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      1 /*
      2  * Copyright 2015 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkNx_DEFINED
      9 #define SkNx_DEFINED
     10 
     11 #include "SkSafe_math.h"
     12 #include "SkScalar.h"
     13 #include "SkTypes.h"
     14 #include <limits>
     15 #include <type_traits>
     16 
     17 // Every single SkNx method wants to be fully inlined.  (We know better than MSVC).
     18 #define AI SK_ALWAYS_INLINE
     19 
     20 namespace {
     21 
     22 // The default SkNx<N,T> just proxies down to a pair of SkNx<N/2, T>.
     23 template <int N, typename T>
     24 struct SkNx {
     25     typedef SkNx<N/2, T> Half;
     26 
     27     Half fLo, fHi;
     28 
     29     AI SkNx() = default;
     30     AI SkNx(const Half& lo, const Half& hi) : fLo(lo), fHi(hi) {}
     31 
     32     AI SkNx(T v) : fLo(v), fHi(v) {}
     33 
     34     AI SkNx(T a, T b)           : fLo(a)  , fHi(b)   { static_assert(N==2, ""); }
     35     AI SkNx(T a, T b, T c, T d) : fLo(a,b), fHi(c,d) { static_assert(N==4, ""); }
     36     AI SkNx(T a, T b, T c, T d,  T e, T f, T g, T h) : fLo(a,b,c,d), fHi(e,f,g,h) {
     37         static_assert(N==8, "");
     38     }
     39     AI SkNx(T a, T b, T c, T d,  T e, T f, T g, T h,
     40             T i, T j, T k, T l,  T m, T n, T o, T p)
     41         : fLo(a,b,c,d, e,f,g,h), fHi(i,j,k,l, m,n,o,p) {
     42         static_assert(N==16, "");
     43     }
     44 
     45     AI T operator[](int k) const {
     46         SkASSERT(0 <= k && k < N);
     47         return k < N/2 ? fLo[k] : fHi[k-N/2];
     48     }
     49 
     50     AI static SkNx Load(const void* vptr) {
     51         auto ptr = (const char*)vptr;
     52         return { Half::Load(ptr), Half::Load(ptr + N/2*sizeof(T)) };
     53     }
     54     AI void store(void* vptr) const {
     55         auto ptr = (char*)vptr;
     56         fLo.store(ptr);
     57         fHi.store(ptr + N/2*sizeof(T));
     58     }
     59 
     60     AI static void Load4(const void* vptr, SkNx* a, SkNx* b, SkNx* c, SkNx* d) {
     61         auto ptr = (const char*)vptr;
     62         Half al, bl, cl, dl,
     63              ah, bh, ch, dh;
     64         Half::Load4(ptr                  , &al, &bl, &cl, &dl);
     65         Half::Load4(ptr + 4*N/2*sizeof(T), &ah, &bh, &ch, &dh);
     66         *a = SkNx{al, ah};
     67         *b = SkNx{bl, bh};
     68         *c = SkNx{cl, ch};
     69         *d = SkNx{dl, dh};
     70     }
     71     AI static void Load3(const void* vptr, SkNx* a, SkNx* b, SkNx* c) {
     72         auto ptr = (const char*)vptr;
     73         Half al, bl, cl,
     74              ah, bh, ch;
     75         Half::Load3(ptr                  , &al, &bl, &cl);
     76         Half::Load3(ptr + 3*N/2*sizeof(T), &ah, &bh, &ch);
     77         *a = SkNx{al, ah};
     78         *b = SkNx{bl, bh};
     79         *c = SkNx{cl, ch};
     80     }
     81     AI static void Store4(void* vptr, const SkNx& a, const SkNx& b, const SkNx& c, const SkNx& d) {
     82         auto ptr = (char*)vptr;
     83         Half::Store4(ptr,                   a.fLo, b.fLo, c.fLo, d.fLo);
     84         Half::Store4(ptr + 4*N/2*sizeof(T), a.fHi, b.fHi, c.fHi, d.fHi);
     85     }
     86 
     87     AI bool anyTrue() const { return fLo.anyTrue() || fHi.anyTrue(); }
     88     AI bool allTrue() const { return fLo.allTrue() && fHi.allTrue(); }
     89 
     90     AI SkNx    abs() const { return { fLo.   abs(), fHi.   abs() }; }
     91     AI SkNx   sqrt() const { return { fLo.  sqrt(), fHi.  sqrt() }; }
     92     AI SkNx  rsqrt() const { return { fLo. rsqrt(), fHi. rsqrt() }; }
     93     AI SkNx  floor() const { return { fLo. floor(), fHi. floor() }; }
     94     AI SkNx invert() const { return { fLo.invert(), fHi.invert() }; }
     95 
     96     AI SkNx operator!() const { return { !fLo, !fHi }; }
     97     AI SkNx operator-() const { return { -fLo, -fHi }; }
     98     AI SkNx operator~() const { return { ~fLo, ~fHi }; }
     99 
    100     AI SkNx operator<<(int bits) const { return { fLo << bits, fHi << bits }; }
    101     AI SkNx operator>>(int bits) const { return { fLo >> bits, fHi >> bits }; }
    102 
    103     AI SkNx operator+(const SkNx& y) const { return { fLo + y.fLo, fHi + y.fHi }; }
    104     AI SkNx operator-(const SkNx& y) const { return { fLo - y.fLo, fHi - y.fHi }; }
    105     AI SkNx operator*(const SkNx& y) const { return { fLo * y.fLo, fHi * y.fHi }; }
    106     AI SkNx operator/(const SkNx& y) const { return { fLo / y.fLo, fHi / y.fHi }; }
    107 
    108     AI SkNx operator&(const SkNx& y) const { return { fLo & y.fLo, fHi & y.fHi }; }
    109     AI SkNx operator|(const SkNx& y) const { return { fLo | y.fLo, fHi | y.fHi }; }
    110     AI SkNx operator^(const SkNx& y) const { return { fLo ^ y.fLo, fHi ^ y.fHi }; }
    111 
    112     AI SkNx operator==(const SkNx& y) const { return { fLo == y.fLo, fHi == y.fHi }; }
    113     AI SkNx operator!=(const SkNx& y) const { return { fLo != y.fLo, fHi != y.fHi }; }
    114     AI SkNx operator<=(const SkNx& y) const { return { fLo <= y.fLo, fHi <= y.fHi }; }
    115     AI SkNx operator>=(const SkNx& y) const { return { fLo >= y.fLo, fHi >= y.fHi }; }
    116     AI SkNx operator< (const SkNx& y) const { return { fLo <  y.fLo, fHi <  y.fHi }; }
    117     AI SkNx operator> (const SkNx& y) const { return { fLo >  y.fLo, fHi >  y.fHi }; }
    118 
    119     AI SkNx saturatedAdd(const SkNx& y) const {
    120         return { fLo.saturatedAdd(y.fLo), fHi.saturatedAdd(y.fHi) };
    121     }
    122     AI SkNx thenElse(const SkNx& t, const SkNx& e) const {
    123         return { fLo.thenElse(t.fLo, e.fLo), fHi.thenElse(t.fHi, e.fHi) };
    124     }
    125 
    126     AI static SkNx Min(const SkNx& x, const SkNx& y) {
    127         return { Half::Min(x.fLo, y.fLo), Half::Min(x.fHi, y.fHi) };
    128     }
    129     AI static SkNx Max(const SkNx& x, const SkNx& y) {
    130         return { Half::Max(x.fLo, y.fLo), Half::Max(x.fHi, y.fHi) };
    131     }
    132 };
    133 
    134 // The N -> N/2 recursion bottoms out at N == 1, a scalar value.
    135 template <typename T>
    136 struct SkNx<1,T> {
    137     T fVal;
    138 
    139     AI SkNx() = default;
    140     AI SkNx(T v) : fVal(v) {}
    141 
    142     // Android complains against unused parameters, so we guard it
    143     AI T operator[](int SkDEBUGCODE(k)) const {
    144         SkASSERT(k == 0);
    145         return fVal;
    146     }
    147 
    148     AI static SkNx Load(const void* ptr) {
    149         SkNx v;
    150         memcpy(&v, ptr, sizeof(T));
    151         return v;
    152     }
    153     AI void store(void* ptr) const { memcpy(ptr, &fVal, sizeof(T)); }
    154 
    155     AI static void Load4(const void* vptr, SkNx* a, SkNx* b, SkNx* c, SkNx* d) {
    156         auto ptr = (const char*)vptr;
    157         *a = Load(ptr + 0*sizeof(T));
    158         *b = Load(ptr + 1*sizeof(T));
    159         *c = Load(ptr + 2*sizeof(T));
    160         *d = Load(ptr + 3*sizeof(T));
    161     }
    162     AI static void Load3(const void* vptr, SkNx* a, SkNx* b, SkNx* c) {
    163         auto ptr = (const char*)vptr;
    164         *a = Load(ptr + 0*sizeof(T));
    165         *b = Load(ptr + 1*sizeof(T));
    166         *c = Load(ptr + 2*sizeof(T));
    167     }
    168     AI static void Store4(void* vptr, const SkNx& a, const SkNx& b, const SkNx& c, const SkNx& d) {
    169         auto ptr = (char*)vptr;
    170         a.store(ptr + 0*sizeof(T));
    171         b.store(ptr + 1*sizeof(T));
    172         c.store(ptr + 2*sizeof(T));
    173         d.store(ptr + 3*sizeof(T));
    174     }
    175 
    176     AI bool anyTrue() const { return fVal != 0; }
    177     AI bool allTrue() const { return fVal != 0; }
    178 
    179     AI SkNx    abs() const { return Abs(fVal); }
    180     AI SkNx   sqrt() const { return Sqrt(fVal); }
    181     AI SkNx  rsqrt() const { return T(1) / this->sqrt(); }
    182     AI SkNx  floor() const { return Floor(fVal); }
    183     AI SkNx invert() const { return T(1) / *this; }
    184 
    185     AI SkNx operator!() const { return !fVal; }
    186     AI SkNx operator-() const { return -fVal; }
    187     AI SkNx operator~() const { return FromBits(~ToBits(fVal)); }
    188 
    189     AI SkNx operator<<(int bits) const { return fVal << bits; }
    190     AI SkNx operator>>(int bits) const { return fVal >> bits; }
    191 
    192     AI SkNx operator+(const SkNx& y) const { return fVal + y.fVal; }
    193     AI SkNx operator-(const SkNx& y) const { return fVal - y.fVal; }
    194     AI SkNx operator*(const SkNx& y) const { return fVal * y.fVal; }
    195     AI SkNx operator/(const SkNx& y) const { return fVal / y.fVal; }
    196 
    197     AI SkNx operator&(const SkNx& y) const { return FromBits(ToBits(fVal) & ToBits(y.fVal)); }
    198     AI SkNx operator|(const SkNx& y) const { return FromBits(ToBits(fVal) | ToBits(y.fVal)); }
    199     AI SkNx operator^(const SkNx& y) const { return FromBits(ToBits(fVal) ^ ToBits(y.fVal)); }
    200 
    201     AI SkNx operator==(const SkNx& y) const { return FromBits(fVal == y.fVal ? ~0 : 0); }
    202     AI SkNx operator!=(const SkNx& y) const { return FromBits(fVal != y.fVal ? ~0 : 0); }
    203     AI SkNx operator<=(const SkNx& y) const { return FromBits(fVal <= y.fVal ? ~0 : 0); }
    204     AI SkNx operator>=(const SkNx& y) const { return FromBits(fVal >= y.fVal ? ~0 : 0); }
    205     AI SkNx operator< (const SkNx& y) const { return FromBits(fVal <  y.fVal ? ~0 : 0); }
    206     AI SkNx operator> (const SkNx& y) const { return FromBits(fVal >  y.fVal ? ~0 : 0); }
    207 
    208     AI static SkNx Min(const SkNx& x, const SkNx& y) { return x.fVal < y.fVal ? x : y; }
    209     AI static SkNx Max(const SkNx& x, const SkNx& y) { return x.fVal > y.fVal ? x : y; }
    210 
    211     AI SkNx saturatedAdd(const SkNx& y) const {
    212         static_assert(std::is_unsigned<T>::value, "");
    213         T sum = fVal + y.fVal;
    214         return sum < fVal ? std::numeric_limits<T>::max() : sum;
    215     }
    216 
    217     AI SkNx thenElse(const SkNx& t, const SkNx& e) const { return fVal != 0 ? t : e; }
    218 
    219 private:
    220     // Helper functions to choose the right float/double methods.  (In <cmath> madness lies...)
    221     AI static float   Abs(float val) { return  ::fabsf(val); }
    222     AI static float  Sqrt(float val) { return  ::sqrtf(val); }
    223     AI static float Floor(float val) { return ::floorf(val); }
    224 
    225     AI static double   Abs(double val) { return  ::fabs(val); }
    226     AI static double  Sqrt(double val) { return  ::sqrt(val); }
    227     AI static double Floor(double val) { return ::floor(val); }
    228 
    229     // Helper functions for working with floats/doubles as bit patterns.
    230     template <typename U>
    231     AI static U ToBits(U v) { return v; }
    232     AI static int32_t ToBits(float  v) { int32_t bits; memcpy(&bits, &v, sizeof(v)); return bits; }
    233     AI static int64_t ToBits(double v) { int64_t bits; memcpy(&bits, &v, sizeof(v)); return bits; }
    234 
    235     template <typename Bits>
    236     AI static T FromBits(Bits bits) {
    237         static_assert(std::is_pod<T   >::value &&
    238                       std::is_pod<Bits>::value &&
    239                       sizeof(T) <= sizeof(Bits), "");
    240         T val;
    241         memcpy(&val, &bits, sizeof(T));
    242         return val;
    243     }
    244 };
    245 
    246 // Allow scalars on the left or right of binary operators, and things like +=, &=, etc.
    247 #define V template <int N, typename T> AI static SkNx<N,T>
    248     V operator+ (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) +  y; }
    249     V operator- (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) -  y; }
    250     V operator* (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) *  y; }
    251     V operator/ (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) /  y; }
    252     V operator& (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) &  y; }
    253     V operator| (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) |  y; }
    254     V operator^ (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) ^  y; }
    255     V operator==(T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) == y; }
    256     V operator!=(T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) != y; }
    257     V operator<=(T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) <= y; }
    258     V operator>=(T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) >= y; }
    259     V operator< (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) <  y; }
    260     V operator> (T x, const SkNx<N,T>& y) { return SkNx<N,T>(x) >  y; }
    261 
    262     V operator+ (const SkNx<N,T>& x, T y) { return x +  SkNx<N,T>(y); }
    263     V operator- (const SkNx<N,T>& x, T y) { return x -  SkNx<N,T>(y); }
    264     V operator* (const SkNx<N,T>& x, T y) { return x *  SkNx<N,T>(y); }
    265     V operator/ (const SkNx<N,T>& x, T y) { return x /  SkNx<N,T>(y); }
    266     V operator& (const SkNx<N,T>& x, T y) { return x &  SkNx<N,T>(y); }
    267     V operator| (const SkNx<N,T>& x, T y) { return x |  SkNx<N,T>(y); }
    268     V operator^ (const SkNx<N,T>& x, T y) { return x ^  SkNx<N,T>(y); }
    269     V operator==(const SkNx<N,T>& x, T y) { return x == SkNx<N,T>(y); }
    270     V operator!=(const SkNx<N,T>& x, T y) { return x != SkNx<N,T>(y); }
    271     V operator<=(const SkNx<N,T>& x, T y) { return x <= SkNx<N,T>(y); }
    272     V operator>=(const SkNx<N,T>& x, T y) { return x >= SkNx<N,T>(y); }
    273     V operator< (const SkNx<N,T>& x, T y) { return x <  SkNx<N,T>(y); }
    274     V operator> (const SkNx<N,T>& x, T y) { return x >  SkNx<N,T>(y); }
    275 
    276     V& operator<<=(SkNx<N,T>& x, int bits) { return (x = x << bits); }
    277     V& operator>>=(SkNx<N,T>& x, int bits) { return (x = x >> bits); }
    278 
    279     V& operator +=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x + y); }
    280     V& operator -=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x - y); }
    281     V& operator *=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x * y); }
    282     V& operator /=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x / y); }
    283     V& operator &=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x & y); }
    284     V& operator |=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x | y); }
    285     V& operator ^=(SkNx<N,T>& x, const SkNx<N,T>& y) { return (x = x ^ y); }
    286 
    287     V& operator +=(SkNx<N,T>& x, T y) { return (x = x + SkNx<N,T>(y)); }
    288     V& operator -=(SkNx<N,T>& x, T y) { return (x = x - SkNx<N,T>(y)); }
    289     V& operator *=(SkNx<N,T>& x, T y) { return (x = x * SkNx<N,T>(y)); }
    290     V& operator /=(SkNx<N,T>& x, T y) { return (x = x / SkNx<N,T>(y)); }
    291     V& operator &=(SkNx<N,T>& x, T y) { return (x = x & SkNx<N,T>(y)); }
    292     V& operator |=(SkNx<N,T>& x, T y) { return (x = x | SkNx<N,T>(y)); }
    293     V& operator ^=(SkNx<N,T>& x, T y) { return (x = x ^ SkNx<N,T>(y)); }
    294 #undef V
    295 
    296 // SkNx<N,T> ~~> SkNx<N/2,T> + SkNx<N/2,T>
    297 template <int N, typename T>
    298 AI static void SkNx_split(const SkNx<N,T>& v, SkNx<N/2,T>* lo, SkNx<N/2,T>* hi) {
    299     *lo = v.fLo;
    300     *hi = v.fHi;
    301 }
    302 
    303 // SkNx<N/2,T> + SkNx<N/2,T> ~~> SkNx<N,T>
    304 template <int N, typename T>
    305 AI static SkNx<N*2,T> SkNx_join(const SkNx<N,T>& lo, const SkNx<N,T>& hi) {
    306     return { lo, hi };
    307 }
    308 
    309 // A very generic shuffle.  Can reorder, duplicate, contract, expand...
    310 //    Sk4f v = { R,G,B,A };
    311 //    SkNx_shuffle<2,1,0,3>(v)         ~~> {B,G,R,A}
    312 //    SkNx_shuffle<2,1>(v)             ~~> {B,G}
    313 //    SkNx_shuffle<2,1,2,1,2,1,2,1>(v) ~~> {B,G,B,G,B,G,B,G}
    314 //    SkNx_shuffle<3,3,3,3>(v)         ~~> {A,A,A,A}
    315 template <int... Ix, int N, typename T>
    316 AI static SkNx<sizeof...(Ix),T> SkNx_shuffle(const SkNx<N,T>& v) {
    317     return { v[Ix]... };
    318 }
    319 
    320 // Cast from SkNx<N, Src> to SkNx<N, Dst>, as if you called static_cast<Dst>(Src).
    321 template <typename Dst, typename Src, int N>
    322 AI static SkNx<N,Dst> SkNx_cast(const SkNx<N,Src>& v) {
    323     return { SkNx_cast<Dst>(v.fLo), SkNx_cast<Dst>(v.fHi) };
    324 }
    325 template <typename Dst, typename Src>
    326 AI static SkNx<1,Dst> SkNx_cast(const SkNx<1,Src>& v) {
    327     return static_cast<Dst>(v.fVal);
    328 }
    329 
    330 template <int N, typename T>
    331 AI static SkNx<N,T> SkNx_fma(const SkNx<N,T>& f, const SkNx<N,T>& m, const SkNx<N,T>& a) {
    332     return f*m+a;
    333 }
    334 
    335 }  // namespace
    336 
    337 typedef SkNx<2,     float> Sk2f;
    338 typedef SkNx<4,     float> Sk4f;
    339 typedef SkNx<8,     float> Sk8f;
    340 typedef SkNx<16,    float> Sk16f;
    341 
    342 typedef SkNx<2,  SkScalar> Sk2s;
    343 typedef SkNx<4,  SkScalar> Sk4s;
    344 typedef SkNx<8,  SkScalar> Sk8s;
    345 typedef SkNx<16, SkScalar> Sk16s;
    346 
    347 typedef SkNx<4,   uint8_t> Sk4b;
    348 typedef SkNx<8,   uint8_t> Sk8b;
    349 typedef SkNx<16,  uint8_t> Sk16b;
    350 
    351 typedef SkNx<4,  uint16_t> Sk4h;
    352 typedef SkNx<8,  uint16_t> Sk8h;
    353 typedef SkNx<16, uint16_t> Sk16h;
    354 
    355 typedef SkNx<4,  int32_t> Sk4i;
    356 typedef SkNx<8,  int32_t> Sk8i;
    357 typedef SkNx<4, uint32_t> Sk4u;
    358 
    359 // Include platform specific specializations if available.
    360 #if !defined(SKNX_NO_SIMD) && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
    361     #include "../opts/SkNx_sse.h"
    362 #elif !defined(SKNX_NO_SIMD) && defined(SK_ARM_HAS_NEON)
    363     #include "../opts/SkNx_neon.h"
    364 #else
    365 
    366 AI static Sk4i Sk4f_round(const Sk4f& x) {
    367     return { (int) lrintf (x[0]),
    368              (int) lrintf (x[1]),
    369              (int) lrintf (x[2]),
    370              (int) lrintf (x[3]), };
    371 }
    372 
    373 #endif
    374 
    375 AI static void Sk4f_ToBytes(uint8_t p[16],
    376                             const Sk4f& a, const Sk4f& b, const Sk4f& c, const Sk4f& d) {
    377     SkNx_cast<uint8_t>(SkNx_join(SkNx_join(a,b), SkNx_join(c,d))).store(p);
    378 }
    379 
    380 #undef AI
    381 
    382 #endif//SkNx_DEFINED
    383