; 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(ptr %dest) { ; CHECK-LABEL: @test( ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] call void @llvm.memcpy.p0.p0.i64(ptr %dest, ptr %a, i64 7, i1 false) ret void } ; Some non-undef elements define void @test2(ptr %dest) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: [[A:%.*]] = alloca [7 x i8], align 1 ; CHECK-NEXT: store i8 0, ptr [[A]], align 1 ; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 1 dereferenceable(7) [[DEST:%.*]], ptr noundef nonnull align 1 dereferenceable(7) [[A]], i64 7, i1 false) ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] store i8 0, ptr %a call void @llvm.memcpy.p0.p0.i64(ptr %dest, ptr %a, i64 7, i1 false) ret void } ; Volatile write is still required define void @test3(ptr %dest) { ; CHECK-LABEL: @test3( ; CHECK-NEXT: [[A:%.*]] = alloca [7 x i8], align 1 ; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr [[DEST:%.*]], ptr [[A]], i64 7, i1 true) ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] call void @llvm.memcpy.p0.p0.i64(ptr %dest, ptr %a, i64 7, i1 true) ret void } define void @test4(ptr %dest) { ; CHECK-LABEL: @test4( ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] call void @llvm.memcpy.p0.p0.i64(ptr %dest, ptr %a, i64 7, i1 false) ret void } define void @test5(ptr %dest) { ; CHECK-LABEL: @test5( ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %p2 = getelementptr i32, ptr %a, i32 1 call void @llvm.memcpy.p0.p0.i64(ptr %dest, ptr %p2, i64 3, i1 false) ret void } define void @test6(ptr %dest) { ; CHECK-LABEL: @test6( ; CHECK-NEXT: [[A:%.*]] = alloca [7 x i8], align 1 ; CHECK-NEXT: [[P2:%.*]] = getelementptr inbounds i16, ptr [[A]], i64 1 ; CHECK-NEXT: store i16 42, ptr [[P2]], align 2 ; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 1 dereferenceable(7) [[DEST:%.*]], ptr noundef nonnull align 1 dereferenceable(7) [[P2]], i64 7, i1 false) ; CHECK-NEXT: ret void ; %a = alloca [7 x i8] %p2 = getelementptr i16, ptr %a, i32 1 store i16 42, ptr %p2 call void @llvm.memcpy.p0.p0.i64(ptr %dest, ptr %p2, i64 7, i1 false) ret void } declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i1)