Color dodge and burn with SkPMFloat.

src/opts/SkNx_neon.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkNx_neon_DEFINED
 #define SkNx_neon_DEFINED
 
@@ skipping 279 matching lines @@
         auto v = vreinterpretq_u32_f32(fVec);
         return vgetq_lane_u32(v,0) && vgetq_lane_u32(v,1)
             && vgetq_lane_u32(v,2) && vgetq_lane_u32(v,3);
     }
     bool anyTrue() const {
         auto v = vreinterpretq_u32_f32(fVec);
         return vgetq_lane_u32(v,0) || vgetq_lane_u32(v,1)
             || vgetq_lane_u32(v,2) || vgetq_lane_u32(v,3);
     }
 
+    SkNf thenElse(const SkNf& t, const SkNf& e) const {
+        uint32x4_t ci = vreinterpretq_u32_f32(fVec),
+                   ti = vreinterpretq_u32_f32(t.fVec),
+                   ei = vreinterpretq_u32_f32(e.fVec);
+        return vreinterpretq_f32_u32(vorrq_u32(vandq_u32(ti, ci), vbicq_u32(ei, ci)));
+    }
+
     float32x4_t fVec;
 };
 
 template <>
 class SkNi<8, uint16_t> {
 public:
     SkNi(const uint16x8_t& vec) : fVec(vec) {}
 
     SkNi() {}
     explicit SkNi(uint16_t val) : fVec(vdupq_n_u16(val)) {}
@@ skipping 62 matching lines @@
     uint8x16_t fVec;
 };
 
 #undef SHIFT32
 #undef SHIFT16
 #undef SHIFT8
 
 }  // namespace
 
 #endif//SkNx_neon_DEFINED