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version 1.1.1.1, 2000/01/10 15:35:25

version 1.1.1.2, 2003/08/25 16:06:26

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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; see the file COPYING.LIB. If not, write to

the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA

02111-1307, USA.

This directory contains mpn functions for various SPARC chips. Code that

runs only on version 8 SPARC implementations, is in the v8 subdirectory.

Line 8 RELEVANT OPTIMIZATION ISSUES

Line 31 RELEVANT OPTIMIZATION ISSUES

On most early SPARC implementations, the ST instructions takes multiple

cycles, while a STD takes just a single cycle more than an ST. For the CPUs

in SPARCstation I and II, the times are 3 and 4 cycles, respectively.

Therefore, combining two ST instrucitons into a STD when possible is a

Therefore, combining two ST instructions into a STD when possible is a

significant optimiation.

significant optimization.

Later SPARC implementations have single cycle ST.

Line 19 programs that perform so many memory operations that t

Line 42 programs that perform so many memory operations that t

non-memory operations to issue in parallel with all memory operations, using

LDD and STD when possible helps.

UltraSPARC-1/2 has very slow integer multiplication. In the v9 subdirectory,

we therefore use floating-point multiplication.

STATUS

1. On a SuperSPARC, mpn_lshift and mpn_rshift run at 3 cycles/limb, or 2.5

Line 31 STATUS

Line 57 STATUS

3. mpn_mul_1 runs at what is believed to be optimal speed.

4. On SuperSPARC, mpn_addmul_1 and mpn_submul_1 could both be improved by a

cycle by avoiding one of the add instrucitons. See a29k/addmul_1.

cycle by avoiding one of the add instructions. See a29k/addmul_1.

The speed of the code for other SPARC implementations is uncertain.