xref: /aosp_15_r20/external/llvm/test/Transforms/LoopStrengthReduce/dead-phi.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt < %s -loop-reduce -S | grep phi | count 1
2*9880d681SAndroid Build Coastguard Worker
3*9880d681SAndroid Build Coastguard Workerdefine void @foo(i32 %n) {
4*9880d681SAndroid Build Coastguard Workerentry:
5*9880d681SAndroid Build Coastguard Worker  br label %loop
6*9880d681SAndroid Build Coastguard Worker
7*9880d681SAndroid Build Coastguard Workerloop:
8*9880d681SAndroid Build Coastguard Worker  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
9*9880d681SAndroid Build Coastguard Worker
10*9880d681SAndroid Build Coastguard Worker  ; These three instructions form an isolated cycle and can be deleted.
11*9880d681SAndroid Build Coastguard Worker  %j = phi i32 [ 0, %entry ], [ %j.y, %loop ]
12*9880d681SAndroid Build Coastguard Worker  %j.x = add i32 %j, 1
13*9880d681SAndroid Build Coastguard Worker  %j.y = mul i32 %j.x, 2
14*9880d681SAndroid Build Coastguard Worker
15*9880d681SAndroid Build Coastguard Worker  %i.next = add i32 %i, 1
16*9880d681SAndroid Build Coastguard Worker  %c = icmp ne i32 %i.next, %n
17*9880d681SAndroid Build Coastguard Worker  br i1 %c, label %loop, label %exit
18*9880d681SAndroid Build Coastguard Worker
19*9880d681SAndroid Build Coastguard Workerexit:
20*9880d681SAndroid Build Coastguard Worker  ret void
21*9880d681SAndroid Build Coastguard Worker}
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