1/**
2 * \file libyasm/floatnum.h
3 * \brief YASM floating point (IEEE) interface.
4 *
5 * \license
6 *  Copyright (C) 2001-2007  Peter Johnson
7 *
8 *  Based on public-domain x86 assembly code by Randall Hyde (8/28/91).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *  - Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *  - Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
20 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
23 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 * \endlicense
31 */
32#ifndef YASM_FLOATNUM_H
33#define YASM_FLOATNUM_H
34
35#ifndef YASM_LIB_DECL
36#define YASM_LIB_DECL
37#endif
38
39/** Initialize floatnum internal data structures. */
40YASM_LIB_DECL
41void yasm_floatnum_initialize(void);
42
43/** Clean up internal floatnum allocations. */
44YASM_LIB_DECL
45void yasm_floatnum_cleanup(void);
46
47/** Create a new floatnum from a decimal string.  The input string must be in
48 * standard C representation ([+-]123.456e[-+]789).
49 * \param str   floating point decimal string
50 * \return Newly allocated floatnum.
51 */
52YASM_LIB_DECL
53/*@only@*/ yasm_floatnum *yasm_floatnum_create(const char *str);
54
55/** Duplicate a floatnum.
56 * \param flt   floatnum
57 * \return Newly allocated floatnum with the same value as flt.
58 */
59YASM_LIB_DECL
60/*@only@*/ yasm_floatnum *yasm_floatnum_copy(const yasm_floatnum *flt);
61
62/** Destroy (free allocated memory for) a floatnum.
63 * \param flt   floatnum
64 */
65YASM_LIB_DECL
66void yasm_floatnum_destroy(/*@only@*/ yasm_floatnum *flt);
67
68/** Floating point calculation function: acc = acc op operand.
69 * \note Not all operations in yasm_expr_op may be supported; unsupported
70 *       operations will result in an error.
71 * \param acc       floatnum accumulator
72 * \param op        operation
73 * \param operand   floatnum operand
74 * \return Nonzero on error.
75 */
76YASM_LIB_DECL
77int yasm_floatnum_calc(yasm_floatnum *acc, yasm_expr_op op,
78                       yasm_floatnum *operand);
79
80/** Convert a floatnum to single-precision and return as 32-bit value.
81 * The 32-bit value is a "standard" C value (eg, of unknown endian).
82 * \param flt       floatnum
83 * \param ret_val   pointer to storage for 32-bit output
84 * \return Nonzero if flt can't fit into single precision: -1 if underflow
85 *         occurred, 1 if overflow occurred.
86 */
87YASM_LIB_DECL
88int yasm_floatnum_get_int(const yasm_floatnum *flt,
89                          /*@out@*/ unsigned long *ret_val);
90
91/** Output a #yasm_floatnum to buffer in little-endian or big-endian.  Puts the
92 * value into the least significant bits of the destination, or may be shifted
93 * into more significant bits by the shift parameter.  The destination bits are
94 * cleared before being set.  [0] should be the first byte output to the file.
95 * \note Not all sizes are valid.  Currently, only 32 (single-precision), 64
96 *       (double-precision), and 80 (extended-precision) are valid sizes.
97 *       Use yasm_floatnum_check_size() to check for supported sizes.
98 * \param flt       floatnum
99 * \param ptr       pointer to storage for size bytes of output
100 * \param destsize  destination size (in bytes)
101 * \param valsize   size (in bits)
102 * \param shift     left shift (in bits)
103 * \param bigendian endianness (nonzero=big, zero=little)
104 * \param warn      enables standard overflow/underflow warnings
105 * \return Nonzero if flt can't fit into the specified precision: -1 if
106 *         underflow occurred, 1 if overflow occurred.
107 */
108YASM_LIB_DECL
109int yasm_floatnum_get_sized(const yasm_floatnum *flt, unsigned char *ptr,
110                            size_t destsize, size_t valsize, size_t shift,
111                            int bigendian, int warn);
112
113/** Basic check to see if size is valid for flt conversion (using
114 * yasm_floatnum_get_sized()).  Doesn't actually check for underflow/overflow
115 * but rather checks for size=32,64,80
116 * (at present).
117 * \param flt       floatnum
118 * \param size      number of bits of output space
119 * \return 1 if valid size, 0 if invalid size.
120 */
121YASM_LIB_DECL
122int yasm_floatnum_check_size(const yasm_floatnum *flt, size_t size);
123
124/** Print various representations of a floatnum.  For debugging purposes only.
125 * \param f         file
126 * \param flt       floatnum
127 */
128YASM_LIB_DECL
129void yasm_floatnum_print(const yasm_floatnum *flt, FILE *f);
130
131#endif
132