1 Copyright 2002, 2005 Free Software Foundation, Inc.
3 This file is part of the GNU MP Library.
5 The GNU MP Library is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or (at your
8 option) any later version.
10 The GNU MP Library is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
13 License for more details.
15 You should have received a copy of the GNU Lesser General Public License
16 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
22 POWERPC 32-BIT MPN SUBROUTINES
25 This directory contains mpn functions for various 32-bit PowerPC chips.
31 ================================================
32 powerpc generic, 604, 604e, 744x, 745x
33 powerpc/750 740, 750, 7400, 7410
36 The top-level powerpc directory is currently mostly aimed at 604/604e but
37 should be reasonable on all powerpcs.
43 The code is quite well optimized for the 604e, other chips have had less
46 Altivec SIMD available in 74xx might hold some promise, but unfortunately
47 GMP only guarantees 32-bit data alignment, so there's lots of fiddling
48 around with partial operations at the start and end of limb vectors. A
49 128-bit limb would be a novel idea, but is unlikely to be practical, since
50 it would have to work with ordinary +, -, * etc in the C code.
52 Also, Altivec isn't very well suited for the GMP multiplication needs.
53 Using floating-point based multiplication has much better better performance
54 potential for all current powerpcs, both the ones with slow integer multiply
55 units (603, 740, 750, 7400, 7410) and those with fast (604, 604e, 744x,
56 745x). This is because all powerpcs do some level of pipelining in the FPU:
58 603 and 750 can sustain one fmadd every 2nd cycle.
59 604 and 604e can sustain one fmadd per cycle.
60 7400 and 7410 can sustain 3 fmadd in 4 cycles.
61 744x and 745x can sustain 4 fmadd in 5 cycles.
67 The normal powerpc convention is to give registers as plain numbers, like
68 "mtctr 6", but on Apple MacOS X (powerpc*-*-rhapsody* and
69 powerpc*-*-darwin*) the assembler demands an "r" like "mtctr r6". Note
70 however when register 0 in an instruction means a literal zero the "r" is
71 omitted, for instance "lwzx r6,0,r7".
73 The GMP code uses the "r" forms, powerpc-defs.m4 transforms them to plain
74 numbers according to what GMP_ASM_POWERPC_R_REGISTERS finds is needed.
75 (Note that this style isn't fully general, as the identifier r4 and the
76 register r4 will not be distinguishable on some systems. However, this is
77 not a problem for the limited GMP assembly usage.)
84 lis 9, __gmp_binvert_limb_table@ha
85 rlwinm 11, 5, 31, 25, 31
86 la 9, __gmp_binvert_limb_table@l(9)
95 lwz 7, .LCL0-.LCF0(30)
97 lwz 11, .LC0-.LCTOC1(30)
98 rlwinm 3, 5, 31, 25, 31
103 .tc __gmp_binvert_limb_table[TC],__gmp_binvert_limb_table[RW]
105 rlwinm 0, 5, 31, 25, 31
109 lis r2, ha16(___gmp_binvert_limb_table)
110 rlwinm r9, r5, 31, 25, 31
111 la r2, lo16(___gmp_binvert_limb_table)(r2)
119 addis r2, r7, ha16(L___gmp_binvert_limb_table$non_lazy_ptr-L0001$pb)
120 rlwinm r9, r5, 31, 25, 31
121 lwz r2, lo16(L___gmp_binvert_limb_table$non_lazy_ptr-L0001$pb)(r2)
124 .non_lazy_symbol_pointer
125 L___gmp_binvert_limb_table$non_lazy_ptr:
126 .indirect_symbol ___gmp_binvert_limb_table
128 .subsections_via_symbols
131 For GNU/Linux and Darwin, we might want to duplicate __gmp_binvert_limb_table
132 into the text section in this file. We should thus be able to reach it like
137 rlwinm r9, r5, 31, 25, 31
138 addi r9, r9, lo16(local_binvert_table-L0)
145 PowerPC Microprocessor Family: The Programming Environments for 32-bit
146 Microprocessors, IBM document G522-0290-01, 2000.
148 PowerPC 604e RISC Microprocessor User's Manual with Supplement for PowerPC
149 604 Microprocessor, IBM document G552-0330-00, Freescale document
150 MPC604EUM/AD, 3/1998.
152 MPC7410/MPC7400 RISC Microprocessor User's Manual, Freescale document
153 MPC7400UM/D, rev 1, 11/2002.
155 MPC7450 RISC Microprocessor Family Reference Manual, Freescale document
156 MPC7450UM, rev 5, 1/2005.
158 The above are available online from
160 http://www.ibm.com/chips/techlib/techlib.nsf/productfamilies/PowerPC
161 http://www.freescale.com/PowerPC