;! HP-PA-1.1 __mpn_mul_1 -- Multiply a limb vector with a limb and store

;! the result in a second limb vector.

;! Copyright (C) 1992-2018 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 Lesser General Public License as published by

;! the Free Software Foundation; either version 2.1 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 Lesser General Public

;! License for more details.

;! You should have received a copy of the GNU Lesser General Public License

;! along with the GNU MP Library.  If not, see

;! <http://www.gnu.org/licenses/>.

;! INPUT PARAMETERS

;! res_ptr	r26

;! s1_ptr	r25

;! size		r24

;! s2_limb	r23

;! This runs at 9 cycles/limb on a PA7000.  With the used instructions, it can

;! not become faster due to data cache contention after a store.  On the

;! PA7100 it runs at 7 cycles/limb, and that can not be improved either, since

;! only the xmpyu does not need the integer pipeline, so the only dual-issue

;! we will get are addc+xmpyu.  Unrolling would not help either CPU.

;! We could use fldds to read two limbs at a time from the S1 array, and that

;! could bring down the times to 8.5 and 6.5 cycles/limb for the PA7000 and

;! PA7100, respectively.  We don't do that since it does not seem worth the

;! (alignment) troubles...

;! At least the PA7100 is rumored to be able to deal with cache-misses

;! without stalling instruction issue.  If this is true, and the cache is

;! actually also lockup-free, we should use a deeper software pipeline, and

;! load from S1 very early;  (The loads and stores to -12(sp) will surely be

;! in the cache.)

	.text

	.export		__mpn_mul_1

__mpn_mul_1:

	.proc

	.callinfo	frame=64,no_calls

	.entry

	ldo		64(%r30),%r30

	fldws,ma	4(%r25),%fr5

	stw		%r23,-16(%r30)		;! move s2_limb ...

	addib,=		-1,%r24,L$just_one_limb

	 fldws		-16(%r30),%fr4		;! ... into fr4

	add		%r0,%r0,%r0		;! clear carry

	xmpyu		%fr4,%fr5,%fr6

	fldws,ma	4(%r25),%fr7

	fstds	 	%fr6,-16(%r30)

	xmpyu		%fr4,%fr7,%fr8

	ldw		-12(%r30),%r20		;! least significant limb in product

	ldw		-16(%r30),%r28

	fstds		%fr8,-16(%r30)

	addib,=		-1,%r24,L$end

	 ldw		-12(%r30),%r1

;! Main loop

L$loop:

	fldws,ma	4(%r25),%fr5

	stws,ma		%r20,4(%r26)

	addc		%r28,%r1,%r20

	xmpyu		%fr4,%fr5,%fr6

	ldw		-16(%r30),%r28

	fstds		%fr6,-16(%r30)

	addib,<>	-1,%r24,L$loop

	 ldw		-12(%r30),%r1

L$end:

	stws,ma		%r20,4(%r26)

	addc		%r28,%r1,%r20

	ldw		-16(%r30),%r28

	stws,ma		%r20,4(%r26)

	addc		%r0,%r28,%r28

	bv		0(%r2)

	 ldo		-64(%r30),%r30

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)

	.exit

	.procend