diff options
Diffstat (limited to 'src/base/math/nan.c')
-rw-r--r-- | src/base/math/nan.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/base/math/nan.c b/src/base/math/nan.c new file mode 100644 index 0000000..c1f85c2 --- /dev/null +++ b/src/base/math/nan.c @@ -0,0 +1,54 @@ +#include <u.h> +#include <base.h> + +#define NANEXP (2047<<20) +#define NANMASK (2047<<20) +#define NANSIGN (1<<31) + +double +math·NaN(void) +{ + sys·DoubleWord a; + + a.hi = NANEXP; + a.lo = 1; + return a.x; +} + +int +math·isNaN(double d) +{ + sys·DoubleWord a; + + a.x = d; + if((a.hi & NANMASK) != NANEXP) + return 0; + return !math·isInf(d, 0); +} + +double +math·Inf(int sign) +{ + sys·DoubleWord a; + + a.hi = NANEXP; + a.lo = 0; + if(sign < 0) + a.hi |= NANSIGN; + return a.x; +} + +int +math·isInf(double d, int sign) +{ + sys·DoubleWord a; + + a.x = d; + if(a.lo != 0) + return 0; + if(a.hi == NANEXP) + return sign >= 0; + if(a.hi == (NANEXP|NANSIGN)) + return sign <= 0; + return 0; +} |