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 //#define SKNX_NO_SIMD
12 
13 #include "SkScalar.h"
14 #include "SkTypes.h"
15 #include <math.h>
16 
17 // The default implementations just fall back on a pair of size N/2.
18 // These support the union of operations we might do to ints and floats, but
19 // platform specializations might support fewer (e.g. no float <<, no int /).
20 template <int N, typename T>
21 class SkNx {
22 public:
SkNx()23     SkNx() {}
SkNx(T val)24     SkNx(T val) : fLo(val), fHi(val) {}
25 
26     typedef SkNx<N/2, T> Half;
SkNx(const Half & lo,const Half & hi)27     SkNx(const Half& lo, const Half& hi) : fLo(lo), fHi(hi) {}
28 
SkNx(T a,T b)29     SkNx(T a, T b)                                : fLo(a),       fHi(b)       {}
SkNx(T a,T b,T c,T d)30     SkNx(T a, T b, T c, T d)                      : fLo(a,b),     fHi(c,d)     {}
SkNx(T a,T b,T c,T d,T e,T f,T g,T h)31     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) {}
SkNx(T a,T b,T c,T d,T e,T f,T g,T h,T i,T j,T k,T l,T m,T n,T o,T p)32     SkNx(T a, T b, T c, T d,  T e, T f, T g, T h,
33          T i, T j, T k, T l,  T m, T n, T o, T p) : fLo(a,b,c,d, e,f,g,h), fHi(i,j,k,l, m,n,o,p) {}
34 
Load(const void * ptr)35     static SkNx Load(const void* ptr) {
36         auto vals = (const T*)ptr;
37         return SkNx(Half::Load(vals), Half::Load(vals+N/2));
38     }
39 
store(void * ptr)40     void store(void* ptr) const {
41         auto vals = (T*)ptr;
42         fLo.store(vals);
43         fHi.store(vals+N/2);
44     }
45 
46 #define OP(op) SkNx operator op(const SkNx& o) const { return {fLo op o.fLo, fHi op o.fHi}; }
47     OP(+) OP(-) OP(*) OP(/)
48     OP(&) OP(|) OP(^)
49     OP(==) OP(!=) OP(<) OP(>) OP(<=) OP(>=)
50 #undef OP
51 
52 #define OP(op) SkNx op() const { return {fLo.op(), fHi.op()}; }
53     OP(abs) OP(floor)
54     OP(sqrt) OP(rsqrt0) OP(rsqrt1) OP(rsqrt2)
55     OP(invert) OP(approxInvert)
56 #undef OP
57 
58     SkNx operator << (int bits) const { return SkNx(fLo << bits, fHi << bits); }
59     SkNx operator >> (int bits) const { return SkNx(fLo >> bits, fHi >> bits); }
60 
saturatedAdd(const SkNx & o)61     SkNx saturatedAdd(const SkNx& o) const {
62         return {fLo.saturatedAdd(o.fLo), fHi.saturatedAdd(o.fHi)};
63     }
64 
Min(const SkNx & a,const SkNx & b)65     static SkNx Min(const SkNx& a, const SkNx& b) {
66         return {Half::Min(a.fLo, b.fLo), Half::Min(a.fHi, b.fHi)};
67     }
Max(const SkNx & a,const SkNx & b)68     static SkNx Max(const SkNx& a, const SkNx& b) {
69         return {Half::Max(a.fLo, b.fLo), Half::Max(a.fHi, b.fHi)};
70     }
71 
72     T operator[](int k) const {
73         SkASSERT(0 <= k && k < N);
74         return k < N/2 ? fLo[k] : fHi[k-N/2];
75     }
76 
allTrue()77     bool allTrue() const { return fLo.allTrue() && fHi.allTrue(); }
anyTrue()78     bool anyTrue() const { return fLo.anyTrue() || fHi.anyTrue(); }
thenElse(const SkNx & t,const SkNx & e)79     SkNx thenElse(const SkNx& t, const SkNx& e) const {
80         return SkNx(fLo.thenElse(t.fLo, e.fLo), fHi.thenElse(t.fHi, e.fHi));
81     }
82 
83 protected:
84     static_assert(0 == (N & (N-1)), "N must be a power of 2.");
85 
86     Half fLo, fHi;
87 };
88 
89 // Bottom out the default implementations with scalars when nothing's been specialized.
90 template <typename T>
91 class SkNx<1, T> {
92 public:
SkNx()93     SkNx() {}
SkNx(T val)94     SkNx(T val) : fVal(val) {}
95 
Load(const void * ptr)96     static SkNx Load(const void* ptr) {
97         auto vals = (const T*)ptr;
98         return SkNx(vals[0]);
99     }
100 
store(void * ptr)101     void store(void* ptr) const {
102         auto vals = (T*) ptr;
103         vals[0] = fVal;
104     }
105 
106 #define OP(op) SkNx operator op(const SkNx& o) const { return fVal op o.fVal; }
107     OP(+) OP(-) OP(*) OP(/)
108     OP(&) OP(|) OP(^)
109     OP(==) OP(!=) OP(<) OP(>) OP(<=) OP(>=)
110 #undef OP
111 
112     SkNx operator << (int bits) const { return fVal << bits; }
113     SkNx operator >> (int bits) const { return fVal >> bits; }
114 
saturatedAdd(const SkNx & o)115     SkNx saturatedAdd(const SkNx& o) const {
116         SkASSERT((T)(~0) > 0); // TODO: support signed T?
117         T sum = fVal + o.fVal;
118         return sum < fVal ? (T)(~0) : sum;
119     }
120 
Min(const SkNx & a,const SkNx & b)121     static SkNx Min(const SkNx& a, const SkNx& b) { return SkTMin(a.fVal, b.fVal); }
Max(const SkNx & a,const SkNx & b)122     static SkNx Max(const SkNx& a, const SkNx& b) { return SkTMax(a.fVal, b.fVal); }
123 
abs()124     SkNx abs() const { return SkTAbs(fVal); }
floor()125     SkNx floor() const { return Floor(fVal); }
126 
sqrt()127     SkNx  sqrt () const { return Sqrt(fVal); }
rsqrt0()128     SkNx rsqrt0() const { return this->sqrt().invert(); }
rsqrt1()129     SkNx rsqrt1() const { return this->rsqrt0(); }
rsqrt2()130     SkNx rsqrt2() const { return this->rsqrt1(); }
131 
invert()132     SkNx       invert() const { return 1 / fVal; }
approxInvert()133     SkNx approxInvert() const { return this->invert(); }
134 
135     T operator[](int k) const {
136         SkASSERT(0 == k);
137         return fVal;
138     }
139 
allTrue()140     bool allTrue() const { return fVal != 0; }
anyTrue()141     bool anyTrue() const { return fVal != 0; }
thenElse(const SkNx & t,const SkNx & e)142     SkNx thenElse(const SkNx& t, const SkNx& e) const { return fVal != 0 ? t : e; }
143 
144 protected:
Floor(double val)145     static double Floor(double val) { return ::floor (val); }
Floor(float val)146     static float  Floor(float  val) { return ::floorf(val); }
Sqrt(double val)147     static double Sqrt(double val) { return ::sqrt (val); }
Sqrt(float val)148     static float  Sqrt(float  val) { return ::sqrtf(val); }
149 
150     T fVal;
151 };
152 
153 // This generic shuffle can be called to create any valid SkNx<N,T>.
154 //     Sk4f f(a,b,c,d);
155 //     Sk2f t = SkNx_shuffle<2,1>(f);  // ~~~> Sk2f(c,b)
156 //     f = SkNx_shuffle<0,1,1,0>(t);   // ~~~> Sk4f(c,b,b,c)
157 template <int... Ix, int N, typename T>
SkNx_shuffle(const SkNx<N,T> & src)158 static inline SkNx<sizeof...(Ix), T> SkNx_shuffle(const SkNx<N,T>& src) { return { src[Ix]... }; }
159 
160 // This is a generic cast between two SkNx with the same number of elements N.  E.g.
161 //   Sk4b bs = ...;                     // Load 4 bytes.
162 //   Sk4f fs = SkNx_cast<float>(bs);    // Cast each byte to a float.
163 //   Sk4h hs = SkNx_cast<uint16_t>(fs); // Cast each float to uint16_t.
164 template <typename D, typename S>
SkNx_cast(const SkNx<2,S> & src)165 static inline SkNx<2,D> SkNx_cast(const SkNx<2,S>& src) {
166     return { (D)src[0], (D)src[1] };
167 }
168 
169 template <typename D, typename S>
SkNx_cast(const SkNx<4,S> & src)170 static inline SkNx<4,D> SkNx_cast(const SkNx<4,S>& src) {
171     return { (D)src[0], (D)src[1], (D)src[2], (D)src[3] };
172 }
173 
174 template <typename D, typename S>
SkNx_cast(const SkNx<8,S> & src)175 static inline SkNx<8,D> SkNx_cast(const SkNx<8,S>& src) {
176     return { (D)src[0], (D)src[1], (D)src[2], (D)src[3],
177              (D)src[4], (D)src[5], (D)src[6], (D)src[7] };
178 }
179 
180 template <typename D, typename S>
SkNx_cast(const SkNx<16,S> & src)181 static inline SkNx<16,D> SkNx_cast(const SkNx<16,S>& src) {
182     return { (D)src[ 0], (D)src[ 1], (D)src[ 2], (D)src[ 3],
183              (D)src[ 4], (D)src[ 5], (D)src[ 6], (D)src[ 7],
184              (D)src[ 8], (D)src[ 9], (D)src[10], (D)src[11],
185              (D)src[12], (D)src[13], (D)src[14], (D)src[15] };
186 }
187 
188 typedef SkNx<2,     float> Sk2f;
189 typedef SkNx<4,     float> Sk4f;
190 typedef SkNx<2,  SkScalar> Sk2s;
191 typedef SkNx<4,  SkScalar> Sk4s;
192 
193 typedef SkNx<4,   uint8_t> Sk4b;
194 typedef SkNx<16,  uint8_t> Sk16b;
195 typedef SkNx<4,  uint16_t> Sk4h;
196 typedef SkNx<16, uint16_t> Sk16h;
197 typedef SkNx<4,       int> Sk4i;
198 
199 typedef SkNx<4, int> Sk4i;
200 
201 // Include platform specific specializations if available.
202 #if !defined(SKNX_NO_SIMD) && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
203     #include "../opts/SkNx_sse.h"
204 #elif !defined(SKNX_NO_SIMD) && defined(SK_ARM_HAS_NEON)
205     #include "../opts/SkNx_neon.h"
206 #else
207     static inline
Sk4f_ToBytes(uint8_t p[16],const Sk4f & a,const Sk4f & b,const Sk4f & c,const Sk4f & d)208     void Sk4f_ToBytes(uint8_t p[16], const Sk4f& a, const Sk4f& b, const Sk4f& c, const Sk4f& d) {
209         SkNx_cast<uint8_t>(a).store(p+ 0);
210         SkNx_cast<uint8_t>(b).store(p+ 4);
211         SkNx_cast<uint8_t>(c).store(p+ 8);
212         SkNx_cast<uint8_t>(d).store(p+12);
213     }
214 #endif
215 
216 #endif//SkNx_DEFINED
217