1/* PowerPC-32 add_n -- Add two limb vectors of equal, non-zero length. 2 * 3 * Copyright (C) 1992, 1994, 1995, 1998, 2002 Free Software Foundation, Inc. 4 * 5 * This file is part of Libgcrypt. 6 * 7 * Libgcrypt is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU Lesser General Public License as 9 * published by the Free Software Foundation; either version 2.1 of 10 * the License, or (at your option) any later version. 11 * 12 * Libgcrypt is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 20 */ 21 22#include "sysdep.h" 23#include "asm-syntax.h" 24 25 26#ifndef USE_PPC_PATCHES 27 28/******************* 29 * mpi_limb_t 30 * _gcry_mpih_add_n( mpi_ptr_t res_ptr, (r3) 31 * mpi_ptr_t s1_ptr, (r4) 32 * mpi_ptr_t s2_ptr, (r5) 33 * mpi_size_t size) (r6) 34 */ 35 36 .toc 37 .extern _gcry_mpih_add_n[DS] 38 .extern ._gcry_mpih_add_n 39.csect [PR] 40 .align 2 41 .globl _gcry_mpih_add_n 42 .globl ._gcry_mpih_add_n 43 .csect _gcry_mpih_add_n[DS] 44_gcry_mpih_add_n: 45 .long ._gcry_mpih_add_n, TOC[tc0], 0 46 .csect [PR] 47._gcry_mpih_add_n: 48 mtctr 6 # copy size into CTR 49 lwz 8,0(4) # load least significant s1 limb 50 lwz 0,0(5) # load least significant s2 limb 51 addi 3,3,-4 # offset res_ptr, it is updated before used 52 addc 7,0,8 # add least significant limbs, set cy 53 bdz Lend # If done, skip loop 54Loop: lwzu 8,4(4) # load s1 limb and update s1_ptr 55 lwzu 0,4(5) # load s2 limb and update s2_ptr 56 stwu 7,4(3) # store previous limb in load latency slot 57 adde 7,0,8 # add new limbs with cy, set cy 58 bdnz Loop # decrement CTR and loop back 59Lend: stw 7,4(3) # store ultimate result limb 60 li 3,0 # load cy into ... 61 addze 3,3 # ... return value register 62 blr 63 64#else 65/* Add two limb vectors of equal, non-zero length for PowerPC. 66 Copyright (C) 1997 Free Software Foundation, Inc. 67 This file is part of the GNU C Library. 68 69 The GNU C Library is free software; you can redistribute it and/or 70 modify it under the terms of the GNU Library General Public License as 71 published by the Free Software Foundation; either version 2 of the 72 License, or (at your option) any later version. 73 74 The GNU C Library is distributed in the hope that it will be useful, 75 but WITHOUT ANY WARRANTY; without even the implied warranty of 76 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 77 Library General Public License for more details. 78 79 You should have received a copy of the GNU Library General Public 80 License along with the GNU C Library; see the file COPYING.LIB. If not, 81 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, 82 Boston, MA 02111-1307, USA. */ 83 84#include "sysdep.h" 85#include "asm-syntax.h" 86 87 88/* mp_limb_t mpn_add_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, 89 mp_size_t size) 90 Calculate s1+s2 and put result in res_ptr; return carry, 0 or 1. */ 91 92/* Note on optimisation: This code is optimal for the 601. Almost every other 93 possible 2-unrolled inner loop will not be. Also, watch out for the 94 alignment... */ 95 96EALIGN(_gcry_mpih_add_n,3,0) 97/* Set up for loop below. */ 98 mtcrf 0x01,%r6 99 srwi. %r7,%r6,1 100 li %r10,0 101 mtctr %r7 102 bt 31,2f 103 104/* Clear the carry. */ 105 addic %r0,%r0,0 106/* Adjust pointers for loop. */ 107 addi %r3,%r3,-4 108 addi %r4,%r4,-4 109 addi %r5,%r5,-4 110 b 0f 111 1122: lwz %r7,0(%r5) 113 lwz %r6,0(%r4) 114 addc %r6,%r6,%r7 115 stw %r6,0(%r3) 116 beq 1f 117 118/* The loop. */ 119 120/* Align start of loop to an odd word boundary to guarantee that the 121 last two words can be fetched in one access (for 601). */ 1220: lwz %r9,4(%r4) 123 lwz %r8,4(%r5) 124 lwzu %r6,8(%r4) 125 lwzu %r7,8(%r5) 126 adde %r8,%r9,%r8 127 stw %r8,4(%r3) 128 adde %r6,%r6,%r7 129 stwu %r6,8(%r3) 130 bdnz 0b 131/* Return the carry. */ 1321: addze %r3,%r10 133 blr 134END(_gcry_mpih_add_n) 135#endif 136 137