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| author | Scott Shawcroft <scott@tannewt.org> | 2017-08-28 13:59:26 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-08-28 13:59:26 -0700 |
| commit | 447a4b1ecd5655357c9daaace03b91355d2e2c6d (patch) | |
| tree | 46ca08a93e9870aab4fbb533843f3c99796cbdf4 /lib/libm_dbl/rint.c | |
| parent | 4e63d55d8d0df6d7600bb684fa90a8cb54708ba8 (diff) | |
| parent | c679c80c710fd4a0e37ad87200d8a721e19727aa (diff) | |
Merge pull request #208 from adafruit/merge-v1.9.2
Merge MicroPython v1.9.2
Diffstat (limited to 'lib/libm_dbl/rint.c')
| -rw-r--r-- | lib/libm_dbl/rint.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/libm_dbl/rint.c b/lib/libm_dbl/rint.c new file mode 100644 index 000000000..fbba390e7 --- /dev/null +++ b/lib/libm_dbl/rint.c @@ -0,0 +1,28 @@ +#include <float.h> +#include <math.h> +#include <stdint.h> + +#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1 +#define EPS DBL_EPSILON +#elif FLT_EVAL_METHOD==2 +#define EPS LDBL_EPSILON +#endif +static const double_t toint = 1/EPS; + +double rint(double x) +{ + union {double f; uint64_t i;} u = {x}; + int e = u.i>>52 & 0x7ff; + int s = u.i>>63; + double_t y; + + if (e >= 0x3ff+52) + return x; + if (s) + y = x - toint + toint; + else + y = x + toint - toint; + if (y == 0) + return s ? -0.0 : 0; + return y; +} |