NEON has a ternary instruction.

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 280 matching lines @@
         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)));
+        return vbslq_f32(vreinterpretq_u32_f32(fVec), t.fVec, e.fVec);
     }
 
     float32x4_t fVec;
 };
 
 template <>
 class SkNi<8, uint16_t> {
 public:
     SkNi(const uint16x8_t& vec) : fVec(vec) {}
 
@@ skipping 16 matching lines @@
     SkNi operator >> (int bits) const { SHIFT16(vshrq_n_u16, fVec, bits); }
 
     static SkNi Min(const SkNi& a, const SkNi& b) { return vminq_u16(a.fVec, b.fVec); }
 
     template <int k> uint16_t kth() const {
         SkASSERT(0 <= k && k < 8);
         return vgetq_lane_u16(fVec, k&7);
     }
 
     SkNi thenElse(const SkNi& t, const SkNi& e) const {
-        return vorrq_u16(vandq_u16(t.fVec, fVec),
-                         vbicq_u16(e.fVec, fVec));
+        return vbslq_u16(fVec, t.fVec, e.fVec);
     }
 
     uint16x8_t fVec;
 };
 
 template <>
 class SkNi<16, uint8_t> {
 public:
     SkNi(const uint8x16_t& vec) : fVec(vec) {}
 
@@ skipping 17 matching lines @@
 
     static SkNi Min(const SkNi& a, const SkNi& b) { return vminq_u8(a.fVec, b.fVec); }
     SkNi operator < (const SkNi& o) const { return vcltq_u8(fVec, o.fVec); }
 
     template <int k> uint8_t kth() const {
         SkASSERT(0 <= k && k < 15);
         return vgetq_lane_u8(fVec, k&16);
     }
 
     SkNi thenElse(const SkNi& t, const SkNi& e) const {
-        return vorrq_u8(vandq_u8(t.fVec, fVec),
-                        vbicq_u8(e.fVec, fVec));
+        return vbslq_u8(fVec, t.fVec, e.fVec);
     }
 
     uint8x16_t fVec;
 };
 
 #undef SHIFT32
 #undef SHIFT16
 #undef SHIFT8
 
 }  // namespace
 
 #endif//SkNx_neon_DEFINED