diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/llvm_util.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm_util.rs | 137 |
1 files changed, 67 insertions, 70 deletions
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index 5cc4f4ab9e6..36e35f81392 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -256,7 +256,6 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea ("aarch64", "pmuv3") => Some(LLVMFeature::new("perfmon")), ("aarch64", "paca") => Some(LLVMFeature::new("pauth")), ("aarch64", "pacg") => Some(LLVMFeature::new("pauth")), - ("aarch64", "pauth-lr") if get_version().0 < 19 => None, // Before LLVM 20 those two features were packaged together as b16b16 ("aarch64", "sve-b16b16") if get_version().0 < 20 => Some(LLVMFeature::new("b16b16")), ("aarch64", "sme-b16b16") if get_version().0 < 20 => Some(LLVMFeature::new("b16b16")), @@ -270,18 +269,9 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea ("aarch64", "fhm") => Some(LLVMFeature::new("fp16fml")), ("aarch64", "fp16") => Some(LLVMFeature::new("fullfp16")), // Filter out features that are not supported by the current LLVM version - ("aarch64", "fpmr") if get_version().0 != 18 => None, + ("aarch64", "fpmr") => None, // only existed in 18 ("arm", "fp16") => Some(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 => { - Some(LLVMFeature::new("fast-unaligned-access")) - } // Filter out features that are not supported by the current LLVM version - ("riscv32" | "riscv64", "zaamo") if get_version().0 < 19 => None, - ("riscv32" | "riscv64", "zabha") if get_version().0 < 19 => None, - ("riscv32" | "riscv64", "zalrsc") if get_version().0 < 19 => None, - ("riscv32" | "riscv64", "zama16b") if get_version().0 < 19 => None, ("riscv32" | "riscv64", "zacas") if get_version().0 < 20 => None, // Enable the evex512 target feature if an avx512 target feature is enabled. ("x86", s) if s.starts_with("avx512") => { @@ -293,11 +283,17 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea ("sparc", "leoncasa") => Some(LLVMFeature::new("hasleoncasa")), // In LLVM 19, there is no `v8plus` feature and `v9` means "SPARC-V9 instruction available and SPARC-V8+ ABI used". // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/Sparc/MCTargetDesc/SparcELFObjectWriter.cpp#L27-L28 - // Before LLVM 19, there is no `v8plus` feature and `v9` means "SPARC-V9 instruction available". + // Before LLVM 19, there was no `v8plus` feature and `v9` means "SPARC-V9 instruction available". // https://github.com/llvm/llvm-project/blob/llvmorg-18.1.0/llvm/lib/Target/Sparc/MCTargetDesc/SparcELFObjectWriter.cpp#L26 ("sparc", "v8plus") if get_version().0 == 19 => Some(LLVMFeature::new("v9")), - ("sparc", "v8plus") if get_version().0 < 19 => None, ("powerpc", "power8-crypto") => Some(LLVMFeature::new("crypto")), + // These new `amx` variants and `movrs` were introduced in LLVM20 + ("x86", "amx-avx512" | "amx-fp8" | "amx-movrs" | "amx-tf32" | "amx-transpose") + if get_version().0 < 20 => + { + None + } + ("x86", "movrs") if get_version().0 < 20 => None, (_, s) => Some(LLVMFeature::new(s)), } } @@ -306,45 +302,44 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea /// Must express features in the way Rust understands them. /// /// We do not have to worry about RUSTC_SPECIFIC_FEATURES here, those are handled outside codegen. -pub(crate) fn target_features_cfg(sess: &Session, allow_unstable: bool) -> Vec<Symbol> { - let mut features: FxHashSet<Symbol> = Default::default(); - +pub(crate) fn target_features_cfg(sess: &Session) -> (Vec<Symbol>, Vec<Symbol>) { // Add base features for the target. // We do *not* add the -Ctarget-features there, and instead duplicate the logic for that below. // The reason is that if LLVM considers a feature implied but we do not, we don't want that to // show up in `cfg`. That way, `cfg` is entirely under our control -- except for the handling of - // the target CPU, that is still expanded to target features (with all their implied features) by - // LLVM. + // the target CPU, that is still expanded to target features (with all their implied features) + // by LLVM. let target_machine = create_informational_target_machine(sess, true); - // Compute which of the known target features are enabled in the 'base' target machine. - // We only consider "supported" features; "forbidden" features are not reflected in `cfg` as of now. - features.extend( - sess.target - .rust_target_features() - .iter() - .filter(|(feature, _, _)| { - // skip checking special features, as LLVM may not understand them - if RUSTC_SPECIAL_FEATURES.contains(feature) { - return true; - } - // check that all features in a given smallvec are enabled - if let Some(feat) = to_llvm_features(sess, feature) { - for llvm_feature in feat { - let cstr = SmallCStr::new(llvm_feature); - if !unsafe { llvm::LLVMRustHasFeature(target_machine.raw(), cstr.as_ptr()) } - { - return false; - } + // Compute which of the known target features are enabled in the 'base' target machine. We only + // consider "supported" features; "forbidden" features are not reflected in `cfg` as of now. + let mut features: FxHashSet<Symbol> = sess + .target + .rust_target_features() + .iter() + .filter(|(feature, _, _)| { + // skip checking special features, as LLVM may not understand them + if RUSTC_SPECIAL_FEATURES.contains(feature) { + return true; + } + if let Some(feat) = to_llvm_features(sess, feature) { + for llvm_feature in feat { + let cstr = SmallCStr::new(llvm_feature); + // `LLVMRustHasFeature` is moderately expensive. On targets with many + // features (e.g. x86) these calls take a non-trivial fraction of runtime + // when compiling very small programs. + if !unsafe { llvm::LLVMRustHasFeature(target_machine.raw(), cstr.as_ptr()) } { + return false; } - true - } else { - false } - }) - .map(|(feature, _, _)| Symbol::intern(feature)), - ); + true + } else { + false + } + }) + .map(|(feature, _, _)| Symbol::intern(feature)) + .collect(); - // Add enabled features + // Add enabled and remove disabled features. for (enabled, feature) in sess.opts.cg.target_feature.split(',').filter_map(|s| match s.chars().next() { Some('+') => Some((true, Symbol::intern(&s[1..]))), @@ -360,7 +355,7 @@ pub(crate) fn target_features_cfg(sess: &Session, allow_unstable: bool) -> Vec<S #[allow(rustc::potential_query_instability)] features.extend( sess.target - .implied_target_features(std::iter::once(feature.as_str())) + .implied_target_features(feature.as_str()) .iter() .map(|s| Symbol::intern(s)), ); @@ -371,11 +366,7 @@ pub(crate) fn target_features_cfg(sess: &Session, allow_unstable: bool) -> Vec<S // `features.contains` below. #[allow(rustc::potential_query_instability)] features.retain(|f| { - if sess - .target - .implied_target_features(std::iter::once(f.as_str())) - .contains(&feature.as_str()) - { + if sess.target.implied_target_features(f.as_str()).contains(&feature.as_str()) { // If `f` if implies `feature`, then `!feature` implies `!f`, so we have to // remove `f`. (This is the standard logical contraposition principle.) false @@ -387,25 +378,31 @@ pub(crate) fn target_features_cfg(sess: &Session, allow_unstable: bool) -> Vec<S } } - // Filter enabled features based on feature gates - sess.target - .rust_target_features() - .iter() - .filter_map(|(feature, gate, _)| { - // The `allow_unstable` set is used by rustc internally to determined which target - // features are truly available, so we want to return even perma-unstable "forbidden" - // features. - if allow_unstable - || (gate.in_cfg() && (sess.is_nightly_build() || gate.requires_nightly().is_none())) - { - Some(*feature) - } else { - None - } - }) - .filter(|feature| features.contains(&Symbol::intern(feature))) - .map(|feature| Symbol::intern(feature)) - .collect() + // Filter enabled features based on feature gates. + let f = |allow_unstable| { + sess.target + .rust_target_features() + .iter() + .filter_map(|(feature, gate, _)| { + // The `allow_unstable` set is used by rustc internally to determined which target + // features are truly available, so we want to return even perma-unstable + // "forbidden" features. + if allow_unstable + || (gate.in_cfg() + && (sess.is_nightly_build() || gate.requires_nightly().is_none())) + { + Some(Symbol::intern(feature)) + } else { + None + } + }) + .filter(|feature| features.contains(&feature)) + .collect() + }; + + let target_features = f(false); + let unstable_target_features = f(true); + (target_features, unstable_target_features) } pub(crate) fn print_version() { @@ -682,7 +679,7 @@ pub(crate) fn global_llvm_features( for feature in sess.opts.cg.target_feature.split(',') { if let Some(feature) = feature.strip_prefix('+') { all_rust_features.extend( - UnordSet::from(sess.target.implied_target_features(std::iter::once(feature))) + UnordSet::from(sess.target.implied_target_features(feature)) .to_sorted_stable_ord() .iter() .map(|&&s| (true, s)), |