1 /* i80386 __mpn_rshift --
2 Copyright (C) 1992, 1994, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
3 This file is part of the GNU MP Library.
5 The GNU MP Library is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation; either version 2.1 of the License, or (at your
8 option) any later version.
10 The GNU MP Library is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
13 License for more details.
15 You should have received a copy of the GNU Lesser General Public License
16 along with the GNU MP Library; see the file COPYING.LIB. If not, write to
17 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
18 MA 02111-1307, USA. */
21 #include "asm-syntax.h"
25 #define PARMS LINKAGE+12 /* space for 3 saved regs */
27 #define S RES+PTR_SIZE
28 #define SIZE S+PTR_SIZE
32 ENTRY (BP_SYM (__mpn_rshift))
43 #if __BOUNDED_POINTERS__
44 shll $2, %edx /* convert limbs to bytes */
45 CHECK_BOUNDS_BOTH_WIDE (%edi, RES(%esp), %edx)
46 CHECK_BOUNDS_BOTH_WIDE (%esi, S(%esp), %edx)
49 leal -4(%edi,%edx,4),%edi
50 leal (%esi,%edx,4),%esi
53 movl (%esi,%edx,4),%ebx /* read least significant limb */
55 shrdl %cl,%ebx,%eax /* compute carry limb */
58 pushl %eax /* push carry limb onto stack */
60 jnz L(1) /* enter loop in the middle */
64 L(oop): movl (%esi,%edx,4),%ebx /* load next higher limb */
65 shrdl %cl,%ebx,%eax /* compute result limb */
66 movl %eax,(%edi,%edx,4) /* store it */
68 L(1): movl (%esi,%edx,4),%eax
70 movl %ebx,(%edi,%edx,4)
74 shrl %cl,%eax /* compute most significant limb */
75 movl %eax,(%edi) /* store it */
77 popl %eax /* pop carry limb */
86 L(end): shrl %cl,%ebx /* compute most significant limb */
87 movl %ebx,(%edi) /* store it */
95 END (BP_SYM (__mpn_rshift))