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Re: Fix libgomp Fortran tests


On Fri, Sep 08, 2006 at 03:27:00AM -0400, Jakub Jelinek wrote:
> On Fri, Sep 08, 2006 at 12:20:15AM -0700, Brooks Moses wrote:
> > >This can't be right.  The test really needs an integer with all bits set,
> > >-huge(x) - 1 is Z'80000000'.  That's what the OpenMP standard mandates
> > >that iand reduction var should be initialized to.
> > 
> > Indeed.  This should be x=-1.  Or, possibly more clearly, x=not(0).
> 
> Well, -1 only if you know it is two's complement, I believe Fortran standard
> doesn't mandate that.  So not(0), but won't the FE do the compile time range
> checking on it?  I.e. don't we have to write
> x = 0
> x = not(x)

The frontend may optimize the above, but it should be legal
to do not(0) as long as -huge()-1 <= not <= huge().  If not,
you can do it the hard way

  integer i, x
  x = 0
  do i = 1, bit_size(x)
     x = ibset(x,i)
  end do

BTW, does gcc run on any non-twos-complement hardware?

-- 
Steve


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