xref: /aosp_15_r20/external/llvm/test/Transforms/GVN/br-identical.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt -gvn -S -o - %s | FileCheck %s
2*9880d681SAndroid Build Coastguard Worker
3*9880d681SAndroid Build Coastguard Worker; If a branch has two identical successors, we cannot declare either dead.
4*9880d681SAndroid Build Coastguard Worker
5*9880d681SAndroid Build Coastguard Workerdefine void @widget(i1 %p) {
6*9880d681SAndroid Build Coastguard Workerentry:
7*9880d681SAndroid Build Coastguard Worker  br label %bb2
8*9880d681SAndroid Build Coastguard Worker
9*9880d681SAndroid Build Coastguard Workerbb2:
10*9880d681SAndroid Build Coastguard Worker  %t1 = phi i64 [ 0, %entry ], [ %t5, %bb7 ]
11*9880d681SAndroid Build Coastguard Worker  %t2 = add i64 %t1, 1
12*9880d681SAndroid Build Coastguard Worker  %t3 = icmp ult i64 0, %t2
13*9880d681SAndroid Build Coastguard Worker  br i1 %t3, label %bb3, label %bb4
14*9880d681SAndroid Build Coastguard Worker
15*9880d681SAndroid Build Coastguard Workerbb3:
16*9880d681SAndroid Build Coastguard Worker  %t4 = call i64 @f()
17*9880d681SAndroid Build Coastguard Worker  br label %bb4
18*9880d681SAndroid Build Coastguard Worker
19*9880d681SAndroid Build Coastguard Workerbb4:
20*9880d681SAndroid Build Coastguard Worker  ; CHECK-NOT: phi {{.*}} undef
21*9880d681SAndroid Build Coastguard Worker  %foo = phi i64 [ %t4, %bb3 ], [ 0, %bb2 ]
22*9880d681SAndroid Build Coastguard Worker  br i1 %p, label %bb5, label %bb6
23*9880d681SAndroid Build Coastguard Worker
24*9880d681SAndroid Build Coastguard Workerbb5:
25*9880d681SAndroid Build Coastguard Worker  br i1 true, label %bb7, label %bb7
26*9880d681SAndroid Build Coastguard Worker
27*9880d681SAndroid Build Coastguard Workerbb6:
28*9880d681SAndroid Build Coastguard Worker  br i1 true, label %bb7, label %bb7
29*9880d681SAndroid Build Coastguard Worker
30*9880d681SAndroid Build Coastguard Workerbb7:
31*9880d681SAndroid Build Coastguard Worker  %t5 = add i64 %t1, 1
32*9880d681SAndroid Build Coastguard Worker  br i1 %p, label %bb2, label %bb8
33*9880d681SAndroid Build Coastguard Worker
34*9880d681SAndroid Build Coastguard Workerbb8:
35*9880d681SAndroid Build Coastguard Worker  ret void
36*9880d681SAndroid Build Coastguard Worker}
37*9880d681SAndroid Build Coastguard Worker
38*9880d681SAndroid Build Coastguard Workerdeclare i64 @f()
39