Several fixes

lang/pc/libpc/cvt.c

@@ -3,6 +3,9 @@
 
 #if __STDC__
 #include <float.h>
+#else
+#include <math.h>
+#define DBL_MAX	M_MAX_D
 #endif
 
 static char *cvt();
@@ -59,11 +62,9 @@ cvt(value, ndigit, decpt, sign, ecvtflag)
 	}
 
 	*decpt = 0;
-#if __STDC__
 	if (value >= DBL_MAX) {
 		value = DBL_MAX;
 	}
-#endif
 	if (value != 0.0) {
 		register struct powers_of_10 *pp = &p10[0];
 

lang/pc/libpc/exp.c

@@ -16,8 +16,9 @@ extern	_trp();
 #include <pc_math.h>
 #define M_MIN_D	DBL_MIN
 #define M_MAX_D	DBL_MAX
-#define HUGE	HUGE_VAL
 #endif
+#undef HUGE
+#define HUGE	1e1000
 
 static double
 Ldexp(fl,exp)
@@ -77,7 +78,16 @@ _exp(x)
 	int	negative = x < 0;
 
 	if (x <= M_LN_MIN_D) {
-		return M_MIN_D;
+		g = M_MIN_D/4.0;
+
+		if (g != 0.0) {
+			/* unnormalized numbers apparently exist */
+			if (x < (M_LN2 * (DBL_MIN_EXP - 53))) return 0.0;
+		}
+		else {
+			if (x < M_LN_MIN_D) return 0.0;
+			return M_MIN_D;
+		}
 	}
 	if (x >= M_LN_MAX_D) {
 		if (x > M_LN_MAX_D) {
@@ -88,8 +98,6 @@ _exp(x)
 	}
 	if (negative) x = -x;
 
-	/* ??? avoid underflow ??? */
-
 	n = x * M_LOG2E + 0.5;	/* 1/ln(2) = log2(e), 0.5 added for rounding */
 	xn = n;
 	{

lang/pc/libpc/log.c

@@ -13,8 +13,10 @@
 
 #if __STDC__
 #include <pc_math.h>
-#define HUGE	HUGE_VAL
+#include <float.h>
 #endif
+#undef HUGE
+#define HUGE	1e1000
 
 double
 _log(x)

lang/pc/libpc/opn.c

@@ -39,10 +39,11 @@ extern int		_unlink();
 extern long		_lseek();
 
 static int tmpfil() {
+	static char *namebuf[] = "/usr/tmp/plf.xxxxx";
 	int i; char *p,*q;
 
 	i = _getpid();
-	p = "/usr/tmp/plf.xxxxx";
+	p = namebuf;
 	q = p + 13;
 	do
 		*q++ = (i & 07) + '0';

lang/pc/libpc/wrf.c

@@ -26,10 +26,15 @@ extern char	*_fcvt();
 
 #define	assert(x)	/* nothing */
 
-#define	HUGE_DIG	39	/* log10(maxreal) */
+#if __STDC__
+#include <float.h>
+#define	HUGE_DIG	DBL_MAX_10_EXP	/* log10(maxreal) */
+#else
+#define	HUGE_DIG	400	/* log10(maxreal) */
+#endif
 #define	PREC_DIG	80	/* the maximum digits returned by _fcvt() */
 #define	FILL_CHAR	'0'	/* char printed if all of _fcvt() used */
-#define	BUFSIZE		HUGE_DIG + PREC_DIG + 2
+#define	BUFSIZE		HUGE_DIG + PREC_DIG + 3
 
 _wrf(n,w,r,f) int n,w; double r; struct file *f; {
 	char *p,*b; int s,d; char buf[BUFSIZE];