🚀 go-pugleaf

In article <1993May1.192516.15296@uvm.edu>
	wollman@sadye.emba.uvm.edu (Garrett Wollman) writes:
>For this particular situation, it would be nice if GCC had a
>`-funsigned-preserving' switch.  (A `-muse-halfword-ops' switch would
>be nice, too.)

There's a macro in the machine description which may help, but I'm not sure
if it was in 2.3 (it will be in 2.4).

Try adding this to i386.h.  It should cause gcc to use fewer halfword
operations on a 486.


#define PROMOTE_MODE(MODE,UNSIGNEDP,TYPE)	\
  if (TARGET_486 && (MODE) == HImode) (MODE) = SImode


This macro is intended for RISC machines which don't have instructions that
operate on objects smaller than a word.  The example above would make gcc use
32 bit registers and operations to hold 16 bit automatic variables.  (This is
done so as not to change results; a short still can not exceed 2^16.)

--
    John Carr (jfc@athena.mit.edu)