re-enable neon opts for some xfermodes

src/core/SkXfermode.cpp

 
 /*
  * 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.
  */
 
 #include "SkXfermode.h"
 #include "SkXfermode_opts_SSE2.h"
 #include "SkXfermode_proccoeff.h"
 #include "SkColorPriv.h"
 #include "SkLazyPtr.h"
 #include "SkMathPriv.h"
 #include "SkPMFloat.h"
 #include "SkReadBuffer.h"
 #include "SkString.h"
 #include "SkUtilsArm.h"
 #include "SkWriteBuffer.h"
 
-//#define SK_SUPPORT_LEGACY_SCALAR_XFERMODES
+#ifndef SK_SUPPORT_LEGACY_SCALAR_XFERMODES
+#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
+    /*
+     * To be conservative, we only enable the new code path (using SkPMFloat) when we
+     * "know" we're faster, which at the moment is only when we have SSE2 or better.
+     */
+#else
+    #define SK_SUPPORT_LEGACY_SCALAR_XFERMODES
+#endif
+#endif
 
 #if !SK_ARM_NEON_IS_NONE
 #include "SkXfermode_opts_arm_neon.h"
 #endif
 
 #define SkAlphaMulAlpha(a, b)   SkMulDiv255Round(a, b)
 
 static inline unsigned saturated_add(unsigned a, unsigned b) {
     SkASSERT(a <= 255);
     SkASSERT(b <= 255);
@@ skipping 1721 matching lines @@
         } else {
             proc16 = rec.fProc16_General;
         }
     }
     return proc16;
 }
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkProcCoeffXfermode)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END