xref: /llvm-project/llvm/test/Transforms/LoopInterchange/outer-header-jump-to-inner-latch.ll (revision 456ec1c2f4e487de235c953e8f2832b97372e7b0)
1; Remove 'S' Scalar Dependencies #119345
2; Scalar dependencies are not handled correctly, so they were removed to avoid
3; miscompiles. The loop nest in this test case used to be interchanged, but it's
4; no longer triggering. XFAIL'ing this test to indicate that this test should
5; interchanged if scalar deps are handled correctly.
6;
7; XFAIL: *
8
9; RUN: opt -passes=loop-interchange -cache-line-size=64 -verify-dom-info -verify-loop-info -verify-loop-lcssa %s -pass-remarks-output=%t -disable-output
10; RUN: FileCheck -input-file %t %s
11
12@b = global [3 x [5 x [8 x i16]]] [[5 x [8 x i16]] zeroinitializer, [5 x [8 x i16]] [[8 x i16] zeroinitializer, [8 x i16] [i16 0, i16 0, i16 0, i16 6, i16 1, i16 6, i16 0, i16 0], [8 x i16] zeroinitializer, [8 x i16] zeroinitializer, [8 x i16] zeroinitializer], [5 x [8 x i16]] zeroinitializer], align 2
13@a = common global i32 0, align 4
14@d = common dso_local local_unnamed_addr global [1 x [6 x i32]] zeroinitializer, align 4
15
16
17;  Doubly nested loop
18;; C test case:
19;; int a;
20;; short b[3][5][8] = {{}, {{}, 0, 0, 0, 6, 1, 6}};
21;; void test1() {
22;;   int c = 0, d;
23;;   for (; c <= 2; c++) {
24;;     if (c)
25;;       continue;
26;;     d = 0;
27;;     for (; d <= 2; d++)
28;;       a |= b[d][d][c + 5];
29;;   }
30;; }
31;
32; CHECK:       --- !Passed
33; CHECK-NEXT:  Pass:            loop-interchange
34; CHECK-NEXT:  Name:            Interchanged
35; CHECK-NEXT:  Function:        test1
36; CHECK-NEXT:  Args:
37; CHECK-NEXT:    - String:          Loop interchanged with enclosing loop.
38; CHECK-NEXT:  ...
39;
40define void @test1() {
41entry:
42  br label %for.body
43
44for.body:                                         ; preds = %entry, %for.inc8
45  %indvars.iv22 = phi i64 [ 0, %entry ], [ %indvars.iv.next23, %for.inc8 ]
46  %tobool = icmp eq i64 %indvars.iv22, 0
47  br i1 %tobool, label %for.cond1.preheader, label %for.inc8
48
49for.cond1.preheader:                              ; preds = %for.body
50  br label %for.body3
51
52for.body3:                                        ; preds = %for.cond1.preheader, %for.body3
53  %indvars.iv = phi i64 [ 0, %for.cond1.preheader ], [ %indvars.iv.next, %for.body3 ]
54  %0 = add nuw nsw i64 %indvars.iv22, 5
55  %arrayidx7 = getelementptr inbounds [3 x [5 x [8 x i16]]], ptr @b, i64 0, i64 %indvars.iv, i64 %indvars.iv, i64 %0
56  %1 = load i16, ptr %arrayidx7
57  %conv = sext i16 %1 to i32
58  %2 = load i32, ptr @a
59  %or = or i32 %2, %conv
60  store i32 %or, ptr @a
61  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
62  %exitcond = icmp ne i64 %indvars.iv.next, 3
63  br i1 %exitcond, label %for.body3, label %for.inc8.loopexit
64
65for.inc8.loopexit:                                ; preds = %for.body3
66  br label %for.inc8
67
68for.inc8:                                         ; preds = %for.inc8.loopexit, %for.body
69  %indvars.iv.next23 = add nuw nsw i64 %indvars.iv22, 1
70  %exitcond25 = icmp ne i64 %indvars.iv.next23, 3
71  br i1 %exitcond25, label %for.body, label %for.end10
72
73for.end10:                                        ; preds = %for.inc8
74  %3 = load i32, ptr @a
75  ret void
76}
77
78; Triply nested loop
79; The innermost and the middle loop are interchanged.
80; C test case:
81;
82;; a;
83;; d[][6];
84;; void test2() {
85;;   int g = 10;
86;;   for (; g; g = g - 5) {
87;;     short c = 4;
88;;     for (; c; c--) {
89;;       int i = 4;
90;;       for (; i; i--) {
91;;         if (a)
92;;           break;
93;;         d[i][c] = 0;
94;;       }
95;;     }
96;;   }
97;; }
98;
99; CHECK:       --- !Passed
100; CHECK-NEXT:  Pass:            loop-interchange
101; CHECK-NEXT:  Name:            Interchanged
102; CHECK-NEXT:  Function:        test2
103; CHECK-NEXT:  Args:
104; CHECK-NEXT:    - String:          Loop interchanged with enclosing loop.
105; CHECK-NEXT:  ...
106;
107define void @test2() {
108entry:
109  br label %outermost.header
110
111outermost.header:                      ; preds = %outermost.latch, %entry
112  %indvar.outermost = phi i32 [ 10, %entry ], [ %indvar.outermost.next, %outermost.latch ]
113  %0 = load i32, ptr @a, align 4
114  %tobool71.i = icmp eq i32 %0, 0
115  br label %middle.header
116
117middle.header:                            ; preds = %middle.latch, %outermost.header
118  %indvar.middle = phi i64 [ 4, %outermost.header ], [ %indvar.middle.next, %middle.latch ]
119  br i1 %tobool71.i, label %innermost.preheader, label %middle.latch
120
121innermost.preheader:                               ; preds = %middle.header
122  br label %innermost.body
123
124innermost.body:                                         ; preds = %innermost.preheader, %innermost.body
125  %indvar.innermost = phi i64 [ %indvar.innermost.next, %innermost.body ], [ 4, %innermost.preheader ]
126  %arrayidx9.i = getelementptr inbounds [1 x [6 x i32]], ptr @d, i64 0, i64 %indvar.innermost, i64 %indvar.middle
127  store i32 0, ptr %arrayidx9.i, align 4
128  %indvar.innermost.next = add nsw i64 %indvar.innermost, -1
129  %tobool5.i = icmp eq i64 %indvar.innermost.next, 0
130  br i1 %tobool5.i, label %innermost.loopexit, label %innermost.body
131
132innermost.loopexit:                             ; preds = %innermost.body
133  br label %middle.latch
134
135middle.latch:                                      ; preds = %middle.latch.loopexit, %middle.header
136  %indvar.middle.next = add nsw i64 %indvar.middle, -1
137  %tobool2.i = icmp eq i64 %indvar.middle.next, 0
138  br i1 %tobool2.i, label %outermost.latch, label %middle.header
139
140outermost.latch:                                      ; preds = %middle.latch
141  %indvar.outermost.next = add nsw i32 %indvar.outermost, -5
142  %tobool.i = icmp eq i32 %indvar.outermost.next, 0
143  br i1 %tobool.i, label %outermost.exit, label %outermost.header
144
145outermost.exit:                                           ; preds = %outermost.latch
146  ret void
147}
148