intrinsics), &["amx-tile"]),
+    ("amx-tile", Unstable(sym::x86_amx_intrinsics), &[]),
+    ("avx", Stable, &["sse4.2"]),
+    ("avx2", Stable, &["avx"]),
+    ("avx512bf16", Unstable(sym::avx512_target_feature), &["avx512bw"]),
+    ("avx512bitalg", Unstable(sym::avx512_target_feature), &["avx512bw"]),
+    ("avx512bw", Unstable(sym::avx512_target_feature), &["avx512f"]),
+    ("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"]),
+    ("avx512ifma", Unstable(sym::avx512_target_feature), &["avx512f"]),
+    ("avx512vbmi", Unstable(sym::avx512_target_feature), &["avx512bw"]),
+    ("avx512vbmi2", Unstable(sym::avx512_target_feature), &["avx512bw"]),
+    ("avx512vl", Unstable(sym::avx512_target_feature), &["avx512f"]),
+    ("avx512vnni", Unstable(sym::avx512_target_feature), &["avx512f"]),
+    ("avx512vp2intersect", Unstable(sym::avx512_target_feature), &["avx512f"]),
+    ("avx512vpopcntdq", Unstable(sym::avx512_target_feature), &["avx512f"]),
+    ("avxifma", Unstable(sym::avx512_target_feature), &["avx2"]),
+    ("avxneconvert", Unstable(sym::avx512_target_feature), &["avx2"]),
+    ("avxvnni", Unstable(sym::avx512_target_feature), &["avx2"]),
+    ("avxvnniint16", Unstable(sym::avx512_target_feature), &["avx2"]),
+    ("avxvnniint8", Unstable(sym::avx512_target_feature), &["avx2"]),
+    ("bmi1", Stable, &[]),
+    ("bmi2", Stable, &[]),
+    ("cmpxchg16b", Stable, &[]),
+    ("ermsb", Unstable(sym::ermsb_target_feature), &[]),
+    ("f16c", Stable, &["avx"]),
+    ("fma", Stable, &["avx"]),
+    ("fxsr", Stable, &[]),
+    ("gfni", Unstable(sym::avx512_target_feature), &["sse2"]),
+    ("lahfsahf", Unstable(sym::lahfsahf_target_feature), &[]),
+    ("lzcnt", Stable, &[]),
+    ("movbe", Stable, &[]),
+    ("pclmulqdq", Stable, &[]),
+    ("popcnt", Stable, &[]),
+    ("prfchw", Unstable(sym::prfchw_target_feature), &[]),
+    ("rdrand", Stable, &[]),
+    ("rdseed", Stable, &[]),
+    ("rtm", Unstable(sym::rtm_target_feature), &[]),
+    ("sha", Stable, &["sse2"]),
+    ("sha512", Unstable(sym::sha512_sm_x86), &["avx2"]),
+    ("sm3", Unstable(sym::sha512_sm_x86), &["avx"]),
+    ("sm4", Unstable(sym::sha512_sm_x86), &["avx2"]),
+    ("sse", Stable, &[]),
+    ("sse2", Stable, &["sse"]),
+    ("sse3", Stable, &["sse2"]),
+    ("sse4.1", Stable, &["ssse3"]),
+    ("sse4.2", Stable, &["sse4.1"]),
+    ("sse4a", Unstable(sym::sse4a_target_feature), &["sse3"]),
+    ("ssse3", Stable, &["sse3"]),
+    ("tbm", Unstable(sym::tbm_target_feature), &[]),
+    ("vaes", Unstable(sym::avx512_target_feature), &["avx2", "aes"]),
+    ("vpclmulqdq", Unstable(sym::avx512_target_feature), &["avx", "pclmulqdq"]),
+    ("xop", Unstable(sym::xop_target_feature), &[/*"fma4", */ "avx", "sse4a"]),
+    ("xsave", Stable, &[]),
+    ("xsavec", Stable, &["xsave"]),
+    ("xsaveopt", Stable, &["xsave"]),
+    ("xsaves", Stable, &["xsave"]),
     // tidy-alphabetical-end
 ];
 
-const HEXAGON_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const HEXAGON_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("hvx", Unstable(sym::hexagon_target_feature)),
-    ("hvx-length128b", Unstable(sym::hexagon_target_feature)),
+    ("hvx", Unstable(sym::hexagon_target_feature), &[]),
+    ("hvx-length128b", Unstable(sym::hexagon_target_feature), &["hvx"]),
     // tidy-alphabetical-end
 ];
 
-const POWERPC_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const POWERPC_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("altivec", Unstable(sym::powerpc_target_feature)),
-    ("power10-vector", Unstable(sym::powerpc_target_feature)),
-    ("power8-altivec", Unstable(sym::powerpc_target_feature)),
-    ("power8-vector", Unstable(sym::powerpc_target_feature)),
-    ("power9-altivec", Unstable(sym::powerpc_target_feature)),
-    ("power9-vector", Unstable(sym::powerpc_target_feature)),
-    ("vsx", Unstable(sym::powerpc_target_feature)),
+    ("altivec", Unstable(sym::powerpc_target_feature), &[]),
+    ("power10-vector", Unstable(sym::powerpc_target_feature), &["power9-vector"]),
+    ("power8-altivec", Unstable(sym::powerpc_target_feature), &["altivec"]),
+    ("power8-vector", Unstable(sym::powerpc_target_feature), &["vsx", "power8-altivec"]),
+    ("power9-altivec", Unstable(sym::powerpc_target_feature), &["power8-altivec"]),
+    ("power9-vector", Unstable(sym::powerpc_target_feature), &["power8-vector", "power9-altivec"]),
+    ("vsx", Unstable(sym::powerpc_target_feature), &["altivec"]),
     // tidy-alphabetical-end
 ];
 
-const MIPS_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const MIPS_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("fp64", Unstable(sym::mips_target_feature)),
-    ("msa", Unstable(sym::mips_target_feature)),
-    ("virt", Unstable(sym::mips_target_feature)),
+    ("fp64", Unstable(sym::mips_target_feature), &[]),
+    ("msa", Unstable(sym::mips_target_feature), &[]),
+    ("virt", Unstable(sym::mips_target_feature), &[]),
     // tidy-alphabetical-end
 ];
 
-const RISCV_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const RISCV_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("a", Stable),
-    ("c", Stable),
-    ("d", Unstable(sym::riscv_target_feature)),
-    ("e", Unstable(sym::riscv_target_feature)),
-    ("f", Unstable(sym::riscv_target_feature)),
-    ("m", Stable),
-    ("relax", Unstable(sym::riscv_target_feature)),
-    ("unaligned-scalar-mem", Unstable(sym::riscv_target_feature)),
-    ("v", Unstable(sym::riscv_target_feature)),
-    ("zba", Stable),
-    ("zbb", Stable),
-    ("zbc", Stable),
-    ("zbkb", Stable),
-    ("zbkc", Stable),
-    ("zbkx", Stable),
-    ("zbs", Stable),
-    ("zdinx", Unstable(sym::riscv_target_feature)),
-    ("zfh", Unstable(sym::riscv_target_feature)),
-    ("zfhmin", Unstable(sym::riscv_target_feature)),
-    ("zfinx", Unstable(sym::riscv_target_feature)),
-    ("zhinx", Unstable(sym::riscv_target_feature)),
-    ("zhinxmin", Unstable(sym::riscv_target_feature)),
-    ("zk", Stable),
-    ("zkn", Stable),
-    ("zknd", Stable),
-    ("zkne", Stable),
-    ("zknh", Stable),
-    ("zkr", Stable),
-    ("zks", Stable),
-    ("zksed", Stable),
-    ("zksh", Stable),
-    ("zkt", Stable),
+    ("a", Stable, &[]),
+    ("c", Stable, &[]),
+    ("d", Unstable(sym::riscv_target_feature), &["f"]),
+    ("e", Unstable(sym::riscv_target_feature), &[]),
+    ("f", Unstable(sym::riscv_target_feature), &[]),
+    ("m", Stable, &[]),
+    ("relax", Unstable(sym::riscv_target_feature), &[]),
+    ("unaligned-scalar-mem", Unstable(sym::riscv_target_feature), &[]),
+    ("v", Unstable(sym::riscv_target_feature), &[]),
+    ("zba", Stable, &[]),
+    ("zbb", Stable, &[]),
+    ("zbc", Stable, &[]),
+    ("zbkb", Stable, &[]),
+    ("zbkc", Stable, &[]),
+    ("zbkx", Stable, &[]),
+    ("zbs", Stable, &[]),
+    ("zdinx", Unstable(sym::riscv_target_feature), &["zfinx"]),
+    ("zfh", Unstable(sym::riscv_target_feature), &["zfhmin"]),
+    ("zfhmin", Unstable(sym::riscv_target_feature), &["f"]),
+    ("zfinx", Unstable(sym::riscv_target_feature), &[]),
+    ("zhinx", Unstable(sym::riscv_target_feature), &["zhinxmin"]),
+    ("zhinxmin", Unstable(sym::riscv_target_feature), &["zfinx"]),
+    ("zk", Stable, &["zkn", "zkr", "zkt"]),
+    ("zkn", Stable, &["zbkb", "zbkc", "zbkx", "zkne", "zknd", "zknh"]),
+    ("zknd", Stable, &[]),
+    ("zkne", Stable, &[]),
+    ("zknh", Stable, &[]),
+    ("zkr", Stable, &[]),
+    ("zks", Stable, &["zbkb", "bzkc", "zbkx", "zksed", "zksh"]),
+    ("zksed", Stable, &[]),
+    ("zksh", Stable, &[]),
+    ("zkt", Stable, &[]),
     // tidy-alphabetical-end
 ];
 
-const WASM_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const WASM_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("atomics", Unstable(sym::wasm_target_feature)),
-    ("bulk-memory", Stable),
-    ("exception-handling", Unstable(sym::wasm_target_feature)),
-    ("extended-const", Stable),
-    ("multivalue", Unstable(sym::wasm_target_feature)),
-    ("mutable-globals", Stable),
-    ("nontrapping-fptoint", Stable),
-    ("reference-types", Unstable(sym::wasm_target_feature)),
-    ("relaxed-simd", Stable),
-    ("sign-ext", Stable),
-    ("simd128", Stable),
+    ("atomics", Unstable(sym::wasm_target_feature), &[]),
+    ("bulk-memory", Stable, &[]),
+    ("exception-handling", Unstable(sym::wasm_target_feature), &[]),
+    ("extended-const", Stable, &[]),
+    ("multivalue", Unstable(sym::wasm_target_feature), &[]),
+    ("mutable-globals", Stable, &[]),
+    ("nontrapping-fptoint", Stable, &[]),
+    ("reference-types", Unstable(sym::wasm_target_feature), &[]),
+    ("relaxed-simd", Stable, &["simd128"]),
+    ("sign-ext", Stable, &[]),
+    ("simd128", Stable, &[]),
     // tidy-alphabetical-end
 ];
 
-const BPF_ALLOWED_FEATURES: &[(&str, Stability)] = &[("alu32", Unstable(sym::bpf_target_feature))];
+const BPF_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] =
+    &[("alu32", Unstable(sym::bpf_target_feature), &[])];
 
-const CSKY_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+const CSKY_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("10e60", Unstable(sym::csky_target_feature)),
-    ("2e3", Unstable(sym::csky_target_feature)),
-    ("3e3r1", Unstable(sym::csky_target_feature)),
-    ("3e3r2", Unstable(sym::csky_target_feature)),
-    ("3e3r3", Unstable(sym::csky_target_feature)),
-    ("3e7", Unstable(sym::csky_target_feature)),
-    ("7e10", Unstable(sym::csky_target_feature)),
-    ("cache", Unstable(sym::csky_target_feature)),
-    ("doloop", Unstable(sym::csky_target_feature)),
-    ("dsp1e2", Unstable(sym::csky_target_feature)),
-    ("dspe60", Unstable(sym::csky_target_feature)),
-    ("e1", Unstable(sym::csky_target_feature)),
-    ("e2", Unstable(sym::csky_target_feature)),
-    ("edsp", Unstable(sym::csky_target_feature)),
-    ("elrw", Unstable(sym::csky_target_feature)),
-    ("float1e2", Unstable(sym::csky_target_feature)),
-    ("float1e3", Unstable(sym::csky_target_feature)),
-    ("float3e4", Unstable(sym::csky_target_feature)),
-    ("float7e60", Unstable(sym::csky_target_feature)),
-    ("floate1", Unstable(sym::csky_target_feature)),
-    ("hard-tp", Unstable(sym::csky_target_feature)),
-    ("high-registers", Unstable(sym::csky_target_feature)),
-    ("hwdiv", Unstable(sym::csky_target_feature)),
-    ("mp", Unstable(sym::csky_target_feature)),
-    ("mp1e2", Unstable(sym::csky_target_feature)),
-    ("nvic", Unstable(sym::csky_target_feature)),
-    ("trust", Unstable(sym::csky_target_feature)),
-    ("vdsp2e60f", Unstable(sym::csky_target_feature)),
-    ("vdspv1", Unstable(sym::csky_target_feature)),
-    ("vdspv2", Unstable(sym::csky_target_feature)),
+    ("10e60", Unstable(sym::csky_target_feature), &["7e10"]),
+    ("2e3", Unstable(sym::csky_target_feature), &["e2"]),
+    ("3e3r1", Unstable(sym::csky_target_feature), &[]),
+    ("3e3r2", Unstable(sym::csky_target_feature), &["3e3r1", "doloop"]),
+    ("3e3r3", Unstable(sym::csky_target_feature), &["doloop"]),
+    ("3e7", Unstable(sym::csky_target_feature), &["2e3"]),
+    ("7e10", Unstable(sym::csky_target_feature), &["3e7"]),
+    ("cache", Unstable(sym::csky_target_feature), &[]),
+    ("doloop", Unstable(sym::csky_target_feature), &[]),
+    ("dsp1e2", Unstable(sym::csky_target_feature), &[]),
+    ("dspe60", Unstable(sym::csky_target_feature), &[]),
+    ("e1", Unstable(sym::csky_target_feature), &["elrw"]),
+    ("e2", Unstable(sym::csky_target_feature), &["e2"]),
+    ("edsp", Unstable(sym::csky_target_feature), &[]),
+    ("elrw", Unstable(sym::csky_target_feature), &[]),
+    ("float1e2", Unstable(sym::csky_target_feature), &[]),
+    ("float1e3", Unstable(sym::csky_target_feature), &[]),
+    ("float3e4", Unstable(sym::csky_target_feature), &[]),
+    ("float7e60", Unstable(sym::csky_target_feature), &[]),
+    ("floate1", Unstable(sym::csky_target_feature), &[]),
+    ("hard-tp", Unstable(sym::csky_target_feature), &[]),
+    ("high-registers", Unstable(sym::csky_target_feature), &[]),
+    ("hwdiv", Unstable(sym::csky_target_feature), &[]),
+    ("mp", Unstable(sym::csky_target_feature), &["2e3"]),
+    ("mp1e2", Unstable(sym::csky_target_feature), &["3e7"]),
+    ("nvic", Unstable(sym::csky_target_feature), &[]),
+    ("trust", Unstable(sym::csky_target_feature), &[]),
+    ("vdsp2e60f", Unstable(sym::csky_target_feature), &[]),
+    ("vdspv1", Unstable(sym::csky_target_feature), &[]),
+    ("vdspv2", Unstable(sym::csky_target_feature), &[]),
     // tidy-alphabetical-end
     //fpu
     // tidy-alphabetical-start
-    ("fdivdu", Unstable(sym::csky_target_feature)),
-    ("fpuv2_df", Unstable(sym::csky_target_feature)),
-    ("fpuv2_sf", Unstable(sym::csky_target_feature)),
-    ("fpuv3_df", Unstable(sym::csky_target_feature)),
-    ("fpuv3_hf", Unstable(sym::csky_target_feature)),
-    ("fpuv3_hi", Unstable(sym::csky_target_feature)),
-    ("fpuv3_sf", Unstable(sym::csky_target_feature)),
-    ("hard-float", Unstable(sym::csky_target_feature)),
-    ("hard-float-abi", Unstable(sym::csky_target_feature)),
-    // tidy-alphabetical-end
-];
-
-const LOONGARCH_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    ("d", Unstable(sym::loongarch_target_feature)),
-    ("f", Unstable(sym::loongarch_target_feature)),
-    ("frecipe", Unstable(sym::loongarch_target_feature)),
-    ("lasx", Unstable(sym::loongarch_target_feature)),
-    ("lbt", Unstable(sym::loongarch_target_feature)),
-    ("lsx", Unstable(sym::loongarch_target_feature)),
-    ("lvz", Unstable(sym::loongarch_target_feature)),
-    ("relax", Unstable(sym::loongarch_target_feature)),
-    ("ual", Unstable(sym::loongarch_target_feature)),
-    // tidy-alphabetical-end
-];
-
-const IBMZ_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    ("backchain", Unstable(sym::s390x_target_feature)),
-    ("vector", Unstable(sym::s390x_target_feature)),
-    // tidy-alphabetical-end
-];
-
-const X86_IMPLIED_FEATURES: &[(&str, &[&str])] = &[
-    // tidy-alphabetical-start
-    ("aes", &["sse2"]),
-    ("avx", &["sse4.2"]),
-    ("avx2", &["avx"]),
-    ("avx512bf16", &["avx512bw"]),
-    ("avx512bitalg", &["avx512bw"]),
-    ("avx512bw", &["avx512f"]),
-    ("avx512cd", &["avx512f"]),
-    ("avx512dq", &["avx512f"]),
-    ("avx512f", &["avx2"]),
-    ("avx512fp16", &["avx512bw", "avx512vl", "avx512dq"]),
-    ("avx512vbmi", &["avx512bw"]),
-    ("avx512vbmi2", &["avx512bw"]),
-    ("avx512vl", &["avx512f"]),
-    ("avx512vnni", &["avx512f"]),
-    ("avx512vp2intersect", &["avx512f"]),
-    ("avx512vpopcntdq", &["avx512f"]),
-    ("f16c", &["avx"]),
-    ("fma", &["avx"]),
-    ("gfni", &["sse2"]),
-    ("pclmulqdq", &["sse2"]),
-    ("sha", &["sse2"]),
-    ("sse2", &["sse"]),
-    ("sse3", &["sse2"]),
-    ("sse4.1", &["ssse3"]),
-    ("sse4.2", &["sse4.1"]),
-    ("ssse3", &["sse3"]),
-    ("vaes", &["avx", "aes"]),
-    ("vpclmulqdq", &["avx", "pclmulqdq"]),
-    ("xsavec", &["xsave"]),
-    ("xsaveopt", &["xsave"]),
-    ("xsaves", &["xsave"]),
-    // tidy-alphabetical-end
-];
-
-const AARCH64_IMPLIED_FEATURES: &[(&str, &[&str])] = &[
-    // tidy-alphabetical-start
-    ("aes", &["neon"]),
-    ("f32mm", &["sve"]),
-    ("f64mm", &["sve"]),
-    ("fcma", &["neon"]),
-    ("fhm", &["fp16"]),
-    ("fp16", &["neon"]),
-    ("jsconv", &["neon"]),
-    ("rcpc2", &["rcpc"]),
-    ("sha2", &["neon"]),
-    ("sha3", &["sha2"]),
-    ("sm4", &["neon"]),
-    ("sve", &["fp16"]),
-    ("sve2", &["sve"]),
-    ("sve2-aes", &["sve2", "aes"]),
-    ("sve2-bitperm", &["sve2"]),
-    ("sve2-sha3", &["sve2", "sha3"]),
-    ("sve2-sm4", &["sve2", "sm4"]),
+    ("fdivdu", Unstable(sym::csky_target_feature), &[]),
+    ("fpuv2_df", Unstable(sym::csky_target_feature), &[]),
+    ("fpuv2_sf", Unstable(sym::csky_target_feature), &[]),
+    ("fpuv3_df", Unstable(sym::csky_target_feature), &[]),
+    ("fpuv3_hf", Unstable(sym::csky_target_feature), &[]),
+    ("fpuv3_hi", Unstable(sym::csky_target_feature), &[]),
+    ("fpuv3_sf", Unstable(sym::csky_target_feature), &[]),
+    ("hard-float", Unstable(sym::csky_target_feature), &[]),
+    ("hard-float-abi", Unstable(sym::csky_target_feature), &[]),
     // tidy-alphabetical-end
 ];
 
-const RISCV_IMPLIED_FEATURES: &[(&str, &[&str])] = &[
+const LOONGARCH_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("zb", &["zba", "zbc", "zbs"]),
-    ("zk", &["zkn", "zkr", "zks", "zkt", "zbkb", "zbkc", "zkbx"]),
-    ("zkn", &["zknd", "zkne", "zknh", "zbkb", "zbkc", "zkbx"]),
-    ("zks", &["zksed", "zksh", "zbkb", "zbkc", "zkbx"]),
+    ("d", Unstable(sym::loongarch_target_feature), &["f"]),
+    ("f", Unstable(sym::loongarch_target_feature), &[]),
+    ("frecipe", Unstable(sym::loongarch_target_feature), &[]),
+    ("lasx", Unstable(sym::loongarch_target_feature), &["lsx"]),
+    ("lbt", Unstable(sym::loongarch_target_feature), &[]),
+    ("lsx", Unstable(sym::loongarch_target_feature), &["d"]),
+    ("lvz", Unstable(sym::loongarch_target_feature), &[]),
+    ("relax", Unstable(sym::loongarch_target_feature), &[]),
+    ("ual", Unstable(sym::loongarch_target_feature), &[]),
     // tidy-alphabetical-end
 ];
 
-const WASM_IMPLIED_FEATURES: &[(&str, &[&str])] = &[
+const IBMZ_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
-    ("relaxed-simd", &["simd128"]),
+    ("backchain", Unstable(sym::s390x_target_feature), &[]),
+    ("vector", Unstable(sym::s390x_target_feature), &[]),
     // tidy-alphabetical-end
 ];
 
@@ -501,10 +439,13 @@ pub fn all_known_features() -> impl Iterator<Item = (&'static str, Stability)> {
         .chain(LOONGARCH_ALLOWED_FEATURES)
         .chain(IBMZ_ALLOWED_FEATURES)
         .cloned()
+        .map(|(f, s, _)| (f, s))
 }
 
 impl super::spec::Target {
-    pub fn supported_target_features(&self) -> &'static [(&'static str, Stability)] {
+    pub fn supported_target_features(
+        &self,
+    ) -> &'static [(&'static str, Stability, ImpliedFeatures)] {
         match &*self.arch {
             "arm" => ARM_ALLOWED_FEATURES,
             "aarch64" | "arm64ec" => AARCH64_ALLOWED_FEATURES,
@@ -528,14 +469,4 @@ impl super::spec::Target {
             _ => &[],
         }
     }
-
-    pub fn implied_target_features(&self) -> &'static [(&'static str, &'static [&'static str])] {
-        match &*self.arch {
-            "aarch4" => AARCH64_IMPLIED_FEATURES,
-            "riscv32" | "riscv64" => RISCV_IMPLIED_FEATURES,
-            "x86" | "x86_64" => X86_IMPLIED_FEATURES,
-            "wasm32" | "wasm64" => WASM_IMPLIED_FEATURES,
-            _ => &[],
-        }
-    }
 }
-- 
cgit 1.4.1-3-g733a5


From 484aca885765739d5fa1f3d77e082552d8c4bc58 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Sat, 3 Aug 2024 04:45:48 -0400
Subject: Don't use LLVM's target features

---
 compiler/rustc_codegen_llvm/src/back/write.rs     |  8 ++-
 compiler/rustc_codegen_llvm/src/context.rs        |  2 +-
 compiler/rustc_codegen_llvm/src/lib.rs            |  2 +-
 compiler/rustc_codegen_llvm/src/llvm_util.rs      | 63 ++++++++++++++++++-----
 compiler/rustc_codegen_ssa/src/target_features.rs | 23 +--------
 compiler/rustc_target/src/target_features.rs      | 25 +++++++++
 6 files changed, 84 insertions(+), 39 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 5a7909d1511..890fcf508a8 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -95,11 +95,15 @@ pub fn write_output_file<'ll>(
     }
 }
 
-pub fn create_informational_target_machine(sess: &Session) -> OwnedTargetMachine {
+pub fn create_informational_target_machine(
+    sess: &Session,
+    extra_features: bool,
+) -> OwnedTargetMachine {
     let config = TargetMachineFactoryConfig { split_dwarf_file: None, output_obj_file: None };
     // Can't use query system here quite yet because this function is invoked before the query
     // system/tcx is set up.
-    let features = llvm_util::global_llvm_features(sess, false);
+    let features =
+        if extra_features { llvm_util::global_llvm_features(sess, false) } else { Vec::new() };
     target_machine_factory(sess, config::OptLevel::No, &features)(config)
         .unwrap_or_else(|err| llvm_err(sess.dcx(), err).raise())
 }
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index ea930421b58..1dc3fbfc7b3 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -149,7 +149,7 @@ pub unsafe fn create_module<'ll>(
 
     // Ensure the data-layout values hardcoded remain the defaults.
     {
-        let tm = crate::back::write::create_informational_target_machine(tcx.sess);
+        let tm = crate::back::write::create_informational_target_machine(tcx.sess, true);
         unsafe {
             llvm::LLVMRustSetDataLayoutFromTargetMachine(llmod, &tm);
         }
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 41e9cfd1066..333f1fdf6e0 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -434,7 +434,7 @@ impl ModuleLlvm {
             ModuleLlvm {
                 llmod_raw,
                 llcx,
-                tm: ManuallyDrop::new(create_informational_target_machine(tcx.sess)),
+                tm: ManuallyDrop::new(create_informational_target_machine(tcx.sess, true)),
             }
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index c70f6dd8180..e85974b7cc1 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -308,7 +308,53 @@ pub fn check_tied_features(
 /// Used to generate cfg variables and apply features
 /// Must express features in the way Rust understands them
 pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
-    let target_machine = create_informational_target_machine(sess);
+    let rust_features = sess
+        .target
+        .supported_target_features()
+        .iter()
+        .map(|(feature, _, _)| {
+            (to_llvm_features(sess, feature).llvm_feature_name, Symbol::intern(feature))
+        })
+        .collect::<FxHashMap<_, _>>();
+
+    let mut features = FxHashSet::default();
+
+    // Add base features for the target
+    let target_machine = create_informational_target_machine(sess, false);
+    features.extend(
+        sess.target
+            .supported_target_features()
+            .iter()
+            .filter(|(feature, _, _)| {
+                // skip checking special features, as LLVM may not understands them
+                if RUSTC_SPECIAL_FEATURES.contains(feature) {
+                    return true;
+                }
+                // check that all features in a given smallvec are enabled
+                for llvm_feature in to_llvm_features(sess, feature) {
+                    let cstr = SmallCStr::new(llvm_feature);
+                    if !unsafe { llvm::LLVMRustHasFeature(&target_machine, cstr.as_ptr()) } {
+                        return false;
+                    }
+                }
+                true
+            })
+            .map(|(feature, _, _)| Symbol::intern(feature)),
+    );
+
+    // Add enabled features
+    for llvm_feature in global_llvm_features(sess, false) {
+        let (add, llvm_feature) = llvm_feature.split_at(1);
+        let feature =
+            rust_features.get(llvm_feature).cloned().unwrap_or(Symbol::intern(llvm_feature));
+        if add == "+" {
+            features.extend(sess.target.implied_target_features(std::iter::once(feature)));
+        } else if add == "-" {
+            features.remove(&feature);
+        }
+    }
+
+    // Filter enabled features based on feature gates
     sess.target
         .supported_target_features()
         .iter()
@@ -320,18 +366,7 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
             }
         })
         .filter(|feature| {
-            // skip checking special features, as LLVM may not understands them
-            if RUSTC_SPECIAL_FEATURES.contains(feature) {
-                return true;
-            }
-            // check that all features in a given smallvec are enabled
-            for llvm_feature in to_llvm_features(sess, feature) {
-                let cstr = SmallCStr::new(llvm_feature);
-                if !unsafe { llvm::LLVMRustHasFeature(&target_machine, cstr.as_ptr()) } {
-                    return false;
-                }
-            }
-            true
+            RUSTC_SPECIAL_FEATURES.contains(feature) || features.contains(&Symbol::intern(feature))
         })
         .map(|feature| Symbol::intern(feature))
         .collect()
@@ -440,7 +475,7 @@ fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMach
 
 pub(crate) fn print(req: &PrintRequest, mut out: &mut String, sess: &Session) {
     require_inited();
-    let tm = create_informational_target_machine(sess);
+    let tm = create_informational_target_machine(sess, true);
     match req.kind {
         PrintKind::TargetCPUs => {
             // SAFETY generate a C compatible string from a byte slice to pass
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index 536f39375bb..c84b844cd04 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -1,6 +1,6 @@
 use rustc_ast::ast;
 use rustc_attr::InstructionSetAttr;
-use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
+use rustc_data_structures::fx::FxIndexSet;
 use rustc_data_structures::unord::{ExtendUnord, UnordMap, UnordSet};
 use rustc_errors::Applicability;
 use rustc_hir::def::DefKind;
@@ -165,26 +165,7 @@ pub(crate) fn provide(providers: &mut Providers) {
             }
         },
         implied_target_features: |tcx, feature| {
-            let implied_features = tcx
-                .sess
-                .target
-                .supported_target_features()
-                .iter()
-                .map(|(f, _, i)| (Symbol::intern(f), i))
-                .collect::<FxHashMap<_, _>>();
-
-            // implied target features have their own implied target features, so we traverse the
-            // map until there are no more features to add
-            let mut features = UnordSet::new();
-            let mut new_features = vec![feature];
-            while let Some(new_feature) = new_features.pop() {
-                if features.insert(new_feature) {
-                    if let Some(implied_features) = implied_features.get(&new_feature) {
-                        new_features.extend(implied_features.iter().copied().map(Symbol::intern))
-                    }
-                }
-            }
-            features
+            tcx.sess.target.implied_target_features(std::iter::once(feature)).into()
         },
         asm_target_features,
         ..*providers
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
index f408db1dcba..0e9979e1bb7 100644
--- a/compiler/rustc_target/src/target_features.rs
+++ b/compiler/rustc_target/src/target_features.rs
@@ -1,3 +1,4 @@
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_span::symbol::{sym, Symbol};
 
 /// Features that control behaviour of rustc, rather than the codegen.
@@ -469,4 +470,28 @@ impl super::spec::Target {
             _ => &[],
         }
     }
+
+    pub fn implied_target_features(
+        &self,
+        base_features: impl Iterator<Item = Symbol>,
+    ) -> FxHashSet<Symbol> {
+        let implied_features = self
+            .supported_target_features()
+            .iter()
+            .map(|(f, _, i)| (Symbol::intern(f), i))
+            .collect::<FxHashMap<_, _>>();
+
+        // implied target features have their own implied target features, so we traverse the
+        // map until there are no more features to add
+        let mut features = FxHashSet::default();
+        let mut new_features = base_features.collect::<Vec<Symbol>>();
+        while let Some(new_feature) = new_features.pop() {
+            if features.insert(new_feature) {
+                if let Some(implied_features) = implied_features.get(&new_feature) {
+                    new_features.extend(implied_features.iter().copied().map(Symbol::intern))
+                }
+            }
+        }
+        features
+    }
 }
-- 
cgit 1.4.1-3-g733a5


From a25da077cf7606f42ffad17ee1562f932aa19b12 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Sat, 3 Aug 2024 23:51:37 -0400
Subject: Don't use LLVM to compute -Ctarget-feature

---
 compiler/rustc_codegen_llvm/src/back/write.rs |   5 +-
 compiler/rustc_codegen_llvm/src/context.rs    |   2 +-
 compiler/rustc_codegen_llvm/src/lib.rs        |   4 +-
 compiler/rustc_codegen_llvm/src/llvm_util.rs  | 211 +++++++++++++-------------
 compiler/rustc_target/src/target_features.rs  |   8 +-
 tests/codegen/target-feature-overrides.rs     |   2 +-
 6 files changed, 120 insertions(+), 112 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 890fcf508a8..a1f2433ab6f 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -97,13 +97,12 @@ pub fn write_output_file<'ll>(
 
 pub fn create_informational_target_machine(
     sess: &Session,
-    extra_features: bool,
+    only_base_features: bool,
 ) -> OwnedTargetMachine {
     let config = TargetMachineFactoryConfig { split_dwarf_file: None, output_obj_file: None };
     // Can't use query system here quite yet because this function is invoked before the query
     // system/tcx is set up.
-    let features =
-        if extra_features { llvm_util::global_llvm_features(sess, false) } else { Vec::new() };
+    let features = llvm_util::global_llvm_features(sess, false, only_base_features);
     target_machine_factory(sess, config::OptLevel::No, &features)(config)
         .unwrap_or_else(|err| llvm_err(sess.dcx(), err).raise())
 }
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 1dc3fbfc7b3..173b8a479ef 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -149,7 +149,7 @@ pub unsafe fn create_module<'ll>(
 
     // Ensure the data-layout values hardcoded remain the defaults.
     {
-        let tm = crate::back::write::create_informational_target_machine(tcx.sess, true);
+        let tm = crate::back::write::create_informational_target_machine(tcx.sess, false);
         unsafe {
             llvm::LLVMRustSetDataLayoutFromTargetMachine(llmod, &tm);
         }
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 333f1fdf6e0..518a86e0cb0 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -269,7 +269,7 @@ impl CodegenBackend for LlvmCodegenBackend {
 
     fn provide(&self, providers: &mut Providers) {
         providers.global_backend_features =
-            |tcx, ()| llvm_util::global_llvm_features(tcx.sess, true)
+            |tcx, ()| llvm_util::global_llvm_features(tcx.sess, true, false)
     }
 
     fn print(&self, req: &PrintRequest, out: &mut String, sess: &Session) {
@@ -434,7 +434,7 @@ impl ModuleLlvm {
             ModuleLlvm {
                 llmod_raw,
                 llcx,
-                tm: ManuallyDrop::new(create_informational_target_machine(tcx.sess, true)),
+                tm: ManuallyDrop::new(create_informational_target_machine(tcx.sess, false)),
             }
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index e85974b7cc1..3190853a84c 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -308,19 +308,10 @@ pub fn check_tied_features(
 /// Used to generate cfg variables and apply features
 /// Must express features in the way Rust understands them
 pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
-    let rust_features = sess
-        .target
-        .supported_target_features()
-        .iter()
-        .map(|(feature, _, _)| {
-            (to_llvm_features(sess, feature).llvm_feature_name, Symbol::intern(feature))
-        })
-        .collect::<FxHashMap<_, _>>();
-
     let mut features = FxHashSet::default();
 
     // Add base features for the target
-    let target_machine = create_informational_target_machine(sess, false);
+    let target_machine = create_informational_target_machine(sess, true);
     features.extend(
         sess.target
             .supported_target_features()
@@ -343,13 +334,16 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
     );
 
     // Add enabled features
-    for llvm_feature in global_llvm_features(sess, false) {
-        let (add, llvm_feature) = llvm_feature.split_at(1);
-        let feature =
-            rust_features.get(llvm_feature).cloned().unwrap_or(Symbol::intern(llvm_feature));
-        if add == "+" {
+    for (enabled, feature) in
+        sess.opts.cg.target_feature.split(',').filter_map(|s| match s.chars().next() {
+            Some('+') => Some((true, Symbol::intern(&s[1..]))),
+            Some('-') => Some((false, Symbol::intern(&s[1..]))),
+            _ => None,
+        })
+    {
+        if enabled {
             features.extend(sess.target.implied_target_features(std::iter::once(feature)));
-        } else if add == "-" {
+        } else {
             features.remove(&feature);
         }
     }
@@ -475,7 +469,7 @@ fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMach
 
 pub(crate) fn print(req: &PrintRequest, mut out: &mut String, sess: &Session) {
     require_inited();
-    let tm = create_informational_target_machine(sess, true);
+    let tm = create_informational_target_machine(sess, false);
     match req.kind {
         PrintKind::TargetCPUs => {
             // SAFETY generate a C compatible string from a byte slice to pass
@@ -523,7 +517,11 @@ pub fn target_cpu(sess: &Session) -> &str {
 
 /// The list of LLVM features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
 /// `--target` and similar).
-pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<String> {
+pub(crate) fn global_llvm_features(
+    sess: &Session,
+    diagnostics: bool,
+    only_base_features: bool,
+) -> Vec<String> {
     // Features that come earlier are overridden by conflicting features later in the string.
     // Typically we'll want more explicit settings to override the implicit ones, so:
     //
@@ -583,96 +581,109 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
     }
 
     // -Ctarget-features
-    let supported_features = sess.target.supported_target_features();
-    let (llvm_major, _, _) = get_version();
-    let mut featsmap = FxHashMap::default();
-    let feats = sess
-        .opts
-        .cg
-        .target_feature
-        .split(',')
-        .filter_map(|s| {
-            let enable_disable = match s.chars().next() {
-                None => return None,
-                Some(c @ ('+' | '-')) => c,
-                Some(_) => {
-                    if diagnostics {
-                        sess.dcx().emit_warn(UnknownCTargetFeaturePrefix { feature: s });
+    if !only_base_features {
+        let supported_features = sess.target.supported_target_features();
+        let (llvm_major, _, _) = get_version();
+        let mut featsmap = FxHashMap::default();
+        let feats = sess
+            .opts
+            .cg
+            .target_feature
+            .split(',')
+            .filter_map(|s| {
+                let enable_disable = match s.chars().next() {
+                    None => return None,
+                    Some(c @ ('+' | '-')) => c,
+                    Some(_) => {
+                        if diagnostics {
+                            sess.dcx().emit_warn(UnknownCTargetFeaturePrefix { feature: s });
+                        }
+                        return None;
                     }
-                    return None;
-                }
-            };
+                };
 
-            let feature = backend_feature_name(sess, s)?;
-            // Warn against use of LLVM specific feature names and unstable features on the CLI.
-            if diagnostics {
-                let feature_state = supported_features.iter().find(|&&(v, _, _)| v == feature);
-                if feature_state.is_none() {
-                    let rust_feature =
-                        supported_features.iter().find_map(|&(rust_feature, _, _)| {
-                            let llvm_features = to_llvm_features(sess, rust_feature);
-                            if llvm_features.contains(feature)
-                                && !llvm_features.contains(rust_feature)
-                            {
-                                Some(rust_feature)
-                            } else {
-                                None
+                let feature = backend_feature_name(sess, s)?;
+                // Warn against use of LLVM specific feature names and unstable features on the CLI.
+                if diagnostics {
+                    let feature_state = supported_features.iter().find(|&&(v, _, _)| v == feature);
+                    if feature_state.is_none() {
+                        let rust_feature =
+                            supported_features.iter().find_map(|&(rust_feature, _, _)| {
+                                let llvm_features = to_llvm_features(sess, rust_feature);
+                                if llvm_features.contains(feature)
+                                    && !llvm_features.contains(rust_feature)
+                                {
+                                    Some(rust_feature)
+                                } else {
+                                    None
+                                }
+                            });
+                        let unknown_feature = if let Some(rust_feature) = rust_feature {
+                            UnknownCTargetFeature {
+                                feature,
+                                rust_feature: PossibleFeature::Some { rust_feature },
                             }
-                        });
-                    let unknown_feature = if let Some(rust_feature) = rust_feature {
-                        UnknownCTargetFeature {
-                            feature,
-                            rust_feature: PossibleFeature::Some { rust_feature },
-                        }
-                    } else {
-                        UnknownCTargetFeature { feature, rust_feature: PossibleFeature::None }
-                    };
-                    sess.dcx().emit_warn(unknown_feature);
-                } else if feature_state
-                    .is_some_and(|(_name, feature_gate, _implied)| !feature_gate.is_stable())
-                {
-                    // An unstable feature. Warn about using it.
-                    sess.dcx().emit_warn(UnstableCTargetFeature { feature });
+                        } else {
+                            UnknownCTargetFeature { feature, rust_feature: PossibleFeature::None }
+                        };
+                        sess.dcx().emit_warn(unknown_feature);
+                    } else if feature_state
+                        .is_some_and(|(_name, feature_gate, _implied)| !feature_gate.is_stable())
+                    {
+                        // An unstable feature. Warn about using it.
+                        sess.dcx().emit_warn(UnstableCTargetFeature { feature });
+                    }
                 }
-            }
 
-            if diagnostics {
-                // FIXME(nagisa): figure out how to not allocate a full hashset here.
-                featsmap.insert(feature, enable_disable == '+');
-            }
+                if diagnostics {
+                    // FIXME(nagisa): figure out how to not allocate a full hashset here.
+                    featsmap.insert(feature, enable_disable == '+');
+                }
 
-            // rustc-specific features do not get passed down to LLVM…
-            if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
-                return None;
-            }
+                // rustc-specific features do not get passed down to LLVM…
+                if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
+                    return None;
+                }
 
-            // if the target-feature is "backchain" and LLVM version is greater than 18
-            // then we also need to add "+backchain" to the target-features attribute.
-            // otherwise, we will only add the naked `backchain` attribute to the attribute-group.
-            if feature == "backchain" && llvm_major < 18 {
-                return None;
-            }
-            // ... otherwise though we run through `to_llvm_features` when
-            // passing requests down to LLVM. This means that all in-language
-            // features also work on the command line instead of having two
-            // different names when the LLVM name and the Rust name differ.
-            let llvm_feature = to_llvm_features(sess, feature);
-
-            Some(
-                std::iter::once(format!("{}{}", enable_disable, llvm_feature.llvm_feature_name))
-                    .chain(llvm_feature.dependency.into_iter().filter_map(move |feat| {
-                        match (enable_disable, feat) {
+                // if the target-feature is "backchain" and LLVM version is greater than 18
+                // then we also need to add "+backchain" to the target-features attribute.
+                // otherwise, we will only add the naked `backchain` attribute to the attribute-group.
+                if feature == "backchain" && llvm_major < 18 {
+                    return None;
+                }
+                // ... otherwise though we run through `to_llvm_features` when
+                // passing requests down to LLVM. This means that all in-language
+                // features also work on the command line instead of having two
+                // different names when the LLVM name and the Rust name differ.
+                let llvm_feature = to_llvm_features(sess, feature);
+
+                Some(
+                    std::iter::once(format!(
+                        "{}{}",
+                        enable_disable, llvm_feature.llvm_feature_name
+                    ))
+                    .chain(llvm_feature.dependency.into_iter().filter_map(
+                        move |feat| match (enable_disable, feat) {
                             ('-' | '+', TargetFeatureFoldStrength::Both(f))
                             | ('+', TargetFeatureFoldStrength::EnableOnly(f)) => {
                                 Some(format!("{enable_disable}{f}"))
                             }
                             _ => None,
-                        }
-                    })),
-            )
-        })
-        .flatten();
-    features.extend(feats);
+                        },
+                    )),
+                )
+            })
+            .flatten();
+        features.extend(feats);
+
+        if diagnostics && let Some(f) = check_tied_features(sess, &featsmap) {
+            sess.dcx().emit_err(TargetFeatureDisableOrEnable {
+                features: f,
+                span: None,
+                missing_features: None,
+            });
+        }
+    }
 
     // -Zfixed-x18
     if sess.opts.unstable_opts.fixed_x18 {
@@ -683,14 +694,6 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
         }
     }
 
-    if diagnostics && let Some(f) = check_tied_features(sess, &featsmap) {
-        sess.dcx().emit_err(TargetFeatureDisableOrEnable {
-            features: f,
-            span: None,
-            missing_features: None,
-        });
-    }
-
     features
 }
 
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
index 0e9979e1bb7..63bdcfddfc5 100644
--- a/compiler/rustc_target/src/target_features.rs
+++ b/compiler/rustc_target/src/target_features.rs
@@ -164,7 +164,13 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // FEAT_SSBS & FEAT_SSBS2
     ("ssbs", Stable, &[]),
     // FEAT_SVE
-    ("sve", Stable, &[]),
+    // It was decided that SVE requires Neon: https://github.com/rust-lang/rust/pull/91608
+    //
+    // LLVM doesn't enable Neon for SVE. ARM indicates that they're separate, but probably always
+    // exist together: https://developer.arm.com/documentation/102340/0100/New-features-in-SVE2
+    //
+    // "For backwards compatibility, Neon and VFP are required in the latest architectures."
+    ("sve", Stable, &["neon"]),
     // FEAT_SVE2
     ("sve2", Stable, &["sve"]),
     // FEAT_SVE2_AES
diff --git a/tests/codegen/target-feature-overrides.rs b/tests/codegen/target-feature-overrides.rs
index 87783706d95..5b7489c96cf 100644
--- a/tests/codegen/target-feature-overrides.rs
+++ b/tests/codegen/target-feature-overrides.rs
@@ -1,7 +1,7 @@
 //@ revisions: COMPAT INCOMPAT
 //@ needs-llvm-components: x86
 //@ compile-flags: --target=x86_64-unknown-linux-gnu -Copt-level=3
-//@ [COMPAT] compile-flags: -Ctarget-feature=+avx2,+avx,+sse4.2,+sse4.1,+ssse3,+sse3
+//@ [COMPAT] compile-flags: -Ctarget-feature=+avx2,+avx
 //@ [INCOMPAT] compile-flags: -Ctarget-feature=-avx2,-avx
 
 // See also tests/assembly/target-feature-multiple.rs
-- 
cgit 1.4.1-3-g733a5


From 500671174444bb53072abf2d7f09211cdcba8315 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Sun, 4 Aug 2024 01:02:53 -0400
Subject: Remove redundant implied features

---
 compiler/rustc_codegen_llvm/src/llvm_util.rs | 36 ++--------------------------
 compiler/rustc_target/src/target_features.rs |  6 +++--
 2 files changed, 6 insertions(+), 36 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 3190853a84c..10cba179c75 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -239,40 +239,8 @@ pub fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> LLVMFeature<'a> {
         }
         // In LLVM neon implicitly enables fp, but we manually enable
         // neon when a feature only implicitly enables fp
-        ("aarch64", "f32mm") => {
-            LLVMFeature::with_dependency("f32mm", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "f64mm") => {
-            LLVMFeature::with_dependency("f64mm", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "fhm") => {
-            LLVMFeature::with_dependency("fp16fml", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "fp16") => {
-            LLVMFeature::with_dependency("fullfp16", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "jsconv") => {
-            LLVMFeature::with_dependency("jsconv", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "sve") => {
-            LLVMFeature::with_dependency("sve", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "sve2") => {
-            LLVMFeature::with_dependency("sve2", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "sve2-aes") => {
-            LLVMFeature::with_dependency("sve2-aes", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "sve2-sm4") => {
-            LLVMFeature::with_dependency("sve2-sm4", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "sve2-sha3") => {
-            LLVMFeature::with_dependency("sve2-sha3", TargetFeatureFoldStrength::EnableOnly("neon"))
-        }
-        ("aarch64", "sve2-bitperm") => LLVMFeature::with_dependency(
-            "sve2-bitperm",
-            TargetFeatureFoldStrength::EnableOnly("neon"),
-        ),
+        ("aarch64", "fhm") => LLVMFeature::new("fp16fml"),
+        ("aarch64", "fp16") => LLVMFeature::new("fullfp16"),
         // In LLVM 18, `unaligned-scalar-mem` was merged with `unaligned-vector-mem` into a single feature called
         // `fast-unaligned-access`. In LLVM 19, it was split back out.
         ("riscv32" | "riscv64", "unaligned-scalar-mem") if get_version().0 == 18 => {
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
index 63bdcfddfc5..746926308b6 100644
--- a/compiler/rustc_target/src/target_features.rs
+++ b/compiler/rustc_target/src/target_features.rs
@@ -118,13 +118,15 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // FEAT_FLAGM
     ("flagm", Stable, &[]),
     // FEAT_FP16
-    ("fp16", Stable, &[]),
+    // Rust ties FP and Neon: https://github.com/rust-lang/rust/pull/91608
+    ("fp16", Stable, &["neon"]),
     // FEAT_FRINTTS
     ("frintts", Stable, &[]),
     // FEAT_I8MM
     ("i8mm", Stable, &[]),
     // FEAT_JSCVT
-    ("jsconv", Stable, &[]),
+    // Rust ties FP and Neon: https://github.com/rust-lang/rust/pull/91608
+    ("jsconv", Stable, &["neon"]),
     // FEAT_LOR
     ("lor", Stable, &[]),
     // FEAT_LSE
-- 
cgit 1.4.1-3-g733a5


From 6b96a60611c5edaa107b109b5a50e58a64a33fc2 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Sun, 4 Aug 2024 15:32:17 -0400
Subject: Add implied features to non-target-feature functions

---
 compiler/rustc_codegen_llvm/src/llvm_util.rs | 26 +++++++++++++++++++++-----
 tests/codegen/target-feature-overrides.rs    |  6 +++---
 tests/codegen/tied-features-strength.rs      |  2 +-
 3 files changed, 25 insertions(+), 9 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 10cba179c75..1a80824a3b7 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -8,6 +8,7 @@ use libc::c_int;
 use rustc_codegen_ssa::base::wants_wasm_eh;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::small_c_str::SmallCStr;
+use rustc_data_structures::unord::UnordSet;
 use rustc_fs_util::path_to_c_string;
 use rustc_middle::bug;
 use rustc_session::config::{PrintKind, PrintRequest};
@@ -553,11 +554,26 @@ pub(crate) fn global_llvm_features(
         let supported_features = sess.target.supported_target_features();
         let (llvm_major, _, _) = get_version();
         let mut featsmap = FxHashMap::default();
-        let feats = sess
-            .opts
-            .cg
-            .target_feature
-            .split(',')
+
+        // insert implied features
+        let mut all_rust_features = vec![];
+        for feature in sess.opts.cg.target_feature.split(',') {
+            match feature.strip_prefix('+') {
+                Some(feature) => all_rust_features.extend(
+                    UnordSet::from(
+                        sess.target
+                            .implied_target_features(std::iter::once(Symbol::intern(feature))),
+                    )
+                    .to_sorted_stable_ord()
+                    .iter()
+                    .map(|s| format!("+{}", s.as_str())),
+                ),
+                _ => all_rust_features.push(feature.to_string()),
+            }
+        }
+
+        let feats = all_rust_features
+            .iter()
             .filter_map(|s| {
                 let enable_disable = match s.chars().next() {
                     None => return None,
diff --git a/tests/codegen/target-feature-overrides.rs b/tests/codegen/target-feature-overrides.rs
index 5b7489c96cf..f38a1ae72de 100644
--- a/tests/codegen/target-feature-overrides.rs
+++ b/tests/codegen/target-feature-overrides.rs
@@ -1,7 +1,7 @@
 //@ revisions: COMPAT INCOMPAT
 //@ needs-llvm-components: x86
 //@ compile-flags: --target=x86_64-unknown-linux-gnu -Copt-level=3
-//@ [COMPAT] compile-flags: -Ctarget-feature=+avx2,+avx
+//@ [COMPAT] compile-flags: -Ctarget-feature=+avx2
 //@ [INCOMPAT] compile-flags: -Ctarget-feature=-avx2,-avx
 
 // See also tests/assembly/target-feature-multiple.rs
@@ -39,8 +39,8 @@ pub unsafe fn banana() -> u32 {
 }
 
 // CHECK: attributes [[APPLEATTRS]]
-// COMPAT-SAME: "target-features"="+avx2,+avx,{{.*}}"
+// COMPAT-SAME: "target-features"="+avx,+avx2,{{.*}}"
 // INCOMPAT-SAME: "target-features"="-avx2,-avx,+avx,{{.*}}"
 // CHECK: attributes [[BANANAATTRS]]
-// COMPAT-SAME: "target-features"="+avx2,+avx,{{.*}}"
+// COMPAT-SAME: "target-features"="+avx,+avx2,{{.*}}"
 // INCOMPAT-SAME: "target-features"="-avx2,-avx"
diff --git a/tests/codegen/tied-features-strength.rs b/tests/codegen/tied-features-strength.rs
index 7f0805bc1b4..1b4596ae2cb 100644
--- a/tests/codegen/tied-features-strength.rs
+++ b/tests/codegen/tied-features-strength.rs
@@ -8,7 +8,7 @@
 // is LLVM-14 we can remove the optional regex matching for this feature.
 
 //@ [ENABLE_SVE] compile-flags: -C target-feature=+sve -Copt-level=0
-// ENABLE_SVE: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(\+sve,?)|(\+neon,?))*}}" }
+// ENABLE_SVE: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(\+sve,?)|(\+neon,?)|(\+fp-armv8,?))*}}" }
 
 //@ [DISABLE_SVE] compile-flags: -C target-feature=-sve -Copt-level=0
 // DISABLE_SVE: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(-sve,?)|(\+neon,?))*}}" }
-- 
cgit 1.4.1-3-g733a5


From 83276f568032f14b1af7e5cd9f7d928734af8d09 Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Sun, 4 Aug 2024 23:51:59 -0400
Subject: Hide implicit target features from diagnostics when possible

---
 compiler/rustc_codegen_gcc/src/attributes.rs       |  2 +-
 compiler/rustc_codegen_llvm/src/attributes.rs      |  2 +-
 compiler/rustc_codegen_ssa/src/target_features.rs  | 28 ++++++++++++++++------
 compiler/rustc_const_eval/src/interpret/call.rs    | 13 +++++++---
 .../rustc_middle/src/middle/codegen_fn_attrs.rs    | 11 ++++++++-
 compiler/rustc_mir_build/src/check_unsafety.rs     | 26 ++++++++++++++++----
 compiler/rustc_mir_transform/src/inline.rs         |  4 +++-
 .../simd_feature_flag_difference.stderr            |  4 ++--
 .../tests/fail/function_calls/target_feature.rs    |  2 +-
 .../fail/function_calls/target_feature.stderr      |  4 ++--
 .../pass/shims/x86/intrinsics-x86-aes-vaes.rs      |  2 +-
 .../tests/pass/shims/x86/intrinsics-x86-avx.rs     |  2 +-
 .../tests/pass/shims/x86/intrinsics-x86-avx2.rs    |  2 +-
 .../tests/pass/shims/x86/intrinsics-x86-avx512.rs  |  2 +-
 .../const-eval/const_fn_target_feature.stderr      |  2 +-
 .../rfc-2396-target_feature-11/safe-calls.stderr   | 26 ++++++++++----------
 16 files changed, 89 insertions(+), 43 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_gcc/src/attributes.rs b/compiler/rustc_codegen_gcc/src/attributes.rs
index e521551304e..5fdf2680aac 100644
--- a/compiler/rustc_codegen_gcc/src/attributes.rs
+++ b/compiler/rustc_codegen_gcc/src/attributes.rs
@@ -75,7 +75,7 @@ pub fn from_fn_attrs<'gcc, 'tcx>(
     let function_features = codegen_fn_attrs
         .target_features
         .iter()
-        .map(|features| features.as_str())
+        .map(|features| features.name.as_str())
         .collect::<Vec<&str>>();
 
     if let Some(features) = check_tied_features(
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index ad38814a68b..876f05c6277 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -496,7 +496,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
     to_add.extend(tune_cpu_attr(cx));
 
     let function_features =
-        codegen_fn_attrs.target_features.iter().map(|f| f.as_str()).collect::<Vec<&str>>();
+        codegen_fn_attrs.target_features.iter().map(|f| f.name.as_str()).collect::<Vec<&str>>();
 
     if let Some(f) = llvm_util::check_tied_features(
         cx.tcx.sess,
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index c84b844cd04..145b1ece230 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -6,6 +6,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE};
 use rustc_middle::bug;
+use rustc_middle::middle::codegen_fn_attrs::TargetFeature;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::parse::feature_err;
@@ -18,7 +19,7 @@ pub fn from_target_feature(
     tcx: TyCtxt<'_>,
     attr: &ast::Attribute,
     supported_target_features: &UnordMap<String, Option<Symbol>>,
-    target_features: &mut Vec<Symbol>,
+    target_features: &mut Vec<TargetFeature>,
 ) {
     let Some(list) = attr.meta_item_list() else { return };
     let bad_item = |span| {
@@ -99,14 +100,27 @@ pub fn from_target_feature(
         }));
     }
 
-    // Add both explicit and implied target features, using a set to deduplicate
-    let mut target_features_set = UnordSet::new();
+    // Add explicit features
+    target_features.extend(
+        added_target_features.iter().copied().map(|name| TargetFeature { name, implied: false }),
+    );
+
+    // Add implied features
+    let mut implied_target_features = UnordSet::new();
     for feature in added_target_features.iter() {
-        target_features_set
+        implied_target_features
             .extend_unord(tcx.implied_target_features(*feature).clone().into_items());
     }
-    target_features_set.extend(added_target_features);
-    target_features.extend(target_features_set.into_sorted_stable_ord())
+    for feature in added_target_features.iter() {
+        implied_target_features.remove(feature);
+    }
+    target_features.extend(
+        implied_target_features
+            .into_sorted_stable_ord()
+            .iter()
+            .copied()
+            .map(|name| TargetFeature { name, implied: true }),
+    )
 }
 
 /// Computes the set of target features used in a function for the purposes of
@@ -115,7 +129,7 @@ fn asm_target_features(tcx: TyCtxt<'_>, did: DefId) -> &FxIndexSet<Symbol> {
     let mut target_features = tcx.sess.unstable_target_features.clone();
     if tcx.def_kind(did).has_codegen_attrs() {
         let attrs = tcx.codegen_fn_attrs(did);
-        target_features.extend(&attrs.target_features);
+        target_features.extend(attrs.target_features.iter().map(|feature| feature.name));
         match attrs.instruction_set {
             None => {}
             Some(InstructionSetAttr::ArmA32) => {
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs
index 2c5147678e8..e5c195f08d7 100644
--- a/compiler/rustc_const_eval/src/interpret/call.rs
+++ b/compiler/rustc_const_eval/src/interpret/call.rs
@@ -317,19 +317,26 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             && attrs
                 .target_features
                 .iter()
-                .any(|feature| !self.tcx.sess.target_features.contains(feature))
+                .any(|feature| !self.tcx.sess.target_features.contains(&feature.name))
         {
+            // Don't include implicit features in the error, unless only implicit features are
+            // missing. This should be rare, because it can only happen when an implicit feature
+            // is disabled, e.g. `+avx2,-avx`
+            let missing_explicit_features = attrs.target_features.iter().any(|feature| {
+                !feature.implied && !self.tcx.sess.target_features.contains(&feature.name)
+            });
             throw_ub_custom!(
                 fluent::const_eval_unavailable_target_features_for_fn,
                 unavailable_feats = attrs
                     .target_features
                     .iter()
-                    .filter(|&feature| !self.tcx.sess.target_features.contains(feature))
+                    .filter(|&feature| !(missing_explicit_features && feature.implied)
+                        && !self.tcx.sess.target_features.contains(&feature.name))
                     .fold(String::new(), |mut s, feature| {
                         if !s.is_empty() {
                             s.push_str(", ");
                         }
-                        s.push_str(feature.as_str());
+                        s.push_str(feature.name.as_str());
                         s
                     }),
             );
diff --git a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
index ff6a3a9c12d..b7d290e58d2 100644
--- a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
+++ b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
@@ -28,7 +28,7 @@ pub struct CodegenFnAttrs {
     pub link_ordinal: Option<u16>,
     /// The `#[target_feature(enable = "...")]` attribute and the enabled
     /// features (only enabled features are supported right now).
-    pub target_features: Vec<Symbol>,
+    pub target_features: Vec<TargetFeature>,
     /// The `#[linkage = "..."]` attribute on Rust-defined items and the value we found.
     pub linkage: Option<Linkage>,
     /// The `#[linkage = "..."]` attribute on foreign items and the value we found.
@@ -51,6 +51,15 @@ pub struct CodegenFnAttrs {
     pub patchable_function_entry: Option<PatchableFunctionEntry>,
 }
 
+#[derive(Copy, Clone, Debug, TyEncodable, TyDecodable, HashStable)]
+pub struct TargetFeature {
+    /// The name of the target feature (e.g. "avx")
+    pub name: Symbol,
+    /// The feature is implied by another feature, rather than explicitly added by the
+    /// `#[target_feature]` attribute
+    pub implied: bool,
+}
+
 #[derive(Copy, Clone, Debug, TyEncodable, TyDecodable, HashStable)]
 pub struct PatchableFunctionEntry {
     /// Nops to prepend to the function
diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index 48018fcaa36..0b4f0632f2b 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -5,6 +5,7 @@ use std::ops::Bound;
 use rustc_errors::DiagArgValue;
 use rustc_hir::def::DefKind;
 use rustc_hir::{self as hir, BindingMode, ByRef, HirId, Mutability};
+use rustc_middle::middle::codegen_fn_attrs::TargetFeature;
 use rustc_middle::mir::BorrowKind;
 use rustc_middle::span_bug;
 use rustc_middle::thir::visit::Visitor;
@@ -31,7 +32,7 @@ struct UnsafetyVisitor<'a, 'tcx> {
     safety_context: SafetyContext,
     /// The `#[target_feature]` attributes of the body. Used for checking
     /// calls to functions with `#[target_feature]` (RFC 2396).
-    body_target_features: &'tcx [Symbol],
+    body_target_features: &'tcx [TargetFeature],
     /// When inside the LHS of an assignment to a field, this is the type
     /// of the LHS and the span of the assignment expression.
     assignment_info: Option<Ty<'tcx>>,
@@ -442,14 +443,29 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                     // is_like_wasm check in hir_analysis/src/collect.rs
                     let callee_features = &self.tcx.codegen_fn_attrs(func_did).target_features;
                     if !self.tcx.sess.target.options.is_like_wasm
-                        && !callee_features
-                            .iter()
-                            .all(|feature| self.body_target_features.contains(feature))
+                        && !callee_features.iter().all(|feature| {
+                            self.body_target_features.iter().any(|f| f.name == feature.name)
+                        })
                     {
+                        // Don't include implicit features in the error, unless only implicit
+                        // features are missing.
+                        let missing_explicit_features = callee_features.iter().any(|feature| {
+                            !feature.implied
+                                && !self.body_target_features.iter().any(|body_feature| {
+                                    !feature.implied && body_feature.name == feature.name
+                                })
+                        });
                         let missing: Vec<_> = callee_features
                             .iter()
                             .copied()
-                            .filter(|feature| !self.body_target_features.contains(feature))
+                            .filter(|feature| {
+                                !(missing_explicit_features && feature.implied)
+                                    && !self
+                                        .body_target_features
+                                        .iter()
+                                        .any(|body_feature| body_feature.name == feature.name)
+                            })
+                            .map(|feature| feature.name)
                             .collect();
                         let build_enabled = self
                             .tcx
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index f30732e6aaf..0f012242c37 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -479,7 +479,9 @@ impl<'tcx> Inliner<'tcx> {
             return Err("incompatible instruction set");
         }
 
-        if callee_attrs.target_features != self.codegen_fn_attrs.target_features {
+        let callee_feature_names = callee_attrs.target_features.iter().map(|f| f.name);
+        let this_feature_names = self.codegen_fn_attrs.target_features.iter().map(|f| f.name);
+        if callee_feature_names.ne(this_feature_names) {
             // In general it is not correct to inline a callee with target features that are a
             // subset of the caller. This is because the callee might contain calls, and the ABI of
             // those calls depends on the target features of the surrounding function. By moving a
diff --git a/src/tools/miri/tests/fail/function_calls/simd_feature_flag_difference.stderr b/src/tools/miri/tests/fail/function_calls/simd_feature_flag_difference.stderr
index 8ebd5d2726f..2544421c7e8 100644
--- a/src/tools/miri/tests/fail/function_calls/simd_feature_flag_difference.stderr
+++ b/src/tools/miri/tests/fail/function_calls/simd_feature_flag_difference.stderr
@@ -1,8 +1,8 @@
-error: Undefined Behavior: calling a function that requires unavailable target features: avx, sse3, sse4.1, sse4.2, ssse3
+error: Undefined Behavior: calling a function that requires unavailable target features: avx
   --> $DIR/simd_feature_flag_difference.rs:LL:CC
    |
 LL |     unsafe { foo(0.0, x) }
-   |              ^^^^^^^^^^^ calling a function that requires unavailable target features: avx, sse3, sse4.1, sse4.2, ssse3
+   |              ^^^^^^^^^^^ calling a function that requires unavailable target features: avx
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
diff --git a/src/tools/miri/tests/fail/function_calls/target_feature.rs b/src/tools/miri/tests/fail/function_calls/target_feature.rs
index 713d7c16f4c..84e01eb4803 100644
--- a/src/tools/miri/tests/fail/function_calls/target_feature.rs
+++ b/src/tools/miri/tests/fail/function_calls/target_feature.rs
@@ -4,7 +4,7 @@
 fn main() {
     assert!(!is_x86_feature_detected!("ssse3"));
     unsafe {
-        ssse3_fn(); //~ ERROR: calling a function that requires unavailable target features: sse3, ssse3
+        ssse3_fn(); //~ ERROR: calling a function that requires unavailable target features: ssse3
     }
 }
 
diff --git a/src/tools/miri/tests/fail/function_calls/target_feature.stderr b/src/tools/miri/tests/fail/function_calls/target_feature.stderr
index 74a862c7b68..4d3cf6e9d3b 100644
--- a/src/tools/miri/tests/fail/function_calls/target_feature.stderr
+++ b/src/tools/miri/tests/fail/function_calls/target_feature.stderr
@@ -1,8 +1,8 @@
-error: Undefined Behavior: calling a function that requires unavailable target features: sse3, ssse3
+error: Undefined Behavior: calling a function that requires unavailable target features: ssse3
   --> $DIR/target_feature.rs:LL:CC
    |
 LL |         ssse3_fn();
-   |         ^^^^^^^^^^ calling a function that requires unavailable target features: sse3, ssse3
+   |         ^^^^^^^^^^ calling a function that requires unavailable target features: ssse3
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
diff --git a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-aes-vaes.rs b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-aes-vaes.rs
index 13ebe561463..7363c753617 100644
--- a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-aes-vaes.rs
+++ b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-aes-vaes.rs
@@ -7,7 +7,7 @@
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
 //@ignore-target-wasm32
-//@compile-flags: -C target-feature=+aes,+vaes,+avx512f,+sse4.2
+//@compile-flags: -C target-feature=+aes,+vaes,+avx512f
 
 #![feature(avx512_target_feature, stdarch_x86_avx512)]
 
diff --git a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx.rs b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx.rs
index 18693a2a97d..728f57d48f1 100644
--- a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx.rs
+++ b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx.rs
@@ -7,7 +7,7 @@
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
 //@ignore-target-wasm32
-//@compile-flags: -C target-feature=+avx,+sse4.2
+//@compile-flags: -C target-feature=+avx
 
 #[cfg(target_arch = "x86")]
 use std::arch::x86::*;
diff --git a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx2.rs b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx2.rs
index f42ff6dfb51..80d125bb856 100644
--- a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx2.rs
+++ b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx2.rs
@@ -7,7 +7,7 @@
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
 //@ignore-target-wasm32
-//@compile-flags: -C target-feature=+avx2,+sse4.2
+//@compile-flags: -C target-feature=+avx2
 
 #[cfg(target_arch = "x86")]
 use std::arch::x86::*;
diff --git a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx512.rs b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx512.rs
index 7d25854ccc0..66bfcb20f1c 100644
--- a/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx512.rs
+++ b/src/tools/miri/tests/pass/shims/x86/intrinsics-x86-avx512.rs
@@ -7,7 +7,7 @@
 //@ignore-target-s390x
 //@ignore-target-thumbv7em
 //@ignore-target-wasm32
-//@compile-flags: -C target-feature=+avx512f,+avx512vl,+avx512bitalg,+avx512vpopcntdq,+sse4.2
+//@compile-flags: -C target-feature=+avx512f,+avx512vl,+avx512bitalg,+avx512vpopcntdq
 
 #![feature(avx512_target_feature)]
 #![feature(stdarch_x86_avx512)]
diff --git a/tests/ui/consts/const-eval/const_fn_target_feature.stderr b/tests/ui/consts/const-eval/const_fn_target_feature.stderr
index ad40d733546..d3a00b57ebb 100644
--- a/tests/ui/consts/const-eval/const_fn_target_feature.stderr
+++ b/tests/ui/consts/const-eval/const_fn_target_feature.stderr
@@ -2,7 +2,7 @@ error[E0080]: evaluation of constant value failed
   --> $DIR/const_fn_target_feature.rs:11:24
    |
 LL | const B: () = unsafe { avx2_fn() };
-   |                        ^^^^^^^^^ calling a function that requires unavailable target features: avx, avx2, sse4.1, sse4.2
+   |                        ^^^^^^^^^ calling a function that requires unavailable target features: avx2
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/safe-calls.stderr b/tests/ui/rfcs/rfc-2396-target_feature-11/safe-calls.stderr
index c2227f8e847..1ddf05b40a6 100644
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/safe-calls.stderr
+++ b/tests/ui/rfcs/rfc-2396-target_feature-11/safe-calls.stderr
@@ -4,8 +4,8 @@ error[E0133]: call to function `sse2` with `#[target_feature]` is unsafe and req
 LL |     sse2();
    |     ^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: sse and sse2
-   = note: the sse and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
+   = help: in order for the call to be safe, the context requires the following additional target feature: sse2
+   = note: the sse2 target feature being enabled in the build configuration does not remove the requirement to list it in `#[target_feature]`
 
 error[E0133]: call to function `avx_bmi2` with `#[target_feature]` is unsafe and requires unsafe function or block
   --> $DIR/safe-calls.rs:29:5
@@ -13,8 +13,7 @@ error[E0133]: call to function `avx_bmi2` with `#[target_feature]` is unsafe and
 LL |     avx_bmi2();
    |     ^^^^^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: avx, sse, sse2, sse3, sse4.1, sse4.2, ssse3, and bmi2
-   = note: the sse and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
+   = help: in order for the call to be safe, the context requires the following additional target features: avx and bmi2
 
 error[E0133]: call to function `Quux::avx_bmi2` with `#[target_feature]` is unsafe and requires unsafe function or block
   --> $DIR/safe-calls.rs:31:5
@@ -22,8 +21,7 @@ error[E0133]: call to function `Quux::avx_bmi2` with `#[target_feature]` is unsa
 LL |     Quux.avx_bmi2();
    |     ^^^^^^^^^^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: avx, sse, sse2, sse3, sse4.1, sse4.2, ssse3, and bmi2
-   = note: the sse and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
+   = help: in order for the call to be safe, the context requires the following additional target features: avx and bmi2
 
 error[E0133]: call to function `avx_bmi2` with `#[target_feature]` is unsafe and requires unsafe function or block
   --> $DIR/safe-calls.rs:38:5
@@ -31,7 +29,7 @@ error[E0133]: call to function `avx_bmi2` with `#[target_feature]` is unsafe and
 LL |     avx_bmi2();
    |     ^^^^^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: avx, sse3, sse4.1, sse4.2, ssse3, and bmi2
+   = help: in order for the call to be safe, the context requires the following additional target features: avx and bmi2
 
 error[E0133]: call to function `Quux::avx_bmi2` with `#[target_feature]` is unsafe and requires unsafe function or block
   --> $DIR/safe-calls.rs:40:5
@@ -39,7 +37,7 @@ error[E0133]: call to function `Quux::avx_bmi2` with `#[target_feature]` is unsa
 LL |     Quux.avx_bmi2();
    |     ^^^^^^^^^^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: avx, sse3, sse4.1, sse4.2, ssse3, and bmi2
+   = help: in order for the call to be safe, the context requires the following additional target features: avx and bmi2
 
 error[E0133]: call to function `avx_bmi2` with `#[target_feature]` is unsafe and requires unsafe function or block
   --> $DIR/safe-calls.rs:47:5
@@ -63,8 +61,8 @@ error[E0133]: call to function `sse2` with `#[target_feature]` is unsafe and req
 LL | const _: () = sse2();
    |               ^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: sse and sse2
-   = note: the sse and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
+   = help: in order for the call to be safe, the context requires the following additional target feature: sse2
+   = note: the sse2 target feature being enabled in the build configuration does not remove the requirement to list it in `#[target_feature]`
 
 error[E0133]: call to function `sse2_and_fxsr` with `#[target_feature]` is unsafe and requires unsafe function or block
   --> $DIR/safe-calls.rs:64:15
@@ -72,8 +70,8 @@ error[E0133]: call to function `sse2_and_fxsr` with `#[target_feature]` is unsaf
 LL | const _: () = sse2_and_fxsr();
    |               ^^^^^^^^^^^^^^^ call to function with `#[target_feature]`
    |
-   = help: in order for the call to be safe, the context requires the following additional target features: sse, sse2, and fxsr
-   = note: the fxsr, sse, and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
+   = help: in order for the call to be safe, the context requires the following additional target features: sse2 and fxsr
+   = note: the fxsr and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
 
 error[E0133]: call to function `sse2` with `#[target_feature]` is unsafe and requires unsafe block
   --> $DIR/safe-calls.rs:69:5
@@ -82,8 +80,8 @@ LL |     sse2();
    |     ^^^^^^ call to function with `#[target_feature]`
    |
    = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
-   = help: in order for the call to be safe, the context requires the following additional target features: sse and sse2
-   = note: the sse and sse2 target features being enabled in the build configuration does not remove the requirement to list them in `#[target_feature]`
+   = help: in order for the call to be safe, the context requires the following additional target feature: sse2
+   = note: the sse2 target feature being enabled in the build configuration does not remove the requirement to list it in `#[target_feature]`
 note: an unsafe function restricts its caller, but its body is safe by default
   --> $DIR/safe-calls.rs:68:1
    |
-- 
cgit 1.4.1-3-g733a5


From 8818c9552821721e4be5c19832b4e3ac64090feb Mon Sep 17 00:00:00 2001
From: Caleb Zulawski <caleb.zulawski@gmail.com>
Date: Tue, 6 Aug 2024 00:35:32 -0400
Subject: Disallow enabling features without their implied features

---
 compiler/rustc_codegen_llvm/src/llvm_util.rs      |  6 ++++--
 compiler/rustc_codegen_ssa/src/target_features.rs |  8 ++++----
 compiler/rustc_const_eval/src/interpret/call.rs   |  8 +-------
 compiler/rustc_middle/src/query/mod.rs            |  2 +-
 compiler/rustc_mir_build/src/check_unsafety.rs    | 10 +---------
 5 files changed, 11 insertions(+), 23 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 1a80824a3b7..9fd8ca43789 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -277,7 +277,7 @@ pub fn check_tied_features(
 /// Used to generate cfg variables and apply features
 /// Must express features in the way Rust understands them
 pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
-    let mut features = FxHashSet::default();
+    let mut features = vec![];
 
     // Add base features for the target
     let target_machine = create_informational_target_machine(sess, true);
@@ -313,7 +313,9 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
         if enabled {
             features.extend(sess.target.implied_target_features(std::iter::once(feature)));
         } else {
-            features.remove(&feature);
+            features.retain(|f| {
+                !sess.target.implied_target_features(std::iter::once(*f)).contains(&feature)
+            });
         }
     }
 
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index 145b1ece230..cf8f7fa25d8 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -1,7 +1,7 @@
 use rustc_ast::ast;
 use rustc_attr::InstructionSetAttr;
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_data_structures::unord::{ExtendUnord, UnordMap, UnordSet};
+use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_errors::Applicability;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE};
@@ -108,8 +108,7 @@ pub fn from_target_feature(
     // Add implied features
     let mut implied_target_features = UnordSet::new();
     for feature in added_target_features.iter() {
-        implied_target_features
-            .extend_unord(tcx.implied_target_features(*feature).clone().into_items());
+        implied_target_features.extend(tcx.implied_target_features(*feature).clone());
     }
     for feature in added_target_features.iter() {
         implied_target_features.remove(feature);
@@ -179,7 +178,8 @@ pub(crate) fn provide(providers: &mut Providers) {
             }
         },
         implied_target_features: |tcx, feature| {
-            tcx.sess.target.implied_target_features(std::iter::once(feature)).into()
+            UnordSet::from(tcx.sess.target.implied_target_features(std::iter::once(feature)))
+                .into_sorted_stable_ord()
         },
         asm_target_features,
         ..*providers
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs
index e5c195f08d7..b5f3d07d90b 100644
--- a/compiler/rustc_const_eval/src/interpret/call.rs
+++ b/compiler/rustc_const_eval/src/interpret/call.rs
@@ -319,18 +319,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 .iter()
                 .any(|feature| !self.tcx.sess.target_features.contains(&feature.name))
         {
-            // Don't include implicit features in the error, unless only implicit features are
-            // missing. This should be rare, because it can only happen when an implicit feature
-            // is disabled, e.g. `+avx2,-avx`
-            let missing_explicit_features = attrs.target_features.iter().any(|feature| {
-                !feature.implied && !self.tcx.sess.target_features.contains(&feature.name)
-            });
             throw_ub_custom!(
                 fluent::const_eval_unavailable_target_features_for_fn,
                 unavailable_feats = attrs
                     .target_features
                     .iter()
-                    .filter(|&feature| !(missing_explicit_features && feature.implied)
+                    .filter(|&feature| !feature.implied
                         && !self.tcx.sess.target_features.contains(&feature.name))
                     .fold(String::new(), |mut s, feature| {
                         if !s.is_empty() {
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index b6a29432650..5b114c9515c 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -2183,7 +2183,7 @@ rustc_queries! {
         desc { "looking up supported target features" }
     }
 
-    query implied_target_features(feature: Symbol) -> &'tcx UnordSet<Symbol> {
+    query implied_target_features(feature: Symbol) -> &'tcx Vec<Symbol> {
         arena_cache
         eval_always
         desc { "looking up implied target features" }
diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index 0b4f0632f2b..54a4204da71 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -447,19 +447,11 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                             self.body_target_features.iter().any(|f| f.name == feature.name)
                         })
                     {
-                        // Don't include implicit features in the error, unless only implicit
-                        // features are missing.
-                        let missing_explicit_features = callee_features.iter().any(|feature| {
-                            !feature.implied
-                                && !self.body_target_features.iter().any(|body_feature| {
-                                    !feature.implied && body_feature.name == feature.name
-                                })
-                        });
                         let missing: Vec<_> = callee_features
                             .iter()
                             .copied()
                             .filter(|feature| {
-                                !(missing_explicit_features && feature.implied)
+                                !feature.implied
                                     && !self
                                         .body_target_features
                                         .iter()
-- 
cgit 1.4.1-3-g733a5