
                      X86 MPN SUBROUTINES


This directory contains mpn functions for various 80x86 chips.


CODE ORGANIZATION

	x86              i386, i486, generic
	x86/pentium      Intel Pentium (P5, P54)
	x86/pentium/mmx  Intel Pentium with MMX (P55)
	x86/p6           Intel Pentium Pro
	x86/p6/mmx       Intel Pentium II, III
	x86/k6           AMD K6 (and K6-2, K6-3)
	x86/k7           AMD Athalon


The x86 directory is also the main support for P6 at the moment, and
is something of a blended style, meant to be reasonable on all x86s.

	

STATUS

The code is well-optimized for AMD and Intel chips, but not so well
optimized for Cyrix chips.



RELEVANT OPTIMIZATION ISSUES

For implementations with slow double shift instructions (SHLD and
SHRD), it might be better to mimic their operation with SHL+SHR+OR.
(M2 is likely to benefit from that, but not Pentium due to its slow
plain SHL and SHR.)
