mirror of
https://github.com/rust-lang/rust.git
synced 2025-10-30 20:44:34 +00:00
3c9765cff1
This is no longer used only for debugging options (e.g. `-Zoutput-width`, `-Zallow-features`). Rename it to be more clear.
563 lines
22 KiB
Rust
563 lines
22 KiB
Rust
use crate::back::write::create_informational_target_machine;
|
|
use crate::{llvm, llvm_util};
|
|
use libc::c_int;
|
|
use libloading::Library;
|
|
use rustc_codegen_ssa::target_features::{
|
|
supported_target_features, tied_target_features, RUSTC_SPECIFIC_FEATURES,
|
|
};
|
|
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
|
|
use rustc_data_structures::small_c_str::SmallCStr;
|
|
use rustc_fs_util::path_to_c_string;
|
|
use rustc_middle::bug;
|
|
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;
|
|
use std::str;
|
|
use std::sync::Once;
|
|
|
|
static INIT: Once = Once::new();
|
|
|
|
pub(crate) fn init(sess: &Session) {
|
|
unsafe {
|
|
// Before we touch LLVM, make sure that multithreading is enabled.
|
|
if llvm::LLVMIsMultithreaded() != 1 {
|
|
bug!("LLVM compiled without support for threads");
|
|
}
|
|
INIT.call_once(|| {
|
|
configure_llvm(sess);
|
|
});
|
|
}
|
|
}
|
|
|
|
fn require_inited() {
|
|
if !INIT.is_completed() {
|
|
bug!("LLVM is not initialized");
|
|
}
|
|
}
|
|
|
|
unsafe fn configure_llvm(sess: &Session) {
|
|
let n_args = sess.opts.cg.llvm_args.len() + sess.target.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();
|
|
// On Windows, an LLVM assertion will open an Abort/Retry/Ignore dialog
|
|
// box for the purpose of launching a debugger. However, on CI this will
|
|
// cause it to hang until it times out, which can take several hours.
|
|
if std::env::var_os("CI").is_some() {
|
|
llvm::LLVMRustDisableSystemDialogsOnCrash();
|
|
}
|
|
|
|
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().map(AsRef::as_ref);
|
|
let tg_opts = sess.target.llvm_args.iter().map(AsRef::as_ref);
|
|
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.target.generate_arange_section
|
|
&& !sess.opts.unstable_opts.no_generate_arange_section
|
|
{
|
|
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 => {
|
|
add("-mergefunc-use-aliases", false);
|
|
}
|
|
}
|
|
|
|
if sess.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);
|
|
|
|
// Use non-zero `import-instr-limit` multiplier for cold callsites.
|
|
add("-import-cold-multiplier=0.1", false);
|
|
|
|
for arg in sess_args {
|
|
add(&(*arg), true);
|
|
}
|
|
}
|
|
|
|
if sess.opts.unstable_opts.llvm_time_trace {
|
|
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());
|
|
}
|
|
|
|
pub fn time_trace_profiler_finish(file_name: &Path) {
|
|
unsafe {
|
|
let file_name = path_to_c_string(file_name);
|
|
llvm::LLVMTimeTraceProfilerFinish(file_name.as_ptr());
|
|
}
|
|
}
|
|
|
|
// 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
|
|
// 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]> {
|
|
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"]
|
|
}
|
|
}
|
|
("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],
|
|
}
|
|
}
|
|
|
|
// 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>,
|
|
) -> Option<&'static [&'static str]> {
|
|
if !features.is_empty() {
|
|
for tied in tied_target_features(sess) {
|
|
// Tied features must be set to the same value, or not set at all
|
|
let mut tied_iter = tied.iter();
|
|
let enabled = features.get(tied_iter.next().unwrap());
|
|
if tied_iter.any(|f| enabled != features.get(f)) {
|
|
return Some(tied);
|
|
}
|
|
}
|
|
}
|
|
return None;
|
|
}
|
|
|
|
// 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)
|
|
.iter()
|
|
.filter_map(|&(feature, gate)| {
|
|
if sess.is_nightly_build() || allow_unstable || gate.is_none() {
|
|
Some(feature)
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
.filter(|feature| {
|
|
// 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;
|
|
}
|
|
}
|
|
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
|
|
}
|
|
|
|
pub fn print_version() {
|
|
let (major, minor, patch) = get_version();
|
|
println!("LLVM version: {}.{}.{}", major, minor, patch);
|
|
}
|
|
|
|
pub fn get_version() -> (u32, u32, u32) {
|
|
// Can be called without initializing LLVM
|
|
unsafe {
|
|
(llvm::LLVMRustVersionMajor(), llvm::LLVMRustVersionMinor(), llvm::LLVMRustVersionPatch())
|
|
}
|
|
}
|
|
|
|
pub fn print_passes() {
|
|
// Can be called without initializing LLVM
|
|
unsafe {
|
|
llvm::LLVMRustPrintPasses();
|
|
}
|
|
}
|
|
|
|
fn llvm_target_features(tm: &llvm::TargetMachine) -> Vec<(&str, &str)> {
|
|
let len = unsafe { llvm::LLVMRustGetTargetFeaturesCount(tm) };
|
|
let mut ret = Vec::with_capacity(len);
|
|
for i in 0..len {
|
|
unsafe {
|
|
let mut feature = ptr::null();
|
|
let mut desc = ptr::null();
|
|
llvm::LLVMRustGetTargetFeature(tm, i, &mut feature, &mut desc);
|
|
if feature.is_null() || desc.is_null() {
|
|
bug!("LLVM returned a `null` target feature string");
|
|
}
|
|
let feature = CStr::from_ptr(feature).to_str().unwrap_or_else(|e| {
|
|
bug!("LLVM returned a non-utf8 feature string: {}", e);
|
|
});
|
|
let desc = CStr::from_ptr(desc).to_str().unwrap_or_else(|e| {
|
|
bug!("LLVM returned a non-utf8 feature string: {}", e);
|
|
});
|
|
ret.push((feature, desc));
|
|
}
|
|
}
|
|
ret
|
|
}
|
|
|
|
fn print_target_features(sess: &Session, tm: &llvm::TargetMachine) {
|
|
let mut target_features = llvm_target_features(tm);
|
|
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
|
|
})
|
|
.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
|
|
.iter()
|
|
.chain(rustc_target_features.iter())
|
|
.map(|(feature, _desc)| feature.len())
|
|
.max()
|
|
.unwrap_or(0);
|
|
|
|
println!("Features supported by rustc for this target:");
|
|
for (feature, desc) in &rustc_target_features {
|
|
println!(" {1:0$} - {2}.", max_feature_len, feature, desc);
|
|
}
|
|
println!("\nCode-generation features supported by LLVM for this target:");
|
|
for (feature, desc) in &target_features {
|
|
println!(" {1:0$} - {2}.", max_feature_len, feature, desc);
|
|
}
|
|
if 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.");
|
|
println!("For example, rustc -C target-cpu=mycpu -C target-feature=+feature1,-feature2\n");
|
|
println!("Code-generation features cannot be used in cfg or #[target_feature],");
|
|
println!("and may be renamed or removed in a future version of LLVM or rustc.\n");
|
|
}
|
|
|
|
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::TargetFeatures => print_target_features(sess, tm),
|
|
_ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req),
|
|
}
|
|
}
|
|
|
|
fn handle_native(name: &str) -> &str {
|
|
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()
|
|
}
|
|
}
|
|
|
|
pub fn target_cpu(sess: &Session) -> &str {
|
|
match sess.opts.cg.target_cpu {
|
|
Some(ref name) => handle_native(name),
|
|
None => handle_native(sess.target.cpu.as_ref()),
|
|
}
|
|
}
|
|
|
|
/// The list of LLVM features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
|
|
/// `--target` and similar).
|
|
pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<String> {
|
|
// Features that come earlier are overridden by conflicting features later in the string.
|
|
// Typically we'll want more explicit settings to override the implicit ones, so:
|
|
//
|
|
// * Features from -Ctarget-cpu=*; are overridden by [^1]
|
|
// * Features implied by --target; are overridden by
|
|
// * Features from -Ctarget-feature; are overridden by
|
|
// * function specific features.
|
|
//
|
|
// [^1]: target-cpu=native is handled here, other target-cpu values are handled implicitly
|
|
// through LLVM TargetMachine implementation.
|
|
//
|
|
// FIXME(nagisa): it isn't clear what's the best interaction between features implied by
|
|
// `-Ctarget-cpu` and `--target` are. On one hand, you'd expect CLI arguments to always
|
|
// override anything that's implicit, so e.g. when there's no `--target` flag, features implied
|
|
// the host target are overridden by `-Ctarget-cpu=*`. On the other hand, what about when both
|
|
// `--target` and `-Ctarget-cpu=*` are specified? Both then imply some target features and both
|
|
// flags are specified by the user on the CLI. It isn't as clear-cut which order of precedence
|
|
// should be taken in cases like these.
|
|
let mut features = vec![];
|
|
|
|
// -Ctarget-cpu=native
|
|
match sess.opts.cg.target_cpu {
|
|
Some(ref s) if s == "native" => {
|
|
let features_string = unsafe {
|
|
let ptr = llvm::LLVMGetHostCPUFeatures();
|
|
let features_string = if !ptr.is_null() {
|
|
CStr::from_ptr(ptr)
|
|
.to_str()
|
|
.unwrap_or_else(|e| {
|
|
bug!("LLVM returned a non-utf8 features string: {}", e);
|
|
})
|
|
.to_owned()
|
|
} else {
|
|
bug!("could not allocate host CPU features, LLVM returned a `null` string");
|
|
};
|
|
|
|
llvm::LLVMDisposeMessage(ptr);
|
|
|
|
features_string
|
|
};
|
|
features.extend(features_string.split(',').map(String::from));
|
|
}
|
|
Some(_) | None => {}
|
|
};
|
|
|
|
// Features implied by an implicit or explicit `--target`.
|
|
features.extend(
|
|
sess.target
|
|
.features
|
|
.split(',')
|
|
.filter(|v| !v.is_empty() && backend_feature_name(v).is_some())
|
|
.map(String::from),
|
|
);
|
|
|
|
// -Ctarget-features
|
|
let supported_features = supported_target_features(sess);
|
|
let mut featsmap = FxHashMap::default();
|
|
let feats = sess
|
|
.opts
|
|
.cg
|
|
.target_feature
|
|
.split(',')
|
|
.filter_map(|s| {
|
|
let enable_disable = match s.chars().next() {
|
|
None => return None,
|
|
Some(c @ '+' | 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();
|
|
}
|
|
return None;
|
|
}
|
|
};
|
|
|
|
let feature = backend_feature_name(s)?;
|
|
// Warn against use of LLVM specific feature names on the CLI.
|
|
if diagnostics && !supported_features.iter().any(|&(v, _)| v == feature) {
|
|
let rust_feature = supported_features.iter().find_map(|&(rust_feature, _)| {
|
|
let llvm_features = to_llvm_features(sess, rust_feature);
|
|
if llvm_features.contains(&feature) && !llvm_features.contains(&rust_feature) {
|
|
Some(rust_feature)
|
|
} else {
|
|
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));
|
|
} else {
|
|
diag.note("consider filing a feature request");
|
|
}
|
|
diag.emit();
|
|
}
|
|
|
|
if diagnostics {
|
|
// FIXME(nagisa): figure out how to not allocate a full hashset here.
|
|
featsmap.insert(feature, enable_disable == '+');
|
|
}
|
|
|
|
// rustc-specific features do not get passed down to LLVM…
|
|
if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
|
|
return None;
|
|
}
|
|
// ... otherwise though we run through `to_llvm_features` when
|
|
// 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.
|
|
Some(
|
|
to_llvm_features(sess, feature)
|
|
.into_iter()
|
|
.map(move |f| format!("{}{}", enable_disable, f)),
|
|
)
|
|
})
|
|
.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(", ")
|
|
));
|
|
}
|
|
|
|
features
|
|
}
|
|
|
|
/// Returns a feature name for the given `+feature` or `-feature` string.
|
|
///
|
|
/// Only allows features that are backend specific (i.e. not [`RUSTC_SPECIFIC_FEATURES`].)
|
|
fn backend_feature_name(s: &str) -> Option<&str> {
|
|
// features must start with a `+` or `-`.
|
|
let feature = s.strip_prefix(&['+', '-'][..]).unwrap_or_else(|| {
|
|
bug!("target feature `{}` must begin with a `+` or `-`", s);
|
|
});
|
|
// Rustc-specific feature requests like `+crt-static` or `-crt-static`
|
|
// are not passed down to LLVM.
|
|
if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
|
|
return None;
|
|
}
|
|
Some(feature)
|
|
}
|
|
|
|
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))
|
|
}
|