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Initial support for native MSVC compilation. * add MSVC support files: compiler wrappers and support libraries * adapt libiconv to work with MSVC * adapt gettext to work with MSVC
author Michael Goffioul <michael.goffioul@gmail.com>
date Mon, 17 Jun 2013 22:43:11 -0400
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3060:cbdf4575016d 3061:f8299bb6c872
1 #ifndef _ROUND_INTERNAL_H
2 /*
3 * round_internal.h
4 *
5 * $Id: round_internal.h,v 1.1 2008/06/03 18:42:21 keithmarshall Exp $
6 *
7 * Provides a generic implementation of the numerical rounding
8 * algorithm, which is shared by all functions in the `round()',
9 * `lround()' and `llround()' families.
10 *
11 * Written by Keith Marshall <keithmarshall@users.sourceforge.net>
12 *
13 * This is free software. You may redistribute and/or modify it as you
14 * see fit, without restriction of copyright.
15 *
16 * This software is provided "as is", in the hope that it may be useful,
17 * but WITHOUT WARRANTY OF ANY KIND, not even any implied warranty of
18 * MERCHANTABILITY, nor of FITNESS FOR ANY PARTICULAR PURPOSE. At no
19 * time will the author accept any form of liability for any damages,
20 * however caused, resulting from the use of this software.
21 *
22 */
23 #define _ROUND_INTERNAL_H
24
25 #include <math.h>
26 #include <fenv.h>
27
28 #define TYPE_PASTE( NAME, TYPE ) NAME##TYPE
29
30 #define INPUT_TYPE INPUT_TYPEDEF( FUNCTION )
31 #define INPUT_TYPEDEF( FUNCTION ) TYPE_PASTE( FUNCTION, _input_type )
32 /*
33 * The types for the formal parameter, to each of the derived functions.
34 */
35 #define round_input_type double
36 #define roundf_input_type float
37 #define roundl_input_type long double
38
39 #define lround_input_type double
40 #define lroundf_input_type float
41 #define lroundl_input_type long double
42
43 #define llround_input_type double
44 #define llroundf_input_type float
45 #define llroundl_input_type long double
46
47 #define RETURN_TYPE RETURN_TYPEDEF( FUNCTION )
48 #define RETURN_TYPEDEF( FUNCTION ) TYPE_PASTE( FUNCTION, _return_type )
49 /*
50 * The types for the return value, from each of the derived functions.
51 */
52 #define round_return_type double
53 #define roundf_return_type float
54 #define roundl_return_type long double
55
56 #define lround_return_type long
57 #define lroundf_return_type long
58 #define lroundl_return_type long
59
60 #define llround_return_type long long
61 #define llroundf_return_type long long
62 #define llroundl_return_type long long
63
64 #define MAX_RETURN_VALUE RETURN_MAX( FUNCTION )
65 #define RETURN_MAX( FUNCTION ) TYPE_PASTE( FUNCTION, _return_max )
66 /*
67 * The maximum values which may be returned by each of the derived functions
68 * in the `lround' or the `llround' families.
69 */
70 #define lround_return_max LONG_MAX
71 #define lroundf_return_max LONG_MAX
72 #define lroundl_return_max LONG_MAX
73
74 #define llround_return_max LLONG_MAX
75 #define llroundf_return_max LLONG_MAX
76 #define llroundl_return_max LLONG_MAX
77
78 #define MIN_RETURN_VALUE RETURN_MIN( FUNCTION )
79 #define RETURN_MIN( FUNCTION ) TYPE_PASTE( FUNCTION, _return_min )
80 /*
81 * The minimum values which may be returned by each of the derived functions
82 * in the `lround' or the `llround' families.
83 */
84 #define lround_return_min LONG_MIN
85 #define lroundf_return_min LONG_MIN
86 #define lroundl_return_min LONG_MIN
87
88 #define llround_return_min LLONG_MIN
89 #define llroundf_return_min LLONG_MIN
90 #define llroundl_return_min LLONG_MIN
91
92 #define REF_VALUE( VALUE ) REF_TYPE( FUNCTION, VALUE )
93 #define REF_TYPE( FUNC, VAL ) TYPE_PASTE( FUNC, _ref )( VAL )
94 /*
95 * Macros for expressing constant values of the appropriate data type,
96 * for use in each of the derived functions.
97 */
98 #define round_ref( VALUE ) VALUE
99 #define lround_ref( VALUE ) VALUE
100 #define llround_ref( VALUE ) VALUE
101
102 #define roundl_ref( VALUE ) TYPE_PASTE( VALUE, L )
103 #define lroundl_ref( VALUE ) TYPE_PASTE( VALUE, L )
104 #define llroundl_ref( VALUE ) TYPE_PASTE( VALUE, L )
105
106 #define roundf_ref( VALUE ) TYPE_PASTE( VALUE, F )
107 #define lroundf_ref( VALUE ) TYPE_PASTE( VALUE, F )
108 #define llroundf_ref( VALUE ) TYPE_PASTE( VALUE, F )
109
110 static __inline__
111 INPUT_TYPE __attribute__(( always_inline )) round_internal( INPUT_TYPE x )
112 #define ROUND_MODES ( FE_TONEAREST | FE_UPWARD | FE_DOWNWARD | FE_TOWARDZERO )
113 {
114 /* Generic helper function, for rounding of the input parameter value to
115 * the nearest integer value.
116 */
117 INPUT_TYPE z;
118 unsigned short saved_CW, tmp_required_CW;
119
120 /* Rounding method suggested by Danny Smith <dannysmith@users.sf.net>
121 *
122 * Save the FPU control word state, set rounding mode TONEAREST, round the
123 * input value, then restore the original FPU control word state.
124 */
125 __asm__( "fnstcw %0;" : "=m"( saved_CW ));
126 tmp_required_CW = ( saved_CW & ~ROUND_MODES ) | FE_TONEAREST;
127 __asm__( "fldcw %0;" :: "m"( tmp_required_CW ));
128 __asm__( "frndint;" : "=t"( z ) : "0"( x ));
129 __asm__( "fldcw %0;" :: "m"( saved_CW ));
130
131 /* We now have a possible rounded value; unfortunately the FPU uses the
132 * `round-to-even' rule for exact mid-way cases, where both C99 and POSIX
133 * require us to always round away from zero, so we need to adjust those
134 * mid-way cases which the FPU rounded in the wrong direction.
135 *
136 * Correction method suggested by Greg Chicares <gchicares@sbcglobal.net>
137 */
138 return x < REF_VALUE( 0.0 )
139 ? /*
140 * For negative input values, an incorrectly rounded value will be
141 * exactly 0.5 greater than the original value; when we find such an
142 * exact rounding offset, we must subtract an additional 1.0 from the
143 * rounded result, otherwise we return the rounded result unchanged.
144 */
145 z - x == REF_VALUE( 0.5 ) ? z - REF_VALUE( 1.0 ) : z
146
147 : /* For positive input values, an incorrectly rounded value will be
148 * exactly 0.5 less than the original value; when we find such an exact
149 * rounding offset, we must add an additional 1.0 to the rounded result,
150 * otherwise we return the rounded result unchanged.
151 */
152 x - z == REF_VALUE( 0.5 ) ? z + REF_VALUE( 1.0 ) : z;
153 }
154
155 #endif /* !defined _ROUND_INTERNAL_H: $RCSfile: round_internal.h,v $: end of file */