dnl Pentium-4 mpn_copyi -- copy limb vector, incrementing. dnl dnl Copyright 1999, 2000, 2001 Free Software Foundation, Inc. dnl dnl This file is part of the GNU MP Library. dnl dnl The GNU MP Library is free software; you can redistribute it and/or dnl modify it under the terms of the GNU Lesser General Public License as dnl published by the Free Software Foundation; either version 2.1 of the dnl License, or (at your option) any later version. dnl dnl The GNU MP Library is distributed in the hope that it will be useful, dnl but WITHOUT ANY WARRANTY; without even the implied warranty of dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU dnl Lesser General Public License for more details. dnl dnl You should have received a copy of the GNU Lesser General Public dnl License along with the GNU MP Library; see the file COPYING.LIB. If dnl not, write to the Free Software Foundation, Inc., 51 Franklin Street, dnl Fifth Floor, Boston, MA 02110-1301, USA. dnl The rep/movsl is very slow for small blocks on pentium4. Its startup dnl time seems to be about 110 cycles. It then copies at a rate of one dnl limb per cycle. We therefore fall back to an open-coded 2 c/l copying dnl loop for smaller sizes. dnl Ultimately, we may want to use 64-bit movd or 128-bit movdqu in some dnl nifty unrolled arrangement. Clearly, that could reach much higher dnl speeds, at least for large blocks. include(`../config.m4') defframe(PARAM_SIZE, 12) defframe(PARAM_SRC, 8) defframe(PARAM_DST, 4) TEXT ALIGN(8) PROLOGUE(mpn_copyi) deflit(`FRAME',0) movl PARAM_SIZE, %ecx cmpl $150, %ecx jg L(replmovs) movl PARAM_SRC, %eax movl PARAM_DST, %edx movl %ebx, PARAM_SIZE testl %ecx, %ecx jz L(end) L(loop): movl (%eax), %ebx leal 4(%eax), %eax addl $-1, %ecx movl %ebx, (%edx) leal 4(%edx), %edx jnz L(loop) L(end): movl PARAM_SIZE, %ebx ret L(replmovs): cld C better safe than sorry, see mpn/x86/README movl %esi, %eax movl PARAM_SRC, %esi movl %edi, %edx movl PARAM_DST, %edi rep movsl movl %eax, %esi movl %edx, %edi ret EPILOGUE()