diff options
Diffstat (limited to 'sysdeps/m68k/m68020/sub_n.S')
| -rw-r--r-- | sysdeps/m68k/m68020/sub_n.S | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/m68k/m68020/sub_n.S b/sysdeps/m68k/m68020/sub_n.S new file mode 100644 index 0000000000..19f0ec1568 --- /dev/null +++ b/sysdeps/m68k/m68020/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 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 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 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 Library General Public +License for more details. + +You should have received a copy of the GNU Library General Public License +along with the GNU MP Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* + INPUT PARAMETERS + res_ptr (sp + 4) + s1_ptr (sp + 8) + s2_ptr (sp + 16) + size (sp + 12) +*/ + +#include "asm-syntax.h" + + TEXT + ALIGN + GLOBL ___mpn_sub_n + +LAB(___mpn_sub_n) +/* Save used registers on the stack. */ + INSN2(move,l ,MEM_PREDEC(sp),d2) + INSN2(move,l ,MEM_PREDEC(sp),a2) + +/* Copy the arguments to registers. Better use movem? */ + INSN2(move,l ,a2,MEM_DISP(sp,12)) + INSN2(move,l ,a0,MEM_DISP(sp,16)) + INSN2(move,l ,a1,MEM_DISP(sp,20)) + INSN2(move,l ,d2,MEM_DISP(sp,24)) + + INSN2(eor,w ,d2,#1) + INSN2(lsr,l ,d2,#1) + bcc L1 + INSN2(subq,l ,d2,#1) /* clears cy as side effect */ + +LAB(Loop) + INSN2(move,l ,d0,MEM_POSTINC(a0)) + INSN2(move,l ,d1,MEM_POSTINC(a1)) + INSN2(subx,l ,d0,d1) + INSN2(move,l ,MEM_POSTINC(a2),d0) +LAB(L1) INSN2(move,l ,d0,MEM_POSTINC(a0)) + INSN2(move,l ,d1,MEM_POSTINC(a1)) + INSN2(subx,l ,d0,d1) + INSN2(move,l ,MEM_POSTINC(a2),d0) + + dbf d2,Loop /* loop until 16 lsb of %4 == -1 */ + INSN2(subx,l ,d0,d0) /* d0 <= -cy; save cy as 0 or -1 in d0 */ + INSN2(sub,l ,d2,#0x10000) + bcs L2 + INSN2(add,l ,d0,d0) /* restore cy */ + bra Loop + +LAB(L2) + INSN1(neg,l ,d0) + +/* Restore used registers from stack frame. */ + INSN2(move,l ,a2,MEM_POSTINC(sp)) + INSN2(move,l ,d2,MEM_POSTINC(sp)) + + rts |