Intel® Fortran Compiler
Build applications that can scale for the future with optimized code designed for Intel® Xeon® and compatible processors.
Announcements
Welcome to the Intel Community. If you get an answer you like, please mark it as an Accepted Solution to help others. Thank you!
26750 Discussions

do concurrent: Bug in code or in compiler?

Diehl__Martin
Novice
68 Views

Hi,

I've started to substitute "forall" statements with "do concurrent" loops and found an unexpected behavior when compiling with -Ox, x>1 and openMP and autoparallelization, i.e.

 ifort test.f90 -O2  -parallel -qopenmp

for the Intel compiler in versions 18.0.1 and 18.0.3. I seems like that the "do concurrent" loop is not executed at all. Is my code invalid or does the compiler makes a mistake when doing the optimization?

program test
  implicit none
  real, dimension(4) :: c
 
  c = [1.0,2.0,5.0,3.3]
  write(6,*) math_qToR(c)
  write(6,*) math_qToR2(c)

contains

function math_qToR(q)
 implicit none
 real, dimension(4), intent(in) :: q
 real, dimension(3,3) :: math_qToR
 integer :: i, j

 forall (i = 1:3, j = 1:3)
   math_qToR(i,j) = q(i+1) * q(j+1)
 end forall

end function math_qToR

function math_qToR2(q)
 implicit none
 real, dimension(4), intent(in) :: q
 real, dimension(3,3) :: math_qToR2
 integer :: i, j
 
 do concurrent (i = 1:3, j = 1:3)
   !write(6,*) i,j ! cures the behavior
   math_qToR2(i,j) = q(i+1) * q(j+1)
 enddo

end function math_qToR2


end program

 

0 Kudos
0 Replies
Reply