Expose more properties of llvm::fltSemantics

[• jrkoenig]

Summary

Adds accessor functions for all the fields in llvm::fltSemantics. This will be used in MergeFunctions to order two APFloats with different semanatics.

[jfb]

lgtm

For observers: @jrkoenig's purpose could also be achieved with bool operator==(const fltSemantics &, const fltSemantics &). Exposing the getters seems simpler, but I'm OK with either.

[• jrkoenig]

Actually, it would need to be bool operator<(const fltSemantics &, const fltSemantics &), which is not generally useful. I need to totally order APFloats, not just compare for equality.

include/llvm/ADT/APFloat.h

public:
 
   /// A Pseudo fltsemantic used to construct APFloats that cannot conflict with
   /// anything real.
   static const fltSemantics Bogus;
 
   /// @}
 
   static unsigned int semanticsPrecision(const fltSemantics &);
+  static ExponentType semanticsMinExponent(const fltSemantics &);
+  static ExponentType semanticsMaxExponent(const fltSemantics &);
+  static unsigned int semanticsSizeInBits(const fltSemantics &);
 
   /// IEEE-754R 5.11: Floating Point Comparison Relations.
   enum cmpResult {
     cmpLessThan,
     cmpEqual,
     cmpGreaterThan,
     cmpUnordered
   };

lib/Support/APFloat.cpp

APFloat::partCount() const
   return partCountForBits(semantics->precision + 1);
 }
 
 unsigned int
 APFloat::semanticsPrecision(const fltSemantics &semantics)
 {
   return semantics.precision;
 }
+APFloat::ExponentType
+APFloat::semanticsMaxExponent(const fltSemantics &semantics)
+{
+  return semantics.maxExponent;
+}
+APFloat::ExponentType
+APFloat::semanticsMinExponent(const fltSemantics &semantics)
+{
+  return semantics.minExponent;
+}
+unsigned int
+APFloat::semanticsSizeInBits(const fltSemantics &semantics)
+{
+  return semantics.sizeInBits;
+}
 
 const integerPart *
 APFloat::significandParts() const
 {
   return const_cast<APFloat *>(this)->significandParts();
 }
 
 integerPart *