From: ceriel <none@none>
Date: Thu, 11 Aug 1988 12:49:06 +0000 (+0000)
Subject: Added strtod.c, use it in atof
X-Git-Tag: release-5-5~2930
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=ebfc4a15a4067c580d92696b29e17df2a0439fea;p=ack.git

Added strtod.c, use it in atof
---

diff --git a/lang/cem/libcc/gen/LIST b/lang/cem/libcc/gen/LIST
index 97fac09bd..cbb4adf9f 100644
--- a/lang/cem/libcc/gen/LIST
+++ b/lang/cem/libcc/gen/LIST
@@ -1,6 +1,7 @@
 tail_cc.2g.a
 abs.c
 atof.c
+strtod.c
 atoi.c
 atol.c
 bcmp.c
diff --git a/lang/cem/libcc/gen/atof.c b/lang/cem/libcc/gen/atof.c
index 256db5e85..80f84bac6 100644
--- a/lang/cem/libcc/gen/atof.c
+++ b/lang/cem/libcc/gen/atof.c
@@ -1,81 +1,12 @@
 /* $Header$ */
 #ifndef NOFLOAT
-#include <ctype.h>
 
-extern double ldexp();
+extern double strtod();
 
 double
 atof(p)
 	register char *p;
 {
-	register int c;
-	int exp = 0, sign = 1, expsign = 0;
-	double fl;
-	double big = (double)(1L << 30) * (1L << 22);
-
-	while (isspace(*p)) p++;
-	c = *p;
-
-	switch (c) {
-	case '-':
-		sign = -1;
-	case '+': 
-		p++;
-	}
-
-	fl = 0.0;
-	while (isdigit(c = *p++)) {
-		if (fl < big)
-			fl = 10.0 * fl + (double)(c - '0');
-		else
-			exp++;
-	}
-	if (c == '.') {
-		while (isdigit(c = *p++)) {
-			if (fl < big) {
-				fl = 10.0 * fl + (double) (c - '0');
-				exp--;
-			}
-		}
-	}
-	if (fl == 0) return 0;
-	if (c == 'E' || c == 'e') {
-		int exp1 = 0;
-		int sign = 1;
-
-		switch (*p) {
-		case '-':
-			sign = -1;
-		case '+':
-			p++;
-		}
-		while (isdigit(c = *p++)) {
-			exp1 = 10 * exp1 + c - '0';
-		}
-		exp += sign * exp1;
-	}
-
-	if (exp < 0) {
-		expsign = 1;
-		exp = -exp;
-	}
-
-	if (exp != 0) {
-		int oldexp = exp;
-		double exp5 = 5.0;
-		double correction = 1.0;
-
-		while (exp) {
-			if (exp % 2) correction *= exp5;
-			exp /= 2;
-			if (exp != 0) exp5 *= exp5;
-		}
-		if (expsign) fl = fl / correction;
-		else	fl = fl * correction;
-
-		fl = ldexp(fl, expsign ? -oldexp : oldexp);
-	}
-
-	return sign * fl;
+	return strtod(p, (char **) 0);
 }
 #endif
diff --git a/lang/cem/libcc/gen/strtod.c b/lang/cem/libcc/gen/strtod.c
new file mode 100644
index 000000000..88370ad0e
--- /dev/null
+++ b/lang/cem/libcc/gen/strtod.c
@@ -0,0 +1,97 @@
+/* $Header$ */
+#ifndef NOFLOAT
+#include <ctype.h>
+
+extern double ldexp();
+
+#define MAX	(0x7fffffffL/10)
+
+double
+strtod(p, pp)
+	register char *p;
+	char **pp;
+{
+	register int c;
+	int exp = 0, sign = 1, expsign = 0;
+	double fl;
+	long lowl = 0, highl = 0, pos = 1;
+	int dotseen = 0;
+	int digitseen = 0;
+
+	if (pp) *pp = p;
+	while (isspace(*p)) p++;
+	c = *p;
+
+	switch (c) {
+	case '-':
+		sign = -1;
+	case '+': 
+		p++;
+	}
+
+	while (isdigit(c = *p++) || (c == '.' && ! dotseen++)) {
+		if (c == '.') continue;
+		digit_seen = 1;
+		if (highl < MAX) {
+			highl = (highl << 3) + (highl << 1) + (c - '0');
+		}
+		else if (pos < MAX) {
+			pos = (pos << 3) + (pos << 1);
+			lowl = (lowl << 3) + (lowl << 1) + (c - '0');
+		}
+		else exp++;
+		if (dotseen) exp--;
+	}
+	if (! digit_seen) return 0.0;
+	fl = highl;
+	if (pos > 1) {
+		fl = pos * fl + lowl;
+	}
+
+	if (pp) *pp = p-1;
+
+	if (c == 'E' || c == 'e') {
+		int exp1 = 0;
+		int sign = 1;
+
+		switch (*p) {
+		case '-':
+			sign = -1;
+		case '+':
+			p++;
+		}
+		if (isdigit(c = *p)) {
+			do {
+				exp1 = 10 * exp1 + c - '0';
+			} while (isdigit(c = *++p));
+			if (pp) *pp = p;
+		}
+		exp += sign * exp1;
+	}
+
+	if (fl == 0.0) return 0.0;
+
+	if (exp < 0) {
+		expsign = 1;
+		exp = -exp;
+	}
+
+	if (exp != 0) {
+                int oldexp = exp;
+                double exp5 = 5.0;
+                double correction = 1.0;
+ 
+                while (exp) {
+                        if (exp % 2) correction *= exp5;
+                        exp /= 2;
+                        if (exp != 0) exp5 *= exp5;
+                }
+                if (expsign) fl = fl / correction;
+                else    fl = fl * correction;
+ 
+                fl = ldexp(fl, expsign ? -oldexp : oldexp);
+	}
+
+	return sign * fl;
+}
+#endif