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

strings and floating point.

1 files changed, 222 insertions, 0 deletions

diff --git a/contrib/gdtoa/dmisc.c b/contrib/gdtoa/dmisc.c
new file mode 100644
index 0000000..14b5d7e
--- /dev/null
+++ b/contrib/gdtoa/dmisc.c
@@ -0,0 +1,222 @@
+/****************************************************************
+
+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"
+
+#ifndef MULTIPLE_THREADS
+ char *dtoa_result;
+#endif
+
+ char *
+#ifdef KR_headers
+rv_alloc(i) int i;
+#else
+rv_alloc(int i)
+#endif
+{
+	int j, k, *r;
+
+	j = sizeof(ULong);
+	for(k = 0;
+		sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i;
+		j <<= 1)
+			k++;
+	r = (int*)Balloc(k);
+	*r = k;
+	return
+#ifndef MULTIPLE_THREADS
+	dtoa_result =
+#endif
+		(char *)(r+1);
+	}
+
+ char *
+#ifdef KR_headers
+nrv_alloc(s, rve, n) char *s, **rve; int n;
+#else
+nrv_alloc(char *s, char **rve, int n)
+#endif
+{
+	char *rv, *t;
+
+	t = rv = rv_alloc(n);
+	while((*t = *s++) !=0)
+		t++;
+	if (rve)
+		*rve = t;
+	return rv;
+	}
+
+/* freedtoa(s) must be used to free values s returned by dtoa
+ * when MULTIPLE_THREADS is #defined.  It should be used in all cases,
+ * but for consistency with earlier versions of dtoa, it is optional
+ * when MULTIPLE_THREADS is not defined.
+ */
+
+ void
+#ifdef KR_headers
+freedtoa(s) char *s;
+#else
+freedtoa(char *s)
+#endif
+{
+	Bigint *b = (Bigint *)((int *)s - 1);
+	b->maxwds = 1 << (b->k = *(int*)b);
+	Bfree(b);
+#ifndef MULTIPLE_THREADS
+	if (s == dtoa_result)
+		dtoa_result = 0;
+#endif
+	}
+
+ int
+quorem
+#ifdef KR_headers
+	(b, S) Bigint *b, *S;
+#else
+	(Bigint *b, Bigint *S)
+#endif
+{
+	int n;
+	ULong *bx, *bxe, q, *sx, *sxe;
+#ifdef ULLong
+	ULLong borrow, carry, y, ys;
+#else
+	ULong borrow, carry, y, ys;
+#ifdef Pack_32
+	ULong si, z, zs;
+#endif
+#endif
+
+	n = S->wds;
+#ifdef DEBUG
+	/*debug*/ if (b->wds > n)
+	/*debug*/	Bug("oversize b in quorem");
+#endif
+	if (b->wds < n)
+		return 0;
+	sx = S->x;
+	sxe = sx + --n;
+	bx = b->x;
+	bxe = bx + n;
+	q = *bxe / (*sxe + 1);	/* ensure q <= true quotient */
+#ifdef DEBUG
+	/*debug*/ if (q > 9)
+	/*debug*/	Bug("oversized quotient in quorem");
+#endif
+	if (q) {
+		borrow = 0;
+		carry = 0;
+		do {
+#ifdef ULLong
+			ys = *sx++ * (ULLong)q + carry;
+			carry = ys >> 32;
+			y = *bx - (ys & 0xffffffffUL) - borrow;
+			borrow = y >> 32 & 1UL;
+			*bx++ = y & 0xffffffffUL;
+#else
+#ifdef Pack_32
+			si = *sx++;
+			ys = (si & 0xffff) * q + carry;
+			zs = (si >> 16) * q + (ys >> 16);
+			carry = zs >> 16;
+			y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
+			borrow = (y & 0x10000) >> 16;
+			z = (*bx >> 16) - (zs & 0xffff) - borrow;
+			borrow = (z & 0x10000) >> 16;
+			Storeinc(bx, z, y);
+#else
+			ys = *sx++ * q + carry;
+			carry = ys >> 16;
+			y = *bx - (ys & 0xffff) - borrow;
+			borrow = (y & 0x10000) >> 16;
+			*bx++ = y & 0xffff;
+#endif
+#endif
+			}
+			while(sx <= sxe);
+		if (!*bxe) {
+			bx = b->x;
+			while(--bxe > bx && !*bxe)
+				--n;
+			b->wds = n;
+			}
+		}
+	if (cmp(b, S) >= 0) {
+		q++;
+		borrow = 0;
+		carry = 0;
+		bx = b->x;
+		sx = S->x;
+		do {
+#ifdef ULLong
+			ys = *sx++ + carry;
+			carry = ys >> 32;
+			y = *bx - (ys & 0xffffffffUL) - borrow;
+			borrow = y >> 32 & 1UL;
+			*bx++ = y & 0xffffffffUL;
+#else
+#ifdef Pack_32
+			si = *sx++;
+			ys = (si & 0xffff) + carry;
+			zs = (si >> 16) + (ys >> 16);
+			carry = zs >> 16;
+			y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
+			borrow = (y & 0x10000) >> 16;
+			z = (*bx >> 16) - (zs & 0xffff) - borrow;
+			borrow = (z & 0x10000) >> 16;
+			Storeinc(bx, z, y);
+#else
+			ys = *sx++ + carry;
+			carry = ys >> 16;
+			y = *bx - (ys & 0xffff) - borrow;
+			borrow = (y & 0x10000) >> 16;
+			*bx++ = y & 0xffff;
+#endif
+#endif
+			}
+			while(sx <= sxe);
+		bx = b->x;
+		bxe = bx + n;
+		if (!*bxe) {
+			while(--bxe > bx && !*bxe)
+				--n;
+			b->wds = n;
+			}
+		}
+	return q;
+	}