Operator overloading side-effects when using parameterized derived types

jwmwalrus — Wed, 17 Apr 2024 04:25:15 GMT

Hi.

I know this is the less popular feature in the history of Fortran, but I somehow see its merits.

The following code

module itemmod use ISO_FORTRAN_ENV implicit none private save type, public :: item(ilen, k) integer, len :: ilen = 0 integer, kind :: k = real32 real(k) :: val = 0 integer :: delta(2) = 0 end type interface operator(+) module procedure item_PLUS_item end interface public operator(+) interface operator(*) module procedure scalar_TIMES_item end interface public operator(*) type(item(1)), parameter, public :: group1 = item(1)(1., [1, 0]) type(item(2)), parameter, public :: group2 = item(2)(1., [0, 1]) contains subroutine assert_same_group(lhs, rhs) type(item(*)), intent(in) :: lhs type(item(*)), intent(in) :: rhs print*,'assert_lhs=',lhs, ',ilen=',lhs%ilen print*,'assert_rhs=',rhs, ',ilen=',rhs%ilen if (lhs%ilen /= rhs%ilen) error stop 'ilen mismatch' if (.not. all(lhs%delta == rhs%delta)) error stop 'delta mismatch' end subroutine function item_PLUS_item(lhs, rhs) result(res) type(item(*)), intent(in) :: lhs type(item(*)), intent(in) :: rhs type(item(lhs%ilen)) :: res call assert_same_group(lhs, rhs) res%val = lhs%val + rhs%val res%delta = lhs%delta end function pure function scalar_TIMES_item(lhs, rhs) result(res) real, intent(in) :: lhs type(item(*)), intent(in) :: rhs type(item(rhs%ilen)) :: res res%val = lhs * rhs%val res%delta = rhs%delta end function end module itemmod use ISO_FORTRAN_ENV use itemmod implicit none type(item(1)) :: x, v type(item(2)) :: y, w print*,'group1=',group1,', ilen=',group1%ilen print*,'group2=',group2,' ilen=',group2%ilen x = 5. * group1 print*,'x=',x, ', ilen=',x%ilen y = 5. * group2 print*,'y=',y,', ilen=',y%ilen print*, x+y ! v = group1 ! print*,'v=',v, ', ilen=',v%ilen ! w = group2 ! print*,'w=',w,', ilen=',w%ilen ! print*, v+w end

Fails to pass the correct ilen parameter when used in the binary (plus operator) expression at line 71:

$ ifx -V -g -O0 items.f90 && ./a.out Intel(R) Fortran Compiler for applications running on Intel(R) 64, Version 2024.1.0 Build 20240308 Copyright (C) 1985-2024 Intel Corporation. All rights reserved. Intel(R) Fortran 24.0-1472.3 GNU ld (GNU Binutils for Debian) 2.42 group1= 0.0000000E+00 1 0 , ilen= 1 group2= 0.0000000E+00 0 1 ilen= 2 x= 0.0000000E+00 1 0 , ilen= 1 y= 0.0000000E+00 0 1 , ilen= 2 assert_lhs= 0.0000000E+00 1 0 ,ilen= 1 assert_rhs= 0.0000000E+00 0 1 ,ilen= 1 delta mismatch

The assert_same_group subroutine call should have stopped with 'ilen mismatch', but the ilen value for the rhs argument is somehow lost during invocation (and the value shown is not even the default one).

If I comment out lines 67-71 and uncomment lines 73-77, I get correct results for the assert_same_group call, at the expense of not using the overloaded operator(*) :

$ ifx -V -g -O0 items.f90 && ./a.out Intel(R) Fortran Compiler for applications running on Intel(R) 64, Version 2024.1.0 Build 20240308 Copyright (C) 1985-2024 Intel Corporation. All rights reserved. Intel(R) Fortran 24.0-1472.3 GNU ld (GNU Binutils for Debian) 2.42 group1= 0.0000000E+00 1 0 , ilen= 1 group2= 0.0000000E+00 0 1 ilen= 2 v= 0.0000000E+00 1 0 , ilen= 1 w= 0.0000000E+00 0 1 , ilen= 2 assert_lhs= 0.0000000E+00 1 0 ,ilen= 1 assert_rhs= 0.0000000E+00 0 1 ,ilen= 2 ilen mismatch

And also, in all the cases, with ifx, the constructor at lines 25-26 is misbehaving (i.e., not assigning anything to val). With ifort, val is assigned correctly.

Re: Operator overloading side-effects when using parameterized derived types

Barbara_P_Intel — Wed, 17 Apr 2024 20:58:45 GMT

Thanks for reporting this. I filed a bug report, CMPLRLLVM-57787.

We'll let you know when the issues are fixed.

topic Re: Operator overloading side-effects when using parameterized derived types in Intel® Fortran Compiler

Operator overloading side-effects when using parameterized derived types

Re: Operator overloading side-effects when using parameterized derived types