xref: /llvm-project/llvm/test/Transforms/LICM/pr36228.ll (revision 80e8f2beeb954f8c241897099bb01b24da400e8a)
1; RUN: opt -S -passes=licm -o - %s | FileCheck %s
2;
3; Be sure that we don't hoist loads incorrectly if a loop has conditional UB.
4; See PR36228.
5
6declare void @check(i8)
7declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i32, i1)
8
9; CHECK-LABEL: define void @buggy
10define void @buggy(ptr %src, ptr %kOne) {
11entry:
12  %dst = alloca [1 x i8], align 1
13  store i8 42, ptr %dst, align 1
14  %srcval = load i16, ptr %src
15  br label %while.cond
16
17while.cond:                                       ; preds = %if.end, %entry
18  %dp.0 = phi ptr [ %dst, %entry ], [ %dp.1, %if.end ]
19  %0 = load volatile i1, ptr %kOne, align 4
20  br i1 %0, label %if.else, label %if.then
21
22if.then:                                          ; preds = %while.cond
23  store i8 9, ptr %dp.0, align 1
24  br label %if.end
25
26if.else:                                          ; preds = %while.cond
27  call void @llvm.memcpy.p0.p0.i64(ptr %dp.0, ptr %src, i64 2, i32 1, i1 false)
28  %dp.new = getelementptr inbounds i8, ptr %dp.0, i64 1
29  br label %if.end
30
31if.end:                                           ; preds = %if.else, %if.then
32  %dp.1 = phi ptr [ %dp.0, %if.then ], [ %dp.new, %if.else ]
33  ; CHECK: %1 = load i8, ptr %dst
34  %1 = load i8, ptr %dst, align 1
35  ; CHECK-NEXT: call void @check(i8 %1)
36  call void @check(i8 %1)
37  br label %while.cond
38}
39