[MemCpyOpt] Preserve address space

Preserve address space when generating the cast to i8*.

Author: nikic

llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp

@@ -1214,9 +1214,11 @@ bool MemCpyOptPass::processMemSetMemCpyDependence(MemCpyInst *MemCpy,
   Value *SizeDiff = Builder.CreateSub(DestSize, SrcSize);
   Value *MemsetLen = Builder.CreateSelect(
       Ule, ConstantInt::getNullValue(DestSize->getType()), SizeDiff);
+  unsigned DestAS = Dest->getType()->getPointerAddressSpace();
   Instruction *NewMemSet = Builder.CreateMemSet(
       Builder.CreateGEP(Builder.getInt8Ty(),
-                        Builder.CreatePointerCast(Dest, Builder.getInt8PtrTy()),
+                        Builder.CreatePointerCast(Dest,
+                                                  Builder.getInt8PtrTy(DestAS)),
                         SrcSize),
       MemSet->getOperand(1), MemsetLen, MaybeAlign(Align));
 

llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll

@@ -323,6 +323,21 @@ define void @test_weird_element_type(i16* %src, i64 %src_size, i16* noalias %dst
   ret void
 }
 
+define void @test_addrspace(i8 addrspace(1)* %src, i64 %src_size, i8 addrspace(1)* noalias %dst, i64 %dst_size, i8 %c) {
+; CHECK-LABEL: @test_addrspace(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ule i64 [[DST_SIZE:%.*]], [[SRC_SIZE:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = sub i64 [[DST_SIZE]], [[SRC_SIZE]]
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i64 0, i64 [[TMP2]]
+; CHECK-NEXT:    [[TMP4:%.*]] = getelementptr i8, i8 addrspace(1)* [[DST:%.*]], i64 [[SRC_SIZE]]
+; CHECK-NEXT:    call void @llvm.memset.p1i8.i64(i8 addrspace(1)* align 1 [[TMP4]], i8 [[C:%.*]], i64 [[TMP3]], i1 false)
+; CHECK-NEXT:    call void @llvm.memcpy.p1i8.p1i8.i64(i8 addrspace(1)* [[DST]], i8 addrspace(1)* [[SRC:%.*]], i64 [[SRC_SIZE]], i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.memset.p1i8.i64(i8 addrspace(1)* %dst, i8 %c, i64 %dst_size, i1 false)
+  call void @llvm.memcpy.p1i8.p1i8.i64(i8 addrspace(1)* %dst, i8 addrspace(1)* %src, i64 %src_size, i1 false)
+  ret void
+}
+
 declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i1)
 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i1)
 declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i1)
@@ -333,4 +348,6 @@ declare void @llvm.memset.p0.i64(ptr nocapture, i8, i64, i1)
 declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture readonly, i64, i1)
 declare void @llvm.memset.p0i16.i64(i16* nocapture, i8, i64, i1)
 declare void @llvm.memcpy.p0i16.p0i16.i64(i16* nocapture, i16* nocapture readonly, i64, i1)
+declare void @llvm.memset.p1i8.i64(i8 addrspace(1)* nocapture, i8, i64, i1)
+declare void @llvm.memcpy.p1i8.p1i8.i64(i8 addrspace(1)* nocapture, i8 addrspace(1)* nocapture readonly, i64, i1)
 declare void @call()