SkOpts.cpp revision f96bee384dea60a4e96035878e2671cd49d3b406 
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#include "SkOnce.h"
9#include "SkOpts.h"
10#include "SkXfermode_opts.h"
11
12#if defined(SK_CPU_X86)
13    #if defined(SK_BUILD_FOR_WIN32)
14        #include <intrin.h>
15        static void cpuid(uint32_t abcd[4]) { __cpuid((int*)abcd, 1); }
16    #else
17        #include <cpuid.h>
18        static void cpuid(uint32_t abcd[4]) { __get_cpuid(1, abcd+0, abcd+1, abcd+2, abcd+3); }
19    #endif
20#elif !defined(SK_ARM_HAS_NEON) && defined(SK_CPU_ARM32) && defined(SK_BUILD_FOR_ANDROID)
21    #include <cpu-features.h>
22#endif
23
24namespace portable {  // This helps identify methods from this file when debugging / profiling.
25
26static float rsqrt(float x) {
27    // Get initial estimate.
28    int i = *SkTCast<int*>(&x);
29    i = 0x5F1FFFF9 - (i>>1);
30    float estimate = *SkTCast<float*>(&i);
31
32    // One step of Newton's method to refine.
33    const float estimate_sq = estimate*estimate;
34    estimate *= 0.703952253f*(2.38924456f-x*estimate_sq);
35    return estimate;
36}
37
38template <typename T>
39static void memsetT(T dst[], T val, int n) { while (n --> 0) { *dst++ = val; } }
40
41}  // namespace portable
42
43namespace SkOpts {
44    // Define default function pointer values here...
45    decltype(rsqrt)                     rsqrt = portable::rsqrt;
46    decltype(memset16)               memset16 = portable::memsetT<uint16_t>;
47    decltype(memset32)               memset32 = portable::memsetT<uint32_t>;
48    decltype(create_xfermode) create_xfermode = SkCreate4pxXfermode;
49
50    // Each Init_foo() is defined in src/opts/SkOpts_foo.cpp.
51    void Init_sse2();
52    void Init_ssse3();
53    void Init_sse41();
54    void Init_neon();
55    //TODO: _dsp2, _armv7, _armv8, _x86, _x86_64, _sse42, _avx, avx2, ... ?
56
57    static void init() {
58        // TODO: Chrome's not linking _sse* opts on iOS simulator builds.  Bug or feature?
59    #if defined(SK_CPU_X86) && !defined(SK_BUILD_FOR_IOS)
60        uint32_t abcd[] = {0,0,0,0};
61        cpuid(abcd);
62        if (abcd[3] & (1<<26)) { Init_sse2(); }
63        if (abcd[2] & (1<< 9)) { Init_ssse3(); }
64        if (abcd[2] & (1<<19)) { Init_sse41(); }
65    #elif defined(SK_ARM_HAS_NEON)
66        Init_neon();
67    #elif defined(SK_CPU_ARM32) && defined(SK_BUILD_FOR_ANDROID)
68        if (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) { Init_neon(); }
69    #endif
70    }
71
72    SK_DECLARE_STATIC_ONCE(gInitOnce);
73    void Init() { SkOnce(&gInitOnce, init); }
74
75#if SK_ALLOW_STATIC_GLOBAL_INITIALIZERS
76    static struct AutoInit {
77        AutoInit() { Init(); }
78    } gAutoInit;
79#endif
80}
81