1; RUN: opt -S -loop-fusion < %s | FileCheck %s
2;
3;    int A[1024][1024];
4;    int B[1024][1024];
5;
6;    #define EXPENSIVE_PURE_COMPUTATION(i) ((i - 3) * (i + 3) % i)
7;
8;    void dep_free() {
9;
10;      for (int i = 0; i < 100; i++)
11;        for (int j = 0; j < 100; j++)
12;          A[i][j] = EXPENSIVE_PURE_COMPUTATION(i);
13;
14;      for (int i = 0; i < 100; i++)
15;        for (int j = 0; j < 100; j++)
16;          B[i][j] = EXPENSIVE_PURE_COMPUTATION(i);
17;    }
18;
19@A = common global [1024 x [1024 x i32]] zeroinitializer, align 16
20@B = common global [1024 x [1024 x i32]] zeroinitializer, align 16
21
22; CHECK: void @dep_free
23; CHECK-NEXT: bb:
24; CHECK-NEXT: br label %[[LOOP1HEADER:bb[0-9]+]]
25; CHECK: [[LOOP1HEADER]]
26; CHECK: br i1 %exitcond12, label %[[LOOP3PREHEADER:bb[0-9]+.preheader]], label %[[LOOP2HEADER:bb[0-9]+]]
27; CHECK: [[LOOP3PREHEADER]]
28; CHECK: br label %[[LOOP3HEADER:bb[0-9]+]]
29; CHECK: [[LOOP3HEADER]]
30; CHECK: br i1 %exitcond9, label %[[LOOP3BODY:bb[0-9]+]], label %[[LOOP1LATCH:bb[0-9]+]]
31; CHECK: [[LOOP1LATCH]]
32; CHECK: br label %[[LOOP2HEADER:bb[0-9]+]]
33; CHECK: [[LOOP2HEADER]]
34; CHECK: br i1 %exitcond6, label %[[LOOP4PREHEADER:bb[0-9]+.preheader]], label %[[LOOP2EXITBLOCK:bb[0-9]+]]
35; CHECK: [[LOOP4PREHEADER]]
36; CHECK: br label %[[LOOP4HEADER:bb[0-9]+]]
37; CHECK: [[LOOP2EXITBLOCK]]
38; CHECK-NEXT: br label %[[FUNCEXIT:bb[0-9]+]]
39; CHECK: [[LOOP4HEADER]]
40; CHECK: br i1 %exitcond, label %[[LOOP4BODY:bb[0-9]+]], label %[[LOOP2LATCH:bb[0-9]+]]
41; CHECK: [[LOOP2LATCH]]
42; CHECK: br label %[[LOOP1HEADER:bb[0-9]+]]
43; CHECK: [[FUNCEXIT]]
44; CHECK: ret void
45
46; TODO: The current version of loop fusion does not allow the inner loops to be
47; fused because they are not control flow equivalent and adjacent. These are
48; limitations that can be addressed in future improvements to fusion.
49define void @dep_free() {
50bb:
51  br label %bb13
52
53bb13:                                             ; preds = %bb27, %bb
54  %indvars.iv10 = phi i64 [ %indvars.iv.next11, %bb27 ], [ 0, %bb ]
55  %.0 = phi i32 [ 0, %bb ], [ %tmp28, %bb27 ]
56  %exitcond12 = icmp ne i64 %indvars.iv10, 100
57  br i1 %exitcond12, label %bb16, label %bb30
58
59bb16:                                             ; preds = %bb25, %bb13
60  %indvars.iv7 = phi i64 [ %indvars.iv.next8, %bb25 ], [ 0, %bb13 ]
61  %exitcond9 = icmp ne i64 %indvars.iv7, 100
62  br i1 %exitcond9, label %bb18, label %bb27
63
64bb18:                                             ; preds = %bb16
65  %tmp = add nsw i32 %.0, -3
66  %tmp19 = add nuw nsw i64 %indvars.iv10, 3
67  %tmp20 = trunc i64 %tmp19 to i32
68  %tmp21 = mul nsw i32 %tmp, %tmp20
69  %tmp22 = trunc i64 %indvars.iv10 to i32
70  %tmp23 = srem i32 %tmp21, %tmp22
71  %tmp24 = getelementptr inbounds [1024 x [1024 x i32]], [1024 x [1024 x i32]]* @A, i64 0, i64 %indvars.iv10, i64 %indvars.iv7
72  store i32 %tmp23, i32* %tmp24, align 4
73  br label %bb25
74
75bb25:                                             ; preds = %bb18
76  %indvars.iv.next8 = add nuw nsw i64 %indvars.iv7, 1
77  br label %bb16
78
79bb27:                                             ; preds = %bb16
80  %indvars.iv.next11 = add nuw nsw i64 %indvars.iv10, 1
81  %tmp28 = add nuw nsw i32 %.0, 1
82  br label %bb13
83
84bb30:                                             ; preds = %bb45, %bb13
85  %indvars.iv4 = phi i64 [ %indvars.iv.next5, %bb45 ], [ 0, %bb13 ]
86  %.02 = phi i32 [ 0, %bb13 ], [ %tmp46, %bb45 ]
87  %exitcond6 = icmp ne i64 %indvars.iv4, 100
88  br i1 %exitcond6, label %bb33, label %bb31
89
90bb31:                                             ; preds = %bb30
91  br label %bb47
92
93bb33:                                             ; preds = %bb43, %bb30
94  %indvars.iv = phi i64 [ %indvars.iv.next, %bb43 ], [ 0, %bb30 ]
95  %exitcond = icmp ne i64 %indvars.iv, 100
96  br i1 %exitcond, label %bb35, label %bb45
97
98bb35:                                             ; preds = %bb33
99  %tmp36 = add nsw i32 %.02, -3
100  %tmp37 = add nuw nsw i64 %indvars.iv4, 3
101  %tmp38 = trunc i64 %tmp37 to i32
102  %tmp39 = mul nsw i32 %tmp36, %tmp38
103  %tmp40 = trunc i64 %indvars.iv4 to i32
104  %tmp41 = srem i32 %tmp39, %tmp40
105  %tmp42 = getelementptr inbounds [1024 x [1024 x i32]], [1024 x [1024 x i32]]* @B, i64 0, i64 %indvars.iv4, i64 %indvars.iv
106  store i32 %tmp41, i32* %tmp42, align 4
107  br label %bb43
108
109bb43:                                             ; preds = %bb35
110  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
111  br label %bb33
112
113bb45:                                             ; preds = %bb33
114  %indvars.iv.next5 = add nuw nsw i64 %indvars.iv4, 1
115  %tmp46 = add nuw nsw i32 %.02, 1
116  br label %bb30
117
118bb47:                                             ; preds = %bb31
119  ret void
120}
121