Revert "Run ObjCContractPass in Default Codegen Pipeline (#92331)"

This reverts commit 8cc8e5d.
This reverts commit dae55c8.

Causes major compile-time regressions for unoptimized builds.

Author: nikic

clang/lib/CodeGen/BackendUtil.cpp

@@ -587,6 +587,12 @@ bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
   // this also adds codegenerator level optimization passes.
   CodeGenFileType CGFT = getCodeGenFileType(Action);
 
+  // Add ObjC ARC final-cleanup optimizations. This is done as part of the
+  // "codegen" passes so that it isn't run multiple times when there is
+  // inlining happening.
+  if (CodeGenOpts.OptimizationLevel > 0)
+    CodeGenPasses.add(createObjCARCContractPass());
+
   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
     Diags.Report(diag::err_fe_unable_to_interface_with_target);

clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll

@@ -48,6 +48,9 @@ static lto::Config createConfig() {
   c.CPU = getCPUStr();
   c.MAttrs = getMAttrs();
   c.DiagHandler = diagnosticHandler;
+  c.PreCodeGenPassesHook = [](legacy::PassManager &pm) {
+    pm.add(createObjCARCContractPass());
+  };
 
   c.AlwaysEmitRegularLTOObj = !config->ltoObjPath.empty();
 

lld/MachO/LTO.cpp

@@ -41,26 +41,26 @@ extern bool EnableARCOpts;
 /// Test if the given module looks interesting to run ARC optimization
 /// on.
 inline bool ModuleHasARC(const Module &M) {
-  return M.getNamedValue("llvm.objc.retain") ||
-         M.getNamedValue("llvm.objc.release") ||
-         M.getNamedValue("llvm.objc.autorelease") ||
-         M.getNamedValue("llvm.objc.retainAutoreleasedReturnValue") ||
-         M.getNamedValue("llvm.objc.unsafeClaimAutoreleasedReturnValue") ||
-         M.getNamedValue("llvm.objc.retainBlock") ||
-         M.getNamedValue("llvm.objc.autoreleaseReturnValue") ||
-         M.getNamedValue("llvm.objc.autoreleasePoolPush") ||
-         M.getNamedValue("llvm.objc.loadWeakRetained") ||
-         M.getNamedValue("llvm.objc.loadWeak") ||
-         M.getNamedValue("llvm.objc.destroyWeak") ||
-         M.getNamedValue("llvm.objc.storeWeak") ||
-         M.getNamedValue("llvm.objc.initWeak") ||
-         M.getNamedValue("llvm.objc.moveWeak") ||
-         M.getNamedValue("llvm.objc.copyWeak") ||
-         M.getNamedValue("llvm.objc.retainedObject") ||
-         M.getNamedValue("llvm.objc.unretainedObject") ||
-         M.getNamedValue("llvm.objc.unretainedPointer") ||
-         M.getNamedValue("llvm.objc.clang.arc.noop.use") ||
-         M.getNamedValue("llvm.objc.clang.arc.use");
+  return
+    M.getNamedValue("llvm.objc.retain") ||
+    M.getNamedValue("llvm.objc.release") ||
+    M.getNamedValue("llvm.objc.autorelease") ||
+    M.getNamedValue("llvm.objc.retainAutoreleasedReturnValue") ||
+    M.getNamedValue("llvm.objc.unsafeClaimAutoreleasedReturnValue") ||
+    M.getNamedValue("llvm.objc.retainBlock") ||
+    M.getNamedValue("llvm.objc.autoreleaseReturnValue") ||
+    M.getNamedValue("llvm.objc.autoreleasePoolPush") ||
+    M.getNamedValue("llvm.objc.loadWeakRetained") ||
+    M.getNamedValue("llvm.objc.loadWeak") ||
+    M.getNamedValue("llvm.objc.destroyWeak") ||
+    M.getNamedValue("llvm.objc.storeWeak") ||
+    M.getNamedValue("llvm.objc.initWeak") ||
+    M.getNamedValue("llvm.objc.moveWeak") ||
+    M.getNamedValue("llvm.objc.copyWeak") ||
+    M.getNamedValue("llvm.objc.retainedObject") ||
+    M.getNamedValue("llvm.objc.unretainedObject") ||
+    M.getNamedValue("llvm.objc.unretainedPointer") ||
+    M.getNamedValue("llvm.objc.clang.arc.use");
 }
 
 /// This is a wrapper around getUnderlyingObject which also knows how to

llvm/include/llvm/Analysis/ObjCARCAnalysisUtils.h

@@ -46,7 +46,6 @@
 #include "llvm/Support/WithColor.h"
 #include "llvm/Target/CGPassBuilderOption.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils.h"
 #include <cassert>
@@ -947,8 +946,6 @@ void TargetPassConfig::addCodeGenPrepare() {
 void TargetPassConfig::addISelPrepare() {
   addPreISel();
 
-  addPass(createObjCARCContractPass());
-
   // Force codegen to run according to the callgraph.
   if (requiresCodeGenSCCOrder())
     addPass(new DummyCGSCCPass);

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -137,6 +137,10 @@ LTOCodeGenerator::LTOCodeGenerator(LLVMContext &Context)
 
   Config.CodeModel = std::nullopt;
   Config.StatsFile = LTOStatsFile;
+  Config.PreCodeGenPassesHook = [](legacy::PassManager &PM) {
+    PM.add(createObjCARCContractPass());
+  };
+
   Config.RunCSIRInstr = LTORunCSIRInstr;
   Config.CSIRProfile = LTOCSIRProfile;
 }

llvm/lib/LTO/LTOCodeGenerator.cpp

@@ -334,6 +334,10 @@ std::unique_ptr<MemoryBuffer> codegenModule(Module &TheModule,
     raw_svector_ostream OS(OutputBuffer);
     legacy::PassManager PM;
 
+    // If the bitcode files contain ARC code and were compiled with optimization,
+    // the ObjCARCContractPass must be run, so do it unconditionally here.
+    PM.add(createObjCARCContractPass());
+
     // Setup the codegen now.
     if (TM.addPassesToEmitFile(PM, OS, nullptr, CodeGenFileType::ObjectFile,
                                /* DisableVerify */ true))

llvm/lib/LTO/ThinLTOCodeGenerator.cpp

@@ -71,9 +71,6 @@ class ObjCARCContract {
   ARCRuntimeEntryPoints EP;
   BundledRetainClaimRVs *BundledInsts = nullptr;
 
-  /// A flag indicating whether this optimization pass should run.
-  bool Run;
-
   /// The inline asm string to insert between calls and RetainRV calls to make
   /// the optimization work on targets which need it.
   const MDString *RVInstMarker;
@@ -530,10 +527,6 @@ bool ObjCARCContract::tryToPeepholeInstruction(
 //===----------------------------------------------------------------------===//
 
 bool ObjCARCContract::init(Module &M) {
-  Run = ModuleHasARC(M);
-  if (!Run)
-    return false;
-
   EP.init(&M);
 
   // Initialize RVInstMarker.
@@ -546,9 +539,6 @@ bool ObjCARCContract::run(Function &F, AAResults *A, DominatorTree *D) {
   if (!EnableARCOpts)
     return false;
 
-  if (!Run)
-    return false;
-
   Changed = CFGChanged = false;
   AA = A;
   DT = D;

llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp

@@ -31,10 +31,6 @@
 ; CHECK-NEXT:       AArch64 Stack Tagging
 ; CHECK-NEXT:       SME ABI Pass
 ; CHECK-NEXT:       Exception handling preparation
-; CHECK-NEXT:       Dominator Tree Construction
-; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
-; CHECK-NEXT:       Function Alias Analysis Results
-; CHECK-NEXT:       ObjC ARC contraction
 ; CHECK-NEXT:       Prepare callbr
 ; CHECK-NEXT:       Safe Stack instrumentation pass
 ; CHECK-NEXT:       Insert stack protectors

llvm/test/CodeGen/AArch64/O0-pipeline.ll

@@ -103,10 +103,6 @@
 ; CHECK-NEXT:         Dominator Tree Construction
 ; CHECK-NEXT:     FunctionPass Manager
 ; CHECK-NEXT:       Merge internal globals
-; CHECK-NEXT:       Dominator Tree Construction
-; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
-; CHECK-NEXT:       Function Alias Analysis Results
-; CHECK-NEXT:       ObjC ARC contraction
 ; CHECK-NEXT:       Prepare callbr
 ; CHECK-NEXT:       Safe Stack instrumentation pass
 ; CHECK-NEXT:       Insert stack protectors