xref: /llvm-project/flang/test/Lower/infinite_loop.f90 (revision a88677edc0792534ba3157bf7d7a1b98e470f2fb)
1! RUN: bbc -emit-fir -hlfir=false -o - %s | FileCheck %s
2! RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -o - %s | FileCheck %s
3! RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fwrapv -o - %s | FileCheck %s --check-prefix=NO-NSW
4
5! Tests for infinite loop.
6
7! NO-NSW-NOT: overflow<nsw>
8
9subroutine empty_infinite()
10  do
11  end do
12end subroutine
13! CHECK-LABEL: empty_infinite
14! CHECK:  cf.br ^[[BODY:.*]]
15! CHECK: ^[[BODY]]:
16! CHECK:  cf.br ^[[BODY]]
17
18subroutine simple_infinite(i)
19  integer :: i
20  do
21    if (i .gt. 100) exit
22  end do
23end subroutine
24! CHECK-LABEL: simple_infinite
25! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
26! CHECK:  cf.br ^[[BODY1:.*]]
27! CHECK: ^[[BODY1]]:
28! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
29! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
30! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
31! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY1:.*]]
32! CHECK: ^[[EXIT]]:
33! CHECK:  cf.br ^[[RETURN:.*]]
34! CHECK: ^[[RETURN]]:
35! CHECK:   return
36! CHECK: }
37
38subroutine infinite_with_two_body_blocks(i)
39  integer :: i
40  do
41    i = i + 1
42    if (i .gt. 100) exit
43    i = i * 2
44  end do
45end subroutine
46! CHECK-LABEL: infinite_with_two_body_blocks
47! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
48! CHECK:  cf.br ^[[BODY1:.*]]
49! CHECK: ^[[BODY1]]:
50! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
51! CHECK:  %[[C1:.*]] = arith.constant 1 : i32
52! CHECK:  %[[I_NEXT:.*]] = arith.addi %[[I]], %[[C1]] : i32
53! CHECK:  fir.store %[[I_NEXT]] to %[[I_REF]] : !fir.ref<i32>
54! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
55! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
56! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
57! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
58! CHECK: ^[[EXIT]]:
59! CHECK:  cf.br ^[[RETURN:.*]]
60! CHECK: ^[[BODY2]]:
61! CHECK:  %[[C2:.*]] = arith.constant 2 : i32
62! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
63! CHECK:  %[[I_NEXT:.*]] = arith.muli %[[C2]], %[[I]] : i32
64! CHECK:  fir.store %[[I_NEXT]] to %[[I_REF]] : !fir.ref<i32>
65! CHECK:  cf.br ^[[BODY1]]
66! CHECK: ^[[RETURN]]:
67! CHECK:   return
68! CHECK: }
69
70subroutine structured_loop_in_infinite(i)
71  integer :: i
72  integer :: j
73  do
74    if (i .gt. 100) exit
75    do j=1,10
76    end do
77  end do
78end subroutine
79! CHECK-LABEL: structured_loop_in_infinite
80! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
81! CHECK:  %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFstructured_loop_in_infiniteEj"}
82! CHECK:  cf.br ^[[BODY1:.*]]
83! CHECK: ^[[BODY1]]:
84! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
85! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
86! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
87! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
88! CHECK: ^[[EXIT]]:
89! CHECK:  cf.br ^[[RETURN:.*]]
90! CHECK: ^[[BODY2:.*]]:
91! CHECK:  %[[C1:.*]] = arith.constant 1 : i32
92! CHECK:  %[[C1_INDEX:.*]] = fir.convert %[[C1]] : (i32) -> index
93! CHECK:  %[[C10:.*]] = arith.constant 10 : i32
94! CHECK:  %[[C10_INDEX:.*]] = fir.convert %[[C10]] : (i32) -> index
95! CHECK:  %[[C1_1:.*]] = arith.constant 1 : index
96! CHECK:  %[[J_LB:.*]] = fir.convert %[[C1_INDEX]] : (index) -> i32
97! CHECK:  %[[J_FINAL:.*]]:2 = fir.do_loop %[[J:[^ ]*]] =
98! CHECK-SAME: %[[C1_INDEX]] to %[[C10_INDEX]] step %[[C1_1]]
99! CHECK-SAME: iter_args(%[[J_IV:.*]] = %[[J_LB]]) -> (index, i32) {
100! CHECK:    fir.store %[[J_IV]] to %[[J_REF]] : !fir.ref<i32>
101! CHECK:    %[[J_NEXT:.*]] = arith.addi %[[J]], %[[C1_1]] overflow<nsw> : index
102! CHECK:    %[[J_STEPCAST:.*]] = fir.convert %[[C1_1]] : (index) -> i32
103! CHECK:    %[[J_IVLOAD:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
104! CHECK:    %[[J_IVINC:.*]] = arith.addi %[[J_IVLOAD]], %[[J_STEPCAST]] overflow<nsw> : i32
105! CHECK:    fir.result %[[J_NEXT]], %[[J_IVINC]] : index, i32
106! CHECK:  }
107! CHECK:  fir.store %[[J_FINAL]]#1 to %[[J_REF]] : !fir.ref<i32>
108! CHECK:  cf.br ^[[BODY1]]
109! CHECK: ^[[RETURN]]:
110! CHECK:   return
111
112subroutine empty_infinite_in_while(i)
113  integer :: i
114  do while (i .gt. 50)
115    do
116    end do
117  end do
118end subroutine
119
120! CHECK-LABEL: empty_infinite_in_while
121! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
122! CHECK:  cf.br ^bb1
123! CHECK: ^bb1:
124! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
125! CHECK:  %[[C50:.*]] = arith.constant 50 : i32
126! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C50]] : i32
127! CHECK:  cf.cond_br %[[COND]], ^[[INF_HEADER:.*]], ^[[EXIT:.*]]
128! CHECK: ^[[INF_HEADER]]:
129! CHECK:   cf.br ^[[INF_BODY:.*]]
130! CHECK: ^[[INF_BODY]]:
131! CHECK:   cf.br ^[[INF_HEADER]]
132! CHECK: ^[[EXIT]]:
133! CHECK:  return
134