1 files changed, 110 insertions, 0 deletions
diff --git a/lib/msun/src/s_nan.c b/lib/msun/src/s_nan.c
new file mode 100644
index 0000000..890f471
--- /dev/null
+++ b/lib/msun/src/s_nan.c
@@ -0,0 +1,110 @@
+/*-
+ * Copyright (c) 2007 David Schultz
+ * 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 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 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/endian.h>
+#include <ctype.h>
+#include <float.h>
+#include <math.h>
+#include <stdint.h>
+#include <strings.h>
+
+#include "math_private.h"
+
+/*
+ * Scan a string of hexadecimal digits (the format nan(3) expects) and
+ * make a bit array (using the local endianness). We stop when we
+ * encounter an invalid character, NUL, etc.  If we overflow, we do
+ * the same as gcc's __builtin_nan(), namely, discard the high order bits.
+ *
+ * The format this routine accepts needs to be compatible with what is used
+ * in contrib/gdtoa/hexnan.c (for strtod/scanf) and what is used in
+ * __builtin_nan(). In fact, we're only 100% compatible for strings we
+ * consider valid, so we might be violating the C standard. But it's
+ * impossible to use nan(3) portably anyway, so this seems good enough.
+ */
+void
+_scan_nan(uint32_t *words, int num_words, const char *s)
+{
+	int si;		/* index into s */
+	int bitpos;	/* index into words (in bits) */
+
+	bzero(words, num_words * sizeof(uint32_t));
+
+	/* Allow a leading '0x'. (It's expected, but redundant.) */
+	if (s[0] == '0' && (s[1] == 'x' || s[1] == 'X'))
+		s += 2;
+
+	/* Scan forwards in the string, looking for the end of the sequence. */
+	for (si = 0; isxdigit(s[si]); si++)
+		;
+
+	/* Scan backwards, filling in the bits in words[] as we go. */
+#if _BYTE_ORDER == _LITTLE_ENDIAN
+	for (bitpos = 0; bitpos < 32 * num_words; bitpos += 4) {
+#else
+	for (bitpos = 32 * num_words - 4; bitpos >= 0; bitpos -= 4) {
+#endif
+		if (--si < 0)
+			break;
+		words[bitpos / 32] |= digittoint(s[si]) << (bitpos % 32);
+	}
+}
+
+double
+nan(const char *s)
+{
+	union {
+		double d;
+		uint32_t bits[2];
+	} u;
+
+	_scan_nan(u.bits, 2, s);
+#if _BYTE_ORDER == _LITTLE_ENDIAN
+	u.bits[1] |= 0x7ff80000;
+#else
+	u.bits[0] |= 0x7ff80000;
+#endif
+	return (u.d);
+}
+
+float
+nanf(const char *s)
+{
+	union {
+		float f;
+		uint32_t bits[1];
+	} u;
+
+	_scan_nan(u.bits, 1, s);
+	u.bits[0] |= 0x7fc00000;
+	return (u.f);
+}
+
+#if (LDBL_MANT_DIG == 53)
+__weak_reference(nan, nanl);
+#endif