xref: /aosp_15_r20/external/llvm/test/Analysis/LoopAccessAnalysis/underlying-objects-1.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt -basicaa -loop-accesses -analyze < %s | FileCheck %s
2*9880d681SAndroid Build Coastguard Worker; RUN: opt -passes='require<scalar-evolution>,require<aa>,loop(print-access-info)' -disable-output  < %s 2>&1 | FileCheck %s
3*9880d681SAndroid Build Coastguard Worker
4*9880d681SAndroid Build Coastguard Worker; In:
5*9880d681SAndroid Build Coastguard Worker;
6*9880d681SAndroid Build Coastguard Worker;   store_ptr = A;
7*9880d681SAndroid Build Coastguard Worker;   load_ptr = &A[2];
8*9880d681SAndroid Build Coastguard Worker;   for (i = 0; i < n; i++)
9*9880d681SAndroid Build Coastguard Worker;    *store_ptr++ = *load_ptr++ *10;  // A[i] = A[i+2] * 10
10*9880d681SAndroid Build Coastguard Worker;
11*9880d681SAndroid Build Coastguard Worker; make sure, we look through the PHI to conclude that store_ptr and load_ptr
12*9880d681SAndroid Build Coastguard Worker; both have A as their underlying object.  The dependence is safe for
13*9880d681SAndroid Build Coastguard Worker; vectorization requiring no memchecks.
14*9880d681SAndroid Build Coastguard Worker;
15*9880d681SAndroid Build Coastguard Worker; Otherwise we would try to prove independence with a memcheck that is going
16*9880d681SAndroid Build Coastguard Worker; to always fail.
17*9880d681SAndroid Build Coastguard Worker
18*9880d681SAndroid Build Coastguard Workertarget datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
19*9880d681SAndroid Build Coastguard Workertarget triple = "x86_64-apple-macosx10.10.0"
20*9880d681SAndroid Build Coastguard Worker
21*9880d681SAndroid Build Coastguard Worker; CHECK: Memory dependences are safe{{$}}
22*9880d681SAndroid Build Coastguard Worker
23*9880d681SAndroid Build Coastguard Workerdefine void @f(i8* noalias %A, i64 %width) {
24*9880d681SAndroid Build Coastguard Workerfor.body.preheader:
25*9880d681SAndroid Build Coastguard Worker  %A_ahead = getelementptr inbounds i8, i8* %A, i64 2
26*9880d681SAndroid Build Coastguard Worker  br label %for.body
27*9880d681SAndroid Build Coastguard Worker
28*9880d681SAndroid Build Coastguard Workerfor.body:
29*9880d681SAndroid Build Coastguard Worker  %i = phi i64 [ %i.1, %for.body ], [ 0, %for.body.preheader ]
30*9880d681SAndroid Build Coastguard Worker  %load_ptr = phi i8* [ %load_ptr.1, %for.body ], [ %A_ahead, %for.body.preheader ]
31*9880d681SAndroid Build Coastguard Worker  %store_ptr = phi i8* [ %store_ptr.1, %for.body ], [ %A, %for.body.preheader ]
32*9880d681SAndroid Build Coastguard Worker
33*9880d681SAndroid Build Coastguard Worker  %loadA = load i8, i8* %load_ptr, align 1
34*9880d681SAndroid Build Coastguard Worker
35*9880d681SAndroid Build Coastguard Worker  %mul = mul i8 %loadA, 10
36*9880d681SAndroid Build Coastguard Worker
37*9880d681SAndroid Build Coastguard Worker  store i8 %mul, i8* %store_ptr, align 1
38*9880d681SAndroid Build Coastguard Worker
39*9880d681SAndroid Build Coastguard Worker  %load_ptr.1 = getelementptr inbounds i8, i8* %load_ptr, i64 1
40*9880d681SAndroid Build Coastguard Worker  %store_ptr.1 = getelementptr inbounds i8, i8* %store_ptr, i64 1
41*9880d681SAndroid Build Coastguard Worker  %i.1 = add nuw i64 %i, 1
42*9880d681SAndroid Build Coastguard Worker
43*9880d681SAndroid Build Coastguard Worker  %exitcond = icmp eq i64 %i.1, %width
44*9880d681SAndroid Build Coastguard Worker  br i1 %exitcond, label %for.end, label %for.body
45*9880d681SAndroid Build Coastguard Worker
46*9880d681SAndroid Build Coastguard Workerfor.end:
47*9880d681SAndroid Build Coastguard Worker  ret void
48*9880d681SAndroid Build Coastguard Worker}
49