1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -passes='loop(indvars),loop-vectorize' -S %s | FileCheck %s
3
4target triple = "x86_64-unknown-linux-gnu"
5
6; After indvars, the backedge taken count for %loop2 becomes 1, but SCEV
7; retains the cached original BTC, as the loop is in dead code. Make sure
8; LV does not crash when trying to select an interleave count for a loop with zero cost.
9define void @pr54413(i64* %ptr.base) {
10; CHECK-LABEL: @pr54413(
11; CHECK-NEXT:  entry:
12; CHECK-NEXT:    br label [[LOOP1:%.*]]
13; CHECK:       loop1:
14; CHECK-NEXT:    br i1 true, label [[LOOP1_LATCH:%.*]], label [[LOOP2_PREHEADER:%.*]]
15; CHECK:       loop2.preheader:
16; CHECK-NEXT:    br label [[LOOP2:%.*]]
17; CHECK:       loop2:
18; CHECK-NEXT:    [[PTR:%.*]] = phi i64* [ [[PTR_BASE:%.*]], [[LOOP2_PREHEADER]] ], [ [[PTR_NEXT:%.*]], [[LOOP2]] ]
19; CHECK-NEXT:    [[PTR_NEXT]] = getelementptr inbounds i64, i64* [[PTR]], i64 1
20; CHECK-NEXT:    br i1 true, label [[LOOP2_EXIT:%.*]], label [[LOOP2]]
21; CHECK:       loop2.exit:
22; CHECK-NEXT:    [[PTR_NEXT_LCSSA:%.*]] = phi i64* [ [[PTR_NEXT]], [[LOOP2]] ]
23; CHECK-NEXT:    br label [[LOOP1_LATCH]]
24; CHECK:       loop1.latch:
25; CHECK-NEXT:    br label [[LOOP1]]
26;
27entry:
28  br label %loop1
29
30loop1:
31  br i1 true, label %loop1.latch, label %loop2.preheader
32
33loop2.preheader:
34  br label %loop2
35
36loop2:
37  %iv = phi i64 [ 0, %loop2.preheader ], [ %iv.next, %loop2 ]
38  %ptr = phi i64* [ %ptr.base, %loop2.preheader ], [ %ptr.next, %loop2 ]
39  %iv.next = add nuw nsw i64 %iv, 1
40  %ptr.next = getelementptr inbounds i64, i64* %ptr, i64 1
41  %cmp = icmp eq i64 %iv, 1024
42  br i1 %cmp, label %loop2.exit, label %loop2
43
44loop2.exit:
45  %ptr.next.lcssa = phi i64* [ %ptr.next, %loop2 ]
46  br label %loop1.latch
47
48loop1.latch:
49  br label %loop1
50}
51