1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -loop-unroll -unroll-runtime -unroll-runtime-multi-exit < %s | FileCheck %s
3
4; This loop has a known trip count on the non-latch exit. When performing
5; runtime unrolling (at least when using a prologue rather than epilogue) we
6; should not fold that exit based on known trip count information prior to
7; prologue insertion, as that may change the trip count for the modified loop.
8
9define void @test(i32 %s, i32 %n) {
10; CHECK-LABEL: @test(
11; CHECK-NEXT:  entry:
12; CHECK-NEXT:    [[N2:%.*]] = add i32 [[S:%.*]], 123
13; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[N:%.*]], 1
14; CHECK-NEXT:    [[TMP1:%.*]] = sub i32 [[TMP0]], [[S]]
15; CHECK-NEXT:    [[TMP2:%.*]] = sub i32 [[N]], [[S]]
16; CHECK-NEXT:    [[XTRAITER:%.*]] = and i32 [[TMP1]], 7
17; CHECK-NEXT:    [[LCMP_MOD:%.*]] = icmp ne i32 [[XTRAITER]], 0
18; CHECK-NEXT:    br i1 [[LCMP_MOD]], label [[LOOP_PROL_PREHEADER:%.*]], label [[LOOP_PROL_LOOPEXIT:%.*]]
19; CHECK:       loop.prol.preheader:
20; CHECK-NEXT:    br label [[LOOP_PROL:%.*]]
21; CHECK:       loop.prol:
22; CHECK-NEXT:    [[I_PROL:%.*]] = phi i32 [ [[S]], [[LOOP_PROL_PREHEADER]] ], [ [[I_INC_PROL:%.*]], [[LATCH_PROL:%.*]] ]
23; CHECK-NEXT:    [[PROL_ITER:%.*]] = phi i32 [ [[XTRAITER]], [[LOOP_PROL_PREHEADER]] ], [ [[PROL_ITER_SUB:%.*]], [[LATCH_PROL]] ]
24; CHECK-NEXT:    [[C1_PROL:%.*]] = icmp eq i32 [[I_PROL]], [[N2]]
25; CHECK-NEXT:    br i1 [[C1_PROL]], label [[EXIT1_LOOPEXIT1:%.*]], label [[LATCH_PROL]]
26; CHECK:       latch.prol:
27; CHECK-NEXT:    [[C2_PROL:%.*]] = icmp eq i32 [[I_PROL]], [[N]]
28; CHECK-NEXT:    [[I_INC_PROL]] = add i32 [[I_PROL]], 1
29; CHECK-NEXT:    [[PROL_ITER_SUB]] = sub i32 [[PROL_ITER]], 1
30; CHECK-NEXT:    [[PROL_ITER_CMP:%.*]] = icmp ne i32 [[PROL_ITER_SUB]], 0
31; CHECK-NEXT:    br i1 [[PROL_ITER_CMP]], label [[LOOP_PROL]], label [[LOOP_PROL_LOOPEXIT_UNR_LCSSA:%.*]], !llvm.loop [[LOOP0:![0-9]+]]
32; CHECK:       loop.prol.loopexit.unr-lcssa:
33; CHECK-NEXT:    [[I_UNR_PH:%.*]] = phi i32 [ [[I_INC_PROL]], [[LATCH_PROL]] ]
34; CHECK-NEXT:    br label [[LOOP_PROL_LOOPEXIT]]
35; CHECK:       loop.prol.loopexit:
36; CHECK-NEXT:    [[I_UNR:%.*]] = phi i32 [ [[S]], [[ENTRY:%.*]] ], [ [[I_UNR_PH]], [[LOOP_PROL_LOOPEXIT_UNR_LCSSA]] ]
37; CHECK-NEXT:    [[TMP3:%.*]] = icmp ult i32 [[TMP2]], 7
38; CHECK-NEXT:    br i1 [[TMP3]], label [[EXIT2:%.*]], label [[ENTRY_NEW:%.*]]
39; CHECK:       entry.new:
40; CHECK-NEXT:    br label [[LOOP:%.*]]
41; CHECK:       loop:
42; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[I_UNR]], [[ENTRY_NEW]] ], [ [[I_INC_7:%.*]], [[LATCH_7:%.*]] ]
43; CHECK-NEXT:    [[C1:%.*]] = icmp eq i32 [[I]], [[N2]]
44; CHECK-NEXT:    br i1 [[C1]], label [[EXIT1_LOOPEXIT:%.*]], label [[LATCH:%.*]]
45; CHECK:       latch:
46; CHECK-NEXT:    [[I_INC:%.*]] = add i32 [[I]], 1
47; CHECK-NEXT:    [[C1_1:%.*]] = icmp eq i32 [[I_INC]], [[N2]]
48; CHECK-NEXT:    br i1 [[C1_1]], label [[EXIT1_LOOPEXIT]], label [[LATCH_1:%.*]]
49; CHECK:       exit1.loopexit:
50; CHECK-NEXT:    br label [[EXIT1:%.*]]
51; CHECK:       exit1.loopexit1:
52; CHECK-NEXT:    br label [[EXIT1]]
53; CHECK:       exit1:
54; CHECK-NEXT:    ret void
55; CHECK:       exit2.unr-lcssa:
56; CHECK-NEXT:    br label [[EXIT2]]
57; CHECK:       exit2:
58; CHECK-NEXT:    ret void
59; CHECK:       latch.1:
60; CHECK-NEXT:    [[I_INC_1:%.*]] = add i32 [[I_INC]], 1
61; CHECK-NEXT:    [[C1_2:%.*]] = icmp eq i32 [[I_INC_1]], [[N2]]
62; CHECK-NEXT:    br i1 [[C1_2]], label [[EXIT1_LOOPEXIT]], label [[LATCH_2:%.*]]
63; CHECK:       latch.2:
64; CHECK-NEXT:    [[I_INC_2:%.*]] = add i32 [[I_INC_1]], 1
65; CHECK-NEXT:    [[C1_3:%.*]] = icmp eq i32 [[I_INC_2]], [[N2]]
66; CHECK-NEXT:    br i1 [[C1_3]], label [[EXIT1_LOOPEXIT]], label [[LATCH_3:%.*]]
67; CHECK:       latch.3:
68; CHECK-NEXT:    [[I_INC_3:%.*]] = add i32 [[I_INC_2]], 1
69; CHECK-NEXT:    [[C1_4:%.*]] = icmp eq i32 [[I_INC_3]], [[N2]]
70; CHECK-NEXT:    br i1 [[C1_4]], label [[EXIT1_LOOPEXIT]], label [[LATCH_4:%.*]]
71; CHECK:       latch.4:
72; CHECK-NEXT:    [[I_INC_4:%.*]] = add i32 [[I_INC_3]], 1
73; CHECK-NEXT:    [[C1_5:%.*]] = icmp eq i32 [[I_INC_4]], [[N2]]
74; CHECK-NEXT:    br i1 [[C1_5]], label [[EXIT1_LOOPEXIT]], label [[LATCH_5:%.*]]
75; CHECK:       latch.5:
76; CHECK-NEXT:    [[I_INC_5:%.*]] = add i32 [[I_INC_4]], 1
77; CHECK-NEXT:    [[C1_6:%.*]] = icmp eq i32 [[I_INC_5]], [[N2]]
78; CHECK-NEXT:    br i1 [[C1_6]], label [[EXIT1_LOOPEXIT]], label [[LATCH_6:%.*]]
79; CHECK:       latch.6:
80; CHECK-NEXT:    [[I_INC_6:%.*]] = add i32 [[I_INC_5]], 1
81; CHECK-NEXT:    [[C1_7:%.*]] = icmp eq i32 [[I_INC_6]], [[N2]]
82; CHECK-NEXT:    br i1 [[C1_7]], label [[EXIT1_LOOPEXIT]], label [[LATCH_7]]
83; CHECK:       latch.7:
84; CHECK-NEXT:    [[C2_7:%.*]] = icmp eq i32 [[I_INC_6]], [[N]]
85; CHECK-NEXT:    [[I_INC_7]] = add i32 [[I_INC_6]], 1
86; CHECK-NEXT:    br i1 [[C2_7]], label [[EXIT2_UNR_LCSSA:%.*]], label [[LOOP]]
87;
88entry:
89  %n2 = add i32 %s, 123
90  br label %loop
91
92loop:
93  %i = phi i32 [ %s, %entry], [ %i.inc, %latch ]
94  %c1 = icmp eq i32 %i, %n2
95  br i1 %c1, label %exit1, label %latch
96
97latch:
98  %c2 = icmp eq i32 %i, %n
99  %i.inc = add i32 %i, 1
100  br i1 %c2, label %exit2, label %loop
101
102exit1:
103  ret void
104
105exit2:
106  ret void
107}
108