; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s ; Memcpy is copying known-undef, and is thus removable define void @test(i8* %dest) { ; CHECK-LABEL: @test( ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %src = getelementptr inbounds [7 x i8], [7 x i8]* %a, i64 0, i64 0 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dest, i8* %src, i64 7, i1 false) ret void } ; Some non-undef elements define void @test2(i8* %dest) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: [[A:%.*]] = alloca [7 x i8], align 1 ; CHECK-NEXT: [[SRC:%.*]] = getelementptr inbounds [7 x i8], [7 x i8]* [[A]], i64 0, i64 0 ; CHECK-NEXT: store i8 0, i8* [[SRC]], align 1 ; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 1 dereferenceable(7) [[DEST:%.*]], i8* noundef nonnull align 1 dereferenceable(7) [[SRC]], i64 7, i1 false) ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %src = getelementptr inbounds [7 x i8], [7 x i8]* %a, i64 0, i64 0 store i8 0, i8* %src call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dest, i8* %src, i64 7, i1 false) ret void } ; Volatile write is still required define void @test3(i8* %dest) { ; CHECK-LABEL: @test3( ; CHECK-NEXT: [[A:%.*]] = alloca [7 x i8], align 1 ; CHECK-NEXT: [[SRC:%.*]] = getelementptr inbounds [7 x i8], [7 x i8]* [[A]], i64 0, i64 0 ; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[DEST:%.*]], i8* [[SRC]], i64 7, i1 true) ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %src = getelementptr inbounds [7 x i8], [7 x i8]* %a, i64 0, i64 0 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dest, i8* %src, i64 7, i1 true) ret void } define void @test4(i8* %dest) { ; CHECK-LABEL: @test4( ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %src = bitcast [7 x i8]* %a to i8* call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dest, i8* %src, i64 7, i1 false) ret void } define void @test5(i8* %dest) { ; CHECK-LABEL: @test5( ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %p1 = bitcast [7 x i8]* %a to i32* %p2 = getelementptr i32, i32* %p1, i32 1 %src = bitcast i32* %p2 to i8* call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dest, i8* %src, i64 3, i1 false) ret void } define void @test6(i8* %dest) { ; CHECK-LABEL: @test6( ; CHECK-NEXT: [[A:%.*]] = alloca [7 x i8], align 1 ; CHECK-NEXT: [[P2:%.*]] = getelementptr inbounds [7 x i8], [7 x i8]* [[A]], i64 0, i64 2 ; CHECK-NEXT: [[TMP1:%.*]] = bitcast i8* [[P2]] to i16* ; CHECK-NEXT: store i16 42, i16* [[TMP1]], align 2 ; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 1 dereferenceable(7) [[DEST:%.*]], i8* noundef nonnull align 1 dereferenceable(7) [[P2]], i64 7, i1 false) ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %p1 = bitcast [7 x i8]* %a to i16* %p2 = getelementptr i16, i16* %p1, i32 1 store i16 42, i16* %p2 %src = bitcast i16* %p2 to i8* call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dest, i8* %src, i64 7, i1 false) ret void } declare void @llvm.memcpy.p0i8.p0i8.i64(i8*, i8*, i64, i1)