sysdeps/powerpc/powerpc32/mul_1.S

   1 /* Multiply a limb vector by a limb, for PowerPC.
   2    Copyright (C) 1993-2019 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20
  21 /* mp_limb_t mpn_mul_1 (mp_ptr res_ptr, mp_srcptr s1_ptr,
  22                         mp_size_t s1_size, mp_limb_t s2_limb)
  23    Calculate s1*s2 and put result in res_ptr; return carry.  */
  24
  25 ENTRY (__mpn_mul_1)
  26         mtctr   r5
  27
  28         lwz     r0,0(r4)
  29         mullw   r7,r0,r6
  30         mulhwu  r10,r0,r6
  31         addi    r3,r3,-4                # adjust res_ptr
  32         addic   r5,r5,0                 # clear cy with dummy insn
  33         bdz     L(1)
  34
  35 L(0):   lwzu    r0,4(r4)
  36         stwu    r7,4(r3)
  37         mullw   r8,r0,r6
  38         adde    r7,r8,r10
  39         mulhwu  r10,r0,r6
  40         bdnz    L(0)
  41
  42 L(1):   stw     r7,4(r3)
  43         addze   r3,r10
  44         blr
  45 END (__mpn_mul_1)