Remove support for legacy PM

Cargo.lock

@@ -3263,7 +3263,6 @@ dependencies = [
  "bitflags",
  "cstr",
  "libc",
- "libloading",
  "measureme",
  "object 0.29.0",
  "rustc-demangle",

compiler/rustc_codegen_llvm/Cargo.toml

@@ -11,7 +11,6 @@ doctest = false
 bitflags = "1.0"
 cstr = "0.2"
 libc = "0.2"
-libloading = "0.7.1"
 measureme = "10.0.0"
 object = { version = "0.29.0", default-features = false, features = ["std", "read_core", "archive", "coff", "elf", "macho", "pe"] }
 tracing = "0.1"

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -1,8 +1,6 @@
-use crate::back::write::{
-    self, save_temp_bitcode, to_llvm_opt_settings, with_llvm_pmb, DiagnosticHandlers,
-};
-use crate::llvm::{self, build_string, False, True};
-use crate::{llvm_util, LlvmCodegenBackend, ModuleLlvm};
+use crate::back::write::{self, save_temp_bitcode, DiagnosticHandlers};
+use crate::llvm::{self, build_string};
+use crate::{LlvmCodegenBackend, ModuleLlvm};
 use object::read::archive::ArchiveFile;
 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule, ThinShared};
 use rustc_codegen_ssa::back::symbol_export;
@@ -597,61 +595,9 @@ pub(crate) fn run_pass_manager(
                 1,
             );
         }
-        if llvm_util::should_use_new_llvm_pass_manager(
-            &config.new_llvm_pass_manager,
-            &cgcx.target_arch,
-        ) {
-            let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO };
-            let opt_level = config.opt_level.unwrap_or(config::OptLevel::No);
-            write::optimize_with_new_llvm_pass_manager(
-                cgcx,
-                diag_handler,
-                module,
-                config,
-                opt_level,
-                opt_stage,
-            )?;
-            debug!("lto done");
-            return Ok(());
-        }
-
-        let pm = llvm::LLVMCreatePassManager();
-        llvm::LLVMAddAnalysisPasses(module.module_llvm.tm, pm);
-
-        if config.verify_llvm_ir {
-            let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr().cast());
-            llvm::LLVMRustAddPass(pm, pass.unwrap());
-        }
-
-        let opt_level = config
-            .opt_level
-            .map(|x| to_llvm_opt_settings(x).0)
-            .unwrap_or(llvm::CodeGenOptLevel::None);
-        with_llvm_pmb(module.module_llvm.llmod(), config, opt_level, false, &mut |b| {
-            if thin {
-                llvm::LLVMRustPassManagerBuilderPopulateThinLTOPassManager(b, pm);
-            } else {
-                llvm::LLVMRustPassManagerBuilderPopulateLTOPassManager(
-                    b, pm, /* Internalize = */ False, /* RunInliner = */ True,
-                );
-            }
-        });
-
-        // We always generate bitcode through ThinLTOBuffers,
-        // which do not support anonymous globals
-        if config.bitcode_needed() {
-            let pass = llvm::LLVMRustFindAndCreatePass("name-anon-globals\0".as_ptr().cast());
-            llvm::LLVMRustAddPass(pm, pass.unwrap());
-        }
-
-        if config.verify_llvm_ir {
-            let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr().cast());
-            llvm::LLVMRustAddPass(pm, pass.unwrap());
-        }
-
-        llvm::LLVMRunPassManager(pm, module.module_llvm.llmod());
-
-        llvm::LLVMDisposePassManager(pm);
+        let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO };
+        let opt_level = config.opt_level.unwrap_or(config::OptLevel::No);
+        write::llvm_optimize(cgcx, diag_handler, module, config, opt_level, opt_stage)?;
     }
     debug!("lto done");
     Ok(())