[Bug fortran/35946] New: wrong result with array constructor as argument to ATAN2

["dick dot hendrickson at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following program gives the wrong answers when an array
constructor with a "complicated" implied do is used as an
argument to REAL which is then used as an argument to
ATAN2.

Dick Hendrickson 

      program try_fa6013

! fails on Windows XP
! gcc version 4.4.0 20080312 (experimental) [trunk revision 133139]

      call fa6013(10,1,-1)
      end program


      subroutine  FA6013 (nf10,nf1,mf1)

      integer, parameter :: kv=4    !fails
!     integer, parameter :: kv=8    !fails

      REAL(KV) DDA1(10)
      REAL(KV) DDA2(10)
      REAL(KV) DDA(10), dval

      dda = (/ 1,2,3,4,5,6,7,8,9,10/)

      print '(10f5.1)',   REAL((/(J1,J1=nf10,nf1,mf1)/),KV) !works 


       DDA1 = ATAN2 (  (/(REAL(J1,KV),J1=1,10)/) ,
     $                 REAL((/(J1,J1=nf10,nf1,mf1)/),KV))   !fails

!    $                 REAL((/(J1,J1=  10,  1, -1)/),KV))   !works

       DDA2 = ATAN2 ( DDA, DDA(10:1:-1) )

      DVAL = .09967_kv     !atan2(1.0,10.0)
      print '(i3,3f10.5)', 1, dda1(1),dval, dval-dda1(1)

      DO J1 = 2,10
      DVAL = DDA2(J1)
      print '(i3,3f10.5)', j1, dda1(j1),dval, dval-dda1(j1)
  100 ENDDO

      END

c:\gfortran:gfortran fa6013.f

c:\gfortran:a
 10.0  9.0  8.0  7.0  6.0  5.0  4.0  3.0  2.0  1.0
  1   0.11066   0.09967  -0.01099
  2   0.24498   0.21867  -0.02631
  3   0.40489   0.35877  -0.04612
  4   0.58800   0.51915  -0.06886
  5   0.78540   0.69474  -0.09066
  6   0.98279   0.87606  -0.10674
  7   1.16590   1.05165  -0.11425
  8   1.32582   1.21203  -0.11379
  9   1.46014   1.35213  -0.10801
 10   0.00000   1.47113   1.47113


-- 
           Summary: wrong result with array constructor as argument to ATAN2
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dick dot hendrickson at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35946