SkCpu.cpp revision f44703a87f532b3f593d91605d66d52c6bbc45c9 
1/*
2 * Copyright 2016 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 "SkCpu.h"
9#include "SkOnce.h"
10
11#if defined(SK_CPU_X86)
12    #if defined(SK_BUILD_FOR_WIN32)
13        #include <intrin.h>
14        static void cpuid (uint32_t abcd[4]) { __cpuid  ((int*)abcd, 1);    }
15        static void cpuid7(uint32_t abcd[4]) { __cpuidex((int*)abcd, 7, 0); }
16        static uint64_t xgetbv(uint32_t xcr) { return _xgetbv(xcr); }
17    #else
18        #include <cpuid.h>
19        #if !defined(__cpuid_count)  // Old Mac Clang doesn't have this defined.
20            #define  __cpuid_count(eax, ecx, a, b, c, d) \
21                __asm__("cpuid" : "=a"(a), "=b"(b), "=c"(c), "=d"(d) : "0"(eax), "2"(ecx))
22        #endif
23        static void cpuid (uint32_t abcd[4]) { __get_cpuid(1, abcd+0, abcd+1, abcd+2, abcd+3); }
24        static void cpuid7(uint32_t abcd[4]) {
25            __cpuid_count(7, 0, abcd[0], abcd[1], abcd[2], abcd[3]);
26        }
27        static uint64_t xgetbv(uint32_t xcr) {
28            uint32_t eax, edx;
29            __asm__ __volatile__ ( "xgetbv" : "=a"(eax), "=d"(edx) : "c"(xcr));
30            return (uint64_t)(edx) << 32 | eax;
31        }
32    #endif
33
34    static uint32_t read_cpu_features() {
35        uint32_t features = 0;
36        uint32_t abcd[4] = {0,0,0,0};
37
38        // You might want to refer to http://www.sandpile.org/x86/cpuid.htm
39
40        cpuid(abcd);
41        if (abcd[3] & (1<<25)) { features |= SkCpu:: SSE1; }
42        if (abcd[3] & (1<<26)) { features |= SkCpu:: SSE2; }
43        if (abcd[2] & (1<< 0)) { features |= SkCpu:: SSE3; }
44        if (abcd[2] & (1<< 9)) { features |= SkCpu::SSSE3; }
45        if (abcd[2] & (1<<19)) { features |= SkCpu::SSE41; }
46        if (abcd[2] & (1<<20)) { features |= SkCpu::SSE42; }
47
48        if ((abcd[2] & (3<<26)) == (3<<26) && (xgetbv(0) & 6) == 6) {  // XSAVE + OSXSAVE
49            if (abcd[2] & (1<<28)) { features |= SkCpu:: AVX; }
50            if (abcd[2] & (1<<29)) { features |= SkCpu::F16C; }
51            if (abcd[2] & (1<<12)) { features |= SkCpu:: FMA; }
52
53            cpuid7(abcd);
54            if (abcd[1] & (1<<5)) { features |= SkCpu::AVX2; }
55            if (abcd[1] & (1<<3)) { features |= SkCpu::BMI1; }
56            if (abcd[1] & (1<<8)) { features |= SkCpu::BMI2; }
57        }
58        return features;
59    }
60
61#elif defined(SK_CPU_ARM64) && defined(SK_BUILD_FOR_ANDROID)
62    #include <asm/hwcap.h>
63    #include <sys/auxv.h>
64
65    static uint32_t read_cpu_features() {
66        uint32_t features = 0;
67        uint32_t hwcaps = getauxval(AT_HWCAP);
68        if (hwcaps & HWCAP_CRC32) { features |= SkCpu::CRC32; }
69        return features;
70    }
71
72#else
73    static uint32_t read_cpu_features() {
74        return 0;
75    }
76
77#endif
78
79uint32_t SkCpu::gCachedFeatures = 0;
80
81void SkCpu::CacheRuntimeFeatures() {
82    static SkOnce once;
83    once([] { gCachedFeatures = read_cpu_features(); });
84}
85