[clang] a995cda - [CodeGen] Avoid more pointer element type accesses

[Nikita Popov via cfe-commits]

Author: Nikita Popov
Date: 2021-12-21T15:52:18+01:00
New Revision: a995cdab190895382448555b7072a50151768534

URL: https://github.com/llvm/llvm-project/commit/a995cdab190895382448555b7072a50151768534
DIFF: https://github.com/llvm/llvm-project/commit/a995cdab190895382448555b7072a50151768534.diff

LOG: [CodeGen] Avoid more pointer element type accesses

Added: 
    

Modified: 
    clang/lib/CodeGen/CGClass.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index a9e25447a91c..8f99ff0d50ff 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -127,18 +127,18 @@ CodeGenModule::getDynamicOffsetAlignment(CharUnits actualBaseAlign,
 
 Address CodeGenFunction::LoadCXXThisAddress() {
   assert(CurFuncDecl && "loading 'this' without a func declaration?");
-  assert(isa<CXXMethodDecl>(CurFuncDecl));
+  auto *MD = cast<CXXMethodDecl>(CurFuncDecl);
 
   // Lazily compute CXXThisAlignment.
   if (CXXThisAlignment.isZero()) {
     // Just use the best known alignment for the parent.
     // TODO: if we're currently emitting a complete-object ctor/dtor,
     // we can always use the complete-object alignment.
-    auto RD = cast<CXXMethodDecl>(CurFuncDecl)->getParent();
-    CXXThisAlignment = CGM.getClassPointerAlignment(RD);
+    CXXThisAlignment = CGM.getClassPointerAlignment(MD->getParent());
   }
 
-  return Address(LoadCXXThis(), CXXThisAlignment);
+  llvm::Type *Ty = ConvertType(MD->getThisType()->getPointeeType());
+  return Address(LoadCXXThis(), Ty, CXXThisAlignment);
 }
 
 /// Emit the address of a field using a member data pointer.
@@ -286,7 +286,7 @@ ApplyNonVirtualAndVirtualOffset(CodeGenFunction &CGF, Address addr,
   }
   alignment = alignment.alignmentAtOffset(nonVirtualOffset);
 
-  return Address(ptr, alignment);
+  return Address(ptr, CGF.Int8Ty, alignment);
 }
 
 Address CodeGenFunction::GetAddressOfBaseClass(
@@ -996,16 +996,8 @@ namespace {
 
   private:
     void emitMemcpyIR(Address DestPtr, Address SrcPtr, CharUnits Size) {
-      llvm::PointerType *DPT = DestPtr.getType();
-      llvm::Type *DBP =
-        llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), DPT->getAddressSpace());
-      DestPtr = CGF.Builder.CreateBitCast(DestPtr, DBP);
-
-      llvm::PointerType *SPT = SrcPtr.getType();
-      llvm::Type *SBP =
-        llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), SPT->getAddressSpace());
-      SrcPtr = CGF.Builder.CreateBitCast(SrcPtr, SBP);
-
+      DestPtr = CGF.Builder.CreateElementBitCast(DestPtr, CGF.Int8Ty);
+      SrcPtr = CGF.Builder.CreateElementBitCast(SrcPtr, CGF.Int8Ty);
       CGF.Builder.CreateMemCpy(DestPtr, SrcPtr, Size.getQuantity());
     }
 
@@ -2068,8 +2060,8 @@ void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
 
   if (SlotAS != ThisAS) {
     unsigned TargetThisAS = getContext().getTargetAddressSpace(ThisAS);
-    llvm::Type *NewType =
-        ThisPtr->getType()->getPointerElementType()->getPointerTo(TargetThisAS);
+    llvm::Type *NewType = llvm::PointerType::getWithSamePointeeType(
+        This.getType(), TargetThisAS);
     ThisPtr = getTargetHooks().performAddrSpaceCast(*this, This.getPointer(),
                                                     ThisAS, SlotAS, NewType);
   }
@@ -2507,9 +2499,6 @@ void CodeGenFunction::InitializeVTablePointer(const VPtr &Vptr) {
 
   // Apply the offsets.
   Address VTableField = LoadCXXThisAddress();
-  unsigned ThisAddrSpace =
-      VTableField.getPointer()->getType()->getPointerAddressSpace();
-
   if (!NonVirtualOffset.isZero() || VirtualOffset)
     VTableField = ApplyNonVirtualAndVirtualOffset(
         *this, VTableField, NonVirtualOffset, VirtualOffset, Vptr.VTableClass,
@@ -2525,8 +2514,7 @@ void CodeGenFunction::InitializeVTablePointer(const VPtr &Vptr) {
           ->getPointerTo(GlobalsAS);
   // vtable field is is derived from `this` pointer, therefore they should be in
   // the same addr space. Note that this might not be LLVM address space 0.
-  VTableField = Builder.CreateBitCast(VTableField,
-                                      VTablePtrTy->getPointerTo(ThisAddrSpace));
+  VTableField = Builder.CreateElementBitCast(VTableField, VTablePtrTy);
   VTableAddressPoint = Builder.CreateBitCast(VTableAddressPoint, VTablePtrTy);
 
   llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);