sysdeps/m68k/m680x0/m68020/mul_1.S

   1 /* mc68020 __mpn_mul_1 -- Multiply a limb vector with a limb and store
   2    the result in a second limb vector.
   3
   4 Copyright (C) 1992-2015 Free Software Foundation, Inc.
   5
   6 This file is part of the GNU MP Library.
   7
   8 The GNU MP Library is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU Lesser General Public License as published by
  10 the Free Software Foundation; either version 2.1 of the License, or (at your
  11 option) any later version.
  12
  13 The GNU MP Library is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  16 License for more details.
  17
  18 You should have received a copy of the GNU Lesser General Public License
  19 along with the GNU MP Library.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 /*
  22   INPUT PARAMETERS
  23   res_ptr       (sp + 4)
  24   s1_ptr        (sp + 8)
  25   s1_size       (sp + 12)
  26   s2_limb       (sp + 16)
  27 */
  28
  29 #include "sysdep.h"
  30 #include "asm-syntax.h"
  31
  32         TEXT
  33 ENTRY(__mpn_mul_1)
  34
  35 #define res_ptr a0
  36 #define s1_ptr a1
  37 #define s1_size d2
  38 #define s2_limb d4
  39
  40 /* Save used registers on the stack.  */
  41         moveml  R(d2)-R(d4),MEM_PREDEC(sp)
  42         cfi_adjust_cfa_offset (3*4)
  43         cfi_rel_offset (R(d2), 0)
  44         cfi_rel_offset (R(d3), 4)
  45         cfi_rel_offset (R(d4), 8)
  46
  47 /* Copy the arguments to registers.  Better use movem?  */
  48         movel   MEM_DISP(sp,16),R(res_ptr)
  49         movel   MEM_DISP(sp,20),R(s1_ptr)
  50         movel   MEM_DISP(sp,24),R(s1_size)
  51         movel   MEM_DISP(sp,28),R(s2_limb)
  52
  53         eorw    #1,R(s1_size)
  54         clrl    R(d1)
  55         lsrl    #1,R(s1_size)
  56         bcc     L(L1)
  57         subql   #1,R(s1_size)
  58         subl    R(d0),R(d0)     /* (d0,cy) <= (0,0) */
  59
  60 L(Loop:)
  61         movel   MEM_POSTINC(s1_ptr),R(d3)
  62         mulul   R(s2_limb),R(d1):R(d3)
  63         addxl   R(d0),R(d3)
  64         movel   R(d3),MEM_POSTINC(res_ptr)
  65 L(L1:)  movel   MEM_POSTINC(s1_ptr),R(d3)
  66         mulul   R(s2_limb),R(d0):R(d3)
  67         addxl   R(d1),R(d3)
  68         movel   R(d3),MEM_POSTINC(res_ptr)
  69
  70         dbf     R(s1_size),L(Loop)
  71         clrl    R(d3)
  72         addxl   R(d3),R(d0)
  73         subl    #0x10000,R(s1_size)
  74         bcc     L(Loop)
  75
  76 /* Restore used registers from stack frame.  */
  77         moveml  MEM_POSTINC(sp),R(d2)-R(d4)
  78         cfi_adjust_cfa_offset (-3*4)
  79         cfi_restore (R(d2))
  80         cfi_restore (R(d3))
  81         cfi_restore (R(d4))
  82         rts
  83 END(__mpn_mul_1)