Yasm Assembler mainline development tree (ffmpeg 依赖)
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/**
* \file libyasm/floatnum.h
* \brief YASM floating point (IEEE) interface.
*
* \rcs
* $Id$
* \endrcs
*
* \license
* Copyright (C) 2001 Peter Johnson
*
* Based on public-domain x86 assembly code by Randall Hyde (8/28/91).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* \endlicense
*/
#ifndef YASM_FLOATNUM_H
#define YASM_FLOATNUM_H
/** Initialize floatnum internal data structures. */
void yasm_floatnum_initialize(void);
/** Clean up internal floatnum allocations. */
void yasm_floatnum_cleanup(void);
/** Create a new floatnum from a decimal string. The input string must be in
* standard C representation ([+-]123.456e[-+]789).
* \param str floating point decimal string
* \return Newly allocated floatnum.
*/
/*@only@*/ yasm_floatnum *yasm_floatnum_create(const char *str);
/** Duplicate a floatnum.
* \param flt floatnum
* \return Newly allocated floatnum with the same value as flt.
*/
/*@only@*/ yasm_floatnum *yasm_floatnum_copy(const yasm_floatnum *flt);
/** Destroy (free allocated memory for) a floatnum.
* \param flt floatnum
*/
void yasm_floatnum_destroy(/*@only@*/ yasm_floatnum *flt);
/** Floating point calculation function: acc = acc op operand.
* \note Not all operations in yasm_expr_op may be supported; unsupported
* operations will result in an error.
* \param acc floatnum accumulator
* \param op operation
* \param operand floatnum operand
* \param line virtual line (of expression)
*/
void yasm_floatnum_calc(yasm_floatnum *acc, yasm_expr_op op,
yasm_floatnum *operand, unsigned long line);
/** Convert a floatnum to single-precision and return as 32-bit value.
* The 32-bit value is a "standard" C value (eg, of unknown endian).
* \param flt floatnum
* \param ret_val pointer to storage for 32-bit output
* \return Nonzero if flt can't fit into single precision: -1 if underflow
* occurred, 1 if overflow occurred.
*/
int yasm_floatnum_get_int(const yasm_floatnum *flt,
/*@out@*/ unsigned long *ret_val);
/** Output a #yasm_floatnum to buffer in little-endian or big-endian. Puts the
* value into the least significant bits of the destination, or may be shifted
* into more significant bits by the shift parameter. The destination bits are
* cleared before being set. [0] should be the first byte output to the file.
* \note Not all sizes are valid. Currently, only 32 (single-precision), 64
* (double-precision), and 80 (extended-precision) are valid sizes.
* Use yasm_floatnum_check_size() to check for supported sizes.
* \param flt floatnum
* \param ptr pointer to storage for size bytes of output
* \param destsize destination size (in bytes)
* \param valsize size (in bits)
* \param shift left shift (in bits)
* \param bigendian endianness (nonzero=big, zero=little)
* \param warn enables standard overflow/underflow warnings
* \param line virtual line; may be 0 if warn is 0.
* \return Nonzero if flt can't fit into the specified precision: -1 if
* underflow occurred, 1 if overflow occurred.
*/
int yasm_floatnum_get_sized(const yasm_floatnum *flt, unsigned char *ptr,
size_t destsize, size_t valsize, size_t shift,
int bigendian, int warn, unsigned long line);
/** Basic check to see if size is valid for flt conversion (using
* yasm_floatnum_get_sized()). Doesn't actually check for underflow/overflow
* but rather checks for size=32,64,80
* (at present).
* \param flt floatnum
* \param size number of bits of output space
* \return 1 if valid size, 0 if invalid size.
*/
int yasm_floatnum_check_size(const yasm_floatnum *flt, size_t size);
/** Print various representations of a floatnum. For debugging purposes only.
* \param f file
* \param flt floatnum
*/
void yasm_floatnum_print(const yasm_floatnum *flt, FILE *f);
#endif