156 lines
3.7 KiB
NASM
156 lines
3.7 KiB
NASM
dnl Intel Pentium mpn_copyi -- copy limb vector, incrementing.
|
|
|
|
dnl Copyright 1996, 2001, 2002, 2006 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 P5: 1.25 cycles/limb
|
|
|
|
|
|
C void mpn_copyi (mp_ptr dst, mp_srcptr src, mp_size_t size);
|
|
C
|
|
C Destination prefetching is done to avoid repeated write-throughs on lines
|
|
C not already in L1.
|
|
C
|
|
C At least one of the src or dst pointer needs to be incremented rather than
|
|
C using indexing, so that there's somewhere to put the loop control without
|
|
C an AGI. Incrementing one and not two lets us keep loop overhead to 2
|
|
C cycles. Making it the src pointer incremented avoids an AGI on the %ecx
|
|
C subtracts in the finishup code.
|
|
C
|
|
C The block of finishup code is almost as big as the main loop itself, which
|
|
C is unfortunate, but it's faster that way than with say rep movsl, by about
|
|
C 10 cycles for instance on P55.
|
|
C
|
|
C There's nothing to be gained from MMX on P55, since it can do only one
|
|
C movq load (or store) per cycle, so the throughput would be the same as the
|
|
C code here (and even then only if src and dst have the same alignment mod
|
|
C 8).
|
|
|
|
defframe(PARAM_SIZE,12)
|
|
defframe(PARAM_SRC, 8)
|
|
defframe(PARAM_DST, 4)
|
|
|
|
TEXT
|
|
ALIGN(8)
|
|
PROLOGUE(mpn_copyi)
|
|
deflit(`FRAME',0)
|
|
|
|
movl PARAM_SIZE, %ecx
|
|
movl PARAM_DST, %edx
|
|
|
|
pushl %ebx FRAME_pushl()
|
|
pushl %esi FRAME_pushl()
|
|
|
|
leal (%edx,%ecx,4), %edx C &dst[size-1]
|
|
xorl $-1, %ecx C -size-1
|
|
|
|
movl PARAM_SRC, %esi
|
|
addl $8, %ecx C -size+7
|
|
|
|
jns L(end)
|
|
|
|
movl -28(%edx,%ecx,4), %eax C fetch destination cache line, dst[0]
|
|
nop
|
|
|
|
L(top):
|
|
C eax scratch
|
|
C ebx scratch
|
|
C ecx counter, limbs, negative
|
|
C edx &dst[size-1]
|
|
C esi src, incrementing
|
|
C edi
|
|
C ebp
|
|
|
|
movl (%edx,%ecx,4), %eax C fetch destination cache line
|
|
addl $8, %ecx
|
|
|
|
movl (%esi), %eax C read words pairwise
|
|
movl 4(%esi), %ebx
|
|
movl %eax, -60(%edx,%ecx,4) C store words pairwise
|
|
movl %ebx, -56(%edx,%ecx,4)
|
|
|
|
movl 8(%esi), %eax
|
|
movl 12(%esi), %ebx
|
|
movl %eax, -52(%edx,%ecx,4)
|
|
movl %ebx, -48(%edx,%ecx,4)
|
|
|
|
movl 16(%esi), %eax
|
|
movl 20(%esi), %ebx
|
|
movl %eax, -44(%edx,%ecx,4)
|
|
movl %ebx, -40(%edx,%ecx,4)
|
|
|
|
movl 24(%esi), %eax
|
|
movl 28(%esi), %ebx
|
|
movl %eax, -36(%edx,%ecx,4)
|
|
movl %ebx, -32(%edx,%ecx,4)
|
|
|
|
leal 32(%esi), %esi
|
|
js L(top)
|
|
|
|
|
|
L(end):
|
|
C ecx 0 to 7, representing respectively 7 to 0 limbs remaining
|
|
C esi src end
|
|
C edx dst, next location to store
|
|
|
|
subl $4, %ecx
|
|
jns L(no4)
|
|
|
|
movl (%esi), %eax
|
|
movl 4(%esi), %ebx
|
|
movl %eax, -12(%edx,%ecx,4)
|
|
movl %ebx, -8(%edx,%ecx,4)
|
|
|
|
movl 8(%esi), %eax
|
|
movl 12(%esi), %ebx
|
|
movl %eax, -4(%edx,%ecx,4)
|
|
movl %ebx, (%edx,%ecx,4)
|
|
|
|
addl $16, %esi
|
|
addl $4, %ecx
|
|
L(no4):
|
|
|
|
subl $2, %ecx
|
|
jns L(no2)
|
|
|
|
movl (%esi), %eax
|
|
movl 4(%esi), %ebx
|
|
movl %eax, -4(%edx,%ecx,4)
|
|
movl %ebx, (%edx,%ecx,4)
|
|
|
|
addl $8, %esi
|
|
addl $2, %ecx
|
|
L(no2):
|
|
|
|
jnz L(done)
|
|
|
|
movl (%esi), %eax
|
|
movl %eax, -4(%edx,%ecx,4) C risk of cache bank clash here
|
|
|
|
L(done):
|
|
popl %esi
|
|
popl %ebx
|
|
|
|
ret
|
|
|
|
EPILOGUE()
|