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/*
* Copyright (c) 2019, The Linux Foundation. All rights reserved.
*
* 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.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 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.
*/
#ifndef STD_DTOA_H
#define STD_DTOA_H
//
// Constant Definitions
//
// For floating point numbers, the range of a double precision number is
// approximately +/- 10 ^ 308.25 as per the IEEE Standard 754.
// As such, the maximum size of the integer portion of the
// string is assumed to be 311 (309 + sign + \0). The maximum
// size of the fractional part is assumed to be 100. Thus, the
// maximum size of the string that would contain the number
// after conversion is safely assumed to be 420 (including any
// prefix, the null character and exponent specifiers 'e').
//
// The buffers that contain the converted integer and the fraction parts of
// the float are safely assumed to be of size 310.
#define STD_DTOA_FORMAT_FLOAT_SIZE 420
#define STD_DTOA_FORMAT_INTEGER_SIZE 311
#define STD_DTOA_FORMAT_FRACTION_SIZE 100
// Constants for operations on the IEEE 754 representation of double
// precision floating point numbers.
#define STD_DTOA_DP_SIGN_SHIFT_COUNT 63
#define STD_DTOA_DP_EXPONENT_SHIFT_COUNT 52
#define STD_DTOA_DP_EXPONENT_MASK 0x7ff
#define STD_DTOA_DP_EXPONENT_BIAS 1023
#define STD_DTOA_DP_MANTISSA_MASK ( ( (uint64)1 << 52 ) - 1 )
#define STD_DTOA_DP_INFINITY_EXPONENT_ID 0x7FF
#define STD_DTOA_DP_MAX_EXPONENT 1023
#define STD_DTOA_DP_MIN_EXPONENT_NORM -1022
#define STD_DTOA_DP_MIN_EXPONENT_DENORM -1074
#define STD_DTOA_DP_MAX_EXPONENT_DEC 308
#define STD_DTOA_DP_MIN_EXPONENT_DEC_DENORM -323
#define STD_DTOA_PRECISION_ROUNDING_VALUE 4
#define STD_DTOA_DEFAULT_FLOAT_PRECISION 6
#define STD_DTOA_NEGATIVE_INF_UPPER_CASE "-INF"
#define STD_DTOA_NEGATIVE_INF_LOWER_CASE "-inf"
#define STD_DTOA_POSITIVE_INF_UPPER_CASE "INF"
#define STD_DTOA_POSITIVE_INF_LOWER_CASE "inf"
#define STD_DTOA_NAN_UPPER_CASE "NAN"
#define STD_DTOA_NAN_LOWER_CASE "nan"
#define STD_DTOA_FP_POSITIVE_INF 0x7FF0000000000000uLL
#define STD_DTOA_FP_NEGATIVE_INF 0xFFF0000000000000uLL
#define STD_DTOA_FP_SNAN 0xFFF0000000000001uLL
#define STD_DTOA_FP_QNAN 0xFFFFFFFFFFFFFFFFuLL
//
// Useful Macros
//
#define MY_ISDIGIT(c) ( ( (c) >= '0' ) && ( (c) <= '9' ) )
#define FP_EXPONENT(u) ( ( ( (u) >> STD_DTOA_DP_EXPONENT_SHIFT_COUNT ) \
& STD_DTOA_DP_EXPONENT_MASK ) - STD_DTOA_DP_EXPONENT_BIAS )
#define FP_EXPONENT_BIASED(u) ( ( (u) >> STD_DTOA_DP_EXPONENT_SHIFT_COUNT ) \
& STD_DTOA_DP_EXPONENT_MASK )
#define FP_MANTISSA_NORM(u) ( ( (u) & STD_DTOA_DP_MANTISSA_MASK ) | \
( (uint64)1 << STD_DTOA_DP_EXPONENT_SHIFT_COUNT ) )
#define FP_MANTISSA_DENORM(u) ( (u) & STD_DTOA_DP_MANTISSA_MASK )
#define FP_MANTISSA(u) ( FP_EXPONENT_BIASED(u) ? FP_MANTISSA_NORM(u) : \
FP_MANTISSA_DENORM(u) )
#define FP_SIGN(u) ( (u) >> STD_DTOA_DP_SIGN_SHIFT_COUNT )
#define DOUBLE_TO_UINT64(d) ( *( (uint64*) &(d) ) )
#define DOUBLE_TO_INT64(d) ( *( (int64*) &(d) ) )
#define UINT64_TO_DOUBLE(u) ( *( (double*) &(u) ) )
//
// Type Definitions
//
typedef enum
{
FP_TYPE_UNKOWN = 0,
FP_TYPE_NEGATIVE_INF,
FP_TYPE_POSITIVE_INF,
FP_TYPE_NAN,
FP_TYPE_GENERAL,
} FloatingPointType;
//
// Function Declarations
//
#ifdef __cplusplus
extern "C" {
#endif // #ifdef __cplusplus
double fp_pow_10( int nPow );
double fp_round( double dNumber, int nPrecision );
int fp_log_10( double dNumber );
int fp_check_special_cases( double dNumber, FloatingPointType* pNumberType );
int std_dtoa_decimal( double dNumber, int nPrecision,
char acIntegerPart[ STD_DTOA_FORMAT_INTEGER_SIZE ],
char acFractionPart[ STD_DTOA_FORMAT_FRACTION_SIZE ] );
int std_dtoa_hex( double dNumber, int nPrecision, char cFormat,
char acIntegerPart[ STD_DTOA_FORMAT_INTEGER_SIZE ],
char acFractionPart[ STD_DTOA_FORMAT_FRACTION_SIZE ],
int* pnExponent );
#ifdef __cplusplus
}
#endif // #ifdef __cplusplus
#endif // STD_DTOA_H
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