Initial import of David Gay's gdtoa library for conversion between

strings and floating point.

1 files changed, 184 insertions, 0 deletions

diff --git a/contrib/gdtoa/strtopdd.c b/contrib/gdtoa/strtopdd.c
new file mode 100644
index 0000000..f71bced
--- /dev/null
+++ b/contrib/gdtoa/strtopdd.c
@@ -0,0 +1,184 @@
+/****************************************************************
+
+The author of this software is David M. Gay.
+
+Copyright (C) 1998, 2000 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"
+
+ int
+#ifdef KR_headers
+strtopdd(s, sp, dd) CONST char *s; char **sp; double *dd;
+#else
+strtopdd(CONST char *s, char **sp, double *dd)
+#endif
+{
+#ifdef Sudden_Underflow
+	static FPI fpi = { 106, 1-1023, 2046-1023-106+1, 1, 1 };
+#else
+	static FPI fpi = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 };
+#endif
+	ULong bits[4];
+	Long exp;
+	int i, j, rv;
+	typedef union {
+		double d[2];
+		ULong L[4];
+		} U;
+	U *u;
+
+	rv = strtodg(s, sp, &fpi, &exp, bits);
+	u = (U*)dd;
+	switch(rv & STRTOG_Retmask) {
+	  case STRTOG_NoNumber:
+	  case STRTOG_Zero:
+		u->d[0] = u->d[1] = 0.;
+		break;
+
+	  case STRTOG_Normal:
+		u->L[_1] = (bits[1] >> 21 | bits[2] << 11) & 0xffffffffL;
+		u->L[_0] = bits[2] >> 21 | bits[3] << 11 & 0xfffff
+			  | exp + 0x3ff + 105 << 20;
+		exp += 0x3ff + 52;
+		if (bits[1] &= 0x1fffff) {
+			i = hi0bits(bits[1]) - 11;
+			if (i >= exp) {
+				i = exp - 1;
+				exp = 0;
+				}
+			else
+				exp -= i;
+			if (i > 0) {
+				bits[1] = bits[1] << i | bits[0] >> 32-i;
+				bits[0] = bits[0] << i & 0xffffffffL;
+				}
+			}
+		else if (bits[0]) {
+			i = hi0bits(bits[0]) + 21;
+			if (i >= exp) {
+				i = exp - 1;
+				exp = 0;
+				}
+			else
+				exp -= i;
+			if (i < 32) {
+				bits[1] = bits[0] >> 32 - i;
+				bits[0] = bits[0] << i & 0xffffffffL;
+				}
+			else {
+				bits[1] = bits[0] << i - 32;
+				bits[0] = 0;
+				}
+			}
+		else {
+			u->L[2] = u->L[3] = 0;
+			break;
+			}
+		u->L[2+_1] = bits[0];
+		u->L[2+_0] = bits[1] & 0xfffff | exp << 20;
+		break;
+
+	  case STRTOG_Denormal:
+		if (bits[3])
+			goto nearly_normal;
+		if (bits[2])
+			goto partly_normal;
+		if (bits[1] & 0xffe00000)
+			goto hardly_normal;
+		/* completely denormal */
+		u->L[2] = u->L[3] = 0;
+		u->L[_1] = bits[0];
+		u->L[_0] = bits[1];
+		break;
+
+	  nearly_normal:
+		i = hi0bits(bits[3]) - 11;	/* i >= 12 */
+		j = 32 - i;
+		u->L[_0] = (bits[3] << i | bits[2] >> j) & 0xfffff
+			| 65 - i << 20;
+		u->L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
+		u->L[2+_0] = bits[1] & (1L << j) - 1;
+		u->L[2+_1] = bits[0];
+		break;
+
+	  partly_normal:
+		i = hi0bits(bits[2]) - 11;
+		if (i < 0) {
+			j = -i;
+			i += 32;
+			u->L[_0] = bits[2] >> j & 0xfffff | (33 + j) << 20;
+			u->L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
+			u->L[2+_0] = bits[1] & (1L << j) - 1;
+			u->L[2+_1] = bits[0];
+			break;
+			}
+		if (i == 0) {
+			u->L[_0] = bits[2] & 0xfffff | 33 << 20;
+			u->L[_1] = bits[1];
+			u->L[2+_0] = 0;
+			u->L[2+_1] = bits[0];
+			break;
+			}
+		j = 32 - i;
+		u->L[_0] = (bits[2] << i | bits[1] >> j) & 0xfffff
+				| j + 1 << 20;
+		u->L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
+		u->L[2+_0] = 0;
+		u->L[2+_1] = bits[0] & (1L << j) - 1;
+		break;
+
+	  hardly_normal:
+		j = 11 - hi0bits(bits[1]);
+		i = 32 - j;
+		u->L[_0] = bits[1] >> j & 0xfffff | j + 1 << 20;
+		u->L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
+		u->L[2+_0] = 0;
+		u->L[2+_1] = bits[0] & (1L << j) - 1;
+		break;
+
+	  case STRTOG_Infinite:
+		u->L[_0] = u->L[2+_0] = 0x7ff00000;
+		u->L[_1] = u->L[2+_1] = 0;
+		break;
+
+	  case STRTOG_NaN:
+		u->L[_0] = u->L[2+_0] = 0x7fffffff;
+		u->L[_1] = u->L[2+_1] = (ULong)-1;
+	  }
+	if (rv & STRTOG_Neg) {
+		u->L[  _0] |= 0x80000000L;
+		u->L[2+_0] |= 0x80000000L;
+		}
+	return rv;
+	}