xref: /third_party/skia/src/core/SkCpu.cpp (revision cb93a386)
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 "include/core/SkStream.h"
9#include "include/core/SkString.h"
10#include "include/private/SkOnce.h"
11#include "src/core/SkCpu.h"
12
13#if defined(SK_CPU_X86)
14    #if defined(_MSC_VER)
15        #include <intrin.h>
16        static void cpuid (uint32_t abcd[4]) { __cpuid  ((int*)abcd, 1);    }
17        static void cpuid7(uint32_t abcd[4]) { __cpuidex((int*)abcd, 7, 0); }
18        static uint64_t xgetbv(uint32_t xcr) { return _xgetbv(xcr); }
19    #else
20        #include <cpuid.h>
21        #if !defined(__cpuid_count)  // Old Mac Clang doesn't have this defined.
22            #define  __cpuid_count(eax, ecx, a, b, c, d) \
23                __asm__("cpuid" : "=a"(a), "=b"(b), "=c"(c), "=d"(d) : "0"(eax), "2"(ecx))
24        #endif
25        static void cpuid (uint32_t abcd[4]) { __get_cpuid(1, abcd+0, abcd+1, abcd+2, abcd+3); }
26        static void cpuid7(uint32_t abcd[4]) {
27            __cpuid_count(7, 0, abcd[0], abcd[1], abcd[2], abcd[3]);
28        }
29        static uint64_t xgetbv(uint32_t xcr) {
30            uint32_t eax, edx;
31            __asm__ __volatile__ ( "xgetbv" : "=a"(eax), "=d"(edx) : "c"(xcr));
32            return (uint64_t)(edx) << 32 | eax;
33        }
34    #endif
35
36    static uint32_t read_cpu_features() {
37        uint32_t features = 0;
38        uint32_t abcd[4] = {0,0,0,0};
39
40        // You might want to refer to http://www.sandpile.org/x86/cpuid.htm
41
42        cpuid(abcd);
43        if (abcd[3] & (1<<25)) { features |= SkCpu:: SSE1; }
44        if (abcd[3] & (1<<26)) { features |= SkCpu:: SSE2; }
45        if (abcd[2] & (1<< 0)) { features |= SkCpu:: SSE3; }
46        if (abcd[2] & (1<< 9)) { features |= SkCpu::SSSE3; }
47        if (abcd[2] & (1<<19)) { features |= SkCpu::SSE41; }
48        if (abcd[2] & (1<<20)) { features |= SkCpu::SSE42; }
49
50        if ((abcd[2] & (3<<26)) == (3<<26)         // XSAVE + OSXSAVE
51             && (xgetbv(0) & (3<<1)) == (3<<1)) {  // XMM and YMM state enabled.
52            if (abcd[2] & (1<<28)) { features |= SkCpu:: AVX; }
53            if (abcd[2] & (1<<29)) { features |= SkCpu::F16C; }
54            if (abcd[2] & (1<<12)) { features |= SkCpu:: FMA; }
55
56            cpuid7(abcd);
57            if (abcd[1] & (1<<5)) { features |= SkCpu::AVX2; }
58            if (abcd[1] & (1<<3)) { features |= SkCpu::BMI1; }
59            if (abcd[1] & (1<<8)) { features |= SkCpu::BMI2; }
60            if (abcd[1] & (1<<9)) { features |= SkCpu::ERMS; }
61
62            if ((xgetbv(0) & (7<<5)) == (7<<5)) {  // All ZMM state bits enabled too.
63                if (abcd[1] & (1<<16)) { features |= SkCpu::AVX512F; }
64                if (abcd[1] & (1<<17)) { features |= SkCpu::AVX512DQ; }
65                if (abcd[1] & (1<<21)) { features |= SkCpu::AVX512IFMA; }
66                if (abcd[1] & (1<<26)) { features |= SkCpu::AVX512PF; }
67                if (abcd[1] & (1<<27)) { features |= SkCpu::AVX512ER; }
68                if (abcd[1] & (1<<28)) { features |= SkCpu::AVX512CD; }
69                if (abcd[1] & (1<<30)) { features |= SkCpu::AVX512BW; }
70                if (abcd[1] & (1<<31)) { features |= SkCpu::AVX512VL; }
71            }
72        }
73        return features;
74    }
75
76#elif defined(SK_CPU_ARM64) && __has_include(<sys/auxv.h>)
77    #include <sys/auxv.h>
78
79    static uint32_t read_cpu_features() {
80        const uint32_t kHWCAP_CRC32   = (1<< 7),
81                       kHWCAP_ASIMDHP = (1<<10);
82
83        uint32_t features = 0;
84        uint32_t hwcaps = getauxval(AT_HWCAP);
85        if (hwcaps & kHWCAP_CRC32  ) { features |= SkCpu::CRC32; }
86        if (hwcaps & kHWCAP_ASIMDHP) { features |= SkCpu::ASIMDHP; }
87
88        // The Samsung Mongoose 3 core sets the ASIMDHP bit but doesn't support it.
89        for (int core = 0; features & SkCpu::ASIMDHP; core++) {
90            // These /sys files contain the core's MIDR_EL1 register, the source of
91            // CPU {implementer, variant, part, revision} you'd see in /proc/cpuinfo.
92            SkString path =
93                SkStringPrintf("/sys/devices/system/cpu/cpu%d/regs/identification/midr_el1", core);
94
95            // Can't use SkData::MakeFromFileName() here, I think because /sys can't be mmap()'d.
96            SkFILEStream midr_el1(path.c_str());
97            if (!midr_el1.isValid()) {
98                // This is our ordinary exit path.
99                // If we ask for MIDR_EL1 from a core that doesn't exist, we've checked all cores.
100                if (core == 0) {
101                    // On the other hand, if we can't read MIDR_EL1 from any core, assume the worst.
102                    features &= ~(SkCpu::ASIMDHP);
103                }
104                break;
105            }
106
107            const char kMongoose3[] = "0x00000000531f0020";  // 53 == Samsung.
108            char buf[SK_ARRAY_COUNT(kMongoose3) - 1];  // No need for the terminating \0.
109
110            if (SK_ARRAY_COUNT(buf) != midr_el1.read(buf, SK_ARRAY_COUNT(buf))
111                          || 0 == memcmp(kMongoose3, buf, SK_ARRAY_COUNT(buf))) {
112                features &= ~(SkCpu::ASIMDHP);
113            }
114        }
115        return features;
116    }
117
118#elif defined(SK_CPU_ARM32) && __has_include(<sys/auxv.h>) && \
119    (!defined(__ANDROID_API__) || __ANDROID_API__ >= 18)
120    // sys/auxv.h will always be present in the Android NDK due to unified
121    //headers, but getauxval is only defined for API >= 18.
122    #include <sys/auxv.h>
123
124    static uint32_t read_cpu_features() {
125        const uint32_t kHWCAP_NEON  = (1<<12);
126        const uint32_t kHWCAP_VFPv4 = (1<<16);
127
128        uint32_t features = 0;
129        uint32_t hwcaps = getauxval(AT_HWCAP);
130        if (hwcaps & kHWCAP_NEON ) {
131            features |= SkCpu::NEON;
132            if (hwcaps & kHWCAP_VFPv4) { features |= SkCpu::NEON_FMA|SkCpu::VFP_FP16; }
133        }
134        return features;
135    }
136
137#elif defined(SK_CPU_ARM32) && __has_include(<cpu-features.h>)
138    #include <cpu-features.h>
139
140    static uint32_t read_cpu_features() {
141        uint32_t features = 0;
142        uint64_t cpu_features = android_getCpuFeatures();
143        if (cpu_features & ANDROID_CPU_ARM_FEATURE_NEON)     { features |= SkCpu::NEON; }
144        if (cpu_features & ANDROID_CPU_ARM_FEATURE_NEON_FMA) { features |= SkCpu::NEON_FMA; }
145        if (cpu_features & ANDROID_CPU_ARM_FEATURE_VFP_FP16) { features |= SkCpu::VFP_FP16; }
146        return features;
147    }
148
149#else
150    static uint32_t read_cpu_features() {
151        return 0;
152    }
153
154#endif
155
156uint32_t SkCpu::gCachedFeatures = 0;
157
158void SkCpu::CacheRuntimeFeatures() {
159    static SkOnce once;
160    once([] { gCachedFeatures = read_cpu_features(); });
161}
162