rdieee.f

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      subroutine rdieee(rieee,a,num)
 
      real(4),intent(in) :: rieee(num)
      real,intent(out) :: a(num)
      integer,intent(in) :: num
 
      integer(4) :: ieee
 
      real,parameter :: two23=scale(1.0,-23)
      real,parameter :: two126=scale(1.0,-126)
 
      do j=1,num
!
!  Transfer IEEE bit string to integer variable
!
        ieee=transfer(rieee(j),ieee)
!
!  Extract sign bit, exponent, and mantissa
!
        isign=ibits(ieee,31,1)
        iexp=ibits(ieee,23,8)
        imant=ibits(ieee,0,23)
        sign=1.0
        if (isign.eq.1) sign=-1.0
        
        if ( (iexp.gt.0).and.(iexp.lt.255) ) then
          temp=2.0**(iexp-127)
          a(j)=sign*temp*(1.0+(two23*real(imant)))
 
        elseif ( iexp.eq.0 ) then
          if ( imant.ne.0 ) then
            a(j)=sign*two126*two23*real(imant)
          else
            a(j)=sign*0.0
          endif
 
        elseif ( iexp.eq.255 ) then
          a(j)=sign*huge(a(j))
 
        endif
 
      enddo
 
      return
      end