diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/llvm_util.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm_util.rs | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs new file mode 100644 index 00000000000..f0b50459837 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -0,0 +1,368 @@ +use crate::back::write::create_informational_target_machine; +use crate::llvm; +use libc::c_int; +use rustc_data_structures::fx::FxHashSet; +use rustc_feature::UnstableFeatures; +use rustc_middle::bug; +use rustc_session::config::PrintRequest; +use rustc_session::Session; +use rustc_span::symbol::sym; +use rustc_span::symbol::Symbol; +use rustc_target::spec::{MergeFunctions, PanicStrategy}; +use std::ffi::CString; + +use std::slice; +use std::str; +use std::sync::atomic::{AtomicBool, Ordering}; +use std::sync::Once; + +static POISONED: AtomicBool = AtomicBool::new(false); +static INIT: Once = Once::new(); + +pub(crate) fn init(sess: &Session) { + unsafe { + // Before we touch LLVM, make sure that multithreading is enabled. + INIT.call_once(|| { + if llvm::LLVMStartMultithreaded() != 1 { + // use an extra bool to make sure that all future usage of LLVM + // cannot proceed despite the Once not running more than once. + POISONED.store(true, Ordering::SeqCst); + } + + configure_llvm(sess); + }); + + if POISONED.load(Ordering::SeqCst) { + bug!("couldn't enable multi-threaded LLVM"); + } + } +} + +fn require_inited() { + INIT.call_once(|| bug!("llvm is not initialized")); + if POISONED.load(Ordering::SeqCst) { + bug!("couldn't enable multi-threaded LLVM"); + } +} + +unsafe fn configure_llvm(sess: &Session) { + let n_args = sess.opts.cg.llvm_args.len() + sess.target.target.options.llvm_args.len(); + let mut llvm_c_strs = Vec::with_capacity(n_args + 1); + let mut llvm_args = Vec::with_capacity(n_args + 1); + + llvm::LLVMRustInstallFatalErrorHandler(); + + fn llvm_arg_to_arg_name(full_arg: &str) -> &str { + full_arg.trim().split(|c: char| c == '=' || c.is_whitespace()).next().unwrap_or("") + } + + let cg_opts = sess.opts.cg.llvm_args.iter(); + let tg_opts = sess.target.target.options.llvm_args.iter(); + let sess_args = cg_opts.chain(tg_opts); + + let user_specified_args: FxHashSet<_> = + sess_args.clone().map(|s| llvm_arg_to_arg_name(s)).filter(|s| !s.is_empty()).collect(); + + { + // This adds the given argument to LLVM. Unless `force` is true + // user specified arguments are *not* overridden. + let mut add = |arg: &str, force: bool| { + if force || !user_specified_args.contains(llvm_arg_to_arg_name(arg)) { + let s = CString::new(arg).unwrap(); + llvm_args.push(s.as_ptr()); + llvm_c_strs.push(s); + } + }; + // 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() { + add("-time-passes", false); + } + if sess.print_llvm_passes() { + add("-debug-pass=Structure", false); + } + if !sess.opts.debugging_opts.no_generate_arange_section { + add("-generate-arange-section", false); + } + match sess + .opts + .debugging_opts + .merge_functions + .unwrap_or(sess.target.target.options.merge_functions) + { + MergeFunctions::Disabled | MergeFunctions::Trampolines => {} + MergeFunctions::Aliases => { + add("-mergefunc-use-aliases", false); + } + } + + if sess.target.target.target_os == "emscripten" + && sess.panic_strategy() == PanicStrategy::Unwind + { + add("-enable-emscripten-cxx-exceptions", false); + } + + // HACK(eddyb) LLVM inserts `llvm.assume` calls to preserve align attributes + // during inlining. Unfortunately these may block other optimizations. + add("-preserve-alignment-assumptions-during-inlining=false", false); + + for arg in sess_args { + add(&(*arg), true); + } + } + + if sess.opts.debugging_opts.llvm_time_trace && get_major_version() >= 9 { + // time-trace is not thread safe and running it in parallel will cause seg faults. + if !sess.opts.debugging_opts.no_parallel_llvm { + bug!("`-Z llvm-time-trace` requires `-Z no-parallel-llvm") + } + + llvm::LLVMTimeTraceProfilerInitialize(); + } + + llvm::LLVMInitializePasses(); + + ::rustc_llvm::initialize_available_targets(); + + llvm::LLVMRustSetLLVMOptions(llvm_args.len() as c_int, llvm_args.as_ptr()); +} + +pub fn time_trace_profiler_finish(file_name: &str) { + unsafe { + if get_major_version() >= 9 { + let file_name = CString::new(file_name).unwrap(); + llvm::LLVMTimeTraceProfilerFinish(file_name.as_ptr()); + } + } +} + +// WARNING: the features after applying `to_llvm_feature` must be known +// to LLVM or the feature detection code will walk past the end of the feature +// array, leading to crashes. + +const ARM_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("aclass", Some(sym::arm_target_feature)), + ("mclass", Some(sym::arm_target_feature)), + ("rclass", Some(sym::arm_target_feature)), + ("dsp", Some(sym::arm_target_feature)), + ("neon", Some(sym::arm_target_feature)), + ("crc", Some(sym::arm_target_feature)), + ("crypto", Some(sym::arm_target_feature)), + ("v5te", Some(sym::arm_target_feature)), + ("v6", Some(sym::arm_target_feature)), + ("v6k", Some(sym::arm_target_feature)), + ("v6t2", Some(sym::arm_target_feature)), + ("v7", Some(sym::arm_target_feature)), + ("v8", Some(sym::arm_target_feature)), + ("vfp2", Some(sym::arm_target_feature)), + ("vfp3", Some(sym::arm_target_feature)), + ("vfp4", Some(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", Some(sym::arm_target_feature)), +]; + +const AARCH64_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("fp", Some(sym::aarch64_target_feature)), + ("neon", Some(sym::aarch64_target_feature)), + ("sve", Some(sym::aarch64_target_feature)), + ("crc", Some(sym::aarch64_target_feature)), + ("crypto", Some(sym::aarch64_target_feature)), + ("ras", Some(sym::aarch64_target_feature)), + ("lse", Some(sym::aarch64_target_feature)), + ("rdm", Some(sym::aarch64_target_feature)), + ("fp16", Some(sym::aarch64_target_feature)), + ("rcpc", Some(sym::aarch64_target_feature)), + ("dotprod", Some(sym::aarch64_target_feature)), + ("tme", Some(sym::aarch64_target_feature)), + ("v8.1a", Some(sym::aarch64_target_feature)), + ("v8.2a", Some(sym::aarch64_target_feature)), + ("v8.3a", Some(sym::aarch64_target_feature)), +]; + +const X86_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("adx", Some(sym::adx_target_feature)), + ("aes", None), + ("avx", None), + ("avx2", None), + ("avx512bw", Some(sym::avx512_target_feature)), + ("avx512cd", Some(sym::avx512_target_feature)), + ("avx512dq", Some(sym::avx512_target_feature)), + ("avx512er", Some(sym::avx512_target_feature)), + ("avx512f", Some(sym::avx512_target_feature)), + ("avx512ifma", Some(sym::avx512_target_feature)), + ("avx512pf", Some(sym::avx512_target_feature)), + ("avx512vbmi", Some(sym::avx512_target_feature)), + ("avx512vl", Some(sym::avx512_target_feature)), + ("avx512vpopcntdq", Some(sym::avx512_target_feature)), + ("bmi1", None), + ("bmi2", None), + ("cmpxchg16b", Some(sym::cmpxchg16b_target_feature)), + ("f16c", Some(sym::f16c_target_feature)), + ("fma", None), + ("fxsr", None), + ("lzcnt", None), + ("mmx", Some(sym::mmx_target_feature)), + ("movbe", Some(sym::movbe_target_feature)), + ("pclmulqdq", None), + ("popcnt", None), + ("rdrand", None), + ("rdseed", None), + ("rtm", Some(sym::rtm_target_feature)), + ("sha", None), + ("sse", None), + ("sse2", None), + ("sse3", None), + ("sse4.1", None), + ("sse4.2", None), + ("sse4a", Some(sym::sse4a_target_feature)), + ("ssse3", None), + ("tbm", Some(sym::tbm_target_feature)), + ("xsave", None), + ("xsavec", None), + ("xsaveopt", None), + ("xsaves", None), +]; + +const HEXAGON_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("hvx", Some(sym::hexagon_target_feature)), + ("hvx-length128b", Some(sym::hexagon_target_feature)), +]; + +const POWERPC_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("altivec", Some(sym::powerpc_target_feature)), + ("power8-altivec", Some(sym::powerpc_target_feature)), + ("power9-altivec", Some(sym::powerpc_target_feature)), + ("power8-vector", Some(sym::powerpc_target_feature)), + ("power9-vector", Some(sym::powerpc_target_feature)), + ("vsx", Some(sym::powerpc_target_feature)), +]; + +const MIPS_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = + &[("fp64", Some(sym::mips_target_feature)), ("msa", Some(sym::mips_target_feature))]; + +const RISCV_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("m", Some(sym::riscv_target_feature)), + ("a", Some(sym::riscv_target_feature)), + ("c", Some(sym::riscv_target_feature)), + ("f", Some(sym::riscv_target_feature)), + ("d", Some(sym::riscv_target_feature)), + ("e", Some(sym::riscv_target_feature)), +]; + +const WASM_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[ + ("simd128", Some(sym::wasm_target_feature)), + ("atomics", Some(sym::wasm_target_feature)), + ("nontrapping-fptoint", Some(sym::wasm_target_feature)), +]; + +/// 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, Option<Symbol>)> { + 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()) + .cloned() +} + +pub fn to_llvm_feature<'a>(sess: &Session, s: &'a str) -> &'a str { + let arch = if sess.target.target.arch == "x86_64" { "x86" } else { &*sess.target.target.arch }; + match (arch, s) { + ("x86", "pclmulqdq") => "pclmul", + ("x86", "rdrand") => "rdrnd", + ("x86", "bmi1") => "bmi", + ("x86", "cmpxchg16b") => "cx16", + ("aarch64", "fp") => "fp-armv8", + ("aarch64", "fp16") => "fullfp16", + (_, s) => s, + } +} + +pub fn target_features(sess: &Session) -> Vec<Symbol> { + let target_machine = create_informational_target_machine(sess); + supported_target_features(sess) + .iter() + .filter_map(|&(feature, gate)| { + if UnstableFeatures::from_environment().is_nightly_build() || gate.is_none() { + Some(feature) + } else { + None + } + }) + .filter(|feature| { + let llvm_feature = to_llvm_feature(sess, feature); + let cstr = CString::new(llvm_feature).unwrap(); + unsafe { llvm::LLVMRustHasFeature(target_machine, cstr.as_ptr()) } + }) + .map(|feature| Symbol::intern(feature)) + .collect() +} + +pub fn supported_target_features(sess: &Session) -> &'static [(&'static str, Option<Symbol>)] { + match &*sess.target.target.arch { + "arm" => ARM_ALLOWED_FEATURES, + "aarch64" => AARCH64_ALLOWED_FEATURES, + "x86" | "x86_64" => X86_ALLOWED_FEATURES, + "hexagon" => HEXAGON_ALLOWED_FEATURES, + "mips" | "mips64" => MIPS_ALLOWED_FEATURES, + "powerpc" | "powerpc64" => POWERPC_ALLOWED_FEATURES, + "riscv32" | "riscv64" => RISCV_ALLOWED_FEATURES, + "wasm32" => WASM_ALLOWED_FEATURES, + _ => &[], + } +} + +pub fn print_version() { + // Can be called without initializing LLVM + unsafe { + println!("LLVM version: {}.{}", llvm::LLVMRustVersionMajor(), llvm::LLVMRustVersionMinor()); + } +} + +pub fn get_major_version() -> u32 { + unsafe { llvm::LLVMRustVersionMajor() } +} + +pub fn print_passes() { + // Can be called without initializing LLVM + unsafe { + llvm::LLVMRustPrintPasses(); + } +} + +pub(crate) fn print(req: PrintRequest, sess: &Session) { + require_inited(); + let tm = create_informational_target_machine(sess); + unsafe { + match req { + PrintRequest::TargetCPUs => llvm::LLVMRustPrintTargetCPUs(tm), + PrintRequest::TargetFeatures => llvm::LLVMRustPrintTargetFeatures(tm), + _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req), + } + } +} + +pub fn target_cpu(sess: &Session) -> &str { + let name = match sess.opts.cg.target_cpu { + Some(ref s) => &**s, + None => &*sess.target.target.options.cpu, + }; + if name != "native" { + return name; + } + + unsafe { + let mut len = 0; + let ptr = llvm::LLVMRustGetHostCPUName(&mut len); + str::from_utf8(slice::from_raw_parts(ptr as *const u8, len)).unwrap() + } +} |