Revert of Try using std::call_once

src/opts/opts_check_x86.cpp

 /*
  * Copyright 2009 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.
  */
 
 #include "SkBitmapFilter_opts_SSE2.h"
 #include "SkBitmapProcState_opts_SSE2.h"
 #include "SkBitmapProcState_opts_SSSE3.h"
 #include "SkBitmapScaler.h"
 #include "SkBlitMask.h"
 #include "SkBlitRow.h"
 #include "SkBlitRow_opts_SSE2.h"
 #include "SkBlitRow_opts_SSE4.h"
+#include "SkOncePtr.h"
 #include "SkRTConf.h"
-#include <mutex>
 
 #if defined(_MSC_VER) && defined(_WIN64)
 #include <intrin.h>
 #endif
 
 /* This file must *not* be compiled with -msse or any other optional SIMD
    extension, otherwise gcc may generate SIMD instructions even for scalar ops
    (and thus give an invalid instruction on Pentium3 on the code below).
    For example, only files named *_SSE2.cpp in this directory should be
    compiled with -msse2 or higher. */
@@ skipping 33 matching lines @@
         "movl %%ebx, %1   \n\t"
         "popl %%ebx       \n\t"
         : "=a"(info[0]), "=r"(info[1]), "=c"(info[2]), "=d"(info[3])
         : "a"(info_type)
     );
 }
 #endif
 
 ////////////////////////////////////////////////////////////////////////////////
 
+/* Fetch the SIMD level directly from the CPU, at run-time.
+ * Only checks the levels needed by the optimizations in this file.
+ */
+static int* get_SIMD_level() {
+    int cpu_info[4] = { 0, 0, 0, 0 };
+    getcpuid(1, cpu_info);
+
+    int* level = new int;
+
+    if ((cpu_info[2] & (1<<20)) != 0) {
+        *level = SK_CPU_SSE_LEVEL_SSE42;
+    } else if ((cpu_info[2] & (1<<19)) != 0) {
+        *level = SK_CPU_SSE_LEVEL_SSE41;
+    } else if ((cpu_info[2] & (1<<9)) != 0) {
+        *level = SK_CPU_SSE_LEVEL_SSSE3;
+    } else if ((cpu_info[3] & (1<<26)) != 0) {
+        *level = SK_CPU_SSE_LEVEL_SSE2;
+    } else {
+        *level = 0;
+    }
+    return level;
+}
+
+SK_DECLARE_STATIC_ONCE_PTR(int, gSIMDLevel);
+
 /* Verify that the requested SIMD level is supported in the build.
  * If not, check if the platform supports it.
  */
-static inline bool supports_simd(int level) {
+static inline bool supports_simd(int minLevel) {
 #if defined(SK_CPU_SSE_LEVEL)
-    if (level <= SK_CPU_SSE_LEVEL) {
+    if (minLevel <= SK_CPU_SSE_LEVEL) {
         return true;
     } else
 #endif
     {
 #if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
         /* For the Android framework we should always know at compile time if the device
          * we are building for supports SSSE3.  The one exception to this rule is on the
          * emulator where we are compiled without the -mssse3 option (so we have no
          * SSSE3 procs) but can be run on a host machine that supports SSSE3
          * instructions. So for that particular case we disable our SSSE3 options.
          */
         return false;
 #else
-        static std::once_flag once;
-        static int maxLevel = 0;
-        std::call_once(once, [&]{
-            int cpu_info[4] = { 0, 0, 0, 0 };
-            getcpuid(1, cpu_info);
-
-            if (cpu_info[3] & (1<<26)) { maxLevel = SK_CPU_SSE_LEVEL_SSE2 ; }
-            if (cpu_info[2] & (1<< 9)) { maxLevel = SK_CPU_SSE_LEVEL_SSSE3; }
-            if (cpu_info[2] & (1<<19)) { maxLevel = SK_CPU_SSE_LEVEL_SSE41; }
-            if (cpu_info[2] & (1<<20)) { maxLevel = SK_CPU_SSE_LEVEL_SSE42; }
-        });
-        return level <= maxLevel;
+        return minLevel <= *gSIMDLevel.get(get_SIMD_level);
 #endif
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 void SkBitmapScaler::PlatformConvolutionProcs(SkConvolutionProcs* procs) {
     if (supports_simd(SK_CPU_SSE_LEVEL_SSE2)) {
         procs->fExtraHorizontalReads = 3;
         procs->fConvolveVertically = &convolveVertically_SSE2;
@@ skipping 133 matching lines @@
         }
     } else {
         return nullptr;
     }
 
 }
 
 SkBlitMask::RowProc SkBlitMask::PlatformRowProcs(SkColorType, SkMask::Format, RowFlags) {
     return nullptr;
 }