1/* Add two limb vectors of equal, non-zero length for PowerPC. 2 Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, write to the Free 17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 18 02111-1307 USA. */ 19 20#include <sysdep.h> 21#include <bp-sym.h> 22#include <bp-asm.h> 23 24/* mp_limb_t mpn_add_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, 25 mp_size_t size) 26 Calculate s1+s2 and put result in res_ptr; return carry, 0 or 1. */ 27 28/* Note on optimisation: This code is optimal for the 601. Almost every other 29 possible 2-unrolled inner loop will not be. Also, watch out for the 30 alignment... */ 31 32EALIGN (BP_SYM (__mpn_add_n), 3, 0) 33 34#if __BOUNDED_POINTERS__ 35 slwi r10,r6,2 /* convert limbs to bytes */ 36 CHECK_BOUNDS_BOTH_WIDE (r3, r8, r9, r10) 37 CHECK_BOUNDS_BOTH_WIDE (r4, r8, r9, r10) 38 CHECK_BOUNDS_BOTH_WIDE (r5, r8, r9, r10) 39#endif 40/* Set up for loop below. */ 41 mtcrf 0x01,r6 42 srwi. r7,r6,1 43 li r10,0 44 mtctr r7 45 bt 31,L(2) 46 47/* Clear the carry. */ 48 addic r0,r0,0 49/* Adjust pointers for loop. */ 50 addi r3,r3,-4 51 addi r4,r4,-4 52 addi r5,r5,-4 53 b L(0) 54 55L(2): lwz r7,0(r5) 56 lwz r6,0(r4) 57 addc r6,r6,r7 58 stw r6,0(r3) 59 beq L(1) 60 61/* The loop. */ 62 63/* Align start of loop to an odd word boundary to guarantee that the 64 last two words can be fetched in one access (for 601). */ 65L(0): lwz r9,4(r4) 66 lwz r8,4(r5) 67 lwzu r6,8(r4) 68 lwzu r7,8(r5) 69 adde r8,r9,r8 70 stw r8,4(r3) 71 adde r6,r6,r7 72 stwu r6,8(r3) 73 bdnz L(0) 74/* Return the carry. */ 75L(1): addze r3,r10 76 blr 77END (BP_SYM (__mpn_add_n)) 78