-/* origin: FreeBSD /usr/src/lib/msun/src/s_modff.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"
-
-static const float one = 1.0;
+#include <math.h>
+#include <stdint.h>
float modff(float x, float *iptr)
{
- int32_t i0,j0;
- uint32_t i;
+ union {float x; uint32_t n;} u = {x};
+ uint32_t mask;
+ int e;
- GET_FLOAT_WORD(i0, x);
- j0 = ((i0>>23) & 0xff) - 0x7f; /* exponent of x */
- if (j0 < 23) { /* integer part in x */
- if (j0 < 0) { /* |x| < 1 */
- SET_FLOAT_WORD(*iptr, i0 & 0x80000000); /* *iptr = +-0 */
- return x;
- }
- i = 0x007fffff >> j0;
- if ((i0&i) == 0) { /* x is integral */
- uint32_t ix;
- *iptr = x;
- GET_FLOAT_WORD(ix, x);
- SET_FLOAT_WORD(x, ix & 0x80000000); /* return +-0 */
+ e = (int)(u.n>>23 & 0xff) - 0x7f;
+
+ /* no fractional part */
+ if (e >= 23) {
+ *iptr = x;
+ if (e == 0x80 && u.n<<9 != 0) { /* nan */
return x;
}
- SET_FLOAT_WORD(*iptr, i0&~i);
- return x - *iptr;
- } else { /* no fraction part */
- uint32_t ix;
- *iptr = x*one;
- if (x != x) /* NaN */
- return x;
- GET_FLOAT_WORD(ix, x);
- SET_FLOAT_WORD(x, ix & 0x80000000); /* return +-0 */
+ u.n &= 0x80000000;
+ return u.x;
+ }
+ /* no integral part */
+ if (e < 0) {
+ u.n &= 0x80000000;
+ *iptr = u.x;
return x;
}
+
+ mask = 0x007fffff>>e;
+ if ((u.n & mask) == 0) {
+ *iptr = x;
+ u.n &= 0x80000000;
+ return u.x;
+ }
+ u.n &= ~mask;
+ *iptr = u.x;
+ return x - *iptr;
}