Rewrite SamplingCircularQueue

src/globals.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 264 matching lines @@
 
 // Latin1/UTF-16 constants
 // Code-point values in Unicode 4.0 are 21 bits wide.
 // Code units in UTF-16 are 16 bits wide.
 typedef uint16_t uc16;
 typedef int32_t uc32;
 const int kOneByteSize    = kCharSize;
 const int kUC16Size     = sizeof(uc16);      // NOLINT
 
 
+// Round up n to be a multiple of sz, where sz is a power of 2.
+#define ROUND_UP(n, sz) (((n) + ((sz) - 1)) & ~((sz) - 1))
+
+
 // The expression OFFSET_OF(type, field) computes the byte-offset
 // of the specified field relative to the containing type. This
 // corresponds to 'offsetof' (in stddef.h), except that it doesn't
 // use 0 or NULL, which causes a problem with the compiler warnings
 // we have enabled (which is also why 'offsetof' doesn't seem to work).
 // Here we simply use the non-zero value 4, which seems to work.
 #define OFFSET_OF(type, field)                                          \
   (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(4)->field)) - 4)
 
 
@@ skipping 131 matching lines @@
 // the backend, so both modes are represented by the kStrictMode value.
 enum StrictModeFlag {
   kNonStrictMode,
   kStrictMode
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBALS_H_