From f17ac39f29caa1ec26cc2940d196c96e20d2e2ff Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@aps.anl.gov>
Date: Tue, 25 Aug 2009 18:19:49 +0000
Subject: [PATCH] Disable divide by zero warnings on MSVC when generating NAN
 and INF. Use those values rather than calculating them independently.

---
 src/libCom/calc/calcPerform.c |  2 +-
 src/libCom/osi/epicsMath.cpp  | 10 ++++++++++
 src/rec/selRecord.c           | 16 ++++------------
 3 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/libCom/calc/calcPerform.c b/src/libCom/calc/calcPerform.c
index e242e1e3f..e074bbcbc 100644
--- a/src/libCom/calc/calcPerform.c
+++ b/src/libCom/calc/calcPerform.c
@@ -135,7 +135,7 @@ epicsShareFunc long
 	    if (itop)
 		*ptop = (long) *ptop % itop;
 	    else
-		*ptop = 0.0 / itop;   /* NaN */
+		*ptop = epicsNAN;   /* NaN */
 	    break;
 
 	case POWER:
diff --git a/src/libCom/osi/epicsMath.cpp b/src/libCom/osi/epicsMath.cpp
index c0e9d9068..6e53e62a0 100644
--- a/src/libCom/osi/epicsMath.cpp
+++ b/src/libCom/osi/epicsMath.cpp
@@ -9,6 +9,11 @@
 #define epicsExportSharedSymbols
 #include <epicsMath.h>
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable:4723)
+#endif
+
 static float makeNAN ( void )
 {
     float a = 0, b = 0;
@@ -25,3 +30,8 @@ extern "C" {
 epicsShareDef float epicsNAN = makeNAN();
 epicsShareDef float epicsINF = makeINF();
 }
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
diff --git a/src/rec/selRecord.c b/src/rec/selRecord.c
index e8f20f052..4eef2d79a 100644
--- a/src/rec/selRecord.c
+++ b/src/rec/selRecord.c
@@ -84,11 +84,6 @@ static void do_sel(selRecord *);
 static int fetch_values(selRecord *);
 static void monitor(selRecord *);
 
-/* This needed to prevent the MS optimizer from barfing */
-static double divide(double num, double den) { return num / den; }
-
-static double NaN, Inf;
-
 
 static long init_record(selRecord *prec, int pass)
 {
@@ -98,9 +93,6 @@ static long init_record(selRecord *prec, int pass)
 
     if (pass==0) return(0);
 
-    NaN = divide(0.0, 0.0);
-    Inf = divide(1.0, 0.0);
-
     /* get seln initial value if nvl is a constant*/
     if (prec->nvl.type == CONSTANT ) {
 	recGblInitConstantLink(&prec->nvl,DBF_USHORT,&prec->seln);
@@ -109,7 +101,7 @@ static long init_record(selRecord *prec, int pass)
     plink = &prec->inpa;
     pvalue = &prec->a;
     for(i=0; i<SEL_MAX; i++, plink++, pvalue++) {
-	*pvalue = NaN;
+	*pvalue = epicsNAN;
 	if (plink->type==CONSTANT) {
 	    recGblInitConstantLink(plink,DBF_DOUBLE,pvalue);
 	}
@@ -365,7 +357,7 @@ static void do_sel(selRecord *prec)
 	val = *(pvalue+prec->seln);
 	break;
     case (selSELM_High_Signal):
-	val = -Inf;
+	val = -epicsINF;
 	for (i = 0; i < SEL_MAX; i++,pvalue++){
 	    if (!isnan(*pvalue) && val < *pvalue) {
 		val = *pvalue;
@@ -374,7 +366,7 @@ static void do_sel(selRecord *prec)
 	}
 	break;
     case (selSELM_Low_Signal):
-	val = Inf;
+	val = epicsINF;
 	for (i = 0; i < SEL_MAX; i++,pvalue++){
 	    if (!isnan(*pvalue) && val > *pvalue) {
 		val = *pvalue;
@@ -384,7 +376,7 @@ static void do_sel(selRecord *prec)
 	break;
     case (selSELM_Median_Signal):
 	count = 0;
-	order[0] = NaN;
+	order[0] = epicsNAN;
 	for (i = 0; i < SEL_MAX; i++,pvalue++){
 	    if (!isnan(*pvalue)){
 		/* Insertion sort */