xref: /llvm-project/llvm/test/Transforms/SimplifyCFG/PhiNoEliminate.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 | FileCheck %s
3
4;; The PHI node in this example should not be turned into a select, as we are
5;; not able to ifcvt the entire block.  As such, converting to a select just
6;; introduces inefficiency without saving copies.
7
8define i32 @bar(i1 %C) {
9; CHECK-LABEL: @bar(
10; CHECK-NEXT:  entry:
11; CHECK-NEXT:    br i1 [[C:%.*]], label [[THEN:%.*]], label [[ENDIF:%.*]]
12; CHECK:       then:
13; CHECK-NEXT:    [[TMP_3:%.*]] = call i32 @qux()
14; CHECK-NEXT:    br label [[ENDIF]]
15; CHECK:       endif:
16; CHECK-NEXT:    [[R:%.*]] = phi i32 [ 123, [[ENTRY:%.*]] ], [ 12312, [[THEN]] ]
17; CHECK-NEXT:    [[TMP0:%.*]] = call i32 @qux()
18; CHECK-NEXT:    [[TMP1:%.*]] = call i32 @qux()
19; CHECK-NEXT:    [[TMP2:%.*]] = call i32 @qux()
20; CHECK-NEXT:    [[TMP3:%.*]] = call i32 @qux()
21; CHECK-NEXT:    [[TMP4:%.*]] = call i32 @qux()
22; CHECK-NEXT:    [[TMP5:%.*]] = call i32 @qux()
23; CHECK-NEXT:    [[TMP6:%.*]] = call i32 @qux()
24; CHECK-NEXT:    ret i32 [[R]]
25;
26entry:
27  br i1 %C, label %then, label %endif
28then:           ; preds = %entry
29  %tmp.3 = call i32 @qux( )               ; <i32> [#uses=0]
30  br label %endif
31endif:          ; preds = %then, %entry
32  %R = phi i32 [ 123, %entry ], [ 12312, %then ]          ; <i32> [#uses=1]
33  ;; stuff to disable tail duplication
34  call i32 @qux( )                ; <i32>:0 [#uses=0]
35  call i32 @qux( )                ; <i32>:1 [#uses=0]
36  call i32 @qux( )                ; <i32>:2 [#uses=0]
37  call i32 @qux( )                ; <i32>:3 [#uses=0]
38  call i32 @qux( )                ; <i32>:4 [#uses=0]
39  call i32 @qux( )                ; <i32>:5 [#uses=0]
40  call i32 @qux( )                ; <i32>:6 [#uses=0]
41  ret i32 %R
42}
43
44declare i32 @qux()
45