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.)