From: Guy Harris <guy@alum.mit.edu>
Date: Mon, 14 Sep 2015 22:12:28 +0000 (-0700)
Subject: Use double rather than float.
X-Git-Tag: tcpdump-4.8.0~140
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/ff1df423b6a8cda80cef88efa8a3162abcfd0e6e

Use double rather than float.

That means we can fit a 32-bit integer into a floating-point value
without losing precision.

Also, put in explicit casts when we convert a floating-point value to an
integral value, to suppress compiler warnings.
---

diff --git a/print-ntp.c b/print-ntp.c
index 908c5360..0ba62194 100644
--- a/print-ntp.c
+++ b/print-ntp.c
@@ -326,16 +326,16 @@ p_sfix(netdissect_options *ndo,
 {
 	register int i;
 	register int f;
-	register float ff;
+	register double ff;
 
 	i = EXTRACT_16BITS(&sfp->int_part);
 	f = EXTRACT_16BITS(&sfp->fraction);
-	ff = f / 65536.0f;	/* shift radix point by 16 bits */
-	f = ff * 1000000.0f;	/* Treat fraction as parts per million */
+	ff = f / 65536.0;		/* shift radix point by 16 bits */
+	f = (int)(ff * 1000000.0);	/* Treat fraction as parts per million */
 	ND_PRINT((ndo, "%d.%06d", i, f));
 }
 
-#define	FMAXINT	(4294967296.0f)	/* floating point rep. of MAXINT */
+#define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
 
 static void
 p_ntp_time(netdissect_options *ndo,
@@ -344,15 +344,15 @@ p_ntp_time(netdissect_options *ndo,
 	register int32_t i;
 	register uint32_t uf;
 	register uint32_t f;
-	register float ff;
+	register double ff;
 
 	i = EXTRACT_32BITS(&lfp->int_part);
 	uf = EXTRACT_32BITS(&lfp->fraction);
 	ff = uf;
-	if (ff < 0.0f)		/* some compilers are buggy */
+	if (ff < 0.0)		/* some compilers are buggy */
 		ff += FMAXINT;
-	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
-	f = ff * 1000000000.0f;	/* treat fraction as parts per billion */
+	ff = ff / FMAXINT;			/* shift radix point by 32 bits */
+	f = (uint32_t)(ff * 1000000000.0);	/* treat fraction as parts per billion */
 	ND_PRINT((ndo, "%u.%09d", i, f));
 
 #ifdef HAVE_STRFTIME
@@ -381,7 +381,7 @@ p_ntp_delta(netdissect_options *ndo,
 	register uint32_t u, uf;
 	register uint32_t ou, ouf;
 	register uint32_t f;
-	register float ff;
+	register double ff;
 	int signbit;
 
 	u = EXTRACT_32BITS(&lfp->int_part);
@@ -417,10 +417,10 @@ p_ntp_delta(netdissect_options *ndo,
 	}
 
 	ff = f;
-	if (ff < 0.0f)		/* some compilers are buggy */
+	if (ff < 0.0)		/* some compilers are buggy */
 		ff += FMAXINT;
-	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
-	f = ff * 1000000000.0f;	/* treat fraction as parts per billion */
+	ff = ff / FMAXINT;			/* shift radix point by 32 bits */
+	f = (uint32_t)(ff * 1000000000.0);	/* treat fraction as parts per billion */
 	ND_PRINT((ndo, "%s%d.%09d", signbit ? "-" : "+", i, f));
 }