diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index 33bdfd3825c82..92a857c2adcf4 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -521,9 +521,10 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>( let function_features = function_features .iter() - .flat_map(|feat| { - llvm_util::to_llvm_features(cx.tcx.sess, feat).into_iter().map(|f| format!("+{f}")) - }) + // Convert to LLVMFeatures and filter out unavailable ones + .flat_map(|feat| llvm_util::to_llvm_features(cx.tcx.sess, feat)) + // Convert LLVMFeatures & dependencies to +s + .flat_map(|feat| feat.into_iter().map(|f| format!("+{f}"))) .chain(codegen_fn_attrs.instruction_set.iter().map(|x| match x { InstructionSetAttr::ArmA32 => "-thumb-mode".to_string(), InstructionSetAttr::ArmT32 => "+thumb-mode".to_string(), diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index a0ef6483ed650..618602ed70f44 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -209,7 +209,7 @@ impl<'a> IntoIterator for LLVMFeature<'a> { // Though note that Rust can also be build with an external precompiled version of LLVM // which might lead to failures if the oldest tested / supported LLVM version // doesn't yet support the relevant intrinsics -pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> LLVMFeature<'a> { +pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option> { let arch = if sess.target.arch == "x86_64" { "x86" } else if sess.target.arch == "arm64ec" { @@ -218,42 +218,59 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> LLVMFeature<'a &*sess.target.arch }; match (arch, s) { - ("x86", "sse4.2") => { - LLVMFeature::with_dependency("sse4.2", TargetFeatureFoldStrength::EnableOnly("crc32")) - } - ("x86", "pclmulqdq") => LLVMFeature::new("pclmul"), - ("x86", "rdrand") => LLVMFeature::new("rdrnd"), - ("x86", "bmi1") => LLVMFeature::new("bmi"), - ("x86", "cmpxchg16b") => LLVMFeature::new("cx16"), - ("x86", "lahfsahf") => LLVMFeature::new("sahf"), - ("aarch64", "rcpc2") => LLVMFeature::new("rcpc-immo"), - ("aarch64", "dpb") => LLVMFeature::new("ccpp"), - ("aarch64", "dpb2") => LLVMFeature::new("ccdp"), - ("aarch64", "frintts") => LLVMFeature::new("fptoint"), - ("aarch64", "fcma") => LLVMFeature::new("complxnum"), - ("aarch64", "pmuv3") => LLVMFeature::new("perfmon"), - ("aarch64", "paca") => LLVMFeature::new("pauth"), - ("aarch64", "pacg") => LLVMFeature::new("pauth"), - ("aarch64", "sve-b16b16") => LLVMFeature::new("b16b16"), - ("aarch64", "flagm2") => LLVMFeature::new("altnzcv"), + ("x86", "sse4.2") => Some(LLVMFeature::with_dependency( + "sse4.2", + TargetFeatureFoldStrength::EnableOnly("crc32"), + )), + ("x86", "pclmulqdq") => Some(LLVMFeature::new("pclmul")), + ("x86", "rdrand") => Some(LLVMFeature::new("rdrnd")), + ("x86", "bmi1") => Some(LLVMFeature::new("bmi")), + ("x86", "cmpxchg16b") => Some(LLVMFeature::new("cx16")), + ("x86", "lahfsahf") => Some(LLVMFeature::new("sahf")), + ("aarch64", "rcpc2") => Some(LLVMFeature::new("rcpc-immo")), + ("aarch64", "dpb") => Some(LLVMFeature::new("ccpp")), + ("aarch64", "dpb2") => Some(LLVMFeature::new("ccdp")), + ("aarch64", "frintts") => Some(LLVMFeature::new("fptoint")), + ("aarch64", "fcma") => Some(LLVMFeature::new("complxnum")), + ("aarch64", "pmuv3") => Some(LLVMFeature::new("perfmon")), + ("aarch64", "paca") => Some(LLVMFeature::new("pauth")), + ("aarch64", "pacg") => Some(LLVMFeature::new("pauth")), + ("aarch64", "sve-b16b16") => Some(LLVMFeature::new("b16b16")), + ("aarch64", "flagm2") => Some(LLVMFeature::new("altnzcv")), // Rust ties fp and neon together. ("aarch64", "neon") => { - LLVMFeature::with_dependency("neon", TargetFeatureFoldStrength::Both("fp-armv8")) + Some(LLVMFeature::with_dependency("neon", TargetFeatureFoldStrength::Both("fp-armv8"))) } // In LLVM neon implicitly enables fp, but we manually enable // neon when a feature only implicitly enables fp - ("aarch64", "fhm") => LLVMFeature::new("fp16fml"), - ("aarch64", "fp16") => LLVMFeature::new("fullfp16"), + ("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", "faminmax") if get_version().0 < 18 => None, + ("aarch64", "fp8") if get_version().0 < 18 => None, + ("aarch64", "fp8dot2") if get_version().0 < 18 => None, + ("aarch64", "fp8dot4") if get_version().0 < 18 => None, + ("aarch64", "fp8fma") if get_version().0 < 18 => None, + ("aarch64", "fpmr") if get_version().0 != 18 => None, + ("aarch64", "lut") if get_version().0 < 18 => None, + ("aarch64", "sme-f8f16") if get_version().0 < 18 => None, + ("aarch64", "sme-f8f32") if get_version().0 < 18 => None, + ("aarch64", "sme-fa64") if get_version().0 < 18 => None, + ("aarch64", "sme-lutv2") if get_version().0 < 18 => None, + ("aarch64", "ssve-fp8dot2") if get_version().0 < 18 => None, + ("aarch64", "ssve-fp8dot4") if get_version().0 < 18 => None, + ("aarch64", "ssve-fp8fma") if get_version().0 < 18 => None, + ("aarch64", "v9.5a") if get_version().0 < 18 => None, // 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 => { - LLVMFeature::new("fast-unaligned-access") + Some(LLVMFeature::new("fast-unaligned-access")) } // For LLVM 18, enable the evex512 target feature if a avx512 target feature is enabled. ("x86", s) if get_version().0 >= 18 && s.starts_with("avx512") => { - LLVMFeature::with_dependency(s, TargetFeatureFoldStrength::EnableOnly("evex512")) + Some(LLVMFeature::with_dependency(s, TargetFeatureFoldStrength::EnableOnly("evex512"))) } - (_, s) => LLVMFeature::new(s), + (_, s) => Some(LLVMFeature::new(s)), } } @@ -293,13 +310,17 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec { 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; + 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, cstr.as_ptr()) } { + return false; + } } + true + } else { + false } - true }) .map(|(feature, _, _)| Symbol::intern(feature)), ); @@ -388,9 +409,9 @@ fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMach .target .supported_target_features() .iter() - .map(|(feature, _gate, _implied)| { + .filter_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 llvm_feature = to_llvm_features(sess, *feature)?.llvm_feature_name; let desc = match llvm_target_features.binary_search_by_key(&llvm_feature, |(f, _d)| f).ok() { Some(index) => { @@ -400,7 +421,7 @@ fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMach None => "", }; - (*feature, desc) + Some((*feature, desc)) }) .collect::>(); @@ -597,7 +618,7 @@ pub(crate) fn global_llvm_features( if feature_state.is_none() { let rust_feature = supported_features.iter().find_map(|&(rust_feature, _, _)| { - let llvm_features = to_llvm_features(sess, rust_feature); + let llvm_features = to_llvm_features(sess, rust_feature)?; if llvm_features.contains(feature) && !llvm_features.contains(rust_feature) { @@ -643,7 +664,7 @@ pub(crate) fn global_llvm_features( // 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); + let llvm_feature = to_llvm_features(sess, feature)?; Some( std::iter::once(format!( @@ -693,6 +714,9 @@ fn backend_feature_name<'a>(sess: &Session, s: &'a str) -> Option<&'a str> { let feature = s .strip_prefix(&['+', '-'][..]) .unwrap_or_else(|| sess.dcx().emit_fatal(InvalidTargetFeaturePrefix { feature: s })); + if s.is_empty() { + return None; + } // Rustc-specific feature requests like `+crt-static` or `-crt-static` // are not passed down to LLVM. if RUSTC_SPECIFIC_FEATURES.contains(&feature) {