Blame view

kernel/linux-imx6_3.14.28/lib/mpi/mpi-inline.h 3.27 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
  /* mpi-inline.h  -  Internal to the Multi Precision Integers
   *	Copyright (C) 1994, 1996, 1998, 1999 Free Software Foundation, Inc.
   *
   * This file is part of GnuPG.
   *
   * GnuPG is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * GnuPG 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
   *
   * Note: This code is heavily based on the GNU MP Library.
   *	 Actually it's the same code with only minor changes in the
   *	 way the data is stored; this is to support the abstraction
   *	 of an optional secure memory allocation which may be used
   *	 to avoid revealing of sensitive data due to paging etc.
   *	 The GNU MP Library itself is published under the LGPL;
   *	 however I decided to publish this code under the plain GPL.
   */
  
  #ifndef G10_MPI_INLINE_H
  #define G10_MPI_INLINE_H
  
  #ifndef G10_MPI_INLINE_DECL
  #define G10_MPI_INLINE_DECL  extern inline
  #endif
  
  G10_MPI_INLINE_DECL mpi_limb_t
  mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  	      mpi_size_t s1_size, mpi_limb_t s2_limb)
  {
  	mpi_limb_t x;
  
  	x = *s1_ptr++;
  	s2_limb += x;
  	*res_ptr++ = s2_limb;
  	if (s2_limb < x) {	/* sum is less than the left operand: handle carry */
  		while (--s1_size) {
  			x = *s1_ptr++ + 1;	/* add carry */
  			*res_ptr++ = x;	/* and store */
  			if (x)	/* not 0 (no overflow): we can stop */
  				goto leave;
  		}
  		return 1;	/* return carry (size of s1 to small) */
  	}
  
  leave:
  	if (res_ptr != s1_ptr) {	/* not the same variable */
  		mpi_size_t i;	/* copy the rest */
  		for (i = 0; i < s1_size - 1; i++)
  			res_ptr[i] = s1_ptr[i];
  	}
  	return 0;		/* no carry */
  }
  
  G10_MPI_INLINE_DECL mpi_limb_t
  mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
  	    mpi_ptr_t s2_ptr, mpi_size_t s2_size)
  {
  	mpi_limb_t cy = 0;
  
  	if (s2_size)
  		cy = mpihelp_add_n(res_ptr, s1_ptr, s2_ptr, s2_size);
  
  	if (s1_size - s2_size)
  		cy = mpihelp_add_1(res_ptr + s2_size, s1_ptr + s2_size,
  				   s1_size - s2_size, cy);
  	return cy;
  }
  
  G10_MPI_INLINE_DECL mpi_limb_t
  mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  	      mpi_size_t s1_size, mpi_limb_t s2_limb)
  {
  	mpi_limb_t x;
  
  	x = *s1_ptr++;
  	s2_limb = x - s2_limb;
  	*res_ptr++ = s2_limb;
  	if (s2_limb > x) {
  		while (--s1_size) {
  			x = *s1_ptr++;
  			*res_ptr++ = x - 1;
  			if (x)
  				goto leave;
  		}
  		return 1;
  	}
  
  leave:
  	if (res_ptr != s1_ptr) {
  		mpi_size_t i;
  		for (i = 0; i < s1_size - 1; i++)
  			res_ptr[i] = s1_ptr[i];
  	}
  	return 0;
  }
  
  G10_MPI_INLINE_DECL mpi_limb_t
  mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
  	    mpi_ptr_t s2_ptr, mpi_size_t s2_size)
  {
  	mpi_limb_t cy = 0;
  
  	if (s2_size)
  		cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size);
  
  	if (s1_size - s2_size)
  		cy = mpihelp_sub_1(res_ptr + s2_size, s1_ptr + s2_size,
  				   s1_size - s2_size, cy);
  	return cy;
  }
  
  #endif /*G10_MPI_INLINE_H */