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Diffstat (limited to 'src/std_dtoa.h')
| -rw-r--r-- | src/std_dtoa.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/std_dtoa.h b/src/std_dtoa.h new file mode 100644 index 0000000..cea00c4 --- /dev/null +++ b/src/std_dtoa.h @@ -0,0 +1,137 @@ +/* + * 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 + |