Move rustc_codegen_ssa target features to rustc_target

6 files changed, 450 insertions, 442 deletions

diff --git a/compiler/rustc_codegen_gcc/src/gcc_util.rs b/compiler/rustc_codegen_gcc/src/gcc_util.rs
index 1248fdcd259..2aa84f26797 100644
--- a/compiler/rustc_codegen_gcc/src/gcc_util.rs
+++ b/compiler/rustc_codegen_gcc/src/gcc_util.rs
@@ -2,12 +2,10 @@
 use gccjit::Context;
 use smallvec::{smallvec, SmallVec};
 
-use rustc_codegen_ssa::target_features::{
-    supported_target_features, tied_target_features, RUSTC_SPECIFIC_FEATURES,
-};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::bug;
 use rustc_session::Session;
+use rustc_target::target_features::RUSTC_SPECIFIC_FEATURES;
 
 use crate::errors::{PossibleFeature, TargetFeatureDisableOrEnable, UnknownCTargetFeature, UnknownCTargetFeaturePrefix};
 
@@ -44,7 +42,7 @@ pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<Stri
     );
 
     // -Ctarget-features
-    let supported_features = supported_target_features(sess);
+    let supported_features = sess.target.supported_target_features();
     let mut featsmap = FxHashMap::default();
     let feats = sess.opts.cg.target_feature
         .split(',')
@@ -187,7 +185,7 @@ pub fn to_gcc_features<'a>(sess: &Session, s: &'a str) -> SmallVec<[&'a str; 2]>
 // Given a map from target_features to whether they are enabled or disabled,
 // ensure only valid combinations are allowed.
 pub fn check_tied_features(sess: &Session, features: &FxHashMap<&str, bool>) -> Option<&'static [&'static str]> {
-    for tied in tied_target_features(sess) {
+    for tied in sess.target.tied_target_features() {
         // Tied features must be set to the same value, or not set at all
         let mut tied_iter = tied.iter();
         let enabled = features.get(tied_iter.next().unwrap());
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index d54057615d2..0ececc5dda0 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -97,7 +97,6 @@ use rustc_codegen_ssa::{CodegenResults, CompiledModule, ModuleCodegen};
 use rustc_codegen_ssa::base::codegen_crate;
 use rustc_codegen_ssa::back::write::{CodegenContext, FatLtoInput, ModuleConfig, TargetMachineFactoryFn};
 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule};
-use rustc_codegen_ssa::target_features::supported_target_features;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync::IntoDynSyncSend;
 use rustc_codegen_ssa::traits::{CodegenBackend, ExtraBackendMethods, ThinBufferMethods, WriteBackendMethods};
@@ -397,7 +396,9 @@ fn to_gcc_opt_level(optlevel: Option<OptLevel>) -> OptimizationLevel {
 }
 
 pub fn target_features(sess: &Session, allow_unstable: bool, target_info: &LockedTargetInfo) -> Vec<Symbol> {
-    supported_target_features(sess)
+    sess
+        .target
+        .supported_target_features()
         .iter()
         .filter_map(
             |&(feature, gate)| {
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 93cb7327a01..08519723eba 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -5,9 +5,6 @@ use crate::errors::{
 };
 use crate::llvm;
 use libc::c_int;
-use rustc_codegen_ssa::target_features::{
-    supported_target_features, tied_target_features, RUSTC_SPECIFIC_FEATURES,
-};
 use rustc_codegen_ssa::traits::PrintBackendInfo;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::small_c_str::SmallCStr;
@@ -17,6 +14,7 @@ use rustc_session::config::{PrintKind, PrintRequest};
 use rustc_session::Session;
 use rustc_span::symbol::Symbol;
 use rustc_target::spec::{MergeFunctions, PanicStrategy};
+use rustc_target::target_features::RUSTC_SPECIFIC_FEATURES;
 
 use std::ffi::{c_char, c_void, CStr, CString};
 use std::path::Path;
@@ -278,7 +276,7 @@ pub fn check_tied_features(
     features: &FxHashMap<&str, bool>,
 ) -> Option<&'static [&'static str]> {
     if !features.is_empty() {
-        for tied in tied_target_features(sess) {
+        for tied in sess.target.tied_target_features() {
             // Tied features must be set to the same value, or not set at all
             let mut tied_iter = tied.iter();
             let enabled = features.get(tied_iter.next().unwrap());
@@ -294,7 +292,8 @@ pub fn check_tied_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);
-    supported_target_features(sess)
+    sess.target
+        .supported_target_features()
         .iter()
         .filter_map(|&(feature, gate)| {
             if sess.is_nightly_build() || allow_unstable || gate.is_stable() {
@@ -362,7 +361,9 @@ fn llvm_target_features(tm: &llvm::TargetMachine) -> Vec<(&str, &str)> {
 fn print_target_features(out: &mut dyn PrintBackendInfo, sess: &Session, tm: &llvm::TargetMachine) {
     let mut llvm_target_features = llvm_target_features(tm);
     let mut known_llvm_target_features = FxHashSet::<&'static str>::default();
-    let mut rustc_target_features = supported_target_features(sess)
+    let mut rustc_target_features = sess
+        .target
+        .supported_target_features()
         .iter()
         .map(|(feature, _gate)| {
             // LLVM asserts that these are sorted. LLVM and Rust both use byte comparison for these strings.
@@ -515,7 +516,7 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
     );
 
     // -Ctarget-features
-    let supported_features = supported_target_features(sess);
+    let supported_features = sess.target.supported_target_features();
     let mut featsmap = FxHashMap::default();
     let feats = sess
         .opts
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index c3b8859c779..0b9b08c6a24 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -11,436 +11,10 @@ use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::parse::feature_err;
-use rustc_session::Session;
 use rustc_span::symbol::sym;
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 
-/// Features that control behaviour of rustc, rather than the codegen.
-pub const RUSTC_SPECIFIC_FEATURES: &[&str] = &["crt-static"];
-
-/// Stability information for target features.
-#[derive(Debug, Clone, Copy)]
-pub enum Stability {
-    /// This target feature is stable, it can be used in `#[target_feature]` and
-    /// `#[cfg(target_feature)]`.
-    Stable,
-    /// This target feature is unstable; using it in `#[target_feature]` or `#[cfg(target_feature)]`
-    /// requires enabling the given nightly feature.
-    Unstable(Symbol),
-}
-use Stability::*;
-
-impl Stability {
-    fn as_feature_name(self) -> Option<Symbol> {
-        match self {
-            Stable => None,
-            Unstable(s) => Some(s),
-        }
-    }
-
-    pub fn is_stable(self) -> bool {
-        matches!(self, Stable)
-    }
-}
-
-// Here we list target features that rustc "understands": they can be used in `#[target_feature]`
-// and `#[cfg(target_feature)]`. They also do not trigger any warnings when used with
-// `-Ctarget-feature`.
-//
-// When adding features to the below lists
-// check whether they're named already elsewhere in rust
-// e.g. in stdarch and whether the given name matches LLVM's
-// if it doesn't, to_llvm_feature in llvm_util in rustc_codegen_llvm needs to be adapted.
-//
-// Also note that all target features listed here must be purely additive: for target_feature 1.1 to
-// be sound, we can never allow features like `+soft-float` (on x86) to be controlled on a
-// per-function level, since we would then allow safe calls from functions with `+soft-float` to
-// functions without that feature!
-//
-// When adding a new feature, be particularly mindful of features that affect function ABIs. Those
-// need to be treated very carefully to avoid introducing unsoundness! This often affects features
-// that enable/disable hardfloat support (see https://github.com/rust-lang/rust/issues/116344 for an
-// example of this going wrong), but features enabling new SIMD registers are also a concern (see
-// https://github.com/rust-lang/rust/issues/116558 for an example of this going wrong).
-//
-// Stabilizing a target feature requires t-lang approval.
-
-const ARM_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // 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)),
-    // 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)),
-    // tidy-alphabetical-end
-];
-
-const AARCH64_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    // FEAT_AES
-    ("aes", Stable),
-    // FEAT_BF16
-    ("bf16", Stable),
-    // FEAT_BTI
-    ("bti", Stable),
-    // FEAT_CRC
-    ("crc", Stable),
-    // FEAT_DIT
-    ("dit", Stable),
-    // FEAT_DotProd
-    ("dotprod", Stable),
-    // FEAT_DPB
-    ("dpb", Stable),
-    // FEAT_DPB2
-    ("dpb2", Stable),
-    // FEAT_F32MM
-    ("f32mm", Stable),
-    // FEAT_F64MM
-    ("f64mm", Stable),
-    // FEAT_FCMA
-    ("fcma", Stable),
-    // FEAT_FHM
-    ("fhm", Stable),
-    // FEAT_FLAGM
-    ("flagm", Stable),
-    // FEAT_FP16
-    ("fp16", Stable),
-    // FEAT_FRINTTS
-    ("frintts", Stable),
-    // FEAT_I8MM
-    ("i8mm", Stable),
-    // FEAT_JSCVT
-    ("jsconv", Stable),
-    // FEAT_LOR
-    ("lor", Stable),
-    // FEAT_LSE
-    ("lse", Stable),
-    // FEAT_MTE
-    ("mte", Stable),
-    // FEAT_AdvSimd & FEAT_FP
-    ("neon", Stable),
-    // FEAT_PAUTH (address authentication)
-    ("paca", Stable),
-    // FEAT_PAUTH (generic authentication)
-    ("pacg", Stable),
-    // FEAT_PAN
-    ("pan", Stable),
-    // FEAT_PMUv3
-    ("pmuv3", Stable),
-    // FEAT_RAND
-    ("rand", Stable),
-    // FEAT_RAS
-    ("ras", Stable),
-    // FEAT_RCPC
-    ("rcpc", Stable),
-    // FEAT_RCPC2
-    ("rcpc2", Stable),
-    // FEAT_RDM
-    ("rdm", Stable),
-    // FEAT_SB
-    ("sb", Stable),
-    // FEAT_SHA1 & FEAT_SHA256
-    ("sha2", Stable),
-    // FEAT_SHA512 & FEAT_SHA3
-    ("sha3", Stable),
-    // FEAT_SM3 & FEAT_SM4
-    ("sm4", Stable),
-    // FEAT_SPE
-    ("spe", Stable),
-    // FEAT_SSBS
-    ("ssbs", Stable),
-    // FEAT_SVE
-    ("sve", Stable),
-    // FEAT_SVE2
-    ("sve2", Stable),
-    // FEAT_SVE2_AES
-    ("sve2-aes", Stable),
-    // FEAT_SVE2_BitPerm
-    ("sve2-bitperm", Stable),
-    // FEAT_SVE2_SHA3
-    ("sve2-sha3", Stable),
-    // FEAT_SVE2_SM4
-    ("sve2-sm4", Stable),
-    // 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)),
-    // FEAT_VHE
-    ("vh", Stable),
-    // tidy-alphabetical-end
-];
-
-const AARCH64_TIED_FEATURES: &[&[&str]] = &[
-    &["paca", "pacg"], // Together these represent `pauth` in LLVM
-];
-
-const X86_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    ("adx", Stable),
-    ("aes", Stable),
-    ("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)),
-    ("avx512er", Unstable(sym::avx512_target_feature)),
-    ("avx512f", Unstable(sym::avx512_target_feature)),
-    ("avx512ifma", Unstable(sym::avx512_target_feature)),
-    ("avx512pf", 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)),
-    ("bmi1", Stable),
-    ("bmi2", Stable),
-    ("cmpxchg16b", Stable),
-    ("ermsb", Unstable(sym::ermsb_target_feature)),
-    ("f16c", Stable),
-    ("fma", Stable),
-    ("fxsr", Stable),
-    ("gfni", Unstable(sym::avx512_target_feature)),
-    ("lzcnt", Stable),
-    ("movbe", Stable),
-    ("pclmulqdq", Stable),
-    ("popcnt", Stable),
-    ("rdrand", Stable),
-    ("rdseed", Stable),
-    ("rtm", Unstable(sym::rtm_target_feature)),
-    ("sha", Stable),
-    ("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)),
-    ("xsave", Stable),
-    ("xsavec", Stable),
-    ("xsaveopt", Stable),
-    ("xsaves", Stable),
-    // tidy-alphabetical-end
-];
-
-const HEXAGON_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    ("hvx", Unstable(sym::hexagon_target_feature)),
-    ("hvx-length128b", Unstable(sym::hexagon_target_feature)),
-    // tidy-alphabetical-end
-];
-
-const POWERPC_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // 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)),
-    // tidy-alphabetical-end
-];
-
-const MIPS_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    ("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)] = &[
-    // 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)),
-    ("fast-unaligned-access", Unstable(sym::riscv_target_feature)),
-    ("m", Stable),
-    ("relax", 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),
-    // tidy-alphabetical-end
-];
-
-const WASM_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // tidy-alphabetical-start
-    ("atomics", Unstable(sym::wasm_target_feature)),
-    ("bulk-memory", Unstable(sym::wasm_target_feature)),
-    ("exception-handling", Unstable(sym::wasm_target_feature)),
-    ("multivalue", Unstable(sym::wasm_target_feature)),
-    ("mutable-globals", Unstable(sym::wasm_target_feature)),
-    ("nontrapping-fptoint", Unstable(sym::wasm_target_feature)),
-    ("reference-types", Unstable(sym::wasm_target_feature)),
-    ("relaxed-simd", Unstable(sym::wasm_target_feature)),
-    ("sign-ext", Unstable(sym::wasm_target_feature)),
-    ("simd128", Stable),
-    // tidy-alphabetical-end
-];
-
-const BPF_ALLOWED_FEATURES: &[(&str, Stability)] = &[("alu32", Unstable(sym::bpf_target_feature))];
-
-const CSKY_ALLOWED_FEATURES: &[(&str, Stability)] = &[
-    // 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)),
-    // 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)),
-    ("lasx", Unstable(sym::loongarch_target_feature)),
-    ("lbt", Unstable(sym::loongarch_target_feature)),
-    ("lsx", Unstable(sym::loongarch_target_feature)),
-    ("lvz", Unstable(sym::loongarch_target_feature)),
-    ("ual", Unstable(sym::loongarch_target_feature)),
-    // tidy-alphabetical-end
-];
-
-/// When rustdoc is running, provide a list of all known features so that all their respective
-/// primitives may be documented.
-///
-/// IMPORTANT: If you're adding another feature list above, make sure to add it to this iterator!
-pub fn all_known_features() -> impl Iterator<Item = (&'static str, Stability)> {
-    std::iter::empty()
-        .chain(ARM_ALLOWED_FEATURES.iter())
-        .chain(AARCH64_ALLOWED_FEATURES.iter())
-        .chain(X86_ALLOWED_FEATURES.iter())
-        .chain(HEXAGON_ALLOWED_FEATURES.iter())
-        .chain(POWERPC_ALLOWED_FEATURES.iter())
-        .chain(MIPS_ALLOWED_FEATURES.iter())
-        .chain(RISCV_ALLOWED_FEATURES.iter())
-        .chain(WASM_ALLOWED_FEATURES.iter())
-        .chain(BPF_ALLOWED_FEATURES.iter())
-        .chain(CSKY_ALLOWED_FEATURES)
-        .chain(LOONGARCH_ALLOWED_FEATURES)
-        .cloned()
-}
-
-pub fn supported_target_features(sess: &Session) -> &'static [(&'static str, Stability)] {
-    match &*sess.target.arch {
-        "arm" => ARM_ALLOWED_FEATURES,
-        "aarch64" => AARCH64_ALLOWED_FEATURES,
-        "x86" | "x86_64" => X86_ALLOWED_FEATURES,
-        "hexagon" => HEXAGON_ALLOWED_FEATURES,
-        "mips" | "mips32r6" | "mips64" | "mips64r6" => MIPS_ALLOWED_FEATURES,
-        "powerpc" | "powerpc64" => POWERPC_ALLOWED_FEATURES,
-        "riscv32" | "riscv64" => RISCV_ALLOWED_FEATURES,
-        "wasm32" | "wasm64" => WASM_ALLOWED_FEATURES,
-        "bpf" => BPF_ALLOWED_FEATURES,
-        "csky" => CSKY_ALLOWED_FEATURES,
-        "loongarch64" => LOONGARCH_ALLOWED_FEATURES,
-        _ => &[],
-    }
-}
-
-pub fn tied_target_features(sess: &Session) -> &'static [&'static [&'static str]] {
-    match &*sess.target.arch {
-        "aarch64" => AARCH64_TIED_FEATURES,
-        _ => &[],
-    }
-}
-
 pub fn from_target_feature(
     tcx: TyCtxt<'_>,
     attr: &ast::Attribute,
@@ -562,9 +136,13 @@ pub(crate) fn provide(providers: &mut Providers) {
             if tcx.sess.opts.actually_rustdoc {
                 // rustdoc needs to be able to document functions that use all the features, so
                 // whitelist them all
-                all_known_features().map(|(a, b)| (a.to_string(), b.as_feature_name())).collect()
+                rustc_target::target_features::all_known_features()
+                    .map(|(a, b)| (a.to_string(), b.as_feature_name()))
+                    .collect()
             } else {
-                supported_target_features(tcx.sess)
+                tcx.sess
+                    .target
+                    .supported_target_features()
                     .iter()
                     .map(|&(a, b)| (a.to_string(), b.as_feature_name()))
                     .collect()
diff --git a/compiler/rustc_target/src/lib.rs b/compiler/rustc_target/src/lib.rs
index e17b81d4652..257c6777996 100644
--- a/compiler/rustc_target/src/lib.rs
+++ b/compiler/rustc_target/src/lib.rs
@@ -35,6 +35,7 @@ pub mod abi;
 pub mod asm;
 pub mod json;
 pub mod spec;
+pub mod target_features;
 
 #[cfg(test)]
 mod tests;
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
new file mode 100644
index 00000000000..5f5de57dd1d
--- /dev/null
+++ b/compiler/rustc_target/src/target_features.rs
@@ -0,0 +1,429 @@
+use rustc_span::symbol::sym;
+use rustc_span::symbol::Symbol;
+
+/// Features that control behaviour of rustc, rather than the codegen.
+pub const RUSTC_SPECIFIC_FEATURES: &[&str] = &["crt-static"];
+
+/// Stability information for target features.
+#[derive(Debug, Clone, Copy)]
+pub enum Stability {
+    /// This target feature is stable, it can be used in `#[target_feature]` and
+    /// `#[cfg(target_feature)]`.
+    Stable,
+    /// This target feature is unstable; using it in `#[target_feature]` or `#[cfg(target_feature)]`
+    /// requires enabling the given nightly feature.
+    Unstable(Symbol),
+}
+use Stability::*;
+
+impl Stability {
+    pub fn as_feature_name(self) -> Option<Symbol> {
+        match self {
+            Stable => None,
+            Unstable(s) => Some(s),
+        }
+    }
+
+    pub fn is_stable(self) -> bool {
+        matches!(self, Stable)
+    }
+}
+
+// Here we list target features that rustc "understands": they can be used in `#[target_feature]`
+// and `#[cfg(target_feature)]`. They also do not trigger any warnings when used with
+// `-Ctarget-feature`.
+//
+// When adding features to the below lists
+// check whether they're named already elsewhere in rust
+// e.g. in stdarch and whether the given name matches LLVM's
+// if it doesn't, to_llvm_feature in llvm_util in rustc_codegen_llvm needs to be adapted.
+//
+// Also note that all target features listed here must be purely additive: for target_feature 1.1 to
+// be sound, we can never allow features like `+soft-float` (on x86) to be controlled on a
+// per-function level, since we would then allow safe calls from functions with `+soft-float` to
+// functions without that feature!
+//
+// When adding a new feature, be particularly mindful of features that affect function ABIs. Those
+// need to be treated very carefully to avoid introducing unsoundness! This often affects features
+// that enable/disable hardfloat support (see https://github.com/rust-lang/rust/issues/116344 for an
+// example of this going wrong), but features enabling new SIMD registers are also a concern (see
+// https://github.com/rust-lang/rust/issues/116558 for an example of this going wrong).
+//
+// Stabilizing a target feature requires t-lang approval.
+
+const ARM_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // 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)),
+    // 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)),
+    // tidy-alphabetical-end
+];
+
+const AARCH64_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // tidy-alphabetical-start
+    // FEAT_AES
+    ("aes", Stable),
+    // FEAT_BF16
+    ("bf16", Stable),
+    // FEAT_BTI
+    ("bti", Stable),
+    // FEAT_CRC
+    ("crc", Stable),
+    // FEAT_DIT
+    ("dit", Stable),
+    // FEAT_DotProd
+    ("dotprod", Stable),
+    // FEAT_DPB
+    ("dpb", Stable),
+    // FEAT_DPB2
+    ("dpb2", Stable),
+    // FEAT_F32MM
+    ("f32mm", Stable),
+    // FEAT_F64MM
+    ("f64mm", Stable),
+    // FEAT_FCMA
+    ("fcma", Stable),
+    // FEAT_FHM
+    ("fhm", Stable),
+    // FEAT_FLAGM
+    ("flagm", Stable),
+    // FEAT_FP16
+    ("fp16", Stable),
+    // FEAT_FRINTTS
+    ("frintts", Stable),
+    // FEAT_I8MM
+    ("i8mm", Stable),
+    // FEAT_JSCVT
+    ("jsconv", Stable),
+    // FEAT_LOR
+    ("lor", Stable),
+    // FEAT_LSE
+    ("lse", Stable),
+    // FEAT_MTE
+    ("mte", Stable),
+    // FEAT_AdvSimd & FEAT_FP
+    ("neon", Stable),
+    // FEAT_PAUTH (address authentication)
+    ("paca", Stable),
+    // FEAT_PAUTH (generic authentication)
+    ("pacg", Stable),
+    // FEAT_PAN
+    ("pan", Stable),
+    // FEAT_PMUv3
+    ("pmuv3", Stable),
+    // FEAT_RAND
+    ("rand", Stable),
+    // FEAT_RAS
+    ("ras", Stable),
+    // FEAT_RCPC
+    ("rcpc", Stable),
+    // FEAT_RCPC2
+    ("rcpc2", Stable),
+    // FEAT_RDM
+    ("rdm", Stable),
+    // FEAT_SB
+    ("sb", Stable),
+    // FEAT_SHA1 & FEAT_SHA256
+    ("sha2", Stable),
+    // FEAT_SHA512 & FEAT_SHA3
+    ("sha3", Stable),
+    // FEAT_SM3 & FEAT_SM4
+    ("sm4", Stable),
+    // FEAT_SPE
+    ("spe", Stable),
+    // FEAT_SSBS
+    ("ssbs", Stable),
+    // FEAT_SVE
+    ("sve", Stable),
+    // FEAT_SVE2
+    ("sve2", Stable),
+    // FEAT_SVE2_AES
+    ("sve2-aes", Stable),
+    // FEAT_SVE2_BitPerm
+    ("sve2-bitperm", Stable),
+    // FEAT_SVE2_SHA3
+    ("sve2-sha3", Stable),
+    // FEAT_SVE2_SM4
+    ("sve2-sm4", Stable),
+    // 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)),
+    // FEAT_VHE
+    ("vh", Stable),
+    // tidy-alphabetical-end
+];
+
+const AARCH64_TIED_FEATURES: &[&[&str]] = &[
+    &["paca", "pacg"], // Together these represent `pauth` in LLVM
+];
+
+const X86_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // tidy-alphabetical-start
+    ("adx", Stable),
+    ("aes", Stable),
+    ("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)),
+    ("avx512er", Unstable(sym::avx512_target_feature)),
+    ("avx512f", Unstable(sym::avx512_target_feature)),
+    ("avx512ifma", Unstable(sym::avx512_target_feature)),
+    ("avx512pf", 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)),
+    ("bmi1", Stable),
+    ("bmi2", Stable),
+    ("cmpxchg16b", Stable),
+    ("ermsb", Unstable(sym::ermsb_target_feature)),
+    ("f16c", Stable),
+    ("fma", Stable),
+    ("fxsr", Stable),
+    ("gfni", Unstable(sym::avx512_target_feature)),
+    ("lzcnt", Stable),
+    ("movbe", Stable),
+    ("pclmulqdq", Stable),
+    ("popcnt", Stable),
+    ("rdrand", Stable),
+    ("rdseed", Stable),
+    ("rtm", Unstable(sym::rtm_target_feature)),
+    ("sha", Stable),
+    ("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)),
+    ("xsave", Stable),
+    ("xsavec", Stable),
+    ("xsaveopt", Stable),
+    ("xsaves", Stable),
+    // tidy-alphabetical-end
+];
+
+const HEXAGON_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // tidy-alphabetical-start
+    ("hvx", Unstable(sym::hexagon_target_feature)),
+    ("hvx-length128b", Unstable(sym::hexagon_target_feature)),
+    // tidy-alphabetical-end
+];
+
+const POWERPC_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // 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)),
+    // tidy-alphabetical-end
+];
+
+const MIPS_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // tidy-alphabetical-start
+    ("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)] = &[
+    // 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)),
+    ("fast-unaligned-access", Unstable(sym::riscv_target_feature)),
+    ("m", Stable),
+    ("relax", 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),
+    // tidy-alphabetical-end
+];
+
+const WASM_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // tidy-alphabetical-start
+    ("atomics", Unstable(sym::wasm_target_feature)),
+    ("bulk-memory", Unstable(sym::wasm_target_feature)),
+    ("exception-handling", Unstable(sym::wasm_target_feature)),
+    ("multivalue", Unstable(sym::wasm_target_feature)),
+    ("mutable-globals", Unstable(sym::wasm_target_feature)),
+    ("nontrapping-fptoint", Unstable(sym::wasm_target_feature)),
+    ("reference-types", Unstable(sym::wasm_target_feature)),
+    ("relaxed-simd", Unstable(sym::wasm_target_feature)),
+    ("sign-ext", Unstable(sym::wasm_target_feature)),
+    ("simd128", Stable),
+    // tidy-alphabetical-end
+];
+
+const BPF_ALLOWED_FEATURES: &[(&str, Stability)] = &[("alu32", Unstable(sym::bpf_target_feature))];
+
+const CSKY_ALLOWED_FEATURES: &[(&str, Stability)] = &[
+    // 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)),
+    // 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)),
+    ("lasx", Unstable(sym::loongarch_target_feature)),
+    ("lbt", Unstable(sym::loongarch_target_feature)),
+    ("lsx", Unstable(sym::loongarch_target_feature)),
+    ("lvz", Unstable(sym::loongarch_target_feature)),
+    ("ual", Unstable(sym::loongarch_target_feature)),
+    // tidy-alphabetical-end
+];
+
+/// When rustdoc is running, provide a list of all known features so that all their respective
+/// primitives may be documented.
+///
+/// IMPORTANT: If you're adding another feature list above, make sure to add it to this iterator!
+pub fn all_known_features() -> impl Iterator<Item = (&'static str, Stability)> {
+    std::iter::empty()
+        .chain(ARM_ALLOWED_FEATURES.iter())
+        .chain(AARCH64_ALLOWED_FEATURES.iter())
+        .chain(X86_ALLOWED_FEATURES.iter())
+        .chain(HEXAGON_ALLOWED_FEATURES.iter())
+        .chain(POWERPC_ALLOWED_FEATURES.iter())
+        .chain(MIPS_ALLOWED_FEATURES.iter())
+        .chain(RISCV_ALLOWED_FEATURES.iter())
+        .chain(WASM_ALLOWED_FEATURES.iter())
+        .chain(BPF_ALLOWED_FEATURES.iter())
+        .chain(CSKY_ALLOWED_FEATURES)
+        .chain(LOONGARCH_ALLOWED_FEATURES)
+        .cloned()
+}
+
+impl super::spec::Target {
+    pub fn supported_target_features(&self) -> &'static [(&'static str, Stability)] {
+        match &*self.arch {
+            "arm" => ARM_ALLOWED_FEATURES,
+            "aarch64" => AARCH64_ALLOWED_FEATURES,
+            "x86" | "x86_64" => X86_ALLOWED_FEATURES,
+            "hexagon" => HEXAGON_ALLOWED_FEATURES,
+            "mips" | "mips32r6" | "mips64" | "mips64r6" => MIPS_ALLOWED_FEATURES,
+            "powerpc" | "powerpc64" => POWERPC_ALLOWED_FEATURES,
+            "riscv32" | "riscv64" => RISCV_ALLOWED_FEATURES,
+            "wasm32" | "wasm64" => WASM_ALLOWED_FEATURES,
+            "bpf" => BPF_ALLOWED_FEATURES,
+            "csky" => CSKY_ALLOWED_FEATURES,
+            "loongarch64" => LOONGARCH_ALLOWED_FEATURES,
+            _ => &[],
+        }
+    }
+
+    pub fn tied_target_features(&self) -> &'static [&'static [&'static str]] {
+        match &*self.arch {
+            "aarch64" => AARCH64_TIED_FEATURES,
+            _ => &[],
+        }
+    }
+}