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1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py2; RUN: opt < %s -S -passes=memcpyopt -verify-memoryssa | FileCheck %s3target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"4 5declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture readonly, i64, i1) unnamed_addr nounwind6declare void @llvm.memset.p0.i64(ptr nocapture, i8, i64, i1) nounwind7 8; all bytes of %dst that are touch by the memset are dereferenceable9define void @must_remove_memcpy(ptr noalias nocapture writable dereferenceable(4096) %dst) nofree nosync {10; CHECK-LABEL: @must_remove_memcpy(11; CHECK-NEXT: [[SRC:%.*]] = alloca [4096 x i8], align 112; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr [[DST:%.*]], i8 0, i64 4096, i1 false)13; CHECK-NEXT: ret void14;15 %src = alloca [4096 x i8], align 116 call void @llvm.memset.p0.i64(ptr %src, i8 0, i64 4096, i1 false)17 call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 4096, i1 false) #218 ret void19}20 21; memset touch more bytes than those guaranteed to be dereferenceable22; We can't remove the memcpy, but we can turn it into an independent memset.23define void @must_not_remove_memcpy(ptr noalias nocapture writable dereferenceable(1024) %dst) nofree nosync {24; CHECK-LABEL: @must_not_remove_memcpy(25; CHECK-NEXT: [[SRC:%.*]] = alloca [4096 x i8], align 126; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr [[SRC]], i8 0, i64 4096, i1 false)27; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr [[DST:%.*]], i8 0, i64 4096, i1 false)28; CHECK-NEXT: ret void29;30 %src = alloca [4096 x i8], align 131 call void @llvm.memset.p0.i64(ptr %src, i8 0, i64 4096, i1 false)32 call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 4096, i1 false) #233 ret void34}35