blob: 04c0c68d0efe8772376c6948c01e7d6065b26e73 [file] [log] [blame]
dnl Intel Pentium-4 mpn_add_n -- mpn addition.
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 3 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 License
dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
include(`../config.m4')
C P4 Willamette, Northwood: 4.0 cycles/limb if dst!=src1 and dst!=src2
C 6.0 cycles/limb if dst==src1 or dst==src2
C P4 Prescott: >= 5 cycles/limb
C mp_limb_t mpn_add_n (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
C mp_size_t size);
C mp_limb_t mpn_add_nc (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
C mp_size_t size, mp_limb_t carry);
C
C The 4 c/l achieved here isn't particularly good, but is better than 9 c/l
C for a basic adc loop.
defframe(PARAM_CARRY,20)
defframe(PARAM_SIZE, 16)
defframe(PARAM_SRC2, 12)
defframe(PARAM_SRC1, 8)
defframe(PARAM_DST, 4)
dnl re-use parameter space
define(SAVE_EBX,`PARAM_SRC1')
TEXT
ALIGN(8)
PROLOGUE(mpn_add_nc)
deflit(`FRAME',0)
movd PARAM_CARRY, %mm0
jmp L(start_nc)
EPILOGUE()
ALIGN(8)
PROLOGUE(mpn_add_n)
deflit(`FRAME',0)
pxor %mm0, %mm0
L(start_nc):
movl PARAM_SRC1, %eax
movl %ebx, SAVE_EBX
movl PARAM_SRC2, %ebx
movl PARAM_DST, %edx
movl PARAM_SIZE, %ecx
leal (%eax,%ecx,4), %eax C src1 end
leal (%ebx,%ecx,4), %ebx C src2 end
leal (%edx,%ecx,4), %edx C dst end
negl %ecx C -size
L(top):
C eax src1 end
C ebx src2 end
C ecx counter, limbs, negative
C edx dst end
C mm0 carry bit
movd (%eax,%ecx,4), %mm1
movd (%ebx,%ecx,4), %mm2
paddq %mm2, %mm1
paddq %mm1, %mm0
movd %mm0, (%edx,%ecx,4)
psrlq $32, %mm0
addl $1, %ecx
jnz L(top)
movd %mm0, %eax
movl SAVE_EBX, %ebx
emms
ret
EPILOGUE()