Properly update AA metadata when performing call slot optimization

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7482

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228500 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bjorn Steinbrink 2015-02-07 17:54:36 +00:00
parent f516614e8a
commit 2dd5f23a1d
2 changed files with 32 additions and 0 deletions

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@ -750,6 +750,16 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy,
// its dependence information by changing its parameter.
MD->removeInstruction(C);
// Update AA metadata
// FIXME: MD_tbaa_struct and MD_mem_parallel_loop_access should also be
// handled here, but combineMetadata doesn't support them yet
unsigned KnownIDs[] = {
LLVMContext::MD_tbaa,
LLVMContext::MD_alias_scope,
LLVMContext::MD_noalias,
};
combineMetadata(C, cpy, KnownIDs);
// Remove the memcpy.
MD->removeInstruction(cpy);
++NumMemCpyInstr;

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@ -0,0 +1,22 @@
; RUN: opt < %s -S -basicaa -memcpyopt | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
%T = type { i64, i64 }
define void @test(i8* %src) {
%tmp = alloca i8
%dst = alloca i8
; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 1, i32 8, i1 false)
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %tmp, i8* %src, i64 1, i32 8, i1 false), !noalias !2
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %tmp, i64 1, i32 8, i1 false)
ret void
}
declare void @llvm.memcpy.p0i8.p0i8.i64(i8*, i8*, i64, i32, i1)
; Check that the noalias for "dst" was removed by checking that the metadata is gone
; CHECK-NOT: "dst"
!0 = !{!0}
!1 = distinct !{!1, !0, !"dst"}
!2 = distinct !{!1}