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1 // Copyright 2011 Google Inc. All Rights Reserved.
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the COPYING file in the root of the source
5 // tree. An additional intellectual property rights grant can be found
6 // in the file PATENTS. All contributing project authors may
7 // be found in the AUTHORS file in the root of the source tree.
8 // -----------------------------------------------------------------------------
9 //
10 // CPU detection
11 //
12 // Author: Christian Duvivier (cduvivier@google.com)
13 
14 #include "src/dsp/dsp.h"
15 
16 #if defined(WEBP_HAVE_NEON_RTCD)
17 #include <stdio.h>
18 #include <string.h>
19 #endif
20 
21 #if defined(WEBP_ANDROID_NEON)
22 #include <cpu-features.h>
23 #endif
24 
25 //------------------------------------------------------------------------------
26 // SSE2 detection.
27 //
28 
29 // apple/darwin gcc-4.0.1 defines __PIC__, but not __pic__ with -fPIC.
30 #if (defined(__pic__) || defined(__PIC__)) && defined(__i386__)
GetCPUInfo(int cpu_info[4],int info_type)31 static WEBP_INLINE void GetCPUInfo(int cpu_info[4], int info_type) {
32   __asm__ volatile (
33     "mov %%ebx, %%edi\n"
34     "cpuid\n"
35     "xchg %%edi, %%ebx\n"
36     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
37     : "a"(info_type), "c"(0));
38 }
39 #elif defined(__x86_64__) && \
40       (defined(__code_model_medium__) || defined(__code_model_large__)) && \
41       defined(__PIC__)
GetCPUInfo(int cpu_info[4],int info_type)42 static WEBP_INLINE void GetCPUInfo(int cpu_info[4], int info_type) {
43   __asm__ volatile (
44     "xchg{q}\t{%%rbx}, %q1\n"
45     "cpuid\n"
46     "xchg{q}\t{%%rbx}, %q1\n"
47     : "=a"(cpu_info[0]), "=&r"(cpu_info[1]), "=c"(cpu_info[2]),
48       "=d"(cpu_info[3])
49     : "a"(info_type), "c"(0));
50 }
51 #elif defined(__i386__) || defined(__x86_64__)
GetCPUInfo(int cpu_info[4],int info_type)52 static WEBP_INLINE void GetCPUInfo(int cpu_info[4], int info_type) {
53   __asm__ volatile (
54     "cpuid\n"
55     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
56     : "a"(info_type), "c"(0));
57 }
58 #elif (defined(_M_X64) || defined(_M_IX86)) && \
59       defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 150030729  // >= VS2008 SP1
60 #include <intrin.h>
61 #define GetCPUInfo(info, type) __cpuidex(info, type, 0)  // set ecx=0
62 #elif defined(WEBP_MSC_SSE2)
63 #define GetCPUInfo __cpuid
64 #endif
65 
66 // NaCl has no support for xgetbv or the raw opcode.
67 #if !defined(__native_client__) && (defined(__i386__) || defined(__x86_64__))
xgetbv(void)68 static WEBP_INLINE uint64_t xgetbv(void) {
69   const uint32_t ecx = 0;
70   uint32_t eax, edx;
71   // Use the raw opcode for xgetbv for compatibility with older toolchains.
72   __asm__ volatile (
73     ".byte 0x0f, 0x01, 0xd0\n"
74     : "=a"(eax), "=d"(edx) : "c" (ecx));
75   return ((uint64_t)edx << 32) | eax;
76 }
77 #elif (defined(_M_X64) || defined(_M_IX86)) && \
78       defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 160040219  // >= VS2010 SP1
79 #include <immintrin.h>
80 #define xgetbv() _xgetbv(0)
81 #elif defined(_MSC_VER) && defined(_M_IX86)
xgetbv(void)82 static WEBP_INLINE uint64_t xgetbv(void) {
83   uint32_t eax_, edx_;
84   __asm {
85     xor ecx, ecx  // ecx = 0
86     // Use the raw opcode for xgetbv for compatibility with older toolchains.
87     __asm _emit 0x0f __asm _emit 0x01 __asm _emit 0xd0
88     mov eax_, eax
89     mov edx_, edx
90   }
91   return ((uint64_t)edx_ << 32) | eax_;
92 }
93 #else
94 #define xgetbv() 0U  // no AVX for older x64 or unrecognized toolchains.
95 #endif
96 
97 #if defined(__i386__) || defined(__x86_64__) || defined(WEBP_MSC_SSE2)
98 
99 // helper function for run-time detection of slow SSSE3 platforms
CheckSlowModel(int info)100 static int CheckSlowModel(int info) {
101   // Table listing display models with longer latencies for the bsr instruction
102   // (ie 2 cycles vs 10/16 cycles) and some SSSE3 instructions like pshufb.
103   // Refer to Intel 64 and IA-32 Architectures Optimization Reference Manual.
104   static const uint8_t kSlowModels[] = {
105     0x37, 0x4a, 0x4d,  // Silvermont Microarchitecture
106     0x1c, 0x26, 0x27   // Atom Microarchitecture
107   };
108   const uint32_t model = ((info & 0xf0000) >> 12) | ((info >> 4) & 0xf);
109   const uint32_t family = (info >> 8) & 0xf;
110   if (family == 0x06) {
111     size_t i;
112     for (i = 0; i < sizeof(kSlowModels) / sizeof(kSlowModels[0]); ++i) {
113       if (model == kSlowModels[i]) return 1;
114     }
115   }
116   return 0;
117 }
118 
x86CPUInfo(CPUFeature feature)119 static int x86CPUInfo(CPUFeature feature) {
120   int max_cpuid_value;
121   int cpu_info[4];
122   int is_intel = 0;
123 
124   // get the highest feature value cpuid supports
125   GetCPUInfo(cpu_info, 0);
126   max_cpuid_value = cpu_info[0];
127   if (max_cpuid_value < 1) {
128     return 0;
129   } else {
130     const int VENDOR_ID_INTEL_EBX = 0x756e6547;  // uneG
131     const int VENDOR_ID_INTEL_EDX = 0x49656e69;  // Ieni
132     const int VENDOR_ID_INTEL_ECX = 0x6c65746e;  // letn
133     is_intel = (cpu_info[1] == VENDOR_ID_INTEL_EBX &&
134                 cpu_info[2] == VENDOR_ID_INTEL_ECX &&
135                 cpu_info[3] == VENDOR_ID_INTEL_EDX);    // genuine Intel?
136   }
137 
138   GetCPUInfo(cpu_info, 1);
139   if (feature == kSSE2) {
140     return !!(cpu_info[3] & (1 << 26));
141   }
142   if (feature == kSSE3) {
143     return !!(cpu_info[2] & (1 << 0));
144   }
145   if (feature == kSlowSSSE3) {
146     if (is_intel && (cpu_info[2] & (1 << 9))) {   // SSSE3?
147       return CheckSlowModel(cpu_info[0]);
148     }
149     return 0;
150   }
151 
152   if (feature == kSSE4_1) {
153     return !!(cpu_info[2] & (1 << 19));
154   }
155   if (feature == kAVX) {
156     // bits 27 (OSXSAVE) & 28 (256-bit AVX)
157     if ((cpu_info[2] & 0x18000000) == 0x18000000) {
158       // XMM state and YMM state enabled by the OS.
159       return (xgetbv() & 0x6) == 0x6;
160     }
161   }
162   if (feature == kAVX2) {
163     if (x86CPUInfo(kAVX) && max_cpuid_value >= 7) {
164       GetCPUInfo(cpu_info, 7);
165       return !!(cpu_info[1] & (1 << 5));
166     }
167   }
168   return 0;
169 }
170 VP8CPUInfo VP8GetCPUInfo = x86CPUInfo;
171 #elif defined(WEBP_ANDROID_NEON)  // NB: needs to be before generic NEON test.
AndroidCPUInfo(CPUFeature feature)172 static int AndroidCPUInfo(CPUFeature feature) {
173   const AndroidCpuFamily cpu_family = android_getCpuFamily();
174   const uint64_t cpu_features = android_getCpuFeatures();
175   if (feature == kNEON) {
176     return (cpu_family == ANDROID_CPU_FAMILY_ARM &&
177             0 != (cpu_features & ANDROID_CPU_ARM_FEATURE_NEON));
178   }
179   return 0;
180 }
181 VP8CPUInfo VP8GetCPUInfo = AndroidCPUInfo;
182 #elif defined(WEBP_USE_NEON)
183 // define a dummy function to enable turning off NEON at runtime by setting
184 // VP8DecGetCPUInfo = NULL
armCPUInfo(CPUFeature feature)185 static int armCPUInfo(CPUFeature feature) {
186   if (feature != kNEON) return 0;
187 #if defined(__linux__) && defined(WEBP_HAVE_NEON_RTCD)
188   {
189     int has_neon = 0;
190     char line[200];
191     FILE* const cpuinfo = fopen("/proc/cpuinfo", "r");
192     if (cpuinfo == NULL) return 0;
193     while (fgets(line, sizeof(line), cpuinfo)) {
194       if (!strncmp(line, "Features", 8)) {
195         if (strstr(line, " neon ") != NULL) {
196           has_neon = 1;
197           break;
198         }
199       }
200     }
201     fclose(cpuinfo);
202     return has_neon;
203   }
204 #else
205   return 1;
206 #endif
207 }
208 VP8CPUInfo VP8GetCPUInfo = armCPUInfo;
209 #elif defined(WEBP_USE_MIPS32) || defined(WEBP_USE_MIPS_DSP_R2) || \
210       defined(WEBP_USE_MSA)
mipsCPUInfo(CPUFeature feature)211 static int mipsCPUInfo(CPUFeature feature) {
212   if ((feature == kMIPS32) || (feature == kMIPSdspR2) || (feature == kMSA)) {
213     return 1;
214   } else {
215     return 0;
216   }
217 
218 }
219 VP8CPUInfo VP8GetCPUInfo = mipsCPUInfo;
220 #else
221 VP8CPUInfo VP8GetCPUInfo = NULL;
222 #endif
223