Merge pull request #1532 from Idclip/imath_half_3.1

Bumped internal copy of half to Imath 3.1.6

Author: Idclip

openvdb/openvdb/CMakeLists.txt

@@ -417,7 +417,6 @@ set(OPENVDB_LIBRARY_MATH_INCLUDE_FILES
   math/DDA.h
   math/FiniteDifference.h
   math/Half.h
-  math/HalfLimits.h
   math/LegacyFrustum.h
   math/Maps.h
   math/Mat.h

openvdb/openvdb/Platform.h

@@ -80,6 +80,21 @@
 #define OPENVDB_UBSAN_SUPPRESS(X)
 #endif
 
+/// Macros to alias to compiler builtins which hint at critical edge selection
+/// during conditional statements.
+#if defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER)
+#ifdef __cplusplus
+#define OPENVDB_LIKELY(x) (__builtin_expect(static_cast<bool>(x), true))
+#define OPENVDB_UNLIKELY(x) (__builtin_expect(static_cast<bool>(x), false))
+#else
+#define OPENVDB_LIKELY(x) (__builtin_expect((x), 1))
+#define OPENVDB_UNLIKELY(x) (__builtin_expect((x), 0))
+#endif
+#else
+#define OPENVDB_LIKELY(x) (x)
+#define OPENVDB_UNLIKELY(x) (x)
+#endif
+
 /// Bracket code with OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN/_END,
 /// as in the following example, to inhibit ICC remarks about unreachable code:
 /// @code