1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -indvars -replexitval=always -S | FileCheck %s
3; Make sure IndVars preserves LCSSA form, especially across loop nests.
4
5target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
6
7define void @PR18642(i32 %x) {
8; CHECK-LABEL: @PR18642(
9; CHECK-NEXT:  entry:
10; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
11; CHECK:       outer.header:
12; CHECK-NEXT:    br label [[INNER_HEADER:%.*]]
13; CHECK:       inner.header:
14; CHECK-NEXT:    br i1 false, label [[INNER_LATCH:%.*]], label [[OUTER_LATCH:%.*]]
15; CHECK:       inner.latch:
16; CHECK-NEXT:    br i1 true, label [[INNER_HEADER]], label [[EXIT_LOOPEXIT:%.*]]
17; CHECK:       outer.latch:
18; CHECK-NEXT:    br i1 false, label [[OUTER_HEADER]], label [[EXIT_LOOPEXIT1:%.*]]
19; CHECK:       exit.loopexit:
20; CHECK-NEXT:    [[INC_LCSSA:%.*]] = phi i32 [ -2147483648, [[INNER_LATCH]] ]
21; CHECK-NEXT:    br label [[EXIT:%.*]]
22; CHECK:       exit.loopexit1:
23; CHECK-NEXT:    br label [[EXIT]]
24; CHECK:       exit:
25; CHECK-NEXT:    [[EXIT_PHI:%.*]] = phi i32 [ [[INC_LCSSA]], [[EXIT_LOOPEXIT]] ], [ undef, [[EXIT_LOOPEXIT1]] ]
26; CHECK-NEXT:    ret void
27;
28entry:
29  br label %outer.header
30
31outer.header:
32  %outer.iv = phi i32 [ 0, %entry ], [ %x, %outer.latch ]
33  br label %inner.header
34
35inner.header:
36  %inner.iv = phi i32 [ undef, %outer.header ], [ %inc, %inner.latch ]
37  %cmp1 = icmp slt i32 %inner.iv, %outer.iv
38  br i1 %cmp1, label %inner.latch, label %outer.latch
39
40inner.latch:
41  %inc = add nsw i32 %inner.iv, 1
42  %cmp2 = icmp slt i32 %inner.iv, %outer.iv
43  br i1 %cmp2, label %inner.header, label %exit
44
45outer.latch:
46  br i1 undef, label %outer.header, label %exit
47
48exit:
49  %exit.phi = phi i32 [ %inc, %inner.latch ], [ undef, %outer.latch ]
50  ret void
51}
52
53define i64 @unconditional_exit_simplification(i64 %arg) {
54; CHECK-LABEL: @unconditional_exit_simplification(
55; CHECK-NEXT:  entry:
56; CHECK-NEXT:    br label [[LOOP1:%.*]]
57; CHECK:       loop1:
58; CHECK-NEXT:    br label [[LOOP2:%.*]]
59; CHECK:       loop2:
60; CHECK-NEXT:    [[IV2:%.*]] = phi i64 [ 0, [[LOOP1]] ], [ 1, [[LOOP2]] ]
61; CHECK-NEXT:    br i1 true, label [[LOOP2]], label [[LOOP1_LATCH:%.*]]
62; CHECK:       loop1.latch:
63; CHECK-NEXT:    [[RES_LCSSA:%.*]] = phi i64 [ [[IV2]], [[LOOP2]] ]
64; CHECK-NEXT:    br i1 false, label [[LOOP1]], label [[EXIT:%.*]]
65; CHECK:       exit:
66; CHECK-NEXT:    [[RES_LCSSA2:%.*]] = phi i64 [ [[RES_LCSSA]], [[LOOP1_LATCH]] ]
67; CHECK-NEXT:    ret i64 [[RES_LCSSA2]]
68;
69entry:
70  br label %loop1
71
72loop1:
73  %iv1 = phi i64 [ 0, %entry ], [ 1, %loop1.latch ]
74  br label %loop2
75
76loop2:
77  %iv2 = phi i64 [ 0, %loop1 ], [ 1, %loop2 ]
78  %res = add nuw nsw i64 %iv1, %iv2
79  br i1 true, label %loop2, label %loop1.latch
80
81loop1.latch:
82  %res.lcssa = phi i64 [ %res, %loop2 ]
83  br i1 false, label %loop1, label %exit
84
85exit:
86  %res.lcssa2 = phi i64 [ %res.lcssa, %loop1.latch ]
87  ret i64 %res.lcssa2
88}
89