[APFloat] Move setting fcNormal in zeroSignificand() to calling code.

Zeroing the significand of a floating point number does not necessarily cause a
floating point number to become finite non zero. For instance, if one has a NaN,
zeroing the significand will cause it to become +/- infinity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187313 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index ce57442..bc8e1d0 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -778,6 +778,7 @@
 APFloat::APFloat(const fltSemantics &ourSemantics, integerPart value) {
   initialize(&ourSemantics);
   sign = 0;
+  category = fcNormal;
   zeroSignificand();
   exponent = ourSemantics.precision - 1;
   significandParts()[0] = value;
@@ -845,7 +846,6 @@
 void
 APFloat::zeroSignificand()
 {
-  category = fcNormal;
   APInt::tcSet(significandParts(), 0, partCount());
 }
 
@@ -2301,9 +2301,9 @@
 {
   lostFraction lost_fraction = lfExactlyZero;
 
+  category = fcNormal;
   zeroSignificand();
   exponent = 0;
-  category = fcNormal;
 
   integerPart *significand = significandParts();
   unsigned partsCount = partCount();
@@ -2512,6 +2512,7 @@
              (D.normalizedExponent + 1) * 28738 <=
                8651 * (semantics->minExponent - (int) semantics->precision)) {
     /* Underflow to zero and round.  */
+    category = fcNormal;
     zeroSignificand();
     fs = normalize(rounding_mode, lfLessThanHalf);
 
@@ -3398,6 +3399,7 @@
   //   exponent = 0..0
   //   significand = 10..0
 
+  Val.category = fcNormal;
   Val.zeroSignificand();
   Val.sign = Negative;
   Val.exponent = Sem.minExponent;