Temporarily revert just Multiply to see if that's the source of NEON diffs.

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"
@@ skipping 1471 matching lines @@
     ProcCoeff rec = gProcCoeffs[mode];
     SkXfermodeProc pp = SkPlatformXfermodeProcFactory(mode);
     if (pp != NULL) {
         rec.fProc = pp;
     }
 
 #if defined(SK_4PX_XFERMODES_ARE_FAST) && !defined(SK_PREFER_LEGACY_FLOAT_XFERMODES)
     switch (mode) {
         case SkXfermode::kSrcATop_Mode:  return SkT4pxXfermode<SrcATop4f>::Create(rec);
         case SkXfermode::kDstATop_Mode:  return SkT4pxXfermode<DstATop4f>::Create(rec);
-        case SkXfermode::kXor_Mode:      return SkT4pxXfermode<Xor4f>::Create(rec);
+        // Temporarily reverted to see if this is the source of NEON diffs.
+        // If not, try DstATop then SrcATop next.  Multiply is not the problem.
+        // case SkXfermode::kXor_Mode:      return SkT4pxXfermode<Xor4f>::Create(rec);
         case SkXfermode::kPlus_Mode:     return SkT4pxXfermode<Plus4f>::Create(rec);
         case SkXfermode::kModulate_Mode: return SkT4pxXfermode<Modulate4f>::Create(rec);
         case SkXfermode::kScreen_Mode:   return SkT4pxXfermode<Screen4f>::Create(rec);
         case SkXfermode::kMultiply_Mode: return SkT4pxXfermode<Multiply4f>::Create(rec);
         default: break;
     }
 #endif
 
 #if defined(SK_4F_XFERMODES_ARE_FAST)
     switch (mode) {
@@ skipping 303 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