Make SK_PREFETCH work on Windows too.

include/core/SkPostConfig.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.
  */
 
 // IWYU pragma: private, include "SkTypes.h"
 
 #ifndef SkPostConfig_DEFINED
@@ skipping 277 matching lines @@
 #if defined(SK_BUILD_FOR_WIN)
     #define SK_VECTORCALL __vectorcall
 #elif defined(SK_CPU_ARM32)
     #define SK_VECTORCALL __attribute__((pcs("aapcs-vfp")))
 #else
     #define SK_VECTORCALL
 #endif
 
 //////////////////////////////////////////////////////////////////////
 
-#if defined(__clang__) || defined(__GNUC__)
-#  define SK_PREFETCH(ptr) __builtin_prefetch(ptr)
-#  define SK_WRITE_PREFETCH(ptr) __builtin_prefetch(ptr, 1)
+#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE1
+    #define SK_PREFETCH(ptr)       _mm_prefetch(ptr, _MM_HINT_T0)
+    #define SK_WRITE_PREFETCH(ptr) _mm_prefetch(ptr, _MM_HINT_T0)
+#elif defined(__GNUC__)

[Stephen White, 2015/10/27 20:03:20]

We don't need "define(__clang__) ||" here anymore?

[mtklein, 2015/10/27 20:05:55]

Nah, Clang defines __GNUC__.  Seemed confusing to leave it there, as if to
suggest Clang didn't define __GNUC__.

(Usually I find checking for __clang__ is only useful when Clang needs to do
something differently than GCC.  Pretty rare.)

+    #define SK_PREFETCH(ptr)       __builtin_prefetch(ptr)
+    #define SK_WRITE_PREFETCH(ptr) __builtin_prefetch(ptr, 1)
 #else
-#  define SK_PREFETCH(ptr)
-#  define SK_WRITE_PREFETCH(ptr)
+    #define SK_PREFETCH(ptr)
+    #define SK_WRITE_PREFETCH(ptr)
 #endif
 
 //////////////////////////////////////////////////////////////////////
 
 #ifndef SK_PRINTF_LIKE
 #  if defined(__clang__) || defined(__GNUC__)
 #    define SK_PRINTF_LIKE(A, B) __attribute__((format(printf, (A), (B))))
 #  else
 #    define SK_PRINTF_LIKE(A, B)
 #  endif
@@ skipping 35 matching lines @@
 #  define SK_GAMMA_EXPONENT (2.2f)
 #endif
 
 //////////////////////////////////////////////////////////////////////
 
 #ifndef GR_TEST_UTILS
 #  define GR_TEST_UTILS 1
 #endif
 
 #endif // SkPostConfig_DEFINED