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Diffstat (limited to '')
| -rw-r--r-- | mpi/powerpc32/mpih-sub1.S | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/mpi/powerpc32/mpih-sub1.S b/mpi/powerpc32/mpih-sub1.S index b2e0590f6..1387650be 100644 --- a/mpi/powerpc32/mpih-sub1.S +++ b/mpi/powerpc32/mpih-sub1.S @@ -20,6 +20,11 @@ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ +#include "sysdep.h" +#include "asm-syntax.h" + + +#ifndef USE_PPC_PATCHES /******************* * mpi_limb_t @@ -57,4 +62,71 @@ Lend: stw 7,4(3) # store ultimate result limb subfic 3,3,0 # ... return value register blr +#else +/* Subtract two limb vectors of equal, non-zero length for PowerPC. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C 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. */ + +/* mp_limb_t mpn_sub_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, + mp_size_t size) + Calculate s1-s2 and put result in res_ptr; return borrow, 0 or 1. */ + +/* Note on optimisation: This code is optimal for the 601. Almost every other + possible 2-unrolled inner loop will not be. Also, watch out for the + alignment... */ + +EALIGN(_mpihelp_sub_n,3,1) +/* Set up for loop below. */ + mtcrf 0x01,%r6 + srwi. %r7,%r6,1 + mtctr %r7 + bt 31,2f + +/* Set the carry (clear the borrow). */ + subfc %r0,%r0,%r0 +/* Adjust pointers for loop. */ + addi %r3,%r3,-4 + addi %r4,%r4,-4 + addi %r5,%r5,-4 + b 0f + +2: lwz %r7,0(%r5) + lwz %r6,0(%r4) + subfc %r6,%r7,%r6 + stw %r6,0(%r3) + beq 1f +/* Align start of loop to an odd word boundary to guarantee that the + last two words can be fetched in one access (for 601). This turns + out to be important. */ +0: + lwz %r9,4(%r4) + lwz %r8,4(%r5) + lwzu %r6,8(%r4) + lwzu %r7,8(%r5) + subfe %r8,%r8,%r9 + stw %r8,4(%r3) + subfe %r6,%r7,%r6 + stwu %r6,8(%r3) + bdnz 0b +/* Return the borrow. */ +1: subfe %r3,%r3,%r3 + neg %r3,%r3 + blr +END(_mpihelp_sub_n) +#endif |