🚀 go-pugleaf

In article <i6TmR3w163w@doppler> jdries%doppler@faatcrl (J. Francis Dries, III) writes:
>I was hacking up a program to convert Sun Rasterfiles to GIF files when
>I ran into a little problem.  Almost all the non-Intel world (or so I'm
>told) writes ints MSByte first, whereas Borland's TC++ is
>reading/writing ints/longs (I need longs, since I'm working with 32bit
>ints from the Sun) LSByte first.
>
>My Question is, is there a way to reverse the order, quickly or cleanly?
>I could read in each char at a time and OR it onto the long and SHL all
>4 on, but that seems kinda sloppy to me.  I would think that the is a
>flag that can be set, or at least a built in macro...

The i486 has a new instruction BSWAP that does exactly what you want in 1
clock (if the data is already in a register), but I suppose that doesn't 
help you much. I'd do it by loading the two word sized parts, exchanging the 
bytes of each, and writing them out again.  Something like:

   mov ax, word ptr [data]
   mov dx, word ptr [data+2]
   xchg al,ah
   xchg dl,dh
   mov word ptr[data],dx
   mov word ptr[data+2],ax