1dnl Pentium-4 mpn_copyi -- copy limb vector, incrementing. 2 3dnl Copyright 1999-2001 Free Software Foundation, Inc. 4 5dnl This file is part of the GNU MP Library. 6dnl 7dnl The GNU MP Library is free software; you can redistribute it and/or modify 8dnl it under the terms of either: 9dnl 10dnl * the GNU Lesser General Public License as published by the Free 11dnl Software Foundation; either version 3 of the License, or (at your 12dnl option) any later version. 13dnl 14dnl or 15dnl 16dnl * the GNU General Public License as published by the Free Software 17dnl Foundation; either version 2 of the License, or (at your option) any 18dnl later version. 19dnl 20dnl or both in parallel, as here. 21dnl 22dnl The GNU MP Library is distributed in the hope that it will be useful, but 23dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 24dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 25dnl for more details. 26dnl 27dnl You should have received copies of the GNU General Public License and the 28dnl GNU Lesser General Public License along with the GNU MP Library. If not, 29dnl see https://www.gnu.org/licenses/. 30 31 32dnl The rep/movsl is very slow for small blocks on pentium4. Its startup 33dnl time seems to be about 110 cycles. It then copies at a rate of one 34dnl limb per cycle. We therefore fall back to an open-coded 2 c/l copying 35dnl loop for smaller sizes. 36 37dnl Ultimately, we may want to use 64-bit movd or 128-bit movdqu in some 38dnl nifty unrolled arrangement. Clearly, that could reach much higher 39dnl speeds, at least for large blocks. 40 41include(`../config.m4') 42 43 44defframe(PARAM_SIZE, 12) 45defframe(PARAM_SRC, 8) 46defframe(PARAM_DST, 4) 47 48 TEXT 49 ALIGN(8) 50 51PROLOGUE(mpn_copyi) 52deflit(`FRAME',0) 53 54 movl PARAM_SIZE, %ecx 55 cmpl $150, %ecx 56 jg L(replmovs) 57 58 movl PARAM_SRC, %eax 59 movl PARAM_DST, %edx 60 movl %ebx, PARAM_SIZE 61 testl %ecx, %ecx 62 jz L(end) 63 64L(loop): 65 movl (%eax), %ebx 66 leal 4(%eax), %eax 67 addl $-1, %ecx 68 movl %ebx, (%edx) 69 leal 4(%edx), %edx 70 71 jnz L(loop) 72 73L(end): 74 movl PARAM_SIZE, %ebx 75 ret 76 77L(replmovs): 78 cld C better safe than sorry, see mpn/x86/README 79 80 movl %esi, %eax 81 movl PARAM_SRC, %esi 82 movl %edi, %edx 83 movl PARAM_DST, %edi 84 85 rep 86 movsl 87 88 movl %eax, %esi 89 movl %edx, %edi 90 91 ret 92 93EPILOGUE() 94