; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -S -basic-aa -memcpyopt -verify-memoryssa | FileCheck %s target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128" declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i1) unnamed_addr nounwind declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i1) nounwind ; all bytes of %dst that are touch by the memset are dereferenceable define void @must_remove_memcpy(i8* noalias nocapture dereferenceable(4096) %dst) nofree nosync { ; CHECK-LABEL: @must_remove_memcpy( ; CHECK-NEXT: [[SRC:%.*]] = alloca [4096 x i8], align 1 ; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds [4096 x i8], [4096 x i8]* [[SRC]], i64 0, i64 0 ; CHECK-NEXT: [[DST1:%.*]] = bitcast i8* [[DST:%.*]] to [4096 x i8]* ; CHECK-NEXT: [[DST12:%.*]] = bitcast [4096 x i8]* [[DST1]] to i8* ; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[DST12]], i8 0, i64 4096, i1 false) ; CHECK-NEXT: ret void ; %src = alloca [4096 x i8], align 1 %p = getelementptr inbounds [4096 x i8], [4096 x i8]* %src, i64 0, i64 0 call void @llvm.memset.p0i8.i64(i8* %p, i8 0, i64 4096, i1 false) call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %p, i64 4096, i1 false) #2 ret void } ; memset touch more bytes than those guaranteed to be dereferenceable ; We can't remove the memcpy, but we can turn it into an independent memset. define void @must_not_remove_memcpy(i8* noalias nocapture dereferenceable(1024) %dst) nofree nosync { ; CHECK-LABEL: @must_not_remove_memcpy( ; CHECK-NEXT: [[SRC:%.*]] = alloca [4096 x i8], align 1 ; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds [4096 x i8], [4096 x i8]* [[SRC]], i64 0, i64 0 ; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[P]], i8 0, i64 4096, i1 false) ; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[DST:%.*]], i8 0, i64 4096, i1 false) ; CHECK-NEXT: ret void ; %src = alloca [4096 x i8], align 1 %p = getelementptr inbounds [4096 x i8], [4096 x i8]* %src, i64 0, i64 0 call void @llvm.memset.p0i8.i64(i8* %p, i8 0, i64 4096, i1 false) call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %p, i64 4096, i1 false) #2 ret void }