glibc/sysdeps/m68k/m68020/submul_1.S
1995-02-18 01:27:10 +00:00

81 lines
2.1 KiB
ArmAsm

/* mc68020 __mpn_submul_1 -- Multiply a limb vector with a limb and subtract
the result from a second 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)
size (sp + 12)
s2_limb (sp + 16)
*/
#include "asm-syntax.h"
TEXT
ALIGN
GLOBL ___mpn_submul_1
LAB(___mpn_submul_1)
#define res_ptr a0
#define s1_ptr a1
#define size d2
#define s2_limb d4
/* Save used registers on the stack. */
INSN2(movem,l ,MEM_PREDEC(sp),d2-d5)
/* Copy the arguments to registers. Better use movem? */
INSN2(move,l ,res_ptr,MEM_DISP(sp,20))
INSN2(move,l ,s1_ptr,MEM_DISP(sp,24))
INSN2(move,l ,size,MEM_DISP(sp,28))
INSN2(move,l ,s2_limb,MEM_DISP(sp,32))
INSN2(eor,w ,size,#1)
INSN1(clr,l ,d1)
INSN1(clr,l ,d5)
INSN2(lsr,l ,size,#1)
bcc L1
INSN2(subq,l ,size,#1)
INSN2(sub,l ,d0,d0) /* (d0,cy) <= (0,0) */
LAB(Loop)
INSN2(move,l ,d3,MEM_POSTINC(s1_ptr))
INSN2(mulu,l ,d1:d3,s2_limb)
INSN2(addx,l ,d3,d0)
INSN2(addx,l ,d1,d5)
INSN2(sub,l ,MEM_POSTINC(res_ptr),d3)
LAB(L1) INSN2(move,l ,d3,MEM_POSTINC(s1_ptr))
INSN2(mulu,l ,d0:d3,s2_limb)
INSN2(addx,l ,d3,d1)
INSN2(addx,l ,d0,d5)
INSN2(sub,l ,MEM_POSTINC(res_ptr),d3)
dbf size,Loop
INSN2(addx,l ,d0,d5)
INSN2(sub,l ,size,#0x10000)
bcc Loop
/* Restore used registers from stack frame. */
INSN2(movem,l ,d2-d5,MEM_POSTINC(sp))
rts