diff options
Diffstat (limited to 'newlib/libm/common/sf_round.c')
-rw-r--r-- | newlib/libm/common/sf_round.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/newlib/libm/common/sf_round.c b/newlib/libm/common/sf_round.c new file mode 100644 index 0000000..75a72fe --- /dev/null +++ b/newlib/libm/common/sf_round.c @@ -0,0 +1,78 @@ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "fdlibm.h" + +#ifdef __STDC__ + float roundf(float x) +#else + float roundf(x) + float x; +#endif +{ + int signbit; + int w; + /* Most significant word, least significant word. */ + int exponent_less_127; + + GET_FLOAT_WORD(w, x); + + /* Extract sign bit. */ + signbit = w & 0x80000000; + + /* Extract exponent field. */ + exponent_less_127 = ((w & 0x7f800000) >> 23) - 127; + + if (exponent_less_127 < 23) + { + if (exponent_less_127 < 0) + { + w &= 0x80000000; + if (exponent_less_127 == -1) + /* Result is +1.0 or -1.0. */ + w |= (127 << 23); + } + else + { + unsigned int exponent_mask = 0x007fffff >> exponent_less_127; + if ((w & exponent_mask) == 0) + /* x has an integral value. */ + return x; + + w += 0x00400000 >> exponent_less_127; + w &= ~exponent_mask; + } + } + else + { + if (exponent_less_127 == 128) + /* x is NaN or infinite. */ + return x + x; + else + return x; + } + SET_FLOAT_WORD(x, w); + return x; +} + +#ifdef _DOUBLE_IS_32BITS + +#ifdef __STDC__ + double round(double x) +#else + double round(x) + double x; +#endif +{ + return (double) roundf((float) x); +} + +#endif /* defined(_DOUBLE_IS_32BITS) */ |