src/opts/SkNx_neon.h - platform/external/skia - Gitiles

 /*
  * 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

 #include <arm_neon.h>

 #define SKNX_IS_FAST

 // ARMv8 has vrndmq_f32 to floor 4 floats.  Here we emulate it:
 //   - roundtrip through integers via truncation
 //   - subtract 1 if that's too big (possible for negative values).
 // This restricts the domain of our inputs to a maximum somehwere around 2^31.  Seems plenty big.
 static inline float32x4_t armv7_vrndmq_f32(float32x4_t v) {
     auto roundtrip = vcvtq_f32_s32(vcvtq_s32_f32(v));
     auto too_big = vcgtq_f32(roundtrip, v);
     return vsubq_f32(roundtrip, (float32x4_t)vandq_u32(too_big, (uint32x4_t)vdupq_n_f32(1)));
 }

 template <>
 class SkNx<2, float> {
 public:
     SkNx(float32x2_t vec) : fVec(vec) {}

     SkNx() {}
     SkNx(float val)           : fVec(vdup_n_f32(val)) {}
     static SkNx Load(const void* ptr) { return vld1_f32((const float*)ptr); }
     SkNx(float a, float b) { fVec = (float32x2_t) { a, b }; }

     void store(void* ptr) const { vst1_f32((float*)ptr, fVec); }

     SkNx invert() const {
         float32x2_t est0 = vrecpe_f32(fVec),
                     est1 = vmul_f32(vrecps_f32(est0, fVec), est0);
         return est1;
     }

     SkNx operator + (const SkNx& o) const { return vadd_f32(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsub_f32(fVec, o.fVec); }
     SkNx operator * (const SkNx& o) const { return vmul_f32(fVec, o.fVec); }
     SkNx operator / (const SkNx& o) const {
     #if defined(SK_CPU_ARM64)
         return vdiv_f32(fVec, o.fVec);
     #else
         float32x2_t est0 = vrecpe_f32(o.fVec),
                     est1 = vmul_f32(vrecps_f32(est0, o.fVec), est0),
                     est2 = vmul_f32(vrecps_f32(est1, o.fVec), est1);
         return vmul_f32(fVec, est2);
     #endif
     }

     SkNx operator == (const SkNx& o) const { return vreinterpret_f32_u32(vceq_f32(fVec, o.fVec)); }
     SkNx operator  < (const SkNx& o) const { return vreinterpret_f32_u32(vclt_f32(fVec, o.fVec)); }
     SkNx operator  > (const SkNx& o) const { return vreinterpret_f32_u32(vcgt_f32(fVec, o.fVec)); }
     SkNx operator <= (const SkNx& o) const { return vreinterpret_f32_u32(vcle_f32(fVec, o.fVec)); }
     SkNx operator >= (const SkNx& o) const { return vreinterpret_f32_u32(vcge_f32(fVec, o.fVec)); }
     SkNx operator != (const SkNx& o) const {
         return vreinterpret_f32_u32(vmvn_u32(vceq_f32(fVec, o.fVec)));
     }

     static SkNx Min(const SkNx& l, const SkNx& r) { return vmin_f32(l.fVec, r.fVec); }
     static SkNx Max(const SkNx& l, const SkNx& r) { return vmax_f32(l.fVec, r.fVec); }

     SkNx rsqrt() const {
         float32x2_t est0 = vrsqrte_f32(fVec);
         return vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0);
     }

     SkNx sqrt() const {
     #if defined(SK_CPU_ARM64)
         return vsqrt_f32(fVec);
     #else
         float32x2_t est0 = vrsqrte_f32(fVec),
                     est1 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0),
                     est2 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est1, est1)), est1);
         return vmul_f32(fVec, est2);
     #endif
     }

     float operator[](int k) const {
         SkASSERT(0 <= k && k < 2);
         union { float32x2_t v; float fs[2]; } pun = {fVec};
         return pun.fs[k&1];
     }

     bool allTrue() const {
         auto v = vreinterpret_u32_f32(fVec);
         return vget_lane_u32(v,0) && vget_lane_u32(v,1);
     }
     bool anyTrue() const {
         auto v = vreinterpret_u32_f32(fVec);
         return vget_lane_u32(v,0) || vget_lane_u32(v,1);
     }

     float32x2_t fVec;
 };

 template <>
 class SkNx<4, float> {
 public:
     SkNx(float32x4_t vec) : fVec(vec) {}

     SkNx() {}
     SkNx(float val)           : fVec(vdupq_n_f32(val)) {}
     static SkNx Load(const void* ptr) { return vld1q_f32((const float*)ptr); }
     SkNx(float a, float b, float c, float d) { fVec = (float32x4_t) { a, b, c, d }; }

     void store(void* ptr) const { vst1q_f32((float*)ptr, fVec); }
     SkNx invert() const {
         float32x4_t est0 = vrecpeq_f32(fVec),
                     est1 = vmulq_f32(vrecpsq_f32(est0, fVec), est0);
         return est1;
     }

     SkNx operator + (const SkNx& o) const { return vaddq_f32(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsubq_f32(fVec, o.fVec); }
     SkNx operator * (const SkNx& o) const { return vmulq_f32(fVec, o.fVec); }
     SkNx operator / (const SkNx& o) const {
     #if defined(SK_CPU_ARM64)
         return vdivq_f32(fVec, o.fVec);
     #else
         float32x4_t est0 = vrecpeq_f32(o.fVec),
                     est1 = vmulq_f32(vrecpsq_f32(est0, o.fVec), est0),
                     est2 = vmulq_f32(vrecpsq_f32(est1, o.fVec), est1);
         return vmulq_f32(fVec, est2);
     #endif
     }

     SkNx operator==(const SkNx& o) const { return vreinterpretq_f32_u32(vceqq_f32(fVec, o.fVec)); }
     SkNx operator <(const SkNx& o) const { return vreinterpretq_f32_u32(vcltq_f32(fVec, o.fVec)); }
     SkNx operator >(const SkNx& o) const { return vreinterpretq_f32_u32(vcgtq_f32(fVec, o.fVec)); }
     SkNx operator<=(const SkNx& o) const { return vreinterpretq_f32_u32(vcleq_f32(fVec, o.fVec)); }
     SkNx operator>=(const SkNx& o) const { return vreinterpretq_f32_u32(vcgeq_f32(fVec, o.fVec)); }
     SkNx operator!=(const SkNx& o) const {
         return vreinterpretq_f32_u32(vmvnq_u32(vceqq_f32(fVec, o.fVec)));
     }

     static SkNx Min(const SkNx& l, const SkNx& r) { return vminq_f32(l.fVec, r.fVec); }
     static SkNx Max(const SkNx& l, const SkNx& r) { return vmaxq_f32(l.fVec, r.fVec); }

     SkNx abs() const { return vabsq_f32(fVec); }
     SkNx floor() const {
     #if defined(SK_CPU_ARM64)
         return vrndmq_f32(fVec);
     #else
         return armv7_vrndmq_f32(fVec);
     #endif
     }


     SkNx rsqrt() const {
         float32x4_t est0 = vrsqrteq_f32(fVec);
         return vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0);
     }

     SkNx sqrt() const {
     #if defined(SK_CPU_ARM64)
         return vsqrtq_f32(fVec);
     #else
         float32x4_t est0 = vrsqrteq_f32(fVec),
                     est1 = vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0),
                     est2 = vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est1, est1)), est1);
         return vmulq_f32(fVec, est2);
     #endif
     }

     float operator[](int k) const {
         SkASSERT(0 <= k && k < 4);
         union { float32x4_t v; float fs[4]; } pun = {fVec};
         return pun.fs[k&3];
     }

     bool allTrue() 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);
     }
     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);
     }

     SkNx thenElse(const SkNx& t, const SkNx& e) const {
         return vbslq_f32(vreinterpretq_u32_f32(fVec), t.fVec, e.fVec);
     }

     float32x4_t fVec;
 };

 // It's possible that for our current use cases, representing this as
 // half a uint16x8_t might be better than representing it as a uint16x4_t.
 // It'd make conversion to Sk4b one step simpler.
 template <>
 class SkNx<4, uint16_t> {
 public:
     SkNx(const uint16x4_t& vec) : fVec(vec) {}

     SkNx() {}
     SkNx(uint16_t val) : fVec(vdup_n_u16(val)) {}
     static SkNx Load(const void* ptr) { return vld1_u16((const uint16_t*)ptr); }

     SkNx(uint16_t a, uint16_t b, uint16_t c, uint16_t d) {
         fVec = (uint16x4_t) { a,b,c,d };
     }

     void store(void* ptr) const { vst1_u16((uint16_t*)ptr, fVec); }

     SkNx operator + (const SkNx& o) const { return vadd_u16(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsub_u16(fVec, o.fVec); }
     SkNx operator * (const SkNx& o) const { return vmul_u16(fVec, o.fVec); }

     SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
     SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

     static SkNx Min(const SkNx& a, const SkNx& b) { return vmin_u16(a.fVec, b.fVec); }

     uint16_t operator[](int k) const {
         SkASSERT(0 <= k && k < 4);
         union { uint16x4_t v; uint16_t us[4]; } pun = {fVec};
         return pun.us[k&3];
     }

     SkNx thenElse(const SkNx& t, const SkNx& e) const {
         return vbsl_u16(fVec, t.fVec, e.fVec);
     }

     uint16x4_t fVec;
 };

 template <>
 class SkNx<8, uint16_t> {
 public:
     SkNx(const uint16x8_t& vec) : fVec(vec) {}

     SkNx() {}
     SkNx(uint16_t val) : fVec(vdupq_n_u16(val)) {}
     static SkNx Load(const void* ptr) { return vld1q_u16((const uint16_t*)ptr); }

     SkNx(uint16_t a, uint16_t b, uint16_t c, uint16_t d,
          uint16_t e, uint16_t f, uint16_t g, uint16_t h) {
         fVec = (uint16x8_t) { a,b,c,d, e,f,g,h };
     }

     void store(void* ptr) const { vst1q_u16((uint16_t*)ptr, fVec); }

     SkNx operator + (const SkNx& o) const { return vaddq_u16(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsubq_u16(fVec, o.fVec); }
     SkNx operator * (const SkNx& o) const { return vmulq_u16(fVec, o.fVec); }

     SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
     SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

     static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_u16(a.fVec, b.fVec); }

     uint16_t operator[](int k) const {
         SkASSERT(0 <= k && k < 8);
         union { uint16x8_t v; uint16_t us[8]; } pun = {fVec};
         return pun.us[k&7];
     }

     SkNx thenElse(const SkNx& t, const SkNx& e) const {
         return vbslq_u16(fVec, t.fVec, e.fVec);
     }

     uint16x8_t fVec;
 };

 template <>
 class SkNx<4, uint8_t> {
 public:
     typedef uint32_t __attribute__((aligned(1))) unaligned_uint32_t;

     SkNx(const uint8x8_t& vec) : fVec(vec) {}

     SkNx() {}
     SkNx(uint8_t a, uint8_t b, uint8_t c, uint8_t d) {
         fVec = (uint8x8_t){a,b,c,d, 0,0,0,0};
     }
     static SkNx Load(const void* ptr) {
         return (uint8x8_t)vld1_dup_u32((const unaligned_uint32_t*)ptr);
     }
     void store(void* ptr) const {
         return vst1_lane_u32((unaligned_uint32_t*)ptr, (uint32x2_t)fVec, 0);
     }
     uint8_t operator[](int k) const {
         SkASSERT(0 <= k && k < 4);
         union { uint8x8_t v; uint8_t us[8]; } pun = {fVec};
         return pun.us[k&3];
     }

     // TODO as needed

     uint8x8_t fVec;
 };

 template <>
 class SkNx<16, uint8_t> {
 public:
     SkNx(const uint8x16_t& vec) : fVec(vec) {}

     SkNx() {}
     SkNx(uint8_t val) : fVec(vdupq_n_u8(val)) {}
     static SkNx Load(const void* ptr) { return vld1q_u8((const uint8_t*)ptr); }

     SkNx(uint8_t a, uint8_t b, uint8_t c, uint8_t d,
          uint8_t e, uint8_t f, uint8_t g, uint8_t h,
          uint8_t i, uint8_t j, uint8_t k, uint8_t l,
          uint8_t m, uint8_t n, uint8_t o, uint8_t p) {
         fVec = (uint8x16_t) { a,b,c,d, e,f,g,h, i,j,k,l, m,n,o,p };
     }

     void store(void* ptr) const { vst1q_u8((uint8_t*)ptr, fVec); }

     SkNx saturatedAdd(const SkNx& o) const { return vqaddq_u8(fVec, o.fVec); }

     SkNx operator + (const SkNx& o) const { return vaddq_u8(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsubq_u8(fVec, o.fVec); }

     static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_u8(a.fVec, b.fVec); }
     SkNx operator < (const SkNx& o) const { return vcltq_u8(fVec, o.fVec); }

     uint8_t operator[](int k) const {
         SkASSERT(0 <= k && k < 16);
         union { uint8x16_t v; uint8_t us[16]; } pun = {fVec};
         return pun.us[k&15];
     }

     SkNx thenElse(const SkNx& t, const SkNx& e) const {
         return vbslq_u8(fVec, t.fVec, e.fVec);
     }

     uint8x16_t fVec;
 };

 template <>
 class SkNx<4, int32_t> {
 public:
     SkNx(const int32x4_t& vec) : fVec(vec) {}

     SkNx() {}
     SkNx(int32_t v) {
         fVec = vdupq_n_s32(v);
     }
     SkNx(int32_t a, int32_t b, int32_t c, int32_t d) {
         fVec = (int32x4_t){a,b,c,d};
     }
     static SkNx Load(const void* ptr) {
         return vld1q_s32((const int32_t*)ptr);
     }
     void store(void* ptr) const {
         return vst1q_s32((int32_t*)ptr, fVec);
     }
     int32_t operator[](int k) const {
         SkASSERT(0 <= k && k < 4);
         union { int32x4_t v; int32_t is[4]; } pun = {fVec};
         return pun.is[k&3];
     }

     SkNx operator + (const SkNx& o) const { return vaddq_s32(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsubq_s32(fVec, o.fVec); }
     SkNx operator * (const SkNx& o) const { return vmulq_s32(fVec, o.fVec); }

     SkNx operator & (const SkNx& o) const { return vandq_s32(fVec, o.fVec); }
     SkNx operator | (const SkNx& o) const { return vorrq_s32(fVec, o.fVec); }
     SkNx operator ^ (const SkNx& o) const { return veorq_s32(fVec, o.fVec); }

     SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
     SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

     SkNx operator == (const SkNx& o) const {
         return vreinterpretq_s32_u32(vceqq_s32(fVec, o.fVec));
     }
     SkNx operator <  (const SkNx& o) const {
         return vreinterpretq_s32_u32(vcltq_s32(fVec, o.fVec));
     }
     SkNx operator >  (const SkNx& o) const {
         return vreinterpretq_s32_u32(vcgtq_s32(fVec, o.fVec));
     }

     static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_s32(a.fVec, b.fVec); }
     // TODO as needed

     SkNx thenElse(const SkNx& t, const SkNx& e) const {
         return vbslq_s32(vreinterpretq_u32_s32(fVec), t.fVec, e.fVec);
     }

     int32x4_t fVec;
 };

 template <>
 class SkNx<4, uint32_t> {
 public:
     SkNx(const uint32x4_t& vec) : fVec(vec) {}

     SkNx() {}
     SkNx(uint32_t v) {
         fVec = vdupq_n_u32(v);
     }
     SkNx(uint32_t a, uint32_t b, uint32_t c, uint32_t d) {
         fVec = (uint32x4_t){a,b,c,d};
     }
     static SkNx Load(const void* ptr) {
         return vld1q_u32((const uint32_t*)ptr);
     }
     void store(void* ptr) const {
         return vst1q_u32((uint32_t*)ptr, fVec);
     }
     uint32_t operator[](int k) const {
         SkASSERT(0 <= k && k < 4);
         union { uint32x4_t v; uint32_t us[4]; } pun = {fVec};
         return pun.us[k&3];
     }

     SkNx operator + (const SkNx& o) const { return vaddq_u32(fVec, o.fVec); }
     SkNx operator - (const SkNx& o) const { return vsubq_u32(fVec, o.fVec); }
     SkNx operator * (const SkNx& o) const { return vmulq_u32(fVec, o.fVec); }

     SkNx operator & (const SkNx& o) const { return vandq_u32(fVec, o.fVec); }
     SkNx operator | (const SkNx& o) const { return vorrq_u32(fVec, o.fVec); }
     SkNx operator ^ (const SkNx& o) const { return veorq_u32(fVec, o.fVec); }

     SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
     SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

     SkNx operator == (const SkNx& o) const { return vceqq_u32(fVec, o.fVec); }
     SkNx operator <  (const SkNx& o) const { return vcltq_u32(fVec, o.fVec); }
     SkNx operator >  (const SkNx& o) const { return vcgtq_u32(fVec, o.fVec); }

     static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_u32(a.fVec, b.fVec); }
     // TODO as needed

     SkNx thenElse(const SkNx& t, const SkNx& e) const {
         return vbslq_u32(fVec, t.fVec, e.fVec);
     }

     uint32x4_t fVec;
 };

 template<> inline Sk4i SkNx_cast<int32_t, float>(const Sk4f& src) {
     return vcvtq_s32_f32(src.fVec);

 }
 template<> inline Sk4f SkNx_cast<float, int32_t>(const Sk4i& src) {
     return vcvtq_f32_s32(src.fVec);
 }
 template<> inline Sk4f SkNx_cast<float, uint32_t>(const Sk4u& src) {
     return SkNx_cast<float>(Sk4i::Load(&src));
 }

 template<> inline Sk4h SkNx_cast<uint16_t, float>(const Sk4f& src) {
     return vqmovn_u32(vcvtq_u32_f32(src.fVec));
 }

 template<> inline Sk4f SkNx_cast<float, uint16_t>(const Sk4h& src) {
     return vcvtq_f32_u32(vmovl_u16(src.fVec));
 }

 template<> inline Sk4b SkNx_cast<uint8_t, float>(const Sk4f& src) {
     uint32x4_t _32 = vcvtq_u32_f32(src.fVec);
     uint16x4_t _16 = vqmovn_u32(_32);
     return vqmovn_u16(vcombine_u16(_16, _16));
 }

 template<> inline Sk4f SkNx_cast<float, uint8_t>(const Sk4b& src) {
     uint16x8_t _16 = vmovl_u8 (src.fVec) ;
     uint32x4_t _32 = vmovl_u16(vget_low_u16(_16));
     return vcvtq_f32_u32(_32);
 }

 template<> inline Sk16b SkNx_cast<uint8_t, float>(const Sk16f& src) {
     Sk8f ab, cd;
     SkNx_split(src, &ab, &cd);

     Sk4f a,b,c,d;
     SkNx_split(ab, &a, &b);
     SkNx_split(cd, &c, &d);
     return vuzpq_u8(vuzpq_u8((uint8x16_t)vcvtq_u32_f32(a.fVec),
                              (uint8x16_t)vcvtq_u32_f32(b.fVec)).val[0],
                     vuzpq_u8((uint8x16_t)vcvtq_u32_f32(c.fVec),
                              (uint8x16_t)vcvtq_u32_f32(d.fVec)).val[0]).val[0];
 }

 template<> inline Sk4h SkNx_cast<uint16_t, uint8_t>(const Sk4b& src) {
     return vget_low_u16(vmovl_u8(src.fVec));
 }

 template<> inline Sk4b SkNx_cast<uint8_t, uint16_t>(const Sk4h& src) {
     return vmovn_u16(vcombine_u16(src.fVec, src.fVec));
 }

 template<> inline Sk4b SkNx_cast<uint8_t, int32_t>(const Sk4i& src) {
     uint16x4_t _16 = vqmovun_s32(src.fVec);
     return vqmovn_u16(vcombine_u16(_16, _16));
 }

 template<> inline Sk4i SkNx_cast<int32_t, uint16_t>(const Sk4h& src) {
     return vreinterpretq_s32_u32(vmovl_u16(src.fVec));
 }

 template<> inline Sk4h SkNx_cast<uint16_t, int32_t>(const Sk4i& src) {
     return vmovn_u32(vreinterpretq_u32_s32(src.fVec));
 }

 template<> /*static*/ inline Sk4i SkNx_cast<int32_t, uint32_t>(const Sk4u& src) {
     return vreinterpretq_s32_u32(src.fVec);
 }

 static inline Sk4i Sk4f_round(const Sk4f& x) {
     return vcvtq_s32_f32((x + 0.5f).fVec);
 }

 static inline void Sk4h_load4(const void* ptr, Sk4h* r, Sk4h* g, Sk4h* b, Sk4h* a) {
     uint16x4x4_t rgba = vld4_u16((const uint16_t*)ptr);
     *r = rgba.val[0];
     *g = rgba.val[1];
     *b = rgba.val[2];
     *a = rgba.val[3];
 }

 static inline void Sk4h_store4(void* dst, const Sk4h& r, const Sk4h& g, const Sk4h& b,
                                const Sk4h& a) {
     uint16x4x4_t rgba = {{
         r.fVec,
         g.fVec,
         b.fVec,
         a.fVec,
     }};
     vst4_u16((uint16_t*) dst, rgba);
 }

 static inline void Sk4f_load4(const void* ptr, Sk4f* r, Sk4f* g, Sk4f* b, Sk4f* a) {
     float32x4x4_t rgba = vld4q_f32((const float*) ptr);
     *r = rgba.val[0];
     *g = rgba.val[1];
     *b = rgba.val[2];
     *a = rgba.val[3];
 }

 static inline void Sk4f_store4(void* dst, const Sk4f& r, const Sk4f& g, const Sk4f& b,
                                const Sk4f& a) {
     float32x4x4_t rgba = {{
         r.fVec,
         g.fVec,
         b.fVec,
         a.fVec,
     }};
     vst4q_f32((float*) dst, rgba);
 }

 #endif//SkNx_neon_DEFINED
	/*
	* 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

	#include <arm_neon.h>

	#define SKNX_IS_FAST

	// ARMv8 has vrndmq_f32 to floor 4 floats. Here we emulate it:
	// - roundtrip through integers via truncation
	// - subtract 1 if that's too big (possible for negative values).
	// This restricts the domain of our inputs to a maximum somehwere around 2^31. Seems plenty big.
	static inline float32x4_t armv7_vrndmq_f32(float32x4_t v) {
	auto roundtrip = vcvtq_f32_s32(vcvtq_s32_f32(v));
	auto too_big = vcgtq_f32(roundtrip, v);
	return vsubq_f32(roundtrip, (float32x4_t)vandq_u32(too_big, (uint32x4_t)vdupq_n_f32(1)));
	}

	template <>
	class SkNx<2, float> {
	public:
	SkNx(float32x2_t vec) : fVec(vec) {}

	SkNx() {}
	SkNx(float val) : fVec(vdup_n_f32(val)) {}
	static SkNx Load(const void* ptr) { return vld1_f32((const float*)ptr); }
	SkNx(float a, float b) { fVec = (float32x2_t) { a, b }; }

	void store(void* ptr) const { vst1_f32((float*)ptr, fVec); }

	SkNx invert() const {
	float32x2_t est0 = vrecpe_f32(fVec),
	est1 = vmul_f32(vrecps_f32(est0, fVec), est0);
	return est1;
	}

	SkNx operator + (const SkNx& o) const { return vadd_f32(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsub_f32(fVec, o.fVec); }
	SkNx operator * (const SkNx& o) const { return vmul_f32(fVec, o.fVec); }
	SkNx operator / (const SkNx& o) const {
	#if defined(SK_CPU_ARM64)
	return vdiv_f32(fVec, o.fVec);
	#else
	float32x2_t est0 = vrecpe_f32(o.fVec),
	est1 = vmul_f32(vrecps_f32(est0, o.fVec), est0),
	est2 = vmul_f32(vrecps_f32(est1, o.fVec), est1);
	return vmul_f32(fVec, est2);
	#endif
	}

	SkNx operator == (const SkNx& o) const { return vreinterpret_f32_u32(vceq_f32(fVec, o.fVec)); }
	SkNx operator < (const SkNx& o) const { return vreinterpret_f32_u32(vclt_f32(fVec, o.fVec)); }
	SkNx operator > (const SkNx& o) const { return vreinterpret_f32_u32(vcgt_f32(fVec, o.fVec)); }
	SkNx operator <= (const SkNx& o) const { return vreinterpret_f32_u32(vcle_f32(fVec, o.fVec)); }
	SkNx operator >= (const SkNx& o) const { return vreinterpret_f32_u32(vcge_f32(fVec, o.fVec)); }
	SkNx operator != (const SkNx& o) const {
	return vreinterpret_f32_u32(vmvn_u32(vceq_f32(fVec, o.fVec)));
	}

	static SkNx Min(const SkNx& l, const SkNx& r) { return vmin_f32(l.fVec, r.fVec); }
	static SkNx Max(const SkNx& l, const SkNx& r) { return vmax_f32(l.fVec, r.fVec); }

	SkNx rsqrt() const {
	float32x2_t est0 = vrsqrte_f32(fVec);
	return vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0);
	}

	SkNx sqrt() const {
	#if defined(SK_CPU_ARM64)
	return vsqrt_f32(fVec);
	#else
	float32x2_t est0 = vrsqrte_f32(fVec),
	est1 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0),
	est2 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est1, est1)), est1);
	return vmul_f32(fVec, est2);
	#endif
	}

	float operator[](int k) const {
	SkASSERT(0 <= k && k < 2);
	union { float32x2_t v; float fs[2]; } pun = {fVec};
	return pun.fs[k&1];
	}

	bool allTrue() const {
	auto v = vreinterpret_u32_f32(fVec);
	return vget_lane_u32(v,0) && vget_lane_u32(v,1);
	}
	bool anyTrue() const {
	auto v = vreinterpret_u32_f32(fVec);
	return vget_lane_u32(v,0) \|\| vget_lane_u32(v,1);
	}

	float32x2_t fVec;
	};

	template <>
	class SkNx<4, float> {
	public:
	SkNx(float32x4_t vec) : fVec(vec) {}

	SkNx() {}
	SkNx(float val) : fVec(vdupq_n_f32(val)) {}
	static SkNx Load(const void* ptr) { return vld1q_f32((const float*)ptr); }
	SkNx(float a, float b, float c, float d) { fVec = (float32x4_t) { a, b, c, d }; }

	void store(void* ptr) const { vst1q_f32((float*)ptr, fVec); }
	SkNx invert() const {
	float32x4_t est0 = vrecpeq_f32(fVec),
	est1 = vmulq_f32(vrecpsq_f32(est0, fVec), est0);
	return est1;
	}

	SkNx operator + (const SkNx& o) const { return vaddq_f32(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsubq_f32(fVec, o.fVec); }
	SkNx operator * (const SkNx& o) const { return vmulq_f32(fVec, o.fVec); }
	SkNx operator / (const SkNx& o) const {
	#if defined(SK_CPU_ARM64)
	return vdivq_f32(fVec, o.fVec);
	#else
	float32x4_t est0 = vrecpeq_f32(o.fVec),
	est1 = vmulq_f32(vrecpsq_f32(est0, o.fVec), est0),
	est2 = vmulq_f32(vrecpsq_f32(est1, o.fVec), est1);
	return vmulq_f32(fVec, est2);
	#endif
	}

	SkNx operator==(const SkNx& o) const { return vreinterpretq_f32_u32(vceqq_f32(fVec, o.fVec)); }
	SkNx operator <(const SkNx& o) const { return vreinterpretq_f32_u32(vcltq_f32(fVec, o.fVec)); }
	SkNx operator >(const SkNx& o) const { return vreinterpretq_f32_u32(vcgtq_f32(fVec, o.fVec)); }
	SkNx operator<=(const SkNx& o) const { return vreinterpretq_f32_u32(vcleq_f32(fVec, o.fVec)); }
	SkNx operator>=(const SkNx& o) const { return vreinterpretq_f32_u32(vcgeq_f32(fVec, o.fVec)); }
	SkNx operator!=(const SkNx& o) const {
	return vreinterpretq_f32_u32(vmvnq_u32(vceqq_f32(fVec, o.fVec)));
	}

	static SkNx Min(const SkNx& l, const SkNx& r) { return vminq_f32(l.fVec, r.fVec); }
	static SkNx Max(const SkNx& l, const SkNx& r) { return vmaxq_f32(l.fVec, r.fVec); }

	SkNx abs() const { return vabsq_f32(fVec); }
	SkNx floor() const {
	#if defined(SK_CPU_ARM64)
	return vrndmq_f32(fVec);
	#else
	return armv7_vrndmq_f32(fVec);
	#endif
	}


	SkNx rsqrt() const {
	float32x4_t est0 = vrsqrteq_f32(fVec);
	return vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0);
	}

	SkNx sqrt() const {
	#if defined(SK_CPU_ARM64)
	return vsqrtq_f32(fVec);
	#else
	float32x4_t est0 = vrsqrteq_f32(fVec),
	est1 = vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0),
	est2 = vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est1, est1)), est1);
	return vmulq_f32(fVec, est2);
	#endif
	}

	float operator[](int k) const {
	SkASSERT(0 <= k && k < 4);
	union { float32x4_t v; float fs[4]; } pun = {fVec};
	return pun.fs[k&3];
	}

	bool allTrue() 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);
	}
	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);
	}

	SkNx thenElse(const SkNx& t, const SkNx& e) const {
	return vbslq_f32(vreinterpretq_u32_f32(fVec), t.fVec, e.fVec);
	}

	float32x4_t fVec;
	};

	// It's possible that for our current use cases, representing this as
	// half a uint16x8_t might be better than representing it as a uint16x4_t.
	// It'd make conversion to Sk4b one step simpler.
	template <>
	class SkNx<4, uint16_t> {
	public:
	SkNx(const uint16x4_t& vec) : fVec(vec) {}

	SkNx() {}
	SkNx(uint16_t val) : fVec(vdup_n_u16(val)) {}
	static SkNx Load(const void* ptr) { return vld1_u16((const uint16_t*)ptr); }

	SkNx(uint16_t a, uint16_t b, uint16_t c, uint16_t d) {
	fVec = (uint16x4_t) { a,b,c,d };
	}

	void store(void* ptr) const { vst1_u16((uint16_t*)ptr, fVec); }

	SkNx operator + (const SkNx& o) const { return vadd_u16(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsub_u16(fVec, o.fVec); }
	SkNx operator * (const SkNx& o) const { return vmul_u16(fVec, o.fVec); }

	SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
	SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

	static SkNx Min(const SkNx& a, const SkNx& b) { return vmin_u16(a.fVec, b.fVec); }

	uint16_t operator[](int k) const {
	SkASSERT(0 <= k && k < 4);
	union { uint16x4_t v; uint16_t us[4]; } pun = {fVec};
	return pun.us[k&3];
	}

	SkNx thenElse(const SkNx& t, const SkNx& e) const {
	return vbsl_u16(fVec, t.fVec, e.fVec);
	}

	uint16x4_t fVec;
	};

	template <>
	class SkNx<8, uint16_t> {
	public:
	SkNx(const uint16x8_t& vec) : fVec(vec) {}

	SkNx() {}
	SkNx(uint16_t val) : fVec(vdupq_n_u16(val)) {}
	static SkNx Load(const void* ptr) { return vld1q_u16((const uint16_t*)ptr); }

	SkNx(uint16_t a, uint16_t b, uint16_t c, uint16_t d,
	uint16_t e, uint16_t f, uint16_t g, uint16_t h) {
	fVec = (uint16x8_t) { a,b,c,d, e,f,g,h };
	}

	void store(void* ptr) const { vst1q_u16((uint16_t*)ptr, fVec); }

	SkNx operator + (const SkNx& o) const { return vaddq_u16(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsubq_u16(fVec, o.fVec); }
	SkNx operator * (const SkNx& o) const { return vmulq_u16(fVec, o.fVec); }

	SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
	SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

	static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_u16(a.fVec, b.fVec); }

	uint16_t operator[](int k) const {
	SkASSERT(0 <= k && k < 8);
	union { uint16x8_t v; uint16_t us[8]; } pun = {fVec};
	return pun.us[k&7];
	}

	SkNx thenElse(const SkNx& t, const SkNx& e) const {
	return vbslq_u16(fVec, t.fVec, e.fVec);
	}

	uint16x8_t fVec;
	};

	template <>
	class SkNx<4, uint8_t> {
	public:
	typedef uint32_t __attribute__((aligned(1))) unaligned_uint32_t;

	SkNx(const uint8x8_t& vec) : fVec(vec) {}

	SkNx() {}
	SkNx(uint8_t a, uint8_t b, uint8_t c, uint8_t d) {
	fVec = (uint8x8_t){a,b,c,d, 0,0,0,0};
	}
	static SkNx Load(const void* ptr) {
	return (uint8x8_t)vld1_dup_u32((const unaligned_uint32_t*)ptr);
	}
	void store(void* ptr) const {
	return vst1_lane_u32((unaligned_uint32_t*)ptr, (uint32x2_t)fVec, 0);
	}
	uint8_t operator[](int k) const {
	SkASSERT(0 <= k && k < 4);
	union { uint8x8_t v; uint8_t us[8]; } pun = {fVec};
	return pun.us[k&3];
	}

	// TODO as needed

	uint8x8_t fVec;
	};

	template <>
	class SkNx<16, uint8_t> {
	public:
	SkNx(const uint8x16_t& vec) : fVec(vec) {}

	SkNx() {}
	SkNx(uint8_t val) : fVec(vdupq_n_u8(val)) {}
	static SkNx Load(const void* ptr) { return vld1q_u8((const uint8_t*)ptr); }

	SkNx(uint8_t a, uint8_t b, uint8_t c, uint8_t d,
	uint8_t e, uint8_t f, uint8_t g, uint8_t h,
	uint8_t i, uint8_t j, uint8_t k, uint8_t l,
	uint8_t m, uint8_t n, uint8_t o, uint8_t p) {
	fVec = (uint8x16_t) { a,b,c,d, e,f,g,h, i,j,k,l, m,n,o,p };
	}

	void store(void* ptr) const { vst1q_u8((uint8_t*)ptr, fVec); }

	SkNx saturatedAdd(const SkNx& o) const { return vqaddq_u8(fVec, o.fVec); }

	SkNx operator + (const SkNx& o) const { return vaddq_u8(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsubq_u8(fVec, o.fVec); }

	static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_u8(a.fVec, b.fVec); }
	SkNx operator < (const SkNx& o) const { return vcltq_u8(fVec, o.fVec); }

	uint8_t operator[](int k) const {
	SkASSERT(0 <= k && k < 16);
	union { uint8x16_t v; uint8_t us[16]; } pun = {fVec};
	return pun.us[k&15];
	}

	SkNx thenElse(const SkNx& t, const SkNx& e) const {
	return vbslq_u8(fVec, t.fVec, e.fVec);
	}

	uint8x16_t fVec;
	};

	template <>
	class SkNx<4, int32_t> {
	public:
	SkNx(const int32x4_t& vec) : fVec(vec) {}

	SkNx() {}
	SkNx(int32_t v) {
	fVec = vdupq_n_s32(v);
	}
	SkNx(int32_t a, int32_t b, int32_t c, int32_t d) {
	fVec = (int32x4_t){a,b,c,d};
	}
	static SkNx Load(const void* ptr) {
	return vld1q_s32((const int32_t*)ptr);
	}
	void store(void* ptr) const {
	return vst1q_s32((int32_t*)ptr, fVec);
	}
	int32_t operator[](int k) const {
	SkASSERT(0 <= k && k < 4);
	union { int32x4_t v; int32_t is[4]; } pun = {fVec};
	return pun.is[k&3];
	}

	SkNx operator + (const SkNx& o) const { return vaddq_s32(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsubq_s32(fVec, o.fVec); }
	SkNx operator * (const SkNx& o) const { return vmulq_s32(fVec, o.fVec); }

	SkNx operator & (const SkNx& o) const { return vandq_s32(fVec, o.fVec); }
	SkNx operator \| (const SkNx& o) const { return vorrq_s32(fVec, o.fVec); }
	SkNx operator ^ (const SkNx& o) const { return veorq_s32(fVec, o.fVec); }

	SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
	SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

	SkNx operator == (const SkNx& o) const {
	return vreinterpretq_s32_u32(vceqq_s32(fVec, o.fVec));
	}
	SkNx operator < (const SkNx& o) const {
	return vreinterpretq_s32_u32(vcltq_s32(fVec, o.fVec));
	}
	SkNx operator > (const SkNx& o) const {
	return vreinterpretq_s32_u32(vcgtq_s32(fVec, o.fVec));
	}

	static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_s32(a.fVec, b.fVec); }
	// TODO as needed

	SkNx thenElse(const SkNx& t, const SkNx& e) const {
	return vbslq_s32(vreinterpretq_u32_s32(fVec), t.fVec, e.fVec);
	}

	int32x4_t fVec;
	};

	template <>
	class SkNx<4, uint32_t> {
	public:
	SkNx(const uint32x4_t& vec) : fVec(vec) {}

	SkNx() {}
	SkNx(uint32_t v) {
	fVec = vdupq_n_u32(v);
	}
	SkNx(uint32_t a, uint32_t b, uint32_t c, uint32_t d) {
	fVec = (uint32x4_t){a,b,c,d};
	}
	static SkNx Load(const void* ptr) {
	return vld1q_u32((const uint32_t*)ptr);
	}
	void store(void* ptr) const {
	return vst1q_u32((uint32_t*)ptr, fVec);
	}
	uint32_t operator[](int k) const {
	SkASSERT(0 <= k && k < 4);
	union { uint32x4_t v; uint32_t us[4]; } pun = {fVec};
	return pun.us[k&3];
	}

	SkNx operator + (const SkNx& o) const { return vaddq_u32(fVec, o.fVec); }
	SkNx operator - (const SkNx& o) const { return vsubq_u32(fVec, o.fVec); }
	SkNx operator * (const SkNx& o) const { return vmulq_u32(fVec, o.fVec); }

	SkNx operator & (const SkNx& o) const { return vandq_u32(fVec, o.fVec); }
	SkNx operator \| (const SkNx& o) const { return vorrq_u32(fVec, o.fVec); }
	SkNx operator ^ (const SkNx& o) const { return veorq_u32(fVec, o.fVec); }

	SkNx operator << (int bits) const { return fVec << SkNx(bits).fVec; }
	SkNx operator >> (int bits) const { return fVec >> SkNx(bits).fVec; }

	SkNx operator == (const SkNx& o) const { return vceqq_u32(fVec, o.fVec); }
	SkNx operator < (const SkNx& o) const { return vcltq_u32(fVec, o.fVec); }
	SkNx operator > (const SkNx& o) const { return vcgtq_u32(fVec, o.fVec); }

	static SkNx Min(const SkNx& a, const SkNx& b) { return vminq_u32(a.fVec, b.fVec); }
	// TODO as needed

	SkNx thenElse(const SkNx& t, const SkNx& e) const {
	return vbslq_u32(fVec, t.fVec, e.fVec);
	}

	uint32x4_t fVec;
	};

	template<> inline Sk4i SkNx_cast<int32_t, float>(const Sk4f& src) {
	return vcvtq_s32_f32(src.fVec);

	}
	template<> inline Sk4f SkNx_cast<float, int32_t>(const Sk4i& src) {
	return vcvtq_f32_s32(src.fVec);
	}
	template<> inline Sk4f SkNx_cast<float, uint32_t>(const Sk4u& src) {
	return SkNx_cast<float>(Sk4i::Load(&src));
	}

	template<> inline Sk4h SkNx_cast<uint16_t, float>(const Sk4f& src) {
	return vqmovn_u32(vcvtq_u32_f32(src.fVec));
	}

	template<> inline Sk4f SkNx_cast<float, uint16_t>(const Sk4h& src) {
	return vcvtq_f32_u32(vmovl_u16(src.fVec));
	}

	template<> inline Sk4b SkNx_cast<uint8_t, float>(const Sk4f& src) {
	uint32x4_t _32 = vcvtq_u32_f32(src.fVec);
	uint16x4_t _16 = vqmovn_u32(_32);
	return vqmovn_u16(vcombine_u16(_16, _16));
	}

	template<> inline Sk4f SkNx_cast<float, uint8_t>(const Sk4b& src) {
	uint16x8_t _16 = vmovl_u8 (src.fVec) ;
	uint32x4_t _32 = vmovl_u16(vget_low_u16(_16));
	return vcvtq_f32_u32(_32);
	}

	template<> inline Sk16b SkNx_cast<uint8_t, float>(const Sk16f& src) {
	Sk8f ab, cd;
	SkNx_split(src, &ab, &cd);

	Sk4f a,b,c,d;
	SkNx_split(ab, &a, &b);
	SkNx_split(cd, &c, &d);
	return vuzpq_u8(vuzpq_u8((uint8x16_t)vcvtq_u32_f32(a.fVec),
	(uint8x16_t)vcvtq_u32_f32(b.fVec)).val[0],
	vuzpq_u8((uint8x16_t)vcvtq_u32_f32(c.fVec),
	(uint8x16_t)vcvtq_u32_f32(d.fVec)).val[0]).val[0];
	}

	template<> inline Sk4h SkNx_cast<uint16_t, uint8_t>(const Sk4b& src) {
	return vget_low_u16(vmovl_u8(src.fVec));
	}

	template<> inline Sk4b SkNx_cast<uint8_t, uint16_t>(const Sk4h& src) {
	return vmovn_u16(vcombine_u16(src.fVec, src.fVec));
	}

	template<> inline Sk4b SkNx_cast<uint8_t, int32_t>(const Sk4i& src) {
	uint16x4_t _16 = vqmovun_s32(src.fVec);
	return vqmovn_u16(vcombine_u16(_16, _16));
	}

	template<> inline Sk4i SkNx_cast<int32_t, uint16_t>(const Sk4h& src) {
	return vreinterpretq_s32_u32(vmovl_u16(src.fVec));
	}

	template<> inline Sk4h SkNx_cast<uint16_t, int32_t>(const Sk4i& src) {
	return vmovn_u32(vreinterpretq_u32_s32(src.fVec));
	}

	template<> /static/ inline Sk4i SkNx_cast<int32_t, uint32_t>(const Sk4u& src) {
	return vreinterpretq_s32_u32(src.fVec);
	}

	static inline Sk4i Sk4f_round(const Sk4f& x) {
	return vcvtq_s32_f32((x + 0.5f).fVec);
	}

	static inline void Sk4h_load4(const void* ptr, Sk4h* r, Sk4h* g, Sk4h* b, Sk4h* a) {
	uint16x4x4_t rgba = vld4_u16((const uint16_t*)ptr);
	*r = rgba.val[0];
	*g = rgba.val[1];
	*b = rgba.val[2];
	*a = rgba.val[3];
	}

	static inline void Sk4h_store4(void* dst, const Sk4h& r, const Sk4h& g, const Sk4h& b,
	const Sk4h& a) {
	uint16x4x4_t rgba = {{
	r.fVec,
	g.fVec,
	b.fVec,
	a.fVec,
	}};
	vst4_u16((uint16_t*) dst, rgba);
	}

	static inline void Sk4f_load4(const void* ptr, Sk4f* r, Sk4f* g, Sk4f* b, Sk4f* a) {
	float32x4x4_t rgba = vld4q_f32((const float*) ptr);
	*r = rgba.val[0];
	*g = rgba.val[1];
	*b = rgba.val[2];
	*a = rgba.val[3];
	}

	static inline void Sk4f_store4(void* dst, const Sk4f& r, const Sk4f& g, const Sk4f& b,
	const Sk4f& a) {
	float32x4x4_t rgba = {{
	r.fVec,
	g.fVec,
	b.fVec,
	a.fVec,
	}};
	vst4q_f32((float*) dst, rgba);
	}

	#endif//SkNx_neon_DEFINED