1; RUN: opt < %s -S -loop-unroll -unroll-runtime=true | FileCheck %s
2
3; Tests for unrolling loops with run-time trip counts
4
5; CHECK: %xtraiter = and i32 %n
6; CHECK:  %lcmp.mod = icmp ne i32 %xtraiter, 0
7; CHECK:  br i1 %lcmp.mod, label %for.body.prol, label %for.body.preheader.split
8
9; CHECK: for.body.prol:
10; CHECK: %indvars.iv.prol = phi i64 [ %indvars.iv.next.prol, %for.body.prol ], [ 0, %for.body.preheader ]
11; CHECK:  %prol.iter.sub = sub i32 %prol.iter, 1
12; CHECK:  %prol.iter.cmp = icmp ne i32 %prol.iter.sub, 0
13; CHECK:  br i1 %prol.iter.cmp, label %for.body.prol, label %for.body.preheader.split, !llvm.loop !0
14
15define i32 @test(i32* nocapture %a, i32 %n) nounwind uwtable readonly {
16entry:
17  %cmp1 = icmp eq i32 %n, 0
18  br i1 %cmp1, label %for.end, label %for.body
19
20for.body:                                         ; preds = %for.body, %entry
21  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
22  %sum.02 = phi i32 [ %add, %for.body ], [ 0, %entry ]
23  %arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
24  %0 = load i32* %arrayidx, align 4
25  %add = add nsw i32 %0, %sum.02
26  %indvars.iv.next = add i64 %indvars.iv, 1
27  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
28  %exitcond = icmp eq i32 %lftr.wideiv, %n
29  br i1 %exitcond, label %for.end, label %for.body
30
31for.end:                                          ; preds = %for.body, %entry
32  %sum.0.lcssa = phi i32 [ 0, %entry ], [ %add, %for.body ]
33  ret i32 %sum.0.lcssa
34}
35
36
37; Still try to completely unroll loops with compile-time trip counts
38; even if the -unroll-runtime is specified
39
40; CHECK: for.body:
41; CHECK-NOT: for.body.prol:
42
43define i32 @test1(i32* nocapture %a) nounwind uwtable readonly {
44entry:
45  br label %for.body
46
47for.body:                                         ; preds = %for.body, %entry
48  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
49  %sum.01 = phi i32 [ 0, %entry ], [ %add, %for.body ]
50  %arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
51  %0 = load i32* %arrayidx, align 4
52  %add = add nsw i32 %0, %sum.01
53  %indvars.iv.next = add i64 %indvars.iv, 1
54  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
55  %exitcond = icmp eq i32 %lftr.wideiv, 5
56  br i1 %exitcond, label %for.end, label %for.body
57
58for.end:                                          ; preds = %for.body
59  ret i32 %add
60}
61
62; This is test 2007-05-09-UnknownTripCount.ll which can be unrolled now
63; if the -unroll-runtime option is turned on
64
65; CHECK: bb72.2:
66
67define void @foo(i32 %trips) {
68entry:
69        br label %cond_true.outer
70
71cond_true.outer:
72        %indvar1.ph = phi i32 [ 0, %entry ], [ %indvar.next2, %bb72 ]
73        br label %bb72
74
75bb72:
76        %indvar.next2 = add i32 %indvar1.ph, 1
77        %exitcond3 = icmp eq i32 %indvar.next2, %trips
78        br i1 %exitcond3, label %cond_true138, label %cond_true.outer
79
80cond_true138:
81        ret void
82}
83
84
85; Test run-time unrolling for a loop that counts down by -2.
86
87; CHECK: for.body.prol:
88; CHECK: br i1 %prol.iter.cmp, label %for.body.prol, label %for.body.preheader.split
89
90define zeroext i16 @down(i16* nocapture %p, i32 %len) nounwind uwtable readonly {
91entry:
92  %cmp2 = icmp eq i32 %len, 0
93  br i1 %cmp2, label %for.end, label %for.body
94
95for.body:                                         ; preds = %for.body, %entry
96  %p.addr.05 = phi i16* [ %incdec.ptr, %for.body ], [ %p, %entry ]
97  %len.addr.04 = phi i32 [ %sub, %for.body ], [ %len, %entry ]
98  %res.03 = phi i32 [ %add, %for.body ], [ 0, %entry ]
99  %incdec.ptr = getelementptr inbounds i16* %p.addr.05, i64 1
100  %0 = load i16* %p.addr.05, align 2
101  %conv = zext i16 %0 to i32
102  %add = add i32 %conv, %res.03
103  %sub = add nsw i32 %len.addr.04, -2
104  %cmp = icmp eq i32 %sub, 0
105  br i1 %cmp, label %for.cond.for.end_crit_edge, label %for.body
106
107for.cond.for.end_crit_edge:                       ; preds = %for.body
108  %phitmp = trunc i32 %add to i16
109  br label %for.end
110
111for.end:                                          ; preds = %for.cond.for.end_crit_edge, %entry
112  %res.0.lcssa = phi i16 [ %phitmp, %for.cond.for.end_crit_edge ], [ 0, %entry ]
113  ret i16 %res.0.lcssa
114}
115
116; CHECK: !0 = distinct !{!0, !1}
117; CHECK: !1 = !{!"llvm.loop.unroll.disable"}
118
119