107 lines
2.4 KiB
NASM
107 lines
2.4 KiB
NASM
dnl AMD K6 mpn_divexact_by3 -- mpn division by 3, expecting no remainder.
|
|
|
|
dnl Copyright 2000, 2001, 2002 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.
|
|
|
|
include(`../config.m4')
|
|
|
|
|
|
C K6: 10.0 cycles/limb
|
|
|
|
|
|
C mp_limb_t mpn_divexact_by3c (mp_ptr dst, mp_srcptr src, mp_size_t size,
|
|
C mp_limb_t carry);
|
|
C
|
|
C Using %esi in (%esi,%ecx,4) or 0(%esi,%ecx,4) addressing modes doesn't
|
|
C lead to vector decoding, unlike plain (%esi) does.
|
|
|
|
defframe(PARAM_CARRY,16)
|
|
defframe(PARAM_SIZE, 12)
|
|
defframe(PARAM_SRC, 8)
|
|
defframe(PARAM_DST, 4)
|
|
|
|
dnl multiplicative inverse of 3, modulo 2^32
|
|
deflit(INVERSE_3, 0xAAAAAAAB)
|
|
|
|
TEXT
|
|
ALIGN(16)
|
|
|
|
nop C code alignment
|
|
|
|
PROLOGUE(mpn_divexact_by3c)
|
|
deflit(`FRAME',0)
|
|
|
|
movl PARAM_SIZE, %ecx
|
|
pushl %esi defframe_pushl(SAVE_ESI)
|
|
|
|
movl PARAM_SRC, %esi
|
|
pushl %edi defframe_pushl(SAVE_EDI)
|
|
|
|
movl PARAM_DST, %edi
|
|
pushl %ebx defframe_pushl(SAVE_EBX)
|
|
|
|
movl PARAM_CARRY, %edx
|
|
leal (%esi,%ecx,4), %esi
|
|
|
|
pushl %ebp defframe_pushl(SAVE_EBP)
|
|
movl $3, %ebp
|
|
|
|
leal 0(%edi,%ecx,4), %edi
|
|
negl %ecx
|
|
|
|
|
|
L(top):
|
|
C eax scratch, low product
|
|
C ebx carry limb (0 to 2)
|
|
C ecx counter, limbs, negative
|
|
C edx scratch, high product
|
|
C esi &src[size]
|
|
C edi &dst[size]
|
|
C ebp 3
|
|
|
|
movl (%esi,%ecx,4), %eax
|
|
subl %edx, %eax
|
|
|
|
sbbl %ebx, %ebx C borrow 0 or -1
|
|
|
|
imull $INVERSE_3, %eax, %eax
|
|
|
|
movl %eax, (%edi,%ecx,4)
|
|
addl $2, %ecx
|
|
|
|
mull %ebp
|
|
|
|
subl %ebx, %edx C new carry
|
|
loop L(top)
|
|
|
|
|
|
movl SAVE_ESI, %esi
|
|
movl %edx, %eax
|
|
|
|
movl SAVE_EBX, %ebx
|
|
|
|
movl SAVE_EBP, %ebp
|
|
|
|
movl SAVE_EDI, %edi
|
|
addl $FRAME, %esp
|
|
|
|
ret
|
|
|
|
EPILOGUE()
|