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(ptr %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_NEXT:%.*]] = getelementptr inbounds i64, ptr [[PTR_BASE:%.*]], i64 1
19; CHECK-NEXT:    br i1 true, label [[LOOP2_EXIT:%.*]], label [[LOOP2]]
20; CHECK:       loop2.exit:
21; CHECK-NEXT:    [[PTR_NEXT_LCSSA:%.*]] = phi ptr [ [[PTR_NEXT]], [[LOOP2]] ]
22; CHECK-NEXT:    br label [[LOOP1_LATCH]]
23; CHECK:       loop1.latch:
24; CHECK-NEXT:    br label [[LOOP1]]
25;
26entry:
27  br label %loop1
28
29loop1:
30  br i1 true, label %loop1.latch, label %loop2.preheader
31
32loop2.preheader:
33  br label %loop2
34
35loop2:
36  %iv = phi i64 [ 0, %loop2.preheader ], [ %iv.next, %loop2 ]
37  %ptr = phi ptr [ %ptr.base, %loop2.preheader ], [ %ptr.next, %loop2 ]
38  %iv.next = add nuw nsw i64 %iv, 1
39  %ptr.next = getelementptr inbounds i64, ptr %ptr, i64 1
40  %cmp = icmp eq i64 %iv, 1024
41  br i1 %cmp, label %loop2.exit, label %loop2
42
43loop2.exit:
44  %ptr.next.lcssa = phi ptr [ %ptr.next, %loop2 ]
45  br label %loop1.latch
46
47loop1.latch:
48  br label %loop1
49}
50