diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/llvm_util.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm_util.rs | 327 |
1 files changed, 183 insertions, 144 deletions
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index a0a640473eb..03be0654b50 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -1,7 +1,10 @@ use crate::back::write::create_informational_target_machine; -use crate::{llvm, llvm_util}; +use crate::errors::{ + PossibleFeature, TargetFeatureDisableOrEnable, UnknownCTargetFeature, + UnknownCTargetFeaturePrefix, +}; +use crate::llvm; use libc::c_int; -use libloading::Library; use rustc_codegen_ssa::target_features::{ supported_target_features, tied_target_features, RUSTC_SPECIFIC_FEATURES, }; @@ -13,11 +16,8 @@ use rustc_session::config::PrintRequest; use rustc_session::Session; use rustc_span::symbol::Symbol; use rustc_target::spec::{MergeFunctions, PanicStrategy}; -use smallvec::{smallvec, SmallVec}; use std::ffi::{CStr, CString}; -use tracing::debug; -use std::mem; use std::path::Path; use std::ptr; use std::slice; @@ -80,10 +80,10 @@ unsafe fn configure_llvm(sess: &Session) { }; // Set the llvm "program name" to make usage and invalid argument messages more clear. add("rustc -Cllvm-args=\"...\" with", true); - if sess.time_llvm_passes() { + if sess.opts.unstable_opts.time_llvm_passes { add("-time-passes", false); } - if sess.print_llvm_passes() { + if sess.opts.unstable_opts.print_llvm_passes { add("-debug-pass=Structure", false); } if sess.target.generate_arange_section @@ -92,16 +92,6 @@ unsafe fn configure_llvm(sess: &Session) { add("-generate-arange-section", false); } - // Disable the machine outliner by default in LLVM versions 11 and LLVM - // version 12, where it leads to miscompilation. - // - // Ref: - // - https://github.com/rust-lang/rust/issues/85351 - // - https://reviews.llvm.org/D103167 - if llvm_util::get_version() < (13, 0, 0) { - add("-enable-machine-outliner=never", false); - } - match sess.opts.unstable_opts.merge_functions.unwrap_or(sess.target.merge_functions) { MergeFunctions::Disabled | MergeFunctions::Trampolines => {} MergeFunctions::Aliases => { @@ -129,24 +119,6 @@ unsafe fn configure_llvm(sess: &Session) { llvm::LLVMTimeTraceProfilerInitialize(); } - llvm::LLVMInitializePasses(); - - // Use the legacy plugin registration if we don't use the new pass manager - if !should_use_new_llvm_pass_manager( - &sess.opts.unstable_opts.new_llvm_pass_manager, - &sess.target.arch, - ) { - // Register LLVM plugins by loading them into the compiler process. - for plugin in &sess.opts.unstable_opts.llvm_plugins { - let lib = Library::new(plugin).unwrap_or_else(|e| bug!("couldn't load plugin: {}", e)); - debug!("LLVM plugin loaded successfully {:?} ({})", lib, plugin); - - // Intentionally leak the dynamic library. We can't ever unload it - // since the library can make things that will live arbitrarily long. - mem::forget(lib); - } - } - rustc_llvm::initialize_available_targets(); llvm::LLVMRustSetLLVMOptions(llvm_args.len() as c_int, llvm_args.as_ptr()); @@ -159,61 +131,139 @@ pub fn time_trace_profiler_finish(file_name: &Path) { } } +pub enum TargetFeatureFoldStrength<'a> { + // The feature is only tied when enabling the feature, disabling + // this feature shouldn't disable the tied feature. + EnableOnly(&'a str), + // The feature is tied for both enabling and disabling this feature. + Both(&'a str), +} + +impl<'a> TargetFeatureFoldStrength<'a> { + fn as_str(&self) -> &'a str { + match self { + TargetFeatureFoldStrength::EnableOnly(feat) => feat, + TargetFeatureFoldStrength::Both(feat) => feat, + } + } +} + +pub struct LLVMFeature<'a> { + pub llvm_feature_name: &'a str, + pub dependency: Option<TargetFeatureFoldStrength<'a>>, +} + +impl<'a> LLVMFeature<'a> { + pub fn new(llvm_feature_name: &'a str) -> Self { + Self { llvm_feature_name, dependency: None } + } + + pub fn with_dependency( + llvm_feature_name: &'a str, + dependency: TargetFeatureFoldStrength<'a>, + ) -> Self { + Self { llvm_feature_name, dependency: Some(dependency) } + } + + pub fn contains(&self, feat: &str) -> bool { + self.iter().any(|dep| dep == feat) + } + + pub fn iter(&'a self) -> impl Iterator<Item = &'a str> { + let dependencies = self.dependency.iter().map(|feat| feat.as_str()); + std::iter::once(self.llvm_feature_name).chain(dependencies) + } +} + +impl<'a> IntoIterator for LLVMFeature<'a> { + type Item = &'a str; + type IntoIter = impl Iterator<Item = &'a str>; + + fn into_iter(self) -> Self::IntoIter { + let dependencies = self.dependency.into_iter().map(|feat| feat.as_str()); + std::iter::once(self.llvm_feature_name).chain(dependencies) + } +} + // WARNING: the features after applying `to_llvm_features` must be known // to LLVM or the feature detection code will walk past the end of the feature // array, leading to crashes. // // To find a list of LLVM's names, check llvm-project/llvm/include/llvm/Support/*TargetParser.def // where the * matches the architecture's name +// +// For targets not present in the above location, see llvm-project/llvm/lib/Target/{ARCH}/*.td +// where `{ARCH}` is the architecture name. Look for instances of `SubtargetFeature`. +// // Beware to not use the llvm github project for this, but check the git submodule // found in src/llvm-project // 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 fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> SmallVec<[&'a str; 2]> { +pub fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> LLVMFeature<'a> { let arch = if sess.target.arch == "x86_64" { "x86" } else { &*sess.target.arch }; match (arch, s) { ("x86", "sse4.2") => { - if get_version() >= (14, 0, 0) { - smallvec!["sse4.2", "crc32"] - } else { - smallvec!["sse4.2"] - } + LLVMFeature::with_dependency("sse4.2", TargetFeatureFoldStrength::EnableOnly("crc32")) } - ("x86", "pclmulqdq") => smallvec!["pclmul"], - ("x86", "rdrand") => smallvec!["rdrnd"], - ("x86", "bmi1") => smallvec!["bmi"], - ("x86", "cmpxchg16b") => smallvec!["cx16"], - ("x86", "avx512vaes") => smallvec!["vaes"], - ("x86", "avx512gfni") => smallvec!["gfni"], - ("x86", "avx512vpclmulqdq") => smallvec!["vpclmulqdq"], - ("aarch64", "rcpc2") => smallvec!["rcpc-immo"], - ("aarch64", "dpb") => smallvec!["ccpp"], - ("aarch64", "dpb2") => smallvec!["ccdp"], - ("aarch64", "frintts") => smallvec!["fptoint"], - ("aarch64", "fcma") => smallvec!["complxnum"], - ("aarch64", "pmuv3") => smallvec!["perfmon"], - ("aarch64", "paca") => smallvec!["pauth"], - ("aarch64", "pacg") => smallvec!["pauth"], - // Rust ties fp and neon together. In LLVM neon implicitly enables fp, - // but we manually enable neon when a feature only implicitly enables fp - ("aarch64", "f32mm") => smallvec!["f32mm", "neon"], - ("aarch64", "f64mm") => smallvec!["f64mm", "neon"], - ("aarch64", "fhm") => smallvec!["fp16fml", "neon"], - ("aarch64", "fp16") => smallvec!["fullfp16", "neon"], - ("aarch64", "jsconv") => smallvec!["jsconv", "neon"], - ("aarch64", "sve") => smallvec!["sve", "neon"], - ("aarch64", "sve2") => smallvec!["sve2", "neon"], - ("aarch64", "sve2-aes") => smallvec!["sve2-aes", "neon"], - ("aarch64", "sve2-sm4") => smallvec!["sve2-sm4", "neon"], - ("aarch64", "sve2-sha3") => smallvec!["sve2-sha3", "neon"], - ("aarch64", "sve2-bitperm") => smallvec!["sve2-bitperm", "neon"], - (_, s) => smallvec![s], + ("x86", "pclmulqdq") => LLVMFeature::new("pclmul"), + ("x86", "rdrand") => LLVMFeature::new("rdrnd"), + ("x86", "bmi1") => LLVMFeature::new("bmi"), + ("x86", "cmpxchg16b") => LLVMFeature::new("cx16"), + ("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"), + // Rust ties fp and neon together. + ("aarch64", "neon") => { + 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", "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"), + ), + (_, s) => LLVMFeature::new(s), } } -// Given a map from target_features to whether they are enabled or disabled, -// ensure only valid combinations are allowed. +/// 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>, @@ -231,11 +281,11 @@ pub fn check_tied_features( return None; } -// Used to generate cfg variables and apply features -// Must express features in the way Rust understands them +/// 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 mut features: Vec<Symbol> = supported_target_features(sess) + supported_target_features(sess) .iter() .filter_map(|&(feature, gate)| { if sess.is_nightly_build() || allow_unstable || gate.is_none() { @@ -255,16 +305,7 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> { true }) .map(|feature| Symbol::intern(feature)) - .collect(); - - // LLVM 14 changed the ABI for i128 arguments to __float/__fix builtins on Win64 - // (see https://reviews.llvm.org/D110413). This unstable target feature is intended for use - // by compiler-builtins, to export the builtins with the expected, LLVM-version-dependent ABI. - // The target feature can be dropped once we no longer support older LLVM versions. - if sess.is_nightly_build() && get_version() >= (14, 0, 0) { - features.push(Symbol::intern("llvm14-builtins-abi")); - } - features + .collect() } pub fn print_version() { @@ -310,30 +351,32 @@ fn llvm_target_features(tm: &llvm::TargetMachine) -> Vec<(&str, &str)> { } fn print_target_features(sess: &Session, tm: &llvm::TargetMachine) { - let mut target_features = llvm_target_features(tm); + 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) .iter() - .filter_map(|(feature, _gate)| { - for llvm_feature in to_llvm_features(sess, *feature) { - // LLVM asserts that these are sorted. LLVM and Rust both use byte comparison for these strings. - match target_features.binary_search_by_key(&llvm_feature, |(f, _d)| f).ok().map( - |index| { - let (_f, desc) = target_features.remove(index); - (*feature, desc) - }, - ) { - Some(v) => return Some(v), - None => {} - } - } - None + .map(|(feature, _gate)| { + // 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 = + match llvm_target_features.binary_search_by_key(&llvm_feature, |(f, _d)| f).ok() { + Some(index) => { + known_llvm_target_features.insert(llvm_feature); + llvm_target_features[index].1 + } + None => "", + }; + + (*feature, desc) }) .collect::<Vec<_>>(); rustc_target_features.extend_from_slice(&[( "crt-static", "Enables C Run-time Libraries to be statically linked", )]); - let max_feature_len = target_features + llvm_target_features.retain(|(f, _d)| !known_llvm_target_features.contains(f)); + + let max_feature_len = llvm_target_features .iter() .chain(rustc_target_features.iter()) .map(|(feature, _desc)| feature.len()) @@ -345,10 +388,10 @@ fn print_target_features(sess: &Session, tm: &llvm::TargetMachine) { println!(" {1:0$} - {2}.", max_feature_len, feature, desc); } println!("\nCode-generation features supported by LLVM for this target:"); - for (feature, desc) in &target_features { + for (feature, desc) in &llvm_target_features { println!(" {1:0$} - {2}.", max_feature_len, feature, desc); } - if target_features.is_empty() { + if llvm_target_features.is_empty() { println!(" Target features listing is not supported by this LLVM version."); } println!("\nUse +feature to enable a feature, or -feature to disable it."); @@ -361,7 +404,14 @@ pub(crate) fn print(req: PrintRequest, sess: &Session) { require_inited(); let tm = create_informational_target_machine(sess); match req { - PrintRequest::TargetCPUs => unsafe { llvm::LLVMRustPrintTargetCPUs(tm) }, + PrintRequest::TargetCPUs => { + // SAFETY generate a C compatible string from a byte slice to pass + // the target CPU name into LLVM, the lifetime of the reference is + // at least as long as the C function + let cpu_cstring = CString::new(handle_native(sess.target.cpu.as_ref())) + .unwrap_or_else(|e| bug!("failed to convert to cstring: {}", e)); + unsafe { llvm::LLVMRustPrintTargetCPUs(tm, cpu_cstring.as_ptr()) }; + } PrintRequest::TargetFeatures => print_target_features(sess, tm), _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req), } @@ -440,6 +490,8 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str .features .split(',') .filter(|v| !v.is_empty() && backend_feature_name(v).is_some()) + // Drop +atomics-32 feature introduced in LLVM 15. + .filter(|v| *v != "+atomics-32" || get_version() >= (15, 0, 0)) .map(String::from), ); @@ -454,15 +506,10 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str .filter_map(|s| { let enable_disable = match s.chars().next() { None => return None, - Some(c @ '+' | c @ '-') => c, + Some(c @ ('+' | '-')) => c, Some(_) => { if diagnostics { - let mut diag = sess.struct_warn(&format!( - "unknown feature specified for `-Ctarget-feature`: `{}`", - s - )); - diag.note("features must begin with a `+` to enable or `-` to disable it"); - diag.emit(); + sess.emit_warning(UnknownCTargetFeaturePrefix { feature: s }); } return None; } @@ -479,17 +526,15 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str None } }); - let mut diag = sess.struct_warn(&format!( - "unknown feature specified for `-Ctarget-feature`: `{}`", - feature - )); - diag.note("it is still passed through to the codegen backend"); - if let Some(rust_feature) = rust_feature { - diag.help(&format!("you might have meant: `{}`", rust_feature)); + let unknown_feature = if let Some(rust_feature) = rust_feature { + UnknownCTargetFeature { + feature, + rust_feature: PossibleFeature::Some { rust_feature }, + } } else { - diag.note("consider filing a feature request"); - } - diag.emit(); + UnknownCTargetFeature { feature, rust_feature: PossibleFeature::None } + }; + sess.emit_warning(unknown_feature); } if diagnostics { @@ -505,20 +550,30 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str // 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( - to_llvm_features(sess, feature) - .into_iter() - .map(move |f| format!("{}{}", enable_disable, f)), + 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); if diagnostics && let Some(f) = check_tied_features(sess, &featsmap) { - sess.err(&format!( - "target features {} must all be enabled or disabled together", - f.join(", ") - )); + sess.emit_err(TargetFeatureDisableOrEnable { + features: f, + span: None, + missing_features: None, + }); } features @@ -544,19 +599,3 @@ pub fn tune_cpu(sess: &Session) -> Option<&str> { let name = sess.opts.unstable_opts.tune_cpu.as_ref()?; Some(handle_native(name)) } - -pub(crate) fn should_use_new_llvm_pass_manager(user_opt: &Option<bool>, target_arch: &str) -> bool { - // The new pass manager is enabled by default for LLVM >= 13. - // This matches Clang, which also enables it since Clang 13. - - // Since LLVM 15, the legacy pass manager is no longer supported. - if llvm_util::get_version() >= (15, 0, 0) { - return true; - } - - // There are some perf issues with the new pass manager when targeting - // s390x with LLVM 13, so enable the new pass manager only with LLVM 14. - // See https://github.com/rust-lang/rust/issues/89609. - let min_version = if target_arch == "s390x" { 14 } else { 13 }; - user_opt.unwrap_or_else(|| llvm_util::get_version() >= (min_version, 0, 0)) -} |