Provide fast-path for CHECK macro.

src/checks.h

 // Copyright 2006-2008 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 45 matching lines @@
                                int line,
                                const char* source,
                                bool condition) {
   if (!condition)
     V8_Fatal(file, line, "CHECK(%s) failed", source);
 }
 
 
 // The CHECK macro checks that the given condition is true; if not, it
 // prints a message to stderr and aborts.
-#define CHECK(condition) CheckHelper(__FILE__, __LINE__, #condition, condition)
+#define CHECK(condition) do {                                             \
+    if (!(condition)) CheckHelper(__FILE__, __LINE__, #condition, false); \
+  } while(0)
 
 
 // Helper function used by the CHECK_EQ function when given int
 // arguments.  Should not be called directly.
 static inline void CheckEqualsHelper(const char* file, int line,
                                      const char* expected_source, int expected,
                                      const char* value_source, int value) {
   if (expected != value) {
     V8_Fatal(file, line,
              "CHECK_EQ(%s, %s) failed\n#   Expected: %i\n#   Found: %i",
@@ skipping 210 matching lines @@
 // Static asserts has no impact on runtime performance, so they can be
 // safely enabled in release mode. Moreover, the ((void) 0) expression
 // obeys different syntax rules than typedef's, e.g. it can't appear
 // inside class declaration, this leads to inconsistency between debug
 // and release compilation modes behavior.
 #define STATIC_ASSERT(test)  STATIC_CHECK(test)
 
 #define ASSERT_NOT_NULL(p)  ASSERT_NE(NULL, p)
 
 #endif  // V8_CHECKS_H_