Move some compiler intrinsic #defines to base/.

base/compiler_specific.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_COMPILER_SPECIFIC_H_
 #define BASE_COMPILER_SPECIFIC_H_
 
 #include "build/build_config.h"
 
 #if defined(COMPILER_MSVC)
@@ skipping 82 matching lines @@
 // Use like:
 //   NOINLINE void DoStuff() { ... }
 #if defined(COMPILER_GCC)
 #define NOINLINE __attribute__((noinline))
 #elif defined(COMPILER_MSVC)
 #define NOINLINE __declspec(noinline)
 #else
 #define NOINLINE
 #endif
 
+#if COMPILER_GCC && defined(NDEBUG)
+#define ALWAYS_INLINE inline __attribute__((__always_inline__))
+#elif COMPILER_MSVC && defined(NDEBUG)
+#define ALWAYS_INLINE __forceinline
+#else
+#define ALWAYS_INLINE inline
+#endif
+
 // Specify memory alignment for structs, classes, etc.
 // Use like:
 //   class ALIGNAS(16) MyClass { ... }
 //   ALIGNAS(16) int array[4];
 #if defined(COMPILER_MSVC)
 #define ALIGNAS(byte_alignment) __declspec(align(byte_alignment))
 #elif defined(COMPILER_GCC)
 #define ALIGNAS(byte_alignment) __attribute__((aligned(byte_alignment)))
 #endif
 
@@ skipping 76 matching lines @@
 
 // Macro for hinting that an expression is likely to be false.
 #if !defined(UNLIKELY)
 #if defined(COMPILER_GCC)
 #define UNLIKELY(x) __builtin_expect(!!(x), 0)
 #else
 #define UNLIKELY(x) (x)
 #endif  // defined(COMPILER_GCC)
 #endif  // !defined(UNLIKELY)
 
+#if !defined(LIKELY)
+#if defined(COMPILER_GCC)
+#define LIKELY(x) __builtin_expect((x), 1)

[sdefresne, 2016/11/08 08:40:20]

Shouldn't this be __builtin_expect(!!(x), 1)? Otherwise, the following will be
fails the LIKELY:

Foo* ptr = new Foo;
if (LIKELY(ptr)) {
  ...
}

[palmer, 2016/11/16 23:45:21]

Somehow, I missed this comment. Fix coming right up. Thanks!

+#else
+#define LIKELY(x) (x)
+#endif  // defined(COMPILER_GCC)
+#endif  // !defined(LIKELY)
+
 // Compiler feature-detection.
 // clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension
 #if defined(__has_feature)
 #define HAS_FEATURE(FEATURE) __has_feature(FEATURE)
 #else
 #define HAS_FEATURE(FEATURE) 0
 #endif
 
 #endif  // BASE_COMPILER_SPECIFIC_H_