diff options
Diffstat (limited to 'CAN-binder/libs/openxc-message-format/libs/nanopb/examples/using_double_on_avr/double_conversion.c')
-rw-r--r-- | CAN-binder/libs/openxc-message-format/libs/nanopb/examples/using_double_on_avr/double_conversion.c | 123 |
1 files changed, 0 insertions, 123 deletions
diff --git a/CAN-binder/libs/openxc-message-format/libs/nanopb/examples/using_double_on_avr/double_conversion.c b/CAN-binder/libs/openxc-message-format/libs/nanopb/examples/using_double_on_avr/double_conversion.c deleted file mode 100644 index cf79b9a..0000000 --- a/CAN-binder/libs/openxc-message-format/libs/nanopb/examples/using_double_on_avr/double_conversion.c +++ /dev/null @@ -1,123 +0,0 @@ -/* Conversion routines for platforms that do not support 'double' directly. */ - -#include "double_conversion.h" -#include <math.h> - -typedef union { - float f; - uint32_t i; -} conversion_t; - -/* Note: IEE 754 standard specifies float formats as follows: - * Single precision: sign, 8-bit exp, 23-bit frac. - * Double precision: sign, 11-bit exp, 52-bit frac. - */ - -uint64_t float_to_double(float value) -{ - conversion_t in; - in.f = value; - uint8_t sign; - int16_t exponent; - uint64_t mantissa; - - /* Decompose input value */ - sign = (in.i >> 31) & 1; - exponent = ((in.i >> 23) & 0xFF) - 127; - mantissa = in.i & 0x7FFFFF; - - if (exponent == 128) - { - /* Special value (NaN etc.) */ - exponent = 1024; - } - else if (exponent == -127) - { - if (!mantissa) - { - /* Zero */ - exponent = -1023; - } - else - { - /* Denormalized */ - mantissa <<= 1; - while (!(mantissa & 0x800000)) - { - mantissa <<= 1; - exponent--; - } - mantissa &= 0x7FFFFF; - } - } - - /* Combine fields */ - mantissa <<= 29; - mantissa |= (uint64_t)(exponent + 1023) << 52; - mantissa |= (uint64_t)sign << 63; - - return mantissa; -} - -float double_to_float(uint64_t value) -{ - uint8_t sign; - int16_t exponent; - uint32_t mantissa; - conversion_t out; - - /* Decompose input value */ - sign = (value >> 63) & 1; - exponent = ((value >> 52) & 0x7FF) - 1023; - mantissa = (value >> 28) & 0xFFFFFF; /* Highest 24 bits */ - - /* Figure if value is in range representable by floats. */ - if (exponent == 1024) - { - /* Special value */ - exponent = 128; - } - else if (exponent > 127) - { - /* Too large */ - if (sign) - return -INFINITY; - else - return INFINITY; - } - else if (exponent < -150) - { - /* Too small */ - if (sign) - return -0.0f; - else - return 0.0f; - } - else if (exponent < -126) - { - /* Denormalized */ - mantissa |= 0x1000000; - mantissa >>= (-126 - exponent); - exponent = -127; - } - - /* Round off mantissa */ - mantissa = (mantissa + 1) >> 1; - - /* Check if mantissa went over 2.0 */ - if (mantissa & 0x800000) - { - exponent += 1; - mantissa &= 0x7FFFFF; - mantissa >>= 1; - } - - /* Combine fields */ - out.i = mantissa; - out.i |= (uint32_t)(exponent + 127) << 23; - out.i |= (uint32_t)sign << 31; - - return out.f; -} - - |