1 ; RUN: opt < %s -S -basicaa -memcpyopt | FileCheck %s 2 target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128" 3 4 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) unnamed_addr nounwind 5 declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind 6 7 ; all bytes of %dst that are touch by the memset are dereferenceable 8 define void @must_remove_memcpy(i8* noalias nocapture dereferenceable(4096) %dst) { 9 ; CHECK-LABEL: @must_remove_memcpy( 10 ; CHECK: call void @llvm.memset.p0i8.i64 11 ; CHECK-NOT: call void @llvm.memcpy.p0i8.p0i8.i64 12 %src = alloca [4096 x i8], align 1 13 %p = getelementptr inbounds [4096 x i8], [4096 x i8]* %src, i64 0, i64 0 14 call void @llvm.memset.p0i8.i64(i8* %p, i8 0, i64 4096, i32 1, i1 false) 15 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %p, i64 4096, i32 1, i1 false) #2 16 ret void 17 } 18 19 ; memset touch more bytes than those guaranteed to be dereferenceable 20 define void @must_not_remove_memcpy(i8* noalias nocapture dereferenceable(1024) %dst) { 21 ; CHECK-LABEL: @must_not_remove_memcpy( 22 ; CHECK: call void @llvm.memset.p0i8.i64 23 ; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64 24 %src = alloca [4096 x i8], align 1 25 %p = getelementptr inbounds [4096 x i8], [4096 x i8]* %src, i64 0, i64 0 26 call void @llvm.memset.p0i8.i64(i8* %p, i8 0, i64 4096, i32 1, i1 false) 27 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %p, i64 4096, i32 1, i1 false) #2 28 ret void 29 } 30
