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From: "john.harper at vuw dot ac.nz" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/109186] New: nearest(huge(x),-1.0_kind(x)) half of correct value
Date: Sun, 19 Mar 2023 01:46:07 +0000	[thread overview]
Message-ID: <bug-109186-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109186

            Bug ID: 109186
           Summary: nearest(huge(x),-1.0_kind(x)) half of correct value
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: john.harper at vuw dot ac.nz
  Target Milestone: ---

With all four real kinds available in gfortran_12 nearest(x,y) with x = huge
and y = -1 this program gave about half the correct result. Ifort gave correct
results for the 3 different kinds it has: sp,dp,qp.

The program:

  implicit none
  integer,parameter::sp = kind(1.0), dp=kind(1d0), ncases = 2, &
       ep = selected_real_kind(18),qp = selected_real_kind(33)
  character(*),parameter:: fmt(4) = &
       "(A,ES"//["16.08E2","26.17E3","30.20E4","44.34E4"]//")"
  character(24),dimension(2):: splist,dplist,eplist,qplist 
  integer n
  real(sp),parameter::sp1 = 1.0_sp
  real(sp):: spx(ncases) = [huge(sp1),nearest(huge(sp1),-sp1)]
  data splist/'huge(sp1)','nearest(huge(sp1),-sp1)'/
  real(dp),parameter::dp1 = 1.0_dp
  real(dp):: dpx(ncases) = [huge(dp1),nearest(huge(dp1),-dp1)]
  data dplist/'huge(dp1)','nearest(huge(dp1),-dp1)'/
  real(ep),parameter::ep1 = 1.0_ep
  real(ep):: epx(ncases) = [huge(ep1),nearest(huge(ep1),-ep1)]
  data eplist/'huge(ep1)','nearest(huge(ep1),-ep1)'/
  real(qp),parameter::qp1 = 1.0_qp
  real(qp):: qpx(ncases) = [huge(qp1),nearest(huge(qp1),-qp1)]
  data qplist/'huge(qp1)','nearest(huge(qp1),-qp1)'/

  print fmt(1),(splist(n),spx(n),n=1,ncases)
  print fmt(2),(dplist(n),dpx(n),n=1,ncases)
  print fmt(3),(eplist(n),epx(n),n=1,ncases)
  print fmt(4),(qplist(n),qpx(n),n=1,ncases)
end program

The output on ubuntu (Linux 86_64)
huge(sp1)                 3.40282347E+38
nearest(huge(sp1),-sp1)   1.70141173E+38
huge(dp1)                 1.79769313486231571E+308
nearest(huge(dp1),-dp1)   8.98846567431157854E+307
huge(ep1)                 1.18973149535723176502E+4932
nearest(huge(ep1),-ep1)   5.94865747678615882511E+4931
huge(qp1)                 1.1897314953572317650857593266280070E+4932
nearest(huge(qp1),-qp1)   5.9486574767861588254287966331400351E+4931

             reply	other threads:[~2023-03-19  1:46 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-19  1:46 john.harper at vuw dot ac.nz [this message]
2023-03-19  5:06 ` [Bug fortran/109186] " jvdelisle at gcc dot gnu.org
2023-03-19  8:47 ` john.harper at vuw dot ac.nz
2023-03-19 19:30 ` anlauf at gcc dot gnu.org
2023-03-19 19:58 ` anlauf at gcc dot gnu.org
2023-03-19 20:45 ` anlauf at gcc dot gnu.org
2023-03-20 17:46 ` cvs-commit at gcc dot gnu.org
2023-03-22 18:00 ` cvs-commit at gcc dot gnu.org
2023-03-24 18:41 ` cvs-commit at gcc dot gnu.org
2023-03-24 18:44 ` cvs-commit at gcc dot gnu.org
2023-03-24 18:46 ` anlauf at gcc dot gnu.org

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