dnl Intel Pentium-4 mpn_addmul_1 -- Multiply a limb vector with a limb and add
dnl the result to a second limb vector.
dnl Copyright 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., 59 Temple Place -
dnl Suite 330, Boston, MA 02111-1307, USA.
include(`../config.m4')
C P4: 6 cycles/limb, unstable timing, at least on early Pentium4 silicon
C (stepping 10).
C mp_limb_t mpn_addmul_1 (mp_ptr dst, mp_srcptr src, mp_size_t size,
C mp_limb_t multiplier);
C mp_limb_t mpn_addmul_1c (mp_ptr dst, mp_srcptr src, mp_size_t size,
C mp_limb_t multiplier, mp_limb_t carry);
C
C Only the carry limb propagation is on the dependent chain, but some other
C Pentium4 pipeline magic brings down performance to 6 cycles/l from the
C ideal 4 cycles/l.
defframe(PARAM_CARRY, 20)
defframe(PARAM_MULTIPLIER,16)
defframe(PARAM_SIZE, 12)
defframe(PARAM_SRC, 8)
defframe(PARAM_DST, 4)
TEXT
ALIGN(16)
PROLOGUE(mpn_addmul_1c)
deflit(`FRAME',0)
movd PARAM_CARRY, %mm0
jmp L(start_1c)
EPILOGUE()
PROLOGUE(mpn_addmul_1)
deflit(`FRAME',0)
pxor %mm0, %mm0
L(start_1c):
movl PARAM_SRC, %eax
movl PARAM_SIZE, %ecx
movl PARAM_DST, %edx
movd PARAM_MULTIPLIER, %mm7
C eax src, incrementing
C ebx
C ecx loop counter, decrementing
C edx dst, incrementing
C
C mm0 carry, low 32-bits
C mm7 multiplier
L(loop):
movd (%eax), %mm1 C src
leal 4(%eax), %eax
movd (%edx),%mm2 C dst
pmuludq %mm7, %mm1
paddq %mm1, %mm2 C prod
paddq %mm2, %mm0 C carry
subl $1, %ecx
movd %mm0, (%edx) C result
psrlq $32, %mm0
leal 4(%edx), %edx
jnz L(loop)
movd %mm0, %eax
emms
ret
EPILOGUE()