xref: /llvm-project/llvm/test/Transforms/LoopInstSimplify/basic.ll (revision 7425179fee9b4ed1ff6d366ee06487f05a1c0ab3)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S %s -passes=loop-instsimplify | FileCheck %s
3; RUN: opt -S %s -passes='loop-mssa(loop-instsimplify)' -verify-memoryssa | FileCheck %s
4
5; Test very basic folding and propagation occurs within a loop body. This should
6; collapse to the loop iteration structure and the LCSSA PHI node.
7define i32 @test1(i32 %n, i32 %x) {
8; CHECK-LABEL: @test1(
9; CHECK-NEXT:  entry:
10; CHECK-NEXT:    br label [[LOOP:%.*]]
11; CHECK:       loop:
12; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_NEXT:%.*]], [[LOOP]] ]
13; CHECK-NEXT:    [[I_NEXT]] = add nsw i32 [[I]], 1
14; CHECK-NEXT:    [[I_CMP:%.*]] = icmp slt i32 [[I_NEXT]], [[N:%.*]]
15; CHECK-NEXT:    br i1 [[I_CMP]], label [[LOOP]], label [[EXIT:%.*]]
16; CHECK:       exit:
17; CHECK-NEXT:    [[X_LCSSA:%.*]] = phi i32 [ [[X:%.*]], [[LOOP]] ]
18; CHECK-NEXT:    ret i32 [[X_LCSSA]]
19;
20entry:
21  br label %loop
22
23loop:
24  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
25  %x.add = add nsw i32 %x, 0
26  %x.sub = sub i32 %x.add, 0
27  %x.and = and i32 %x.sub, -1
28  %i.next = add nsw i32 %i, 1
29  %i.cmp = icmp slt i32 %i.next, %n
30  br i1 %i.cmp, label %loop, label %exit
31
32exit:
33  %x.lcssa = phi i32 [ %x.and, %loop ]
34  ret i32 %x.lcssa
35}
36
37; Test basic loop structure that still has a simplification feed a prior PHI.
38define i32 @test2(i32 %n, i32 %x) {
39; CHECK-LABEL: @test2(
40; CHECK-NEXT:  entry:
41; CHECK-NEXT:    br label [[LOOP:%.*]]
42; CHECK:       loop:
43; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_NEXT:%.*]], [[LOOP]] ]
44; CHECK-NEXT:    [[I_NEXT]] = add nsw i32 [[I]], 1
45; CHECK-NEXT:    [[I_CMP:%.*]] = icmp slt i32 [[I_NEXT]], [[N:%.*]]
46; CHECK-NEXT:    br i1 [[I_CMP]], label [[LOOP]], label [[EXIT:%.*]]
47; CHECK:       exit:
48; CHECK-NEXT:    [[X_LCSSA:%.*]] = phi i32 [ [[X:%.*]], [[LOOP]] ]
49; CHECK-NEXT:    ret i32 [[X_LCSSA]]
50;
51entry:
52  br label %loop
53
54loop:
55  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
56  %x.loop = phi i32 [ %x, %entry ], [ %x.next, %loop ]
57  %x.next = add nsw i32 %x.loop, 0
58  %i.next = add nsw i32 %i, 1
59  %i.cmp = icmp slt i32 %i.next, %n
60  br i1 %i.cmp, label %loop, label %exit
61
62exit:
63  %x.lcssa = phi i32 [ %x.loop, %loop ]
64  ret i32 %x.lcssa
65}
66
67; Test a diamond CFG with inner PHI nodes.
68define i32 @test3(i32 %n, i32 %x) {
69; CHECK-LABEL: @test3(
70; CHECK-NEXT:  entry:
71; CHECK-NEXT:    br label [[LOOP:%.*]]
72; CHECK:       loop:
73; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_NEXT:%.*]], [[LOOP_LATCH:%.*]] ]
74; CHECK-NEXT:    [[X_CMP:%.*]] = icmp slt i32 [[I]], 42
75; CHECK-NEXT:    br i1 [[X_CMP]], label [[LOOP_LHS:%.*]], label [[LOOP_RHS:%.*]]
76; CHECK:       loop.lhs:
77; CHECK-NEXT:    br label [[LOOP_LATCH]]
78; CHECK:       loop.rhs:
79; CHECK-NEXT:    br label [[LOOP_LATCH]]
80; CHECK:       loop.latch:
81; CHECK-NEXT:    [[I_NEXT]] = add nsw i32 [[I]], 1
82; CHECK-NEXT:    [[I_CMP:%.*]] = icmp slt i32 [[I_NEXT]], [[N:%.*]]
83; CHECK-NEXT:    br i1 [[I_CMP]], label [[LOOP]], label [[EXIT:%.*]]
84; CHECK:       exit:
85; CHECK-NEXT:    [[X_LCSSA:%.*]] = phi i32 [ [[X:%.*]], [[LOOP_LATCH]] ]
86; CHECK-NEXT:    ret i32 [[X_LCSSA]]
87;
88entry:
89  br label %loop
90
91loop:
92  %i = phi i32 [ 0, %entry ], [ %i.next, %loop.latch ]
93  %x.loop = phi i32 [ %x, %entry ], [ %x.phi, %loop.latch ]
94  %x.add = add nsw i32 %x.loop, 0
95  %x.cmp = icmp slt i32 %i, 42
96  br i1 %x.cmp, label %loop.lhs, label %loop.rhs
97
98loop.lhs:
99  %x.l.add = add nsw i32 %x.add, 0
100  br label %loop.latch
101
102loop.rhs:
103  %x.r.sub = sub nsw i32 %x.add, 0
104  br label %loop.latch
105
106loop.latch:
107  %x.phi = phi i32 [ %x.l.add, %loop.lhs ], [ %x.r.sub, %loop.rhs ]
108  %i.next = add nsw i32 %i, 1
109  %i.cmp = icmp slt i32 %i.next, %n
110  br i1 %i.cmp, label %loop, label %exit
111
112exit:
113  %x.lcssa = phi i32 [ %x.loop, %loop.latch ]
114  ret i32 %x.lcssa
115}
116
117; Test an inner loop that is only simplified when processing the outer loop, and
118; an outer loop only simplified when processing the inner loop.
119define i32 @test4(i32 %n, i32 %m, i32 %x) {
120; CHECK-LABEL: @test4(
121; CHECK-NEXT:  entry:
122; CHECK-NEXT:    br label [[LOOP:%.*]]
123; CHECK:       loop:
124; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_NEXT:%.*]], [[LOOP_LATCH:%.*]] ]
125; CHECK-NEXT:    br label [[LOOP_INNER:%.*]]
126; CHECK:       loop.inner:
127; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[LOOP]] ], [ [[J_NEXT:%.*]], [[LOOP_INNER]] ]
128; CHECK-NEXT:    [[J_NEXT]] = add nsw i32 [[J]], 1
129; CHECK-NEXT:    [[J_CMP:%.*]] = icmp slt i32 [[J_NEXT]], [[M:%.*]]
130; CHECK-NEXT:    br i1 [[J_CMP]], label [[LOOP_INNER]], label [[LOOP_LATCH]]
131; CHECK:       loop.latch:
132; CHECK-NEXT:    [[I_NEXT]] = add nsw i32 [[I]], 1
133; CHECK-NEXT:    [[I_CMP:%.*]] = icmp slt i32 [[I_NEXT]], [[N:%.*]]
134; CHECK-NEXT:    br i1 [[I_CMP]], label [[LOOP]], label [[EXIT:%.*]]
135; CHECK:       exit:
136; CHECK-NEXT:    [[X_LCSSA:%.*]] = phi i32 [ [[X:%.*]], [[LOOP_LATCH]] ]
137; CHECK-NEXT:    ret i32 [[X_LCSSA]]
138;
139entry:
140  br label %loop
141
142loop:
143  %i = phi i32 [ 0, %entry ], [ %i.next, %loop.latch ]
144  %x.loop = phi i32 [ %x, %entry ], [ %x.inner.lcssa, %loop.latch ]
145  %x.add = add nsw i32 %x.loop, 0
146  br label %loop.inner
147
148loop.inner:
149  %j = phi i32 [ 0, %loop ], [ %j.next, %loop.inner ]
150  %x.inner.loop = phi i32 [ %x.add, %loop ], [ %x.inner.add, %loop.inner ]
151  %x.inner.add = add nsw i32 %x.inner.loop, 0
152  %j.next = add nsw i32 %j, 1
153  %j.cmp = icmp slt i32 %j.next, %m
154  br i1 %j.cmp, label %loop.inner, label %loop.latch
155
156loop.latch:
157  %x.inner.lcssa = phi i32 [ %x.inner.loop, %loop.inner ]
158  %i.next = add nsw i32 %i, 1
159  %i.cmp = icmp slt i32 %i.next, %n
160  br i1 %i.cmp, label %loop, label %exit
161
162exit:
163  %x.lcssa = phi i32 [ %x.loop, %loop.latch ]
164  ret i32 %x.lcssa
165}
166