1; RUN: opt -jump-threading -S -verify < %s | FileCheck %s
2
3; This is reduced from the Linux net/ipv4/tcp.c file built with ASAN. We
4; don't want jump threading to split up a basic block which has a PHI node with
5; at least one constant incoming value, whose value is used by an is.constant
6; intrinsic with non-local uses. It could lead to later passes no DCE'ing
7; invalid paths.
8
9; CHECK-LABEL:    define void @test1(
10; CHECK-LABEL:    bb_cond:
11; CHECK-NOT:        %sext = phi i64 [ %var, %entry ]
12; CHECK-NEXT:       %sext = phi i64 [ 24, %bb_constant ], [ %var, %entry ]
13; CHECK-NEXT:       %cond2 = icmp
14; CHECK-NEXT:       call i1 @llvm.is.constant.i64(
15
16define void @test1(i32 %a, i64 %var) {
17entry:
18  %cond1 = icmp ugt i32 %a, 24
19  br i1 %cond1, label %bb_constant, label %bb_cond
20
21bb_constant:
22  br label %bb_cond
23
24bb_cond:
25  %sext = phi i64 [ 24, %bb_constant ], [ %var, %entry ]
26  %cond2 = icmp ugt i64 %sext, 24
27  %is_constant = call i1 @llvm.is.constant.i64(i64 %sext)
28  br i1 %cond2, label %bb_then, label %bb_else
29
30bb_then:
31  unreachable
32
33bb_else:
34  unreachable
35}
36
37; Function Attrs: nounwind readnone willreturn
38declare i1 @llvm.is.constant.i64(i64) #0
39
40attributes #0 = { convergent nounwind readnone willreturn }
41