xref: /llvm-project/llvm/test/Transforms/SimplifyCFG/PhiEliminate.ll (revision d1d129356909af2f6fefd6f1b9335a39fe172e9a)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; Test a bunch of cases where the cfg simplification code should
3; be able to fold PHI nodes into computation in common cases.  Folding the PHI
4; nodes away allows the branches to be eliminated, performing a simple form of
5; 'if conversion'.
6
7; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
8
9declare void @use(i1)
10
11declare void @use.upgrd.1(i32)
12
13
14define void @test(i1 %c, i32 %V, i32 %V2) {
15; <label>:0
16; CHECK-LABEL: @test(
17; CHECK-NEXT:  F:
18; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[C:%.*]], i1 false, i1 true
19; CHECK-NEXT:    [[SPEC_SELECT1:%.*]] = select i1 [[C]], i32 0, i32 [[V:%.*]]
20; CHECK-NEXT:    call void @use(i1 [[SPEC_SELECT]])
21; CHECK-NEXT:    call void @use.upgrd.1(i32 [[SPEC_SELECT1]])
22; CHECK-NEXT:    ret void
23;
24  br i1 %c, label %T, label %F
25T:              ; preds = %0
26  br label %F
27F:              ; preds = %T, %0
28  %B1 = phi i1 [ true, %0 ], [ false, %T ]                ; <i1> [#uses=1]
29  %I6 = phi i32 [ %V, %0 ], [ 0, %T ]             ; <i32> [#uses=1]
30  call void @use( i1 %B1 )
31  call void @use.upgrd.1( i32 %I6 )
32  ret void
33}
34
35