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+/* 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