gcc/gmp/mpn/x86/pentium/copyd.asm

dnl  Intel Pentium mpn_copyd -- copy limb vector, decrementing.

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 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 P5: 1.25 cycles/limb


C void mpn_copyd (mp_ptr dst, mp_srcptr src, mp_size_t size);
C
C See comments in copyi.asm.

defframe(PARAM_SIZE,12)
defframe(PARAM_SRC, 8)
defframe(PARAM_DST, 4)

	TEXT
	ALIGN(8)
PROLOGUE(mpn_copyd)
deflit(`FRAME',0)

	movl	PARAM_SRC, %eax
	movl	PARAM_SIZE, %ecx

	pushl	%esi	FRAME_pushl()
	pushl	%edi	FRAME_pushl()

	leal	-4(%eax,%ecx,4), %eax		C &src[size-1]
	movl	PARAM_DST, %edx

	subl	$7, %ecx			C size-7
	jle	L(end)

	movl	28-4(%edx,%ecx,4), %esi		C prefetch cache, dst[size-1]
	nop

L(top):
	C eax	src, decrementing
	C ebx
	C ecx	counter, limbs
	C edx	dst
	C esi	scratch
	C edi	scratch
	C ebp

	movl	28-32(%edx,%ecx,4), %esi	C prefetch dst cache line
	subl	$8, %ecx

	movl	(%eax), %esi			C read words pairwise
	movl	-4(%eax), %edi
	movl	%esi, 56(%edx,%ecx,4)		C store words pairwise
	movl	%edi, 52(%edx,%ecx,4)

	movl	-8(%eax), %esi
	movl	-12(%eax), %edi
	movl	%esi, 48(%edx,%ecx,4)
	movl	%edi, 44(%edx,%ecx,4)

	movl	-16(%eax), %esi
	movl	-20(%eax), %edi
	movl	%esi, 40(%edx,%ecx,4)
	movl	%edi, 36(%edx,%ecx,4)

	movl	-24(%eax), %esi
	movl	-28(%eax), %edi
	movl	%esi, 32(%edx,%ecx,4)
	movl	%edi, 28(%edx,%ecx,4)

	leal	-32(%eax), %eax
	jg	L(top)


L(end):
	C ecx	-7 to 0, representing respectively 0 to 7 limbs remaining
	C eax	src end
	C edx	dst, next location to store

	addl	$4, %ecx
	jle	L(no4)

	movl	(%eax), %esi
	movl	-4(%eax), %edi
	movl	%esi, 8(%edx,%ecx,4)
	movl	%edi, 4(%edx,%ecx,4)

	movl	-8(%eax), %esi
	movl	-12(%eax), %edi
	movl	%esi, (%edx,%ecx,4)
	movl	%edi, -4(%edx,%ecx,4)

	subl	$16, %eax
	subl	$4, %ecx
L(no4):

	addl	$2, %ecx
	jle	L(no2)

	movl	(%eax), %esi
	movl	-4(%eax), %edi
	movl	%esi, (%edx,%ecx,4)
	movl	%edi, -4(%edx,%ecx,4)

	subl	$8, %eax
	subl	$2, %ecx
L(no2):

	jnz	L(done)

	movl	(%eax), %ecx
	movl	%ecx, (%edx)	C risk of cache bank clash here

L(done):
	popl	%edi
	popl	%esi

	ret

EPILOGUE()