X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fmath%2Fmodfl.c;fp=src%2Fmath%2Fmodfl.c;h=2ca67b118bfd1a045a437014609d1d26278be84e;hp=0000000000000000000000000000000000000000;hb=b69f695acedd4ce2798ef9ea28d834ceccc789bd;hpb=d46cf2e14cc4df7cc75e77d7009fcb6df1f48a33

diff --git a/src/math/modfl.c b/src/math/modfl.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/s_modfl.c */
+/*-
+ * Copyright (c) 2007 David Schultz <das@FreeBSD.ORG>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Derived from s_modf.c, which has the following Copyright:
+ * ====================================================
+ * 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"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double modfl(long double x, long double *iptr)
+{
+	return modf(x, iptr);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+
+#if LDBL_MANL_SIZE > 32
+#define MASK    ((uint64_t)-1)
+#else
+#define MASK    ((uint32_t)-1)
+#endif
+/* Return the last n bits of a word, representing the fractional part. */
+#define GETFRAC(bits, n)        ((bits) & ~(MASK << (n)))
+/* The number of fraction bits in manh, not counting the integer bit */
+#define HIBITS  (LDBL_MANT_DIG - LDBL_MANL_SIZE)
+
+static const long double zero[] = { 0.0L, -0.0L };
+
+long double modfl(long double x, long double *iptr)
+{
+	union IEEEl2bits ux;
+	int e;
+
+	ux.e = x;
+	e = ux.bits.exp - LDBL_MAX_EXP + 1;
+	if (e < HIBITS) {                       /* Integer part is in manh. */
+		if (e < 0) {                    /* |x|<1 */
+			*iptr = zero[ux.bits.sign];
+			return x;
+		}
+		if ((GETFRAC(ux.bits.manh, HIBITS - 1 - e)|ux.bits.manl) == 0) {
+			/* x is an integer. */
+			*iptr = x;
+			return zero[ux.bits.sign];
+		}
+		/* Clear all but the top e+1 bits. */
+		ux.bits.manh >>= HIBITS - 1 - e;
+		ux.bits.manh <<= HIBITS - 1 - e;
+		ux.bits.manl = 0;
+		*iptr = ux.e;
+		return x - ux.e;
+	} else if (e >= LDBL_MANT_DIG - 1) {    /* x has no fraction part. */
+		*iptr = x;
+		if (x != x)                     /* Handle NaNs. */
+			return x;
+		return zero[ux.bits.sign];
+	} else {                                /* Fraction part is in manl. */
+		if (GETFRAC(ux.bits.manl, LDBL_MANT_DIG - 1 - e) == 0) {
+			/* x is integral. */
+			*iptr = x;
+			return zero[ux.bits.sign];
+		}
+		/* Clear all but the top e+1 bits. */
+		ux.bits.manl >>= LDBL_MANT_DIG - 1 - e;
+		ux.bits.manl <<= LDBL_MANT_DIG - 1 - e;
+		*iptr = ux.e;
+		return x - ux.e;
+	}
+}
+#endif