------- Additional Comments From tobi at gcc dot gnu dot org 2005-03-19 00:54
-------
Slightly reduced testcase, segfaults at -O2, runs with lower optimization.
Removing any single statement leads to either illegal floating pointn numbers or
makes the segfault disappear:
character(len=8) argv
real*8, parameter :: tstep = 0.01d0
real*8 :: e
type body
real*8 x, y,z,vx,vy,vz, mass
end type body
type(body), parameter :: jupiter = body(1d0, 1d0, 1d0, 1d0, 1d0, 1d0, 1d0 )
type(body), parameter :: sun = body(0.0d0, 0.0d0, 0.0d0, 0.0d0, 0.0d0,
0.0d0,1d0)
type(body), dimension(2) :: bodies
bodies = (/ sun, jupiter/)
argv = "1"
read (argv,*) num
call offsetMomentum(1,bodies)
do i=1,num
call advance(tstep, bodies)
end do
e = 0.
print *, e
contains
subroutine offsetMomentum(k, bodies)
integer, intent(in) :: k
type(body), dimension(:), intent(inout) :: bodies
real*8 :: px, py, pz
do i=1,size(bodies)
px = bodies(i)%vx * bodies(i)%mass;
end do
bodies(k)%vx = -px
end subroutine offsetMomentum
subroutine advance(tstep, bodies)
real*8, intent(in) :: tstep
type(body), dimension(:), intent(inout) :: bodies
real*8 dx, dy, dz, distance, mag
integer i, j
i = 1; j = 2; mag = 1.
dx = bodies(i)%x - bodies(j)%x
bodies(i)%vx = bodies(i)%vx - dx * bodies(j)%mass * mag
bodies(j)%vx = bodies(j)%vx + dx * bodies(i)%mass * mag
bodies(j)%vy = bodies(j)%vy + dy * bodies(i)%mass * mag
bodies(j)%vz = bodies(j)%vz + dz * bodies(i)%mass * mag
do i=1,size(bodies)
bodies(i)%x = bodies(i)%x + tstep * bodies(i)%vx
bodies(i)%y = bodies(i)%y + tstep * bodies(i)%vy
bodies(i)%z = bodies(i)%z + tstep * bodies(i)%vz
end do
end subroutine advance
real*8 function energy(bodies)
type(body), dimension(:), intent(in) :: bodies
real*8 dx, dy, dz, distance
integer i, j
energy = 0.0d0
end function energy
end
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-03-19 00:54:17
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20538
