flang/test/Lower/infinite_loop.f90

   1 ! RUN: bbc -emit-fir -o - %s | FileCheck %s
   2 ! RUN: %flang_fc1 -emit-fir -o - %s | FileCheck %s
   3
   4 ! Tests for infinite loop.
   5
   6 subroutine empty_infinite()
   7   do
   8   end do
   9 end subroutine
  10 ! CHECK-LABEL: empty_infinite
  11 ! CHECK:  cf.br ^[[BODY:.*]]
  12 ! CHECK: ^[[BODY]]:
  13 ! CHECK:  cf.br ^[[BODY]]
  14
  15 subroutine simple_infinite(i)
  16   integer :: i
  17   do
  18     if (i .gt. 100) exit
  19   end do
  20 end subroutine
  21 ! CHECK-LABEL: simple_infinite
  22 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
  23 ! CHECK:  cf.br ^[[BODY1:.*]]
  24 ! CHECK: ^[[BODY1]]:
  25 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  26 ! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
  27 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
  28 ! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY1:.*]]
  29 ! CHECK: ^[[EXIT]]:
  30 ! CHECK:  cf.br ^[[RETURN:.*]]
  31 ! CHECK: ^[[RETURN]]:
  32 ! CHECK:   return
  33 ! CHECK: }
  34
  35 subroutine infinite_with_two_body_blocks(i)
  36   integer :: i
  37   do
  38     i = i + 1
  39     if (i .gt. 100) exit
  40     i = i * 2
  41   end do
  42 end subroutine
  43 ! CHECK-LABEL: infinite_with_two_body_blocks
  44 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
  45 ! CHECK:  cf.br ^[[BODY1:.*]]
  46 ! CHECK: ^[[BODY1]]:
  47 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  48 ! CHECK:  %[[C1:.*]] = arith.constant 1 : i32
  49 ! CHECK:  %[[I_NEXT:.*]] = arith.addi %[[I]], %[[C1]] : i32
  50 ! CHECK:  fir.store %[[I_NEXT]] to %[[I_REF]] : !fir.ref<i32>
  51 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  52 ! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
  53 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
  54 ! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
  55 ! CHECK: ^[[EXIT]]:
  56 ! CHECK:  cf.br ^[[RETURN:.*]]
  57 ! CHECK: ^[[BODY2]]:
  58 ! CHECK:  %[[C2:.*]] = arith.constant 2 : i32
  59 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  60 ! CHECK:  %[[I_NEXT:.*]] = arith.muli %[[C2]], %[[I]] : i32
  61 ! CHECK:  fir.store %[[I_NEXT]] to %[[I_REF]] : !fir.ref<i32>
  62 ! CHECK:  cf.br ^[[BODY1]]
  63 ! CHECK: ^[[RETURN]]:
  64 ! CHECK:   return
  65 ! CHECK: }
  66
  67 subroutine structured_loop_in_infinite(i)
  68   integer :: i
  69   integer :: j
  70   do
  71     if (i .gt. 100) exit
  72     do j=1,10
  73     end do
  74   end do
  75 end subroutine
  76 ! CHECK-LABEL: structured_loop_in_infinite
  77 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
  78 ! CHECK:  %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFstructured_loop_in_infiniteEj"}
  79 ! CHECK:  cf.br ^[[BODY1:.*]]
  80 ! CHECK: ^[[BODY1]]:
  81 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
  82 ! CHECK:  %[[C100:.*]] = arith.constant 100 : i32
  83 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C100]] : i32
  84 ! CHECK:  cf.cond_br %[[COND]], ^[[EXIT:.*]], ^[[BODY2:.*]]
  85 ! CHECK: ^[[EXIT]]:
  86 ! CHECK:  cf.br ^[[RETURN:.*]]
  87 ! CHECK: ^[[BODY2:.*]]:
  88 ! CHECK:  %[[C1:.*]] = arith.constant 1 : i32
  89 ! CHECK:  %[[C1_INDEX:.*]] = fir.convert %[[C1]] : (i32) -> index
  90 ! CHECK:  %[[C10:.*]] = arith.constant 10 : i32
  91 ! CHECK:  %[[C10_INDEX:.*]] = fir.convert %[[C10]] : (i32) -> index
  92 ! CHECK:  %[[C1_1:.*]] = arith.constant 1 : index
  93 ! CHECK:  %[[J_LB:.*]] = fir.convert %[[C1_INDEX]] : (index) -> i32
  94 ! CHECK:  %[[J_FINAL:.*]]:2 = fir.do_loop %[[J:[^ ]*]] =
  95 ! CHECK-SAME: %[[C1_INDEX]] to %[[C10_INDEX]] step %[[C1_1]]
  96 ! CHECK-SAME: iter_args(%[[J_IV:.*]] = %[[J_LB]]) -> (index, i32) {
  97 ! CHECK:    fir.store %[[J_IV]] to %[[J_REF]] : !fir.ref<i32>
  98 ! CHECK:    %[[J_NEXT:.*]] = arith.addi %[[J]], %[[C1_1]] : index
  99 ! CHECK:    %[[J_STEPCAST:.*]] = fir.convert %[[C1_1]] : (index) -> i32
 100 ! CHECK:    %[[J_IVLOAD:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
 101 ! CHECK:    %[[J_IVINC:.*]] = arith.addi %[[J_IVLOAD]], %[[J_STEPCAST]] : i32
 102 ! CHECK:    fir.result %[[J_NEXT]], %[[J_IVINC]] : index, i32
 103 ! CHECK:  }
 104 ! CHECK:  fir.store %[[J_FINAL]]#1 to %[[J_REF]] : !fir.ref<i32>
 105 ! CHECK:  cf.br ^[[BODY1]]
 106 ! CHECK: ^[[RETURN]]:
 107 ! CHECK:   return
 108
 109 subroutine empty_infinite_in_while(i)
 110   integer :: i
 111   do while (i .gt. 50)
 112     do
 113     end do
 114   end do
 115 end subroutine
 116
 117 ! CHECK-LABEL: empty_infinite_in_while
 118 ! CHECK-SAME: %[[I_REF:.*]]: !fir.ref<i32>
 119 ! CHECK:  cf.br ^bb1
 120 ! CHECK: ^bb1:
 121 ! CHECK:  %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
 122 ! CHECK:  %[[C50:.*]] = arith.constant 50 : i32
 123 ! CHECK:  %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C50]] : i32
 124 ! CHECK:  cf.cond_br %[[COND]], ^[[INF_HEADER:.*]], ^[[EXIT:.*]]
 125 ! CHECK: ^[[INF_HEADER]]:
 126 ! CHECK:   cf.br ^[[INF_BODY:.*]]
 127 ! CHECK: ^[[INF_BODY]]:
 128 ! CHECK:   cf.br ^[[INF_HEADER]]
 129 ! CHECK: ^[[EXIT]]:
 130 ! CHECK:  return