1 dnl AMD K7 mpn_copyi -- copy limb vector, incrementing.
3 dnl alignment dst/src, A=0mod8 N=4mod8
5 dnl K7 0.75 1.0 1.0 0.75
8 dnl Copyright (C) 1999, 2000 Free Software Foundation, Inc.
10 dnl This file is part of the GNU MP Library.
12 dnl The GNU MP Library is free software; you can redistribute it and/or
13 dnl modify it under the terms of the GNU Lesser General Public License as
14 dnl published by the Free Software Foundation; either version 2.1 of the
15 dnl License, or (at your option) any later version.
17 dnl The GNU MP Library is distributed in the hope that it will be useful,
18 dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
19 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 dnl Lesser General Public License for more details.
22 dnl You should have received a copy of the GNU Lesser General Public
23 dnl License along with the GNU MP Library; see the file COPYING.LIB. If
24 dnl not, write to the Free Software Foundation, Inc., 59 Temple Place -
25 dnl Suite 330, Boston, MA 02111-1307, USA.
28 include(`../config.m4')
31 C void mpn_copyi (mp_ptr dst, mp_srcptr src, mp_size_t size);
33 C Copy src,size to dst,size.
35 C This code at 0.75 or 1.0 c/l is always faster than a plain rep movsl at
38 C The K7 can do two loads, or two stores, or a load and a store, in one
39 C cycle, so if those are 64-bit operations then 0.5 c/l should be possible,
40 C however nothing under 0.7 c/l is known.
42 C If both source and destination are unaligned then one limb is processed at
43 C the start to make them aligned and so get 0.75 c/l, whereas if they'd been
44 C used unaligned it would be 1.5 c/l.
46 defframe(PARAM_SIZE,12)
47 defframe(PARAM_SRC, 8)
48 defframe(PARAM_DST, 4)
50 dnl parameter space reused
51 define(SAVE_EBX,`PARAM_SIZE')
53 dnl minimum 5 since the unrolled code can't handle less than 5
54 deflit(UNROLL_THRESHOLD, 5)
67 cmpl $UNROLL_THRESHOLD, %ecx
74 C eax src, incrementing
77 C edx dst, incrementing
79 C this loop is 2 cycles/limb
95 leal -12(%eax,%ecx,4), %eax C src end - 12
96 subl $3, %ecx C size-3
99 leal (%edx,%ecx,4), %edx C dst end - 12
102 testl $4, %ebx C testl to pad code closer to 16 bytes for L(top)
105 C both src and dst unaligned, process one limb to align them
106 movl (%eax,%ecx,4), %ebx
107 movl %ebx, (%edx,%ecx,4)
116 C ecx counter, negative, limbs
119 movq (%eax,%ecx,4), %mm0
120 movq 8(%eax,%ecx,4), %mm1
122 movq %mm0, -16(%edx,%ecx,4)
123 movq %mm1, -16+8(%edx,%ecx,4)
124 ja L(top) C jump no carry and not zero
127 C now %ecx is 0 to 3 representing respectively 3 to 0 limbs remaining
130 jnz L(finish_not_two)
132 movq (%eax,%ecx,4), %mm0
133 movq %mm0, (%edx,%ecx,4)