[LTO] enable ObjCARCContractPass only on optimized build

Summary:
\llvm#92331 tried to make `ObjCARCContractPass` by default, but it caused a regression on O0 builds and was reverted.
This patch trys to bring that back by:

1. reverts the [revert](llvm@1579e9c).
2. `createObjCARCContractPass` only on optimized builds.

Tests are updated to refelect the changes. Specifically, all `O0` tests should not include `ObjCARCContractPass`

Signed-off-by: Peter Rong <[email protected]>

Author: DataCorrupted

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

@@ -4,7 +4,7 @@
 ; RUN:   -o %t2.index \
 ; RUN:   -r=%t.o,_use_arc,px
 
-; RUN: %clang_cc1 -triple x86_64-apple-darwin \
+; RUN: %clang_cc1 -O2 -triple x86_64-apple-darwin \
 ; RUN:   -emit-obj -fthinlto-index=%t.o.thinlto.bc \
 ; RUN:   -o %t.native.o -x ir %t.o
 

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -944,7 +944,8 @@ void TargetPassConfig::addCodeGenPrepare() {
 void TargetPassConfig::addISelPrepare() {
   addPreISel();
 
-  addPass(createObjCARCContractPass());
+  if (getOptLevel() != CodeGenOptLevel::None)
+    addPass(createObjCARCContractPass());
 
   // Force codegen to run according to the callgraph.
   if (requiresCodeGenSCCOrder())

llvm/lib/Transforms/ObjCARC/ObjCARCContract.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/test/CodeGen/AArch64/O0-pipeline.ll

@@ -30,10 +30,6 @@
 ; 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/AMDGPU/llc-pipeline.ll

@@ -87,9 +87,6 @@
 ; GCN-O0-NEXT:        AMDGPU Rewrite Undef for PHI
 ; GCN-O0-NEXT:        LCSSA Verifier
 ; GCN-O0-NEXT:        Loop-Closed SSA Form Pass
-; GCN-O0-NEXT:        Basic Alias Analysis (stateless AA impl)
-; GCN-O0-NEXT:        Function Alias Analysis Results
-; GCN-O0-NEXT:        ObjC ARC contraction
 ; GCN-O0-NEXT:      DummyCGSCCPass
 ; GCN-O0-NEXT:      FunctionPass Manager
 ; GCN-O0-NEXT:        Prepare callbr

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

@@ -30,10 +30,6 @@
 ; CHECK-NEXT:       Scalarize Masked Memory Intrinsics
 ; CHECK-NEXT:       Expand reduction intrinsics
 ; 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/PowerPC/O0-pipeline.ll

@@ -29,10 +29,6 @@
 ; CHECK-NEXT:       Scalarize Masked Memory Intrinsics
 ; CHECK-NEXT:       Expand reduction intrinsics
 ; 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/RISCV/O0-pipeline.ll

@@ -30,10 +30,6 @@
 ; CHECK-NEXT:       Scalarize Masked Memory Intrinsics
 ; CHECK-NEXT:       Expand reduction intrinsics
 ; 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/X86/O0-pipeline.ll

@@ -31,10 +31,6 @@
 ; CHECK-NEXT:       Expand reduction intrinsics
 ; CHECK-NEXT:       Expand indirectbr instructions
 ; 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