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/* PowerPC-32 submul_1 -- Multiply a limb vector with a limb and subtract
* the result from a second limb vector.
*
* Copyright (C) 1995, 1998, 2002 Free Software Foundation, Inc.
*
* This file is part of Libgcrypt.
*
* Libgcrypt 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.
*
* Libgcrypt 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "sysdep.h"
#include "asm-syntax.h"
#ifndef USE_PPC_PATCHES
/*******************
* mpi_limb_t
* _gcry_mpih_submul_1( mpi_ptr_t res_ptr, (r3)
* mpi_ptr_t s1_ptr, (r4)
* mpi_size_t s1_size, (r5)
* mpi_limb_t s2_limb) (r6)
*
* This is a fairly straightforward implementation. The timing of the PC601
* is hard to understand, so I will wait to optimize this until I have some
* hardware to play with.
*
* The code trivially generalizes to 64 bit limbs for the PC620.
*/
.toc
.csect ._gcry_mpih_submul_1[PR]
.align 2
.globl _gcry_mpih_submul_1
.globl ._gcry_mpih_submul_1
.csect _gcry_mpih_submul_1[DS]
_gcry_mpih_submul_1:
.long ._gcry_mpih_submul_1[PR], TOC[tc0], 0
.csect ._gcry_mpih_submul_1[PR]
._gcry_mpih_submul_1:
mtctr 5
lwz 0,0(4)
mullw 7,0,6
mulhwu 10,0,6
lwz 9,0(3)
subfc 8,7,9
addc 7,7,8 # invert cy (r7 is junk)
addi 3,3,-4
bdz Lend
Loop: lwzu 0,4(4)
stwu 8,4(3)
mullw 8,0,6
adde 7,8,10
mulhwu 10,0,6
lwz 9,4(3)
addze 10,10
subfc 8,7,9
addc 7,7,8 # invert cy (r7 is junk)
bdnz Loop
Lend: stw 8,4(3)
addze 3,10
blr
#else
/* Multiply a limb vector by a single limb, for PowerPC.
Copyright (C) 1993, 1994, 1995, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C 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 C 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 C 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. */
/* mp_limb_t mpn_submul_1 (mp_ptr res_ptr, mp_srcptr s1_ptr,
mp_size_t s1_size, mp_limb_t s2_limb)
Calculate res-s1*s2 and put result back in res; return carry. */
ENTRY(_gcry_mpih_submul_1)
mtctr %r5
lwz %r0,0(%r4)
mullw %r7,%r0,%r6
mulhwu %r10,%r0,%r6
lwz %r9,0(%r3)
subf %r8,%r7,%r9
addc %r7,%r7,%r8 # invert cy (r7 is junk)
addi %r3,%r3,-4 # adjust res_ptr
bdz 1f
0: lwzu %r0,4(%r4)
stwu %r8,4(%r3)
mullw %r8,%r0,%r6
adde %r7,%r8,%r10
mulhwu %r10,%r0,%r6
lwz %r9,4(%r3)
addze %r10,%r10
subf %r8,%r7,%r9
addc %r7,%r7,%r8 # invert cy (r7 is junk)
bdnz 0b
1: stw %r8,4(%r3)
addze %r3,%r10
blr
END(_gcry_mpih_submul_1)
#endif