From a059e68d118512063e8e3517344178667df951b0 Mon Sep 17 00:00:00 2001 From: Jamie Cunliffe Date: Mon, 22 May 2023 14:46:40 +0100 Subject: [PATCH] Create a structure to define the features from to_llvm_features. Rather than returning an array of features from to_llvm_features, return a structure that contains the dependencies. This also contains metadata on how the features depend on each other to allow for the correct enabling and disabling. --- compiler/rustc_codegen_llvm/src/lib.rs | 1 + compiler/rustc_codegen_llvm/src/llvm_util.rs | 192 ++++++++++++------- tests/codegen/tied-features-strength.rs | 10 +- 3 files changed, 133 insertions(+), 70 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs index 6a86237d79e..805843e5863 100644 --- a/compiler/rustc_codegen_llvm/src/lib.rs +++ b/compiler/rustc_codegen_llvm/src/lib.rs @@ -10,6 +10,7 @@ #![feature(iter_intersperse)] #![feature(let_chains)] #![feature(never_type)] +#![feature(impl_trait_in_assoc_type)] #![recursion_limit = "256"] #![allow(rustc::potential_query_instability)] #![deny(rustc::untranslatable_diagnostic)] diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index a75c15ee4be..03be0654b50 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -16,7 +16,6 @@ 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 std::path::Path; @@ -132,6 +131,60 @@ 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>, +} + +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 { + 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; + + 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. @@ -147,58 +200,65 @@ pub fn time_trace_profiler_finish(file_name: &Path) { // 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 -// -// Note: The first feature in the list that is returned is the mapping to the feature that is -// provided from the `s` parameter. -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") => smallvec!["sse4.2", "crc32"], - ("x86", "pclmulqdq") => smallvec!["pclmul"], - ("x86", "rdrand") => smallvec!["rdrnd"], - ("x86", "bmi1") => smallvec!["bmi"], - ("x86", "cmpxchg16b") => smallvec!["cx16"], - ("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"], + ("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"), + ("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") => smallvec!["neon", "fp-armv8"], + ("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") => 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], - } -} - -pub enum TargetFeatureFoldStrength { - // The feature is only tied when enabling the feature, disabling - // this feature shouldn't disable the tied feature. - EnableOnly, - // The feature is tied for both enabling and disabling this feature. - Both, -} - -// Determines how the features are folded together, some features are -// linked a lot more than some others. -pub fn feature_fold_strength<'a>(feats: &SmallVec<[&'a str; 2]>) -> TargetFeatureFoldStrength { - match (feats.get(0), feats.get(1)) { - (Some(&"neon"), Some(&"fp-armv8")) => TargetFeatureFoldStrength::Both, - _ => TargetFeatureFoldStrength::EnableOnly, + ("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), } } @@ -296,18 +356,17 @@ fn print_target_features(sess: &Session, tm: &llvm::TargetMachine) { let mut rustc_target_features = supported_target_features(sess) .iter() .map(|(feature, _gate)| { - let desc = if let Some(llvm_feature) = to_llvm_features(sess, *feature).first() { - // LLVM asserts that these are sorted. LLVM and Rust both use byte comparison for these strings. + // 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 => "", - } - } else { - "" - }; + }; + (*feature, desc) }) .collect::>(); @@ -491,17 +550,20 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec { - Some(format!("{}{}", enable_disable, f)) - } - _ if idx == 0 => Some(format!("{}{}", enable_disable, f)), - _ => None, - }, - )) + 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); diff --git a/tests/codegen/tied-features-strength.rs b/tests/codegen/tied-features-strength.rs index 5dc9ae47e79..51334c12158 100644 --- a/tests/codegen/tied-features-strength.rs +++ b/tests/codegen/tied-features-strength.rs @@ -5,19 +5,19 @@ // The "+v8a" feature is matched as optional as it isn't added when we // are targeting older LLVM versions. Once the min supported version -// is LLVM-14 we can remove the regex matching for this feature. +// is LLVM-14 we can remove the optional regex matching for this feature. // [ENABLE_SVE] compile-flags: -C target-feature=+sve -// ENABLE_SVE: attributes #0 = { {{.*}} "target-features"="+outline-atomics,+sve,+neon{{(,\+v8a)?}}" } +// ENABLE_SVE: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(\+sve,?)|(\+neon,?))*}}" } // [DISABLE_SVE] compile-flags: -C target-feature=-sve -// DISABLE_SVE: attributes #0 = { {{.*}} "target-features"="+outline-atomics,-sve{{(,\+v8a)?}}" } +// DISABLE_SVE: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(-sve,?)|(\+neon,?))*}}" } // [DISABLE_NEON] compile-flags: -C target-feature=-neon -// DISABLE_NEON: attributes #0 = { {{.*}} "target-features"="+outline-atomics,-neon,-fp-armv8{{(,\+v8a)?}}" } +// DISABLE_NEON: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(-fp-armv8,?)|(-neon,?))*}}" } // [ENABLE_NEON] compile-flags: -C target-feature=+neon -// ENABLE_NEON: attributes #0 = { {{.*}} "target-features"="+outline-atomics,+neon,+fp-armv8{{(,\+v8a)?}}" } +// ENABLE_NEON: attributes #0 = { {{.*}} "target-features"="{{((\+outline-atomics,?)|(\+v8a,?)?|(\+fp-armv8,?)|(\+neon,?))*}}" } #![feature(no_core, lang_items)]