[flang-commits] [flang] [flang] Don't duplicate impure function call for UBOUND() (PR #153648)

[Eugene Epshteyn via flang-commits]

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@@ -0,0 +1,18 @@
+! RUN: %flang_fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
+! Ensure that UBOUND() calculation from LBOUND()+SIZE() isn't applied to
+! variables containing references to impure functions.
+type t
+  real, allocatable :: a(:)
+end type
+interface
+  pure integer function pure(n)
+    integer, intent(in) :: n
+  end
+end interface
+type(t) :: x(10)
+allocate(x(1)%a(2))
+!CHECK: PRINT *, ubound(x(int(impure(1_4),kind=8))%a,dim=1_4)
+print *, ubound(x(impure(1))%a, dim=1)
+!CHECK: PRINT *, int(size(x(int(pure(1_4),kind=8))%a,dim=1,kind=8)+lbound(x(int(pure(1_4),kind=8))%a,dim=1,kind=8)-1_8,kind=4)
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eugeneepshteyn wrote:

Ok, so because it's PURE, it's ok to call it multiple times with the same value, because it's supposed to produce the same results on the same inputs. (And there's no way in Fortran to check how many times it's called without making it impure :-) )


https://github.com/llvm/llvm-project/pull/153648