26 lines
749 B
C
26 lines
749 B
C
/* AVR-GCC does not have real double datatype. Instead its double
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* is equal to float, i.e. 32 bit value. If you need to communicate
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* with other systems that use double in their .proto files, you
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* need to do some conversion.
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*
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* These functions use bitwise operations to mangle floats into doubles
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* and then store them in uint64_t datatype.
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*/
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#ifndef DOUBLE_CONVERSION
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#define DOUBLE_CONVERSION
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#include <stdint.h>
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/* Convert native 4-byte float into a 8-byte double. */
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extern uint64_t float_to_double(float value);
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/* Convert 8-byte double into native 4-byte float.
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* Values are rounded to nearest, 0.5 away from zero.
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* Overflowing values are converted to Inf or -Inf.
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*/
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extern float double_to_float(uint64_t value);
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#endif
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