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

Opaque ptr cleanup effort (NFC).

Author: JOE1994

clang/lib/CodeGen/CodeGenModule.cpp

@@ -3201,10 +3201,9 @@ llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
                                       ".args");
   GV->setSection(AnnotationSection);
   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-  auto *Bitcasted = llvm::ConstantExpr::getBitCast(GV, GlobalsInt8PtrTy);
 
-  Lookup = Bitcasted;
-  return Bitcasted;
+  Lookup = GV;
+  return GV;
 }
 
 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
@@ -3227,11 +3226,7 @@ llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
 
   // Create the ConstantStruct for the global annotation.
   llvm::Constant *Fields[] = {
-      llvm::ConstantExpr::getBitCast(GVInGlobalsAS, GlobalsInt8PtrTy),
-      llvm::ConstantExpr::getBitCast(AnnoGV, ConstGlobalsPtrTy),
-      llvm::ConstantExpr::getBitCast(UnitGV, ConstGlobalsPtrTy),
-      LineNoCst,
-      Args,
+      GVInGlobalsAS, AnnoGV, UnitGV, LineNoCst, Args,
   };
   return llvm::ConstantStruct::getAnon(Fields);
 }
@@ -4697,9 +4692,7 @@ CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
     GV->takeName(Entry);
 
     if (!Entry->use_empty()) {
-      llvm::Constant *NewPtrForOldDecl =
-          llvm::ConstantExpr::getBitCast(GV, Entry->getType());
-      Entry->replaceAllUsesWith(NewPtrForOldDecl);
+      Entry->replaceAllUsesWith(GV);
     }
 
     Entry->eraseFromParent();
@@ -4878,9 +4871,7 @@ llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
     GV->takeName(OldGV);
 
     if (!OldGV->use_empty()) {
-      llvm::Constant *NewPtrForOldDecl =
-      llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
-      OldGV->replaceAllUsesWith(NewPtrForOldDecl);
+      OldGV->replaceAllUsesWith(GV);
     }
 
     OldGV->eraseFromParent();
@@ -5766,8 +5757,7 @@ void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
     // Remove it and replace uses of it with the alias.
     GA->takeName(Entry);
 
-    Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
-                                                          Entry->getType()));
+    Entry->replaceAllUsesWith(GA);
     Entry->eraseFromParent();
   } else {
     GA->setName(MangledName);
@@ -5845,8 +5835,7 @@ void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
     // Remove it and replace uses of it with the ifunc.
     GIF->takeName(Entry);
 
-    Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
-                                                          Entry->getType()));
+    Entry->replaceAllUsesWith(GIF);
     Entry->eraseFromParent();
   } else
     GIF->setName(MangledName);
@@ -6042,9 +6031,6 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   llvm::Constant *Str =
       llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
 
-  if (isUTF16)
-    // Cast the UTF16 string to the correct type.
-    Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
   Fields.add(Str);
 
   // String length.
@@ -6414,8 +6400,7 @@ ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
   // replace it with the new global now.
   llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
   if (Entry) {
-    Entry->replaceAllUsesWith(
-        llvm::ConstantExpr::getBitCast(CV, Entry->getType()));
+    Entry->replaceAllUsesWith(CV);
     llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
   }
   Entry = CV;