1; RUN: opt -S -basic-aa -dse < %s | FileCheck %s
2
3target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
4target triple = "x86_64-unknown-linux-gnu"
5
6; We incorrectly returned noalias in the example below for "ptr.64" and
7; "either_ptr.64".
8; PR18460
9
10%nested = type { %nested.i64 }
11%nested.i64 = type { i64 }
12
13define i64 @testcase(%nested * noalias %p1, %nested * noalias %p2,
14                     i32 %a, i32 %b) {
15  %ptr = getelementptr inbounds %nested, %nested* %p1, i64 -1, i32 0
16  %ptr.64 = getelementptr inbounds %nested.i64, %nested.i64* %ptr, i64 0, i32 0
17  %ptr2= getelementptr inbounds %nested, %nested* %p2, i64 0, i32 0
18  %cmp = icmp ult i32 %a, %b
19  %either_ptr = select i1 %cmp, %nested.i64* %ptr2, %nested.i64* %ptr
20  %either_ptr.64 = getelementptr inbounds %nested.i64, %nested.i64* %either_ptr, i64 0, i32 0
21
22; Because either_ptr.64 and ptr.64 can alias (we used to return noalias)
23; elimination of the first store is not valid.
24
25; CHECK: store i64 2
26; CHECK: load
27; CHECK: store i64 1
28
29  store i64 2, i64* %ptr.64, align 8
30  %r = load i64, i64* %either_ptr.64, align 8
31  store i64 1, i64* %ptr.64, align 8
32  ret i64 %r
33}
34