topic Compiler bug involving complex array parts in Intel® Fortran Compiler

Compiler bug involving complex array parts

NCarlson — Thu, 05 Jun 2025 15:24:02 GMT

I've encountered another bug with complex array parts using ifx 2025.1. Here's a small example. I'll follow-up with a couple workaround attempts that result in either an internal compiler error or incorrect runtime results. The only workaround I've found that works is to manually do copy-in/copy-out to a temporary real array.

type :: foo complex :: z(3) end type type(foo) :: a call bar(a%z%re) contains subroutine bar(x) real, intent(inout) :: x(:) end subroutine end

The compiler gives this spurious error. Clearly the actual argument is neither a constant nor an expression.

$ ifx bug.f90 bug.f90(5): error #6638: An actual argument is an expression or constant; this is not valid since the associated dummy argument has the explicit INTENT(OUT) or INTENT(INOUT) attribute. call bar(a%z%re) ---------^ compilation aborted for bug.f90 (code 1)

Re: Compiler bug involving complex array parts

NCarlson — Thu, 05 Jun 2025 15:27:54 GMT

This attempt at a workaround using an ASSOCIATE block results in an internal compiler error:

type :: foo complex :: z(3) end type type(foo) :: a associate (z => a%z) call bar(z%re) end associate contains subroutine bar(x) real, intent(inout) :: x(:) end subroutine end

$ ifx bug.f90 #0 0x0000000003310581 #1 0x0000000003375357 [...] #28 0x00007fce2f76b20b __libc_start_main + 139 #29 0x000000000308f0ee bug.f90(6): error #5623: **Internal compiler error: internal abort** Please report this error along with the circumstances in which it occurred in a Software Problem Report. Note: File and line given may not be explicit cause of this error. call bar(z%re) -----------^ compilation aborted for bug.f90 (code 3)

Re: Compiler bug involving complex array parts

NCarlson — Thu, 05 Jun 2025 15:30:11 GMT

This attempt at a workaround using an ASSOCIATE block compiles without error, but produces incorrect results:

type :: foo complex :: z(3) end type type(foo) :: a a%z%re = -1 associate (z_re => a%z%re) call bar(z_re) end associate print *, a%z%re if (any(a%z%re /= [1,2,3])) stop 'fail' contains subroutine bar(x) real, intent(inout) :: x(:) x = [1,2,3] end subroutine end

$ ifx bug.f90 $ ./a.out -1.000000 -1.000000 -1.000000 fail

Re: Compiler bug involving complex array parts

NCarlson — Thu, 05 Jun 2025 16:08:41 GMT

Here's the more complete test code from my compiler bug database that should compile and run with a 0 exit status (unix).

Re: Compiler bug involving complex array parts

garraleta_fortran — Mon, 09 Jun 2025 18:11:07 GMT

TYPE :: FOO
COMPLEX :: Z(3)
END TYPE
TYPE(FOO) :: A
CALL BAR(REAL(A.Z(:)))
CONTAINS
SUBROUTINE BAR(X)
REAL, INTENT(IN) :: X(:)
WRITE(*,*)X
END SUBROUTINE
END

Re: Compiler bug involving complex array parts

Devorah_H_Intel — Tue, 10 Jun 2025 12:36:53 GMT

Thank you for reporting this. This bug report is escalated to engineering for further investigation.