Revert "Revert "[APFloat] Removed APFloat constructor which initialized to either zero/NaN but allowed you to arbitrarily set the category of the float.""

This reverts commit r185099.

Looks like both the ppc-64 and mips bots are still failing after I reverted this
change.

Since:

1. The mips bot always performs a clean build,
2. The ppc64-bot failed again after a clean build (I asked the ppc-64
maintainers to clean the bot which they did... Thanks Will!),

I think it is safe to assume that this change was not the cause of the failures
that said builders were seeing. Thus I am recomitting.

llvm-svn: 185111

llvm/include/llvm/ADT/APFloat.h

@@ -191,7 +191,6 @@ public:
   APFloat(const fltSemantics &); // Default construct to 0.0
   APFloat(const fltSemantics &, StringRef);
   APFloat(const fltSemantics &, integerPart);
-  APFloat(const fltSemantics &, fltCategory, bool negative);
   APFloat(const fltSemantics &, uninitializedTag);
   APFloat(const fltSemantics &, const APInt &);
   explicit APFloat(double d);

llvm/lib/Support/APFloat.cpp

@@ -795,17 +795,6 @@ APFloat::APFloat(const fltSemantics &ourSemantics, uninitializedTag tag) {
   initialize(&ourSemantics);
 }
 
-APFloat::APFloat(const fltSemantics &ourSemantics,
-                 fltCategory ourCategory, bool negative) {
-  initialize(&ourSemantics);
-  category = ourCategory;
-  sign = negative;
-  if (isFiniteNonZero())
-    category = fcZero;
-  else if (ourCategory == fcNaN)
-    makeNaN();
-}
-
 APFloat::APFloat(const fltSemantics &ourSemantics, StringRef text) {
   initialize(&ourSemantics);
   convertFromString(text, rmNearestTiesToEven);
@@ -2406,8 +2395,8 @@ APFloat::roundSignificandWithExponent(const integerPart *decSigParts,
     excessPrecision = calcSemantics.precision - semantics->precision;
     truncatedBits = excessPrecision;
 
-    APFloat decSig(calcSemantics, fcZero, sign);
+    APFloat decSig = APFloat::getZero(calcSemantics, sign);
-    APFloat pow5(calcSemantics, fcZero, false);
+    APFloat pow5(calcSemantics);
 
     sigStatus = decSig.convertFromUnsignedParts(decSigParts, sigPartCount,
                                                 rmNearestTiesToEven);
@@ -3388,15 +3377,16 @@ APFloat APFloat::getSmallest(const fltSemantics &Sem, bool Negative) {
 }
 
 APFloat APFloat::getSmallestNormalized(const fltSemantics &Sem, bool Negative) {
-  APFloat Val(Sem, fcNormal, Negative);
+  APFloat Val(Sem, uninitialized);
 
   // We want (in interchange format):
   //   sign = {Negative}
   //   exponent = 0..0
   //   significand = 10..0
 
-  Val.exponent = Sem.minExponent;
   Val.zeroSignificand();
+  Val.sign = Negative;
+  Val.exponent = Sem.minExponent;
   Val.significandParts()[partCountForBits(Sem.precision)-1] |=
     (((integerPart) 1) << ((Sem.precision - 1) % integerPartWidth));
 

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -2888,7 +2888,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I,
   if (!LHSUnsigned) {
     // If the RHS value is > SignedMax, fold the comparison.  This handles +INF
     // and large values.
-    APFloat SMax(RHS.getSemantics(), APFloat::fcZero, false);
+    APFloat SMax(RHS.getSemantics());
     SMax.convertFromAPInt(APInt::getSignedMaxValue(IntWidth), true,
                           APFloat::rmNearestTiesToEven);
     if (SMax.compare(RHS) == APFloat::cmpLessThan) {  // smax < 13123.0
@@ -2900,7 +2900,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I,
   } else {
     // If the RHS value is > UnsignedMax, fold the comparison. This handles
     // +INF and large values.
-    APFloat UMax(RHS.getSemantics(), APFloat::fcZero, false);
+    APFloat UMax(RHS.getSemantics());
     UMax.convertFromAPInt(APInt::getMaxValue(IntWidth), false,
                           APFloat::rmNearestTiesToEven);
     if (UMax.compare(RHS) == APFloat::cmpLessThan) {  // umax < 13123.0
@@ -2913,7 +2913,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I,
 
   if (!LHSUnsigned) {
     // See if the RHS value is < SignedMin.
-    APFloat SMin(RHS.getSemantics(), APFloat::fcZero, false);
+    APFloat SMin(RHS.getSemantics());
     SMin.convertFromAPInt(APInt::getSignedMinValue(IntWidth), true,
                           APFloat::rmNearestTiesToEven);
     if (SMin.compare(RHS) == APFloat::cmpGreaterThan) { // smin > 12312.0
@@ -2924,7 +2924,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I,
     }
   } else {
     // See if the RHS value is < UnsignedMin.
-    APFloat SMin(RHS.getSemantics(), APFloat::fcZero, false);
+    APFloat SMin(RHS.getSemantics());
     SMin.convertFromAPInt(APInt::getMinValue(IntWidth), true,
                           APFloat::rmNearestTiesToEven);
     if (SMin.compare(RHS) == APFloat::cmpGreaterThan) { // umin > 12312.0