xref: /llvm-project/llvm/test/Transforms/SimplifyCFG/PhiEliminate3.ll (revision d1d129356909af2f6fefd6f1b9335a39fe172e9a)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -phi-node-folding-threshold=1 | FileCheck %s
3; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -phi-node-folding-threshold=2 | FileCheck %s
4; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -phi-node-folding-threshold=7 | FileCheck %s
5
6; Test merging of blocks containing complex expressions,
7; with various folding thresholds
8
9define i32 @test(i1 %a, i1 %b, i32 %i, i32 %j, i32 %k) {
10; CHECK-LABEL: @test(
11; CHECK-NEXT:  entry:
12; CHECK-NEXT:    br i1 [[A:%.*]], label [[M:%.*]], label [[O:%.*]]
13; CHECK:       O:
14; CHECK-NEXT:    [[IAJ:%.*]] = add i32 [[I:%.*]], [[J:%.*]]
15; CHECK-NEXT:    [[IAJAK:%.*]] = add i32 [[IAJ]], [[K:%.*]]
16; CHECK-NEXT:    [[IXJ:%.*]] = xor i32 [[I]], [[J]]
17; CHECK-NEXT:    [[IXJXK:%.*]] = xor i32 [[IXJ]], [[K]]
18; CHECK-NEXT:    [[WP:%.*]] = select i1 [[B:%.*]], i32 [[IAJAK]], i32 [[IXJXK]]
19; CHECK-NEXT:    [[WP2:%.*]] = add i32 [[WP]], [[WP]]
20; CHECK-NEXT:    br label [[M]]
21; CHECK:       M:
22; CHECK-NEXT:    [[W:%.*]] = phi i32 [ [[WP2]], [[O]] ], [ 2, [[ENTRY:%.*]] ]
23; CHECK-NEXT:    [[R:%.*]] = add i32 [[W]], 1
24; CHECK-NEXT:    ret i32 [[R]]
25;
26entry:
27  br i1 %a, label %M, label %O
28O:
29  br i1 %b, label %P, label %Q
30P:
31  %iaj = add i32 %i, %j
32  %iajak = add i32 %iaj, %k
33  br label %N
34Q:
35  %ixj = xor i32 %i, %j
36  %ixjxk = xor i32 %ixj, %k
37  br label %N
38N:
39  ; This phi should be foldable if threshold >= 2
40  %Wp = phi i32 [ %iajak, %P ], [ %ixjxk, %Q ]
41  %Wp2 = add i32 %Wp, %Wp
42  br label %M
43M:
44  ; This phi should be foldable if threshold >= 7
45  %W = phi i32 [ %Wp2, %N ], [ 2, %entry ]
46  %R = add i32 %W, 1
47  ret i32 %R
48}
49
50