xref: /aosp_15_r20/external/llvm/test/Transforms/JumpThreading/assume-edge-dom.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt -S -jump-threading < %s | FileCheck %s
2*9880d681SAndroid Build Coastguard Worker
3*9880d681SAndroid Build Coastguard Workerdeclare i8* @escape()
4*9880d681SAndroid Build Coastguard Workerdeclare void @llvm.assume(i1)
5*9880d681SAndroid Build Coastguard Worker
6*9880d681SAndroid Build Coastguard Workerdefine i1 @test1(i1 %cond) {
7*9880d681SAndroid Build Coastguard Workerentry:
8*9880d681SAndroid Build Coastguard Worker    br i1 %cond, label %taken, label %not_taken
9*9880d681SAndroid Build Coastguard Worker
10*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @test1
11*9880d681SAndroid Build Coastguard Worker; CHECK: br i1 %cond, label %no, label %yes
12*9880d681SAndroid Build Coastguard Worker; CHECK: ret i1 true
13*9880d681SAndroid Build Coastguard Worker
14*9880d681SAndroid Build Coastguard Workertaken:
15*9880d681SAndroid Build Coastguard Worker    %res1 = call i8* @escape()
16*9880d681SAndroid Build Coastguard Worker    %a = icmp eq i8* %res1, null
17*9880d681SAndroid Build Coastguard Worker    tail call void @llvm.assume(i1 %a)
18*9880d681SAndroid Build Coastguard Worker    br label %done
19*9880d681SAndroid Build Coastguard Workernot_taken:
20*9880d681SAndroid Build Coastguard Worker    %res2 = call i8* @escape()
21*9880d681SAndroid Build Coastguard Worker    %b = icmp ne i8* %res2, null
22*9880d681SAndroid Build Coastguard Worker    tail call void @llvm.assume(i1 %b)
23*9880d681SAndroid Build Coastguard Worker    br label %done
24*9880d681SAndroid Build Coastguard Worker
25*9880d681SAndroid Build Coastguard Worker; An assume that can be used to simplify this comparison dominates each
26*9880d681SAndroid Build Coastguard Worker; predecessor branch (although no assume dominates the cmp itself). Make sure
27*9880d681SAndroid Build Coastguard Worker; this still can be simplified.
28*9880d681SAndroid Build Coastguard Worker
29*9880d681SAndroid Build Coastguard Workerdone:
30*9880d681SAndroid Build Coastguard Worker    %res = phi i8* [ %res1, %taken ], [ %res2, %not_taken ]
31*9880d681SAndroid Build Coastguard Worker    %cnd = icmp ne i8* %res, null
32*9880d681SAndroid Build Coastguard Worker    br i1 %cnd, label %yes, label %no
33*9880d681SAndroid Build Coastguard Worker
34*9880d681SAndroid Build Coastguard Workeryes:
35*9880d681SAndroid Build Coastguard Worker    ret i1 true
36*9880d681SAndroid Build Coastguard Workerno:
37*9880d681SAndroid Build Coastguard Worker    ret i1 false
38*9880d681SAndroid Build Coastguard Worker}
39*9880d681SAndroid Build Coastguard Worker
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