xref: /llvm-project/llvm/test/Transforms/SCCP/switch-undef-constantfoldterminator.ll (revision 1f88d804083a8a1b68df1e6677920e38ab2a6b40)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature
2; RUN: opt < %s -passes=ipsccp -S | FileCheck %s
3
4; This test case used to end up like this:
5;
6;    While deleting: label %lor.rhs
7;    Use still stuck around after Def is destroyed:  br i1 undef, label %lor.rhs, label %land.end
8;    opt: ../lib/IR/Value.cpp: llvm::Value::~Value(): Assertion `use_empty() && "Uses remain when a value is destroyed!"' failed.
9;
10; due to ConstantFoldTerminator rewriting the switch into
11;
12;    br i1 undef, label %lor.rhs, label %land.end
13;
14; while SCCP implementation relied on the terminator to always be folded into
15; an unconditional branch when ConstantFoldTerminator returned true.
16
17define void @f4() {
18; CHECK-LABEL: define {{[^@]+}}@f4() {
19; CHECK-NEXT:  entry:
20; CHECK-NEXT:    [[CALL:%.*]] = call i16 @f3(i16 undef)
21; CHECK-NEXT:    ret void
22;
23entry:
24  %call = call i16 @f3(i16 undef)
25  ret void
26}
27
28define internal i16 @f3(i16 %p1) {
29; CHECK-LABEL: define {{[^@]+}}@f3
30; CHECK-SAME: (i16 [[P1:%.*]]) {
31; CHECK-NEXT:  entry:
32; CHECK-NEXT:    unreachable
33;
34entry:
35  switch i16 %p1, label %land.end [
36  i16 0, label %land.end
37  i16 1, label %lor.rhs
38  ]
39
40lor.rhs:
41  br label %land.end
42
43land.end:
44  ret i16 0
45}
46
47