1 dnl x86 mpn_rshift -- mpn right shift.
3 dnl Copyright (C) 1992, 1994, 1996, 1999, 2000 Free Software Foundation,
6 dnl This file is part of the GNU MP Library.
8 dnl The GNU MP Library is free software; you can redistribute it and/or
9 dnl modify it under the terms of the GNU Lesser General Public License as
10 dnl published by the Free Software Foundation; either version 2.1 of the
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15 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 dnl Lesser General Public License for more details.
18 dnl You should have received a copy of the GNU Lesser General Public
19 dnl License along with the GNU MP Library; see the file COPYING.LIB. If
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24 include(`../config.m4')
27 C mp_limb_t mpn_rshift (mp_ptr dst, mp_srcptr src, mp_size_t size,
30 defframe(PARAM_SHIFT,16)
31 defframe(PARAM_SIZE, 12)
32 defframe(PARAM_SRC, 8)
33 defframe(PARAM_DST, 4)
49 leal -4(%edi,%edx,4),%edi
50 leal (%esi,%edx,4),%esi
53 movl (%esi,%edx,4),%ebx C read least significant limb
55 shrdl( %cl, %ebx, %eax) C compute carry limb
58 pushl %eax C push carry limb onto stack
60 jnz L(1) C enter loop in the middle
64 L(oop): movl (%esi,%edx,4),%ebx C load next higher limb
65 shrdl( %cl, %ebx, %eax) C compute result limb
66 movl %eax,(%edi,%edx,4) C store it
68 L(1): movl (%esi,%edx,4),%eax
69 shrdl( %cl, %eax, %ebx)
70 movl %ebx,(%edi,%edx,4)
74 shrl %cl,%eax C compute most significant limb
75 movl %eax,(%edi) C store it
77 popl %eax C pop carry limb
84 L(end): shrl %cl,%ebx C compute most significant limb
85 movl %ebx,(%edi) C store it