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-rw-r--r--src/math/modff.c66
1 files changed, 24 insertions, 42 deletions
diff --git a/src/math/modff.c b/src/math/modff.c
index d535314c..bf6e4ced 100644
--- a/src/math/modff.c
+++ b/src/math/modff.c
@@ -1,51 +1,33 @@
-/* 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;
-
float modff(float x, float *iptr)
{
- int32_t i0,j0;
- uint32_t i;
+ uint32_t u, 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 */
- 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 */
+ GET_FLOAT_WORD(u, x);
+ e = (int)(u>>23 & 0xff) - 0x7f;
+
+ /* no fractional part */
+ if (e >= 23) {
+ *iptr = x;
+ if (e == 0x80 && u<<9 != 0) /* nan */
return x;
- GET_FLOAT_WORD(ix, x);
- SET_FLOAT_WORD(x, ix & 0x80000000); /* return +-0 */
+ SET_FLOAT_WORD(x, u & 0x80000000);
+ return x;
+ }
+ /* no integral part */
+ if (e < 0) {
+ SET_FLOAT_WORD(*iptr, u & 0x80000000);
+ return x;
+ }
+
+ mask = 0x007fffff>>e;
+ if ((u & mask) == 0) {
+ *iptr = x;
+ SET_FLOAT_WORD(x, u & 0x80000000);
return x;
}
+ SET_FLOAT_WORD(*iptr, u & ~mask);
+ return x - *iptr;
}