flang/test/Lower/infinite_loop.f90

   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 -flang-experimental-integer-overflow -o - %s | FileCheck %s --check-prefix=NSW
   4
   5 ! Tests for infinite loop.
   6
   7 subroutine empty_infinite()
   8   do
   9   end do
  10 end subroutine
  11 ! CHECK-LABEL: empty_infinite
  12 ! CHECK:  cf.br ^[[BODY:.*]]
  13 ! CHECK: ^[[BODY]]:
  14 ! CHECK:  cf.br ^[[BODY]]
  15
  16 subroutine simple_infinite(i)
  17   integer :: i
  18   do
  19     if (i .gt. 100) exit
  20   end do
  21 end subroutine
  22 ! CHECK-LABEL: simple_infinite
  23 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
  24 ! CHECK:  cf.br ^[[BODY1:.*]]
  25 ! CHECK: ^[[BODY1]]:
  26 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  27 ! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
  28 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
  29 ! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY1:.*]]
  30 ! CHECK: ^[[EXIT]]:
  31 ! CHECK:  cf.br ^[[RETURN:.*]]
  32 ! CHECK: ^[[RETURN]]:
  33 ! CHECK:   return
  34 ! CHECK: }
  35
  36 subroutine infinite_with_two_body_blocks(i)
  37   integer :: i
  38   do
  39     i = i + 1
  40     if (i .gt. 100) exit
  41     i = i * 2
  42   end do
  43 end subroutine
  44 ! CHECK-LABEL: infinite_with_two_body_blocks
  45 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
  46 ! CHECK:  cf.br ^[[BODY1:.*]]
  47 ! CHECK: ^[[BODY1]]:
  48 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  49 ! CHECK:  %[[C1:.*]] = arith.constant 1 : i32
  50 ! CHECK:  %[[I_NEXT:.*]] = arith.addi %[[I]], %[[C1]] : i32
  51 ! CHECK:  fir.store %[[I_NEXT]] to %[[I_REF]] : !fir.ref<i32>
  52 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  53 ! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
  54 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
  55 ! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
  56 ! CHECK: ^[[EXIT]]:
  57 ! CHECK:  cf.br ^[[RETURN:.*]]
  58 ! CHECK: ^[[BODY2]]:
  59 ! CHECK:  %[[C2:.*]] = arith.constant 2 : i32
  60 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  61 ! CHECK:  %[[I_NEXT:.*]] = arith.muli %[[C2]], %[[I]] : i32
  62 ! CHECK:  fir.store %[[I_NEXT]] to %[[I_REF]] : !fir.ref<i32>
  63 ! CHECK:  cf.br ^[[BODY1]]
  64 ! CHECK: ^[[RETURN]]:
  65 ! CHECK:   return
  66 ! CHECK: }
  67
  68 subroutine structured_loop_in_infinite(i)
  69   integer :: i
  70   integer :: j
  71   do
  72     if (i .gt. 100) exit
  73     do j=1,10
  74     end do
  75   end do
  76 end subroutine
  77 ! CHECK-LABEL: structured_loop_in_infinite
  78 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
  79 ! CHECK:  %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFstructured_loop_in_infiniteEj"}
  80 ! CHECK:  cf.br ^[[BODY1:.*]]
  81 ! CHECK: ^[[BODY1]]:
  82 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  83 ! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
  84 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
  85 ! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
  86 ! CHECK: ^[[EXIT]]:
  87 ! CHECK:  cf.br ^[[RETURN:.*]]
  88 ! CHECK: ^[[BODY2:.*]]:
  89 ! CHECK:  %[[C1:.*]] = arith.constant 1 : i32
  90 ! CHECK:  %[[C1_INDEX:.*]] = fir.convert %[[C1]] : (i32) -> index
  91 ! CHECK:  %[[C10:.*]] = arith.constant 10 : i32
  92 ! CHECK:  %[[C10_INDEX:.*]] = fir.convert %[[C10]] : (i32) -> index
  93 ! CHECK:  %[[C1_1:.*]] = arith.constant 1 : index
  94 ! CHECK:  %[[J_LB:.*]] = fir.convert %[[C1_INDEX]] : (index) -> i32
  95 ! CHECK:  %[[J_FINAL:.*]]:2 = fir.do_loop %[[J:[^ ]*]] =
  96 ! CHECK-SAME: %[[C1_INDEX]] to %[[C10_INDEX]] step %[[C1_1]]
  97 ! CHECK-SAME: iter_args(%[[J_IV:.*]] = %[[J_LB]]) -> (index, i32) {
  98 ! CHECK:    fir.store %[[J_IV]] to %[[J_REF]] : !fir.ref<i32>
  99 ! CHECK:    %[[J_NEXT:.*]] = arith.addi %[[J]], %[[C1_1]] : index
 100 ! CHECK:    %[[J_STEPCAST:.*]] = fir.convert %[[C1_1]] : (index) -> i32
 101 ! CHECK:    %[[J_IVLOAD:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
 102 ! CHECK:    %[[J_IVINC:.*]] = arith.addi %[[J_IVLOAD]], %[[J_STEPCAST]] : i32
 103 ! CHECK:    fir.result %[[J_NEXT]], %[[J_IVINC]] : index, i32
 104 ! CHECK:  }
 105 ! CHECK:  fir.store %[[J_FINAL]]#1 to %[[J_REF]] : !fir.ref<i32>
 106 ! CHECK:  cf.br ^[[BODY1]]
 107 ! CHECK: ^[[RETURN]]:
 108 ! CHECK:   return
 109
 110 ! NSW-LABEL: structured_loop_in_infinite
 111 ! NSW-SAME: %[[I_REF:.*]]: !fir.ref<i32>
 112 ! NSW:  %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFstructured_loop_in_infiniteEj"}
 113 ! NSW:  cf.br ^[[BODY1:.*]]
 114 ! NSW: ^[[BODY1]]:
 115 ! NSW:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
 116 ! NSW:  %[[C100:.*]] = arith.constant 100 : i32
 117 ! NSW:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
 118 ! NSW:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
 119 ! NSW: ^[[EXIT]]:
 120 ! NSW:  cf.br ^[[RETURN:.*]]
 121 ! NSW: ^[[BODY2:.*]]:
 122 ! NSW:  %[[C1:.*]] = arith.constant 1 : i32
 123 ! NSW:  %[[C1_INDEX:.*]] = fir.convert %[[C1]] : (i32) -> index
 124 ! NSW:  %[[C10:.*]] = arith.constant 10 : i32
 125 ! NSW:  %[[C10_INDEX:.*]] = fir.convert %[[C10]] : (i32) -> index
 126 ! NSW:  %[[C1_1:.*]] = arith.constant 1 : index
 127 ! NSW:  %[[J_LB:.*]] = fir.convert %[[C1_INDEX]] : (index) -> i32
 128 ! NSW:  %[[J_FINAL:.*]]:2 = fir.do_loop %[[J:[^ ]*]] =
 129 ! NSW-SAME: %[[C1_INDEX]] to %[[C10_INDEX]] step %[[C1_1]]
 130 ! NSW-SAME: iter_args(%[[J_IV:.*]] = %[[J_LB]]) -> (index, i32) {
 131 ! NSW:    fir.store %[[J_IV]] to %[[J_REF]] : !fir.ref<i32>
 132 ! NSW:    %[[J_NEXT:.*]] = arith.addi %[[J]], %[[C1_1]] overflow<nsw> : index
 133 ! NSW:    %[[J_STEPCAST:.*]] = fir.convert %[[C1_1]] : (index) -> i32
 134 ! NSW:    %[[J_IVLOAD:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
 135 ! NSW:    %[[J_IVINC:.*]] = arith.addi %[[J_IVLOAD]], %[[J_STEPCAST]] overflow<nsw> : i32
 136 ! NSW:    fir.result %[[J_NEXT]], %[[J_IVINC]] : index, i32
 137 ! NSW:  }
 138 ! NSW:  fir.store %[[J_FINAL]]#1 to %[[J_REF]] : !fir.ref<i32>
 139 ! NSW:  cf.br ^[[BODY1]]
 140 ! NSW: ^[[RETURN]]:
 141 ! NSW:   return
 142
 143 subroutine empty_infinite_in_while(i)
 144   integer :: i
 145   do while (i .gt. 50)
 146     do
 147     end do
 148   end do
 149 end subroutine
 150
 151 ! CHECK-LABEL: empty_infinite_in_while
 152 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
 153 ! CHECK:  cf.br ^bb1
 154 ! CHECK: ^bb1:
 155 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
 156 ! CHECK:  %[[C50:.*]] = arith.constant 50 : i32
 157 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C50]] : i32
 158 ! CHECK:  cf.cond_br %[[COND]], ^[[INF_HEADER:.*]], ^[[EXIT:.*]]
 159 ! CHECK: ^[[INF_HEADER]]:
 160 ! CHECK:   cf.br ^[[INF_BODY:.*]]
 161 ! CHECK: ^[[INF_BODY]]:
 162 ! CHECK:   cf.br ^[[INF_HEADER]]
 163 ! CHECK: ^[[EXIT]]:
 164 ! CHECK:  return