Return to mul_1.asm CVS log

Up to [local] / OpenXM_contrib / gmp / mpn / pa32 / hppa1_1

Import gmp 4.1.2

dnl  HP-PA 1.1 mpn_mul_1 -- Multiply a limb vector with a limb and store the
dnl  result in a second limb vector.

dnl  Copyright 1992, 1993, 1994, 2000, 2001, 2002 Free Software Foundation,
dnl  Inc.

dnl  This file is part of the GNU MP Library.

dnl  The GNU MP Library is free software; you can redistribute it and/or modify
dnl  it under the terms of the GNU Lesser General Public License as published
dnl  by the Free Software Foundation; either version 2.1 of the License, or (at
dnl  your option) any later version.

dnl  The GNU MP Library is distributed in the hope that it will be useful, but
dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
dnl  License for more details.

dnl  You should have received a copy of the GNU Lesser General Public License
dnl  along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
dnl  the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
dnl  MA 02111-1307, USA.

include(`../config.m4')

C INPUT PARAMETERS
C res_ptr	r26
C s1_ptr	r25
C size		r24
C s2_limb	r23

C This runs at 9 cycles/limb on a PA7000.  With the used instructions, it can
C not become faster due to data cache contention after a store.  On the PA7100
C it runs at 7 cycles/limb.

C We could use fldds to read two limbs at a time from the S1 array, and that
C could bring down the times to 8.5 and 6.5 cycles/limb for the PA7000 and
C PA7100, respectively.  We don't do that since it does not seem worth the
C (alignment) troubles...

C At least the PA7100 is rumored to be able to deal with cache-misses without
C stalling instruction issue.  If this is true, and the cache is actually also
C lockup-free, we should use a deeper software pipeline, and load from S1 very
C early!  (The loads and stores to -12(sp) will surely be in the cache.)

ASM_START()
PROLOGUE(mpn_mul_1)
C	.callinfo	frame=64,no_calls

	ldo		64(%r30),%r30
	fldws,ma	4(%r25),%fr5
	stw		%r23,-16(%r30)		C move s2_limb ...
	addib,=		-1,%r24,L(just_one_limb)
	 fldws		-16(%r30),%fr4		C ... into fr4
	add		%r0,%r0,%r0		C clear carry
	xmpyu		%fr4,%fr5,%fr6
	fldws,ma	4(%r25),%fr7
	fstds		%fr6,-16(%r30)
	xmpyu		%fr4,%fr7,%fr8
	ldw		-12(%r30),%r19		C least significant limb in product
	ldw		-16(%r30),%r28

	fstds		%fr8,-16(%r30)
	addib,=		-1,%r24,L(end)
	 ldw		-12(%r30),%r1

C Main loop
	.label	L(loop)
	fldws,ma	4(%r25),%fr5
	stws,ma		%r19,4(%r26)
	addc		%r28,%r1,%r19
	xmpyu		%fr4,%fr5,%fr6
	ldw		-16(%r30),%r28
	fstds		%fr6,-16(%r30)
	addib,<>	-1,%r24,L(loop)
	 ldw		-12(%r30),%r1

	.label	L(end)
	stws,ma		%r19,4(%r26)
	addc		%r28,%r1,%r19
	ldw		-16(%r30),%r28
	stws,ma		%r19,4(%r26)
	addc		%r0,%r28,%r28
	bv		0(%r2)
	 ldo		-64(%r30),%r30

	.label	L(just_one_limb)
	xmpyu		%fr4,%fr5,%fr6
	fstds		%fr6,-16(%r30)
	ldw		-16(%r30),%r28
	ldo		-64(%r30),%r30
	bv		0(%r2)
	 fstws		%fr6R,0(%r26)
EPILOGUE()