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Diffstat (limited to 'sysdeps/m68k/sub_n.S')
| -rw-r--r-- | sysdeps/m68k/sub_n.S | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/m68k/sub_n.S b/sysdeps/m68k/sub_n.S new file mode 100644 index 0000000000..5833dd2719 --- /dev/null +++ b/sysdeps/m68k/sub_n.S @@ -0,0 +1,76 @@ +/* mc68020 __mpn_sub_n -- Subtract two limb vectors of the same length > 0 and + store difference in a third limb vector. + +Copyright (C) 1992, 1994, 1996, 1998 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as published by +the Free Software Foundation; either version 2.1 of the License, or (at your +option) any later version. + +The GNU MP 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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the GNU MP 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. */ + +/* + INPUT PARAMETERS + res_ptr (sp + 4) + s1_ptr (sp + 8) + s2_ptr (sp + 16) + size (sp + 12) +*/ + +#include "sysdep.h" +#include "asm-syntax.h" + + TEXT +ENTRY(__mpn_sub_n) +/* Save used registers on the stack. */ + movel R(d2),MEM_PREDEC(sp) + movel R(a2),MEM_PREDEC(sp) + +/* Copy the arguments to registers. Better use movem? */ + movel MEM_DISP(sp,12),R(a2) + movel MEM_DISP(sp,16),R(a0) + movel MEM_DISP(sp,20),R(a1) + movel MEM_DISP(sp,24),R(d2) + + eorw #1,R(d2) + lsrl #1,R(d2) + bcc L(L1) + subql #1,R(d2) /* clears cy as side effect */ + +L(Loop:) + movel MEM_POSTINC(a0),R(d0) + movel MEM_POSTINC(a1),R(d1) + subxl R(d1),R(d0) + movel R(d0),MEM_POSTINC(a2) +L(L1:) movel MEM_POSTINC(a0),R(d0) + movel MEM_POSTINC(a1),R(d1) + subxl R(d1),R(d0) + movel R(d0),MEM_POSTINC(a2) + + dbf R(d2),L(Loop) /* loop until 16 lsb of %4 == -1 */ + subxl R(d0),R(d0) /* d0 <= -cy; save cy as 0 or -1 in d0 */ + subl #0x10000,R(d2) + bcs L(L2) + addl R(d0),R(d0) /* restore cy */ + bra L(Loop) + +L(L2:) + negl R(d0) + +/* Restore used registers from stack frame. */ + movel MEM_POSTINC(sp),R(a2) + movel MEM_POSTINC(sp),R(d2) + + rts +END(__mpn_sub_n) |