diff options
Diffstat (limited to 'src/math/nextafterf.c')
-rw-r--r-- | src/math/nextafterf.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/src/math/nextafterf.c b/src/math/nextafterf.c new file mode 100644 index 00000000..bdc88cab --- /dev/null +++ b/src/math/nextafterf.c @@ -0,0 +1,67 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_nextafterf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + */ +/* + * ==================================================== + * 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 "libm.h" + +float nextafterf(float x, float y) +{ + volatile float t; + int32_t hx,hy,ix,iy; + + GET_FLOAT_WORD(hx, x); + GET_FLOAT_WORD(hy, y); + ix = hx & 0x7fffffff; /* |x| */ + iy = hy & 0x7fffffff; /* |y| */ + + if (ix > 0x7f800000 || /* x is nan */ + iy > 0x7f800000) /* y is nan */ + return x+y; + if (x == y) /* x == y */ + return y; + if (ix == 0) { /* x == 0 */ + SET_FLOAT_WORD(x, (hy&0x80000000)|1); /* return +-minsubnormal */ + /* raise underflow flag */ + t = x*x; + if (t == x) + return t; + return x; + } + if (hx >= 0) { /* x > 0 */ + if (hx > hy) { /* x > y, x -= ulp */ + hx--; + } else { /* x < y, x += ulp */ + hx++; + } + } else { /* x < 0 */ + if (hy >= 0 || hx > hy) { /* x < y, x -= ulp */ + hx--; + } else { /* x > y, x += ulp */ + hx++; + } + } + hy = hx & 0x7f800000; + if (hy >= 0x7f800000) /* overflow */ + return x+x; + if (hy < 0x00800000) { /* underflow */ + /* raise underflow flag */ + t = x*x; + if (t != x) { + SET_FLOAT_WORD(y, hx); + return y; + } + } + SET_FLOAT_WORD(x, hx); + return x; +} |