From 7def3d92a4edd807d2df2f016e5c1d6b8e748358 Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@gnu.org>
Date: Mon, 16 Oct 1995 01:18:40 +0000
Subject: Updated from ../=mpn/gmp-1.906.7

---
 sysdeps/alpha/mul_1.s | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 sysdeps/alpha/mul_1.s

(limited to 'sysdeps/alpha/mul_1.s')

diff --git a/sysdeps/alpha/mul_1.s b/sysdeps/alpha/mul_1.s
new file mode 100644
index 0000000000..3ef194d7e6
--- /dev/null
+++ b/sysdeps/alpha/mul_1.s
@@ -0,0 +1,84 @@
+ # Alpha 21064 __mpn_mul_1 -- Multiply a limb vector with a limb and store
+ # the result in a second limb vector.
+
+ # Copyright (C) 1992, 1994 Free Software Foundation, Inc.
+
+ # This file is part of the GNU MP Library.
+
+ # The GNU MP Library is free software; you can redistribute it and/or modify
+ # it under the terms of the GNU Library General Public License as published by
+ # the Free Software Foundation; either version 2 of the License, or (at your
+ # option) any later version.
+
+ # The GNU MP Library is distributed in the hope that it will be useful, but
+ # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
+ # License for more details.
+
+ # You should have received a copy of the GNU Library General Public License
+ # along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
+ # the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+
+ # INPUT PARAMETERS
+ # res_ptr	r16
+ # s1_ptr	r17
+ # size		r18
+ # s2_limb	r19
+
+ # This code runs at 42 cycles/limb on the EV4 and 18 cycles/limb on the EV5.
+
+ # To improve performance for long multiplications, we would use
+ # 'fetch' for S1 and 'fetch_m' for RES.  It's not obvious how to use
+ # these instructions without slowing down the general code: 1. We can
+ # only have two prefetches in operation at any time in the Alpha
+ # architecture.  2. There will seldom be any special alignment
+ # between RES_PTR and S1_PTR.  Maybe we can simply divide the current
+ # loop into an inner and outer loop, having the inner loop handle
+ # exactly one prefetch block?
+
+	.set	noreorder
+	.set	noat
+.text
+	.align	3
+	.globl	__mpn_mul_1
+	.ent	__mpn_mul_1 2
+__mpn_mul_1:
+	.frame	$30,0,$26
+
+	ldq	$2,0($17)	# $2 = s1_limb
+	subq	$18,1,$18	# size--
+	mulq	$2,$19,$3	# $3 = prod_low
+	bic	$31,$31,$4	# clear cy_limb
+	umulh	$2,$19,$0	# $0 = prod_high
+	beq	$18,Lend1	# jump if size was == 1
+	ldq	$2,8($17)	# $2 = s1_limb
+	subq	$18,1,$18	# size--
+	stq	$3,0($16)
+	beq	$18,Lend2	# jump if size was == 2
+
+	.align	3
+Loop:	mulq	$2,$19,$3	# $3 = prod_low
+	addq	$4,$0,$0	# cy_limb = cy_limb + 'cy'
+	subq	$18,1,$18	# size--
+	umulh	$2,$19,$4	# $4 = cy_limb
+	ldq	$2,16($17)	# $2 = s1_limb
+	addq	$17,8,$17	# s1_ptr++
+	addq	$3,$0,$3	# $3 = cy_limb + prod_low
+	stq	$3,8($16)
+	cmpult	$3,$0,$0	# $0 = carry from (cy_limb + prod_low)
+	addq	$16,8,$16	# res_ptr++
+	bne	$18,Loop
+
+Lend2:	mulq	$2,$19,$3	# $3 = prod_low
+	addq	$4,$0,$0	# cy_limb = cy_limb + 'cy'
+	umulh	$2,$19,$4	# $4 = cy_limb
+	addq	$3,$0,$3	# $3 = cy_limb + prod_low
+	cmpult	$3,$0,$0	# $0 = carry from (cy_limb + prod_low)
+	stq	$3,8($16)
+	addq	$4,$0,$0	# cy_limb = prod_high + cy
+	ret	$31,($26),1
+Lend1:	stq	$3,0($16)
+	ret	$31,($26),1
+
+	.end	__mpn_mul_1
-- 
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