Unify ART's various implementations of bit_cast.

ART had several implementations of art::bit_cast:

1. one in runtime/base/casts.h, declared as:

   template <class Dest, class Source>
   inline Dest bit_cast(const Source& source);

2. another one in runtime/utils.h, declared as:

   template<typename U, typename V>
   static inline V bit_cast(U in);

3. and a third local version, in runtime/memory_region.h,
   similar to the previous one:

   template<typename Source, typename Destination>
   static Destination MemoryRegion::local_bit_cast(Source in);

This CL removes versions 2. and 3. and changes their callers
to use 1. instead.  That version was chosen over the others
as:
- it was the oldest one in the code base; and
- its syntax was closer to the standard C++ cast operators,
  as it supports the following use:

    bit_cast<Destination>(source)

  since `Source' can be deduced from `source'.

Change-Id: I7334fd5d55bf0b8a0c52cb33cfbae6894ff83633

1 files changed, 12 insertions, 8 deletions

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 07ff8ba010..df847aaab2 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -1875,20 +1875,22 @@ class HFloatConstant : public HConstant {
   float GetValue() const { return value_; }
 
   bool InstructionDataEquals(HInstruction* other) const OVERRIDE {
-    return bit_cast<float, int32_t>(other->AsFloatConstant()->value_) ==
-        bit_cast<float, int32_t>(value_);
+    return bit_cast<uint32_t, float>(other->AsFloatConstant()->value_) ==
+        bit_cast<uint32_t, float>(value_);
   }
 
   size_t ComputeHashCode() const OVERRIDE { return static_cast<size_t>(GetValue()); }
 
   bool IsMinusOne() const OVERRIDE {
-    return bit_cast<uint32_t>(AsFloatConstant()->GetValue()) == bit_cast<uint32_t>((-1.0f));
+    return bit_cast<uint32_t, float>(AsFloatConstant()->GetValue()) ==
+        bit_cast<uint32_t, float>((-1.0f));
   }
   bool IsZero() const OVERRIDE {
     return AsFloatConstant()->GetValue() == 0.0f;
   }
   bool IsOne() const OVERRIDE {
-    return bit_cast<uint32_t>(AsFloatConstant()->GetValue()) == bit_cast<uint32_t>(1.0f);
+    return bit_cast<uint32_t, float>(AsFloatConstant()->GetValue()) ==
+        bit_cast<uint32_t, float>(1.0f);
   }
 
   DECLARE_INSTRUCTION(FloatConstant);
@@ -1906,20 +1908,22 @@ class HDoubleConstant : public HConstant {
   double GetValue() const { return value_; }
 
   bool InstructionDataEquals(HInstruction* other) const OVERRIDE {
-    return bit_cast<double, int64_t>(other->AsDoubleConstant()->value_) ==
-        bit_cast<double, int64_t>(value_);
+    return bit_cast<uint64_t, double>(other->AsDoubleConstant()->value_) ==
+        bit_cast<uint64_t, double>(value_);
   }
 
   size_t ComputeHashCode() const OVERRIDE { return static_cast<size_t>(GetValue()); }
 
   bool IsMinusOne() const OVERRIDE {
-    return bit_cast<uint64_t>(AsDoubleConstant()->GetValue()) == bit_cast<uint64_t>((-1.0));
+    return bit_cast<uint64_t, double>(AsDoubleConstant()->GetValue()) ==
+        bit_cast<uint64_t, double>((-1.0));
   }
   bool IsZero() const OVERRIDE {
     return AsDoubleConstant()->GetValue() == 0.0;
   }
   bool IsOne() const OVERRIDE {
-    return bit_cast<uint64_t>(AsDoubleConstant()->GetValue()) == bit_cast<uint64_t>(1.0);
+    return bit_cast<uint64_t, double>(AsDoubleConstant()->GetValue()) ==
+        bit_cast<uint64_t, double>(1.0);
   }
 
   DECLARE_INSTRUCTION(DoubleConstant);