remove Sk64 from public API, and start to remove usage internally

include/core/SkMath.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkMath_DEFINED
@@ skipping 17 matching lines @@
 
 /**
  *  Return the integer square root of value, with a bias of bitBias
  */
 int32_t SkSqrtBits(int32_t value, int bitBias);
 
 /** Return the integer square root of n, treated as a SkFixed (16.16)
  */
 #define SkSqrt32(n)         SkSqrtBits(n, 15)
 
+// 64bit -> 32bit utilities
+
+/**
+ *  Return true iff the 64bit value can exactly be represented in signed 32bits
+ */
+static inline bool sk_64_isS32(int64_t value) {
+    return (int32_t)value == value;
+}
+
+/**
+ *  Return the 64bit argument as signed 32bits, asserting in debug that the arg
+ *  exactly fits in signed 32bits. In the release build, no checks are preformed
+ *  and the return value if the arg does not fit is undefined.
+ */
+static inline int32_t sk_64_asS32(int64_t value) {
+    SkASSERT(sk_64_isS32(value));
+    return (int32_t)value;
+}
+
+// Handy util that can be passed two ints, and will automatically promote to
+// 64bits before the multiply, so the caller doesn't have to remember to cast
+// e.g. (int64_t)a * b;
+static inline int64_t sk_64_mul(int64_t a, int64_t b) {
+    return a * b;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 //! Returns the number of leading zero bits (0...32)
 int SkCLZ_portable(uint32_t);
 
 #ifndef SkCLZ
     #if defined(_MSC_VER) && _MSC_VER >= 1400
         #include <intrin.h>
 
         static inline int SkCLZ(uint32_t mask) {
@@ skipping 141 matching lines @@
     *div = static_cast<Out>(d);
     *mod = static_cast<Out>(numer-d*denom);
 #else
     // On x86 this will just be a single idiv.
     *div = static_cast<Out>(numer/denom);
     *mod = static_cast<Out>(numer%denom);
 #endif  // SK_CPU_ARM
 }
 
 #endif