diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/lto.rs | 22 |
1 files changed, 0 insertions, 22 deletions
diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs index 4226ed7d99b..48ca7c0060a 100644 --- a/compiler/rustc_codegen_llvm/src/back/lto.rs +++ b/compiler/rustc_codegen_llvm/src/back/lto.rs @@ -584,12 +584,6 @@ pub(crate) fn run_pass_manager( if write::should_use_new_llvm_pass_manager(config) { let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO }; let opt_level = config.opt_level.unwrap_or(config::OptLevel::No); - // See comment below for why this is necessary. - let opt_level = if let config::OptLevel::No = opt_level { - config::OptLevel::Less - } else { - opt_level - }; write::optimize_with_new_llvm_pass_manager(cgcx, module, config, opt_level, opt_stage); debug!("lto done"); return; @@ -603,26 +597,10 @@ pub(crate) fn run_pass_manager( llvm::LLVMRustAddPass(pm, pass.unwrap()); } - // When optimizing for LTO we don't actually pass in `-O0`, but we force - // it to always happen at least with `-O1`. - // - // With ThinLTO we mess around a lot with symbol visibility in a way - // that will actually cause linking failures if we optimize at O0 which - // notable is lacking in dead code elimination. To ensure we at least - // get some optimizations and correctly link we forcibly switch to `-O1` - // to get dead code elimination. - // - // Note that in general this shouldn't matter too much as you typically - // only turn on ThinLTO when you're compiling with optimizations - // otherwise. let opt_level = config .opt_level .map(|x| to_llvm_opt_settings(x).0) .unwrap_or(llvm::CodeGenOptLevel::None); - let opt_level = match opt_level { - llvm::CodeGenOptLevel::None => llvm::CodeGenOptLevel::Less, - level => level, - }; with_llvm_pmb(module.module_llvm.llmod(), config, opt_level, false, &mut |b| { if thin { llvm::LLVMRustPassManagerBuilderPopulateThinLTOPassManager(b, pm); |