xref: /llvm-project/polly/test/Simplify/dead_access_phi.ll (revision e1f056f692d869708c1898d9d65a69ac5584a0ed)
1; RUN: opt %loadNPMPolly -polly-stmt-granularity=bb "-passes=scop(print<polly-simplify>)" -disable-output -aa-pipeline=basic-aa < %s | FileCheck %s -match-full-lines
2;
3; Remove a dead PHI write/read pair
4; (accesses that are effectively not used)
5;
6; for (int j = 0; j < n; j += 1) {
7; body:
8;   double phi = 42;
9;
10; body_succ:
11;   A[0] = 42.0;
12; }
13;
14define void @func(i32 %n, ptr noalias nonnull %A) {
15entry:
16  br label %for
17
18for:
19  %j = phi i32 [0, %entry], [%j.inc, %inc]
20  %j.cmp = icmp slt i32 %j, %n
21  br i1 %j.cmp, label %body, label %exit
22
23    body:
24      br label %body_succ
25
26    body_succ:
27      %phi = phi double [42.0, %body]
28      store double 42.0, ptr %A
29      br label %inc
30
31inc:
32  %j.inc = add nuw nsw i32 %j, 1
33  br label %for
34
35exit:
36  br label %return
37
38return:
39  ret void
40}
41
42
43; CHECK: Statistics {
44; CHECK:     Dead accesses removed: 2
45; CHECK:     Dead instructions removed: 1
46; CHECK:     Stmts removed: 1
47; CHECK: }
48
49; CHECK:      After accesses {
50; CHECK-NEXT:     Stmt_body_succ
51; CHECK-NEXT:             MustWriteAccess :=  [Reduction Type: NONE] [Scalar: 0]
52; CHECK-NEXT:                 [n] -> { Stmt_body_succ[i0] -> MemRef_A[0] };
53; CHECK-NEXT: }
54