glibc/sysdeps/s390/s390-32/mul_1.S

/* __mpn_mul_1 -- Multiply a limb vector with a limb and store
   the result in a second limb vector.
   Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   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., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.  */

/*
   INPUT PARAMETERS
   res_ptr   %r2
   s1_ptr    %r3
   size	     %r4
   s2_limb   %r5
*/

#include <sysdep.h>
#include "asm-syntax.h"

	.text
ENTRY(__mpn_mul_1)
	st     %r6,24(%r15)
	slr    %r6,%r6            # cy_limb = 0
.L0:    icm    %r1,15,0(%r3)      # get s1_ptr[i]
	mr     %r0,%r5            # umul_ppmm(prod_high,prod_low,s1_ptr[j],s2_limb)
	jnm    .L1
	alr    %r0,%r5
.L1:    ltr    %r5,%r5
	jnm    .L2
	al     %r0,0(%r3)
.L2:    alr    %r1,%r6            # prod_low += cy_limb
	lr     %r6,%r0            # cy_limb = prod_high
	brc    12,.L3
	ahi    %r6,1              #           + (prod_low < cy_limb)
.L3:    st     %r1,0(%r2)
	la     %r2,4(0,%r2)
	la     %r3,4(0,%r3)
	brct   %r4,.L0
	lr     %r2,%r6            # return cy_limb
	l      %r6,24(%r15)
.Lexit: br     %r14
END(__mpn_mul_1)