BUG=skia:
Review URL: https://codereview.chromium.org/
1068783003
#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"