1 files changed, 107 insertions, 0 deletions
diff --git a/lib/libc/gdtoa/_ldtoa.c b/lib/libc/gdtoa/_ldtoa.c
new file mode 100644
index 0000000..60c6b22
--- /dev/null
+++ b/lib/libc/gdtoa/_ldtoa.c
@@ -0,0 +1,107 @@
+/*-
+ * Copyright (c) 2003 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <float.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <math.h>
+#include <stdlib.h>
+#include "fpmath.h"
+#include "gdtoaimp.h"
+
+/*
+ * ldtoa() is a wrapper for gdtoa() that makes it smell like dtoa(),
+ * except that the floating point argument is passed by reference.
+ * When dtoa() is passed a NaN or infinity, it sets expt to 9999.
+ * However, a long double could have a valid exponent of 9999, so we
+ * use INT_MAX in ldtoa() instead.
+ */
+char *
+__ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign,
+    char **rve)
+{
+	FPI fpi = {
+		LDBL_MANT_DIG,			/* nbits */
+		LDBL_MIN_EXP - LDBL_MANT_DIG,	/* emin */
+		LDBL_MAX_EXP - LDBL_MANT_DIG,	/* emax */
+		FLT_ROUNDS,	       		/* rounding */
+#ifdef Sudden_Underflow	/* unused, but correct anyway */
+		1
+#else
+		0
+#endif
+	};
+	int be, kind;
+	char *ret;
+	union IEEEl2bits u;
+	uint32_t bits[(LDBL_MANT_DIG + 31) / 32];
+	void *vbits = bits;
+
+	u.e = *ld;
+
+	/*
+	 * gdtoa doesn't know anything about the sign of the number, so
+	 * if the number is negative, we need to swap rounding modes of
+	 * 2 (upwards) and 3 (downwards).
+	 */
+	*sign = u.bits.sign;
+	fpi.rounding ^= (fpi.rounding >> 1) & u.bits.sign;
+
+	be = u.bits.exp - (LDBL_MAX_EXP - 1) - (LDBL_MANT_DIG - 1);
+	LDBL_TO_ARRAY32(u, bits);
+
+	switch (fpclassify(u.e)) {
+	case FP_NORMAL:
+		kind = STRTOG_Normal;
+#ifdef	LDBL_IMPLICIT_NBIT
+		bits[LDBL_MANT_DIG / 32] |= 1 << ((LDBL_MANT_DIG - 1) % 32);
+#endif /* LDBL_IMPLICIT_NBIT */
+		break;
+	case FP_ZERO:
+		kind = STRTOG_Zero;
+		break;
+	case FP_SUBNORMAL:
+		kind = STRTOG_Denormal;
+		be++;
+		break;
+	case FP_INFINITE:
+		kind = STRTOG_Infinite;
+		break;
+	case FP_NAN:
+		kind = STRTOG_NaN;
+		break;
+	default:
+		abort();
+	}
+
+	ret = gdtoa(&fpi, be, vbits, &kind, mode, ndigits, decpt, rve);
+	if (*decpt == -32768)
+		*decpt = INT_MAX;
+	return ret;
+}