diff options
Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/roundf.c')
| -rw-r--r-- | lib/mlibc/options/ansi/musl-generic-math/roundf.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/roundf.c b/lib/mlibc/options/ansi/musl-generic-math/roundf.c new file mode 100644 index 0000000..e8210af --- /dev/null +++ b/lib/mlibc/options/ansi/musl-generic-math/roundf.c @@ -0,0 +1,36 @@ +#include "libm.h" + +#if FLT_EVAL_METHOD==0 +#define EPS FLT_EPSILON +#elif FLT_EVAL_METHOD==1 +#define EPS DBL_EPSILON +#elif FLT_EVAL_METHOD==2 +#define EPS LDBL_EPSILON +#endif +static const float_t toint = 1/EPS; + +float roundf(float x) +{ + union {float f; uint32_t i;} u = {x}; + int e = u.i >> 23 & 0xff; + float_t y; + + if (e >= 0x7f+23) + return x; + if (u.i >> 31) + x = -x; + if (e < 0x7f-1) { + FORCE_EVAL(x + toint); + return 0*u.f; + } + y = x + toint - toint - x; + if (y > 0.5f) + y = y + x - 1; + else if (y <= -0.5f) + y = y + x + 1; + else + y = y + x; + if (u.i >> 31) + y = -y; + return y; +} |