bjoernager/rust
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Remove support for LLVM's legacy pass manager

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This commit is contained in:
Josh Stone 2022-09-16 16:18:27 -07:00
parent a37499ae66
commit 2860f77a0d
8 changed files with 23 additions and 653 deletions
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36
compiler/rustc_codegen_llvm/src/llvm_util.rs
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@ -1,7 +1,6 @@
use crate::back::write::create_informational_target_machine;
use crate::{llvm, llvm_util};
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,
};
@ -16,7 +15,6 @@ use rustc_target::spec::{MergeFunctions, PanicStrategy};
use smallvec::{smallvec, SmallVec};
use std::ffi::{CStr, CString};
use std::mem;
use std::path::Path;
use std::ptr;
use std::slice;
@ -120,22 +118,6 @@ unsafe fn configure_llvm(sess: &Session) {
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());
@ -539,19 +521,3 @@ 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))
}