[clang] Remove no-op ptr-to-ptr bitcasts (NFC)

Opaque pointer cleanup effort.

Author: JOE1994

clang/lib/CodeGen/CGBuiltin.cpp

@@ -5049,7 +5049,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
   case Builtin::BI__GetExceptionInfo: {
     if (llvm::GlobalVariable *GV =
             CGM.getCXXABI().getThrowInfo(FD->getParamDecl(0)->getType()))
-      return RValue::get(llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy));
+      return RValue::get(GV);
     break;
   }
 

clang/lib/CodeGen/CGDecl.cpp

@@ -386,9 +386,7 @@ CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
     GV->takeName(OldGV);
 
     // Replace all uses of the old global with the new global
-    llvm::Constant *NewPtrForOldDecl =
-    llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
-    OldGV->replaceAllUsesWith(NewPtrForOldDecl);
+    OldGV->replaceAllUsesWith(GV);
 
     // Erase the old global, since it is no longer used.
     OldGV->eraseFromParent();

clang/lib/CodeGen/CodeGenPGO.cpp

@@ -960,9 +960,8 @@ void CodeGenPGO::emitCounterIncrement(CGBuilderTy &Builder, const Stmt *S,
     return;
 
   unsigned Counter = (*RegionCounterMap)[S];
-  auto *I8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext());
 
-  llvm::Value *Args[] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy),
+  llvm::Value *Args[] = {FuncNameVar,
                          Builder.getInt64(FunctionHash),
                          Builder.getInt32(NumRegionCounters),
                          Builder.getInt32(Counter), StepV};
@@ -1000,7 +999,7 @@ void CodeGenPGO::valueProfile(CGBuilderTy &Builder, uint32_t ValueKind,
     auto BuilderInsertPoint = Builder.saveIP();
     Builder.SetInsertPoint(ValueSite);
     llvm::Value *Args[5] = {
-        llvm::ConstantExpr::getBitCast(FuncNameVar, Builder.getInt8PtrTy()),
+        FuncNameVar,
         Builder.getInt64(FunctionHash),
         Builder.CreatePtrToInt(ValuePtr, Builder.getInt64Ty()),
         Builder.getInt32(ValueKind),

clang/lib/CodeGen/ItaniumCXXABI.cpp

@@ -3938,9 +3938,7 @@ llvm::Constant *ItaniumRTTIBuilder::BuildTypeInfo(
   // If there's already an old global variable, replace it with the new one.
   if (OldGV) {
     GV->takeName(OldGV);
-    llvm::Constant *NewPtr =
-      llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
-    OldGV->replaceAllUsesWith(NewPtr);
+    OldGV->replaceAllUsesWith(GV);
     OldGV->eraseFromParent();
   }