1; This test verifies that the loop vectorizer will not vectorizes low trip count
2; loops that require runtime checks (Trip count is computed with profile info).
3; REQUIRES: asserts
4; RUN: opt < %s -loop-vectorize -loop-vectorize-with-block-frequency -S | FileCheck %s
5
6target datalayout = "E-m:e-p:32:32-i64:32-f64:32:64-a:0:32-n32-S128"
7
8@tab = common global [32 x i8] zeroinitializer, align 1
9
10define i32 @foo_low_trip_count1(i32 %bound) {
11; Simple loop with low tripcount. Should not be vectorized.
12
13; CHECK-LABEL: @foo_low_trip_count1(
14; CHECK-NOT: <{{[0-9]+}} x i8>
15
16entry:
17  br label %for.body
18
19for.body:                                         ; preds = %for.body, %entry
20  %i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
21  %arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
22  %0 = load i8, i8* %arrayidx, align 1
23  %cmp1 = icmp eq i8 %0, 0
24  %. = select i1 %cmp1, i8 2, i8 1
25  store i8 %., i8* %arrayidx, align 1
26  %inc = add nsw i32 %i.08, 1
27  %exitcond = icmp eq i32 %i.08, %bound
28  br i1 %exitcond, label %for.end, label %for.body, !prof !1
29
30for.end:                                          ; preds = %for.body
31  ret i32 0
32}
33
34define i32 @foo_low_trip_count2(i32 %bound) !prof !0 {
35; The loop has a same invocation count with the function, but has a low
36; trip_count per invocation and not worth to vectorize.
37
38; CHECK-LABEL: @foo_low_trip_count2(
39; CHECK-NOT: <{{[0-9]+}} x i8>
40
41entry:
42  br label %for.body
43
44for.body:                                         ; preds = %for.body, %entry
45  %i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
46  %arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
47  %0 = load i8, i8* %arrayidx, align 1
48  %cmp1 = icmp eq i8 %0, 0
49  %. = select i1 %cmp1, i8 2, i8 1
50  store i8 %., i8* %arrayidx, align 1
51  %inc = add nsw i32 %i.08, 1
52  %exitcond = icmp eq i32 %i.08, %bound
53  br i1 %exitcond, label %for.end, label %for.body, !prof !1
54
55for.end:                                          ; preds = %for.body
56  ret i32 0
57}
58
59define i32 @foo_low_trip_count3(i1 %cond, i32 %bound) !prof !0 {
60; The loop has low invocation count compare to the function invocation count,
61; but has a high trip count per invocation. Vectorize it.
62
63; CHECK-LABEL: @foo_low_trip_count3(
64; CHECK: vector.body:
65
66entry:
67  br i1 %cond, label %for.preheader, label %for.end, !prof !2
68
69for.preheader:
70  br label %for.body
71
72for.body:                                         ; preds = %for.body, %entry
73  %i.08 = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]
74  %arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
75  %0 = load i8, i8* %arrayidx, align 1
76  %cmp1 = icmp eq i8 %0, 0
77  %. = select i1 %cmp1, i8 2, i8 1
78  store i8 %., i8* %arrayidx, align 1
79  %inc = add nsw i32 %i.08, 1
80  %exitcond = icmp eq i32 %i.08, %bound
81  br i1 %exitcond, label %for.end, label %for.body, !prof !3
82
83for.end:                                          ; preds = %for.body
84  ret i32 0
85}
86
87
88!0 = !{!"function_entry_count", i64 100}
89!1 = !{!"branch_weights", i32 100, i32 0}
90!2 = !{!"branch_weights", i32 10, i32 90}
91!3 = !{!"branch_weights", i32 10, i32 10000}
92