Make improvements

third_party/gdtoa/g_xfmt_p.c

@@ -0,0 +1,136 @@
+#include "third_party/gdtoa/gdtoaimp.h"
+
+/* clang-format off */
+/****************************************************************
+
+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 (dmg at acm dot org,
+ * with " at " changed at "@" and " dot " changed to ".").	*/
+
+ extern UShort NanDflt_ldus_D2A[5];
+
+#undef _0
+#undef _1
+
+/* one or the other of IEEE_MC68k or IEEE_8087 should be #defined */
+
+#ifdef IEEE_MC68k
+#define _0 0
+#define _1 1
+#define _2 2
+#define _3 3
+#define _4 4
+#endif
+#ifdef IEEE_8087
+#define _0 4
+#define _1 3
+#define _2 2
+#define _3 1
+#define _4 0
+#endif
+
+ char*
+#ifdef KR_headers
+g_xfmt_p(buf, V, ndig, bufsize, nik) char *buf; char *V; int ndig; size_t bufsize; int nik;
+#else
+g_xfmt_p(char *buf, void *V, int ndig, size_t bufsize, int nik)
+#endif
+{
+	static const FPI fpi0 = { 64, 1-16383-64+1, 32766 - 16383 - 64 + 1, 1, 0, Int_max };
+	char *b, *s, *se;
+	ULong bits[2], sign;
+	UShort *L;
+	int decpt, ex, i, mode;
+#ifdef Honor_FLT_ROUNDS
+#include "third_party/gdtoa/gdtoa_fltrnds.inc"
+#else
+#define fpi &fpi0
+#endif
+
+	if (ndig < 0)
+		ndig = 0;
+	if (bufsize < (size_t)(ndig + 10))
+		return 0;
+
+	L = (UShort *)V;
+	sign = L[_0] & 0x8000;
+	bits[1] = (L[_1] << 16) | L[_2];
+	bits[0] = (L[_3] << 16) | L[_4];
+	if ( (ex = L[_0] & 0x7fff) !=0) {
+		if (ex == 0x7fff) {
+			/* Infinity or NaN */
+			if (nik < 0 || nik > 35)
+				nik = 0;
+			if (!bits[0] && bits[1]== 0x80000000) {
+				b = buf;
+				if (sign)
+					*b++ = '-';
+				b = strcp(b, InfName[nik%6]);
+				}
+			else {
+				b = buf;
+				if (sign && nik < 18)
+					*b++ = '-';
+				b = strcp(b, NanName[nik%3]);
+				if (nik > 5 && (nik < 12
+						|| L[_1] != NanDflt_ldus_D2A[3]
+						|| L[_2] != NanDflt_ldus_D2A[2]
+						|| L[_3] != NanDflt_ldus_D2A[1]
+						|| L[_4] != NanDflt_ldus_D2A[0])) {
+					bits[1] &= 0x7fffffff;
+					b = add_nanbits(b, bufsize - (b-buf), bits, 2);
+					}
+				}
+			return b;
+			}
+		i = STRTOG_Normal;
+		}
+	else if (bits[0] | bits[1]) {
+		i = STRTOG_Denormal;
+		ex = 1;
+		}
+	else {
+		b = buf;
+#ifndef IGNORE_ZERO_SIGN
+		if (sign)
+			*b++ = '-';
+#endif
+		*b++ = '0';
+		*b = 0;
+		return b;
+		}
+	ex -= 0x3fff + 63;
+	mode = 2;
+	if (ndig <= 0) {
+		if (bufsize < 32)
+			return 0;
+		mode = 0;
+		}
+	s = gdtoa(fpi, ex, bits, &i, mode, ndig, &decpt, &se);
+	return g__fmt(buf, s, se, decpt, sign, bufsize);
+	}