Initial import of David Gay's gdtoa library for conversion betweenvendor/gdtoa/20030305

strings and floating point.

1 files changed, 161 insertions, 0 deletions

diff --git a/contrib/gdtoa/g_ddfmt.c b/contrib/gdtoa/g_ddfmt.c
new file mode 100644
index 000000000000..7d214ba8a401
--- /dev/null
+++ b/contrib/gdtoa/g_ddfmt.c
@@ -0,0 +1,161 @@
+/****************************************************************
+
+The author of this software is David M. Gay.
+
+Copyright (C) 1998 by Lucent Technologies
+All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby
+granted, provided that the above copyright notice appear in all
+copies and that both that the copyright notice and this
+permission notice and warranty disclaimer appear in supporting
+documentation, and that the name of Lucent or any of its entities
+not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior
+permission.
+
+LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
+IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
+SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+THIS SOFTWARE.
+
+****************************************************************/
+
+/* Please send bug reports to
+	David M. Gay
+	Bell Laboratories, Room 2C-463
+	600 Mountain Avenue
+	Murray Hill, NJ 07974-0636
+	U.S.A.
+	dmg@bell-labs.com
+ */
+
+#include "gdtoaimp.h"
+#include <string.h>
+
+ char *
+#ifdef KR_headers
+g_ddfmt(buf, dd, ndig, bufsize) char *buf; double *dd; int ndig; unsigned bufsize;
+#else
+g_ddfmt(char *buf, double *dd, int ndig, unsigned bufsize)
+#endif
+{
+	FPI fpi;
+	char *b, *s, *se;
+	ULong *L, bits0[4], *bits, *zx;
+	int bx, by, decpt, ex, ey, i, j, mode;
+	Bigint *x, *y, *z;
+	double ddx[2];
+
+	if (bufsize < 10 || bufsize < ndig + 8)
+		return 0;
+
+	L = (ULong*)dd;
+	if ((L[_0] & 0x7ff00000L) == 0x7ff00000L) {
+		/* Infinity or NaN */
+		if (L[_0] & 0xfffff || L[_1]) {
+ nanret:
+			return strcp(buf, "NaN");
+			}
+		if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) {
+			if (L[2+_0] & 0xfffff || L[2+_1])
+				goto nanret;
+			if ((L[_0] ^ L[2+_0]) & 0x80000000L)
+				goto nanret;	/* Infinity - Infinity */
+			}
+ infret:
+		b = buf;
+		if (L[_0] & 0x80000000L)
+			*b++ = '-';
+		return strcp(b, "Infinity");
+		}
+	if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) {
+		L += 2;
+		if (L[_0] & 0xfffff || L[_1])
+			goto nanret;
+		goto infret;
+		}
+	if (dd[0] + dd[1] == 0.) {
+		b = buf;
+#ifndef IGNORE_ZERO_SIGN
+		if (L[_0] & L[2+_0] & 0x80000000L)
+			*b++ = '-';
+#endif
+		*b++ = '0';
+		*b = 0;
+		return b;
+		}
+	if ((L[_0] & 0x7ff00000L) < (L[2+_0] & 0x7ff00000L)) {
+		ddx[1] = dd[0];
+		ddx[0] = dd[1];
+		dd = ddx;
+		L = (ULong*)dd;
+		}
+	z = d2b(dd[0], &ex, &bx);
+	if (dd[1] == 0.)
+		goto no_y;
+	x = z;
+	y = d2b(dd[1], &ey, &by);
+	if ( (i = ex - ey) !=0) {
+		if (i > 0) {
+			x = lshift(x, i);
+			ex = ey;
+			}
+		else
+			y = lshift(y, -i);
+		}
+	if ((L[_0] ^ L[2+_0]) & 0x80000000L) {
+		z = diff(x, y);
+		if (L[_0] & 0x80000000L)
+			z->sign = 1 - z->sign;
+		}
+	else {
+		z = sum(x, y);
+		if (L[_0] & 0x80000000L)
+			z->sign = 1;
+		}
+	Bfree(x);
+	Bfree(y);
+ no_y:
+	bits = zx = z->x;
+	for(i = 0; !*zx; zx++)
+		i += 32;
+	i += lo0bits(zx);
+	if (i) {
+		rshift(z, i);
+		ex += i;
+		}
+	fpi.nbits = z->wds * 32 - hi0bits(z->x[j = z->wds-1]);
+	if (fpi.nbits < 106) {
+		fpi.nbits = 106;
+		if (j < 3) {
+			for(i = 0; i <= j; i++)
+				bits0[i] = bits[i];
+			while(i < 4)
+				bits0[i++] = 0;
+			bits = bits0;
+			}
+		}
+	mode = 2;
+	if (ndig <= 0) {
+		if (bufsize < (int)(fpi.nbits * .301029995664) + 10) {
+			Bfree(z);
+			return 0;
+			}
+		mode = 0;
+		}
+	fpi.emin = 1-1023-53+1;
+	fpi.emax = 2046-1023-106+1;
+	fpi.rounding = FPI_Round_near;
+	fpi.sudden_underflow = 0;
+	i = STRTOG_Normal;
+	s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se);
+	b = g__fmt(buf, s, se, decpt, z->sign);
+	Bfree(z);
+	return b;
+	}