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/* hppa1.1 mul_1 -- Multiply a limb vector with a limb and store
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* the result in a second limb vector.
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* Copyright (C) 1992, 1993, 1994, 1998,
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* 2001 Free Software Foundation, Inc.
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* This file is part of GnuPG.
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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* Note: This code is heavily based on the GNU MP Library.
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* Actually it's the same code with only minor changes in the
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* way the data is stored; this is to support the abstraction
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* of an optional secure memory allocation which may be used
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* to avoid revealing of sensitive data due to paging etc.
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* The GNU MP Library itself is published under the LGPL;
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* however I decided to publish this code under the plain GPL.
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* mpihelp_mul_1( mpi_ptr_t res_ptr, (r26)
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* mpi_ptr_t s1_ptr, (r25)
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* mpi_size_t s1_size, (r24)
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* mpi_limb_t s2_limb) (r23)
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* This runs at 9 cycles/limb on a PA7000. With the used instructions, it can
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* not become faster due to data cache contention after a store. On the
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* PA7100 it runs at 7 cycles/limb, and that can not be improved either, since
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* only the xmpyu does not need the integer pipeline, so the only dual-issue
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* we will get are addc+xmpyu. Unrolling would not help either CPU.
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* We could use fldds to read two limbs at a time from the S1 array, and that
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* could bring down the times to 8.5 and 6.5 cycles/limb for the PA7000 and
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* PA7100, respectively. We don't do that since it does not seem worth the
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* (alignment) troubles...
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* At least the PA7100 is rumored to be able to deal with cache-misses
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* without stalling instruction issue. If this is true, and the cache is
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* actually also lockup-free, we should use a deeper software pipeline, and
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* load from S1 very early! (The loads and stores to -12(sp) will surely be
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.callinfo frame=64,no_calls
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stw %r23,-16(%r30) ; move s2_limb ...
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addib,= -1,%r24,L$just_one_limb
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fldws -16(%r30),%fr4 ; ... into fr4
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add %r0,%r0,%r0 ; clear carry
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ldw -12(%r30),%r19 ; least significant limb in product
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addib,<> -1,%r24,L$loop
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.label L$just_one_limb
added
removed
mpi/hppa1.1/mpih-mul1.S
