1 /*
2 * Copyright 2011 The LibYuv Project Authors. All rights reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "libyuv/cpu_id.h"
12
13 #if defined(_MSC_VER)
14 #include <intrin.h> // For __cpuidex()
15 #endif
16 #if !defined(__pnacl__) && !defined(__CLR_VER) && \
17 !defined(__native_client__) && (defined(_M_IX86) || defined(_M_X64)) && \
18 defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
19 #include <immintrin.h> // For _xgetbv()
20 #endif
21
22 #if !defined(__native_client__)
23 #include <stdlib.h> // For getenv()
24 #endif
25
26 // For ArmCpuCaps() but unittested on all platforms
27 #include <stdio.h>
28 #include <string.h>
29
30 #include "libyuv/basic_types.h" // For CPU_X86
31
32 #ifdef __cplusplus
33 namespace libyuv {
34 extern "C" {
35 #endif
36
37 // For functions that use the stack and have runtime checks for overflow,
38 // use SAFEBUFFERS to avoid additional check.
39 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) && \
40 !defined(__clang__)
41 #define SAFEBUFFERS __declspec(safebuffers)
42 #else
43 #define SAFEBUFFERS
44 #endif
45
46 // Low level cpuid for X86.
47 #if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \
48 defined(__x86_64__)) && \
49 !defined(__pnacl__) && !defined(__CLR_VER)
50 LIBYUV_API
CpuId(uint32 info_eax,uint32 info_ecx,uint32 * cpu_info)51 void CpuId(uint32 info_eax, uint32 info_ecx, uint32* cpu_info) {
52 #if defined(_MSC_VER)
53 // Visual C version uses intrinsic or inline x86 assembly.
54 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
55 __cpuidex((int*)(cpu_info), info_eax, info_ecx);
56 #elif defined(_M_IX86)
57 __asm {
58 mov eax, info_eax
59 mov ecx, info_ecx
60 mov edi, cpu_info
61 cpuid
62 mov [edi], eax
63 mov [edi + 4], ebx
64 mov [edi + 8], ecx
65 mov [edi + 12], edx
66 }
67 #else // Visual C but not x86
68 if (info_ecx == 0) {
69 __cpuid((int*)(cpu_info), info_eax);
70 } else {
71 cpu_info[3] = cpu_info[2] = cpu_info[1] = cpu_info[0] = 0u;
72 }
73 #endif
74 // GCC version uses inline x86 assembly.
75 #else // defined(_MSC_VER)
76 uint32 info_ebx, info_edx;
77 asm volatile(
78 #if defined(__i386__) && defined(__PIC__)
79 // Preserve ebx for fpic 32 bit.
80 "mov %%ebx, %%edi \n"
81 "cpuid \n"
82 "xchg %%edi, %%ebx \n"
83 : "=D"(info_ebx),
84 #else
85 "cpuid \n"
86 : "=b"(info_ebx),
87 #endif // defined( __i386__) && defined(__PIC__)
88 "+a"(info_eax), "+c"(info_ecx), "=d"(info_edx));
89 cpu_info[0] = info_eax;
90 cpu_info[1] = info_ebx;
91 cpu_info[2] = info_ecx;
92 cpu_info[3] = info_edx;
93 #endif // defined(_MSC_VER)
94 }
95 #else // (defined(_M_IX86) || defined(_M_X64) ...
96 LIBYUV_API
97 void CpuId(uint32 eax, uint32 ecx, uint32* cpu_info) {
98 (void)eax;
99 (void)ecx;
100 cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0;
101 }
102 #endif
103
104 // For VS2010 and earlier emit can be used:
105 // _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0 // For VS2010 and earlier.
106 // __asm {
107 // xor ecx, ecx // xcr 0
108 // xgetbv
109 // mov xcr0, eax
110 // }
111 // For VS2013 and earlier 32 bit, the _xgetbv(0) optimizer produces bad code.
112 // https://code.google.com/p/libyuv/issues/detail?id=529
113 #if defined(_M_IX86) && (_MSC_VER < 1900)
114 #pragma optimize("g", off)
115 #endif
116 #if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \
117 defined(__x86_64__)) && \
118 !defined(__pnacl__) && !defined(__CLR_VER) && !defined(__native_client__)
119 // X86 CPUs have xgetbv to detect OS saves high parts of ymm registers.
GetXCR0()120 int GetXCR0() {
121 uint32 xcr0 = 0u;
122 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
123 xcr0 = (uint32)(_xgetbv(0)); // VS2010 SP1 required.
124 #elif defined(__i386__) || defined(__x86_64__)
125 asm(".byte 0x0f, 0x01, 0xd0" : "=a"(xcr0) : "c"(0) : "%edx");
126 #endif // defined(__i386__) || defined(__x86_64__)
127 return xcr0;
128 }
129 #else
130 // xgetbv unavailable to query for OSSave support. Return 0.
131 #define GetXCR0() 0
132 #endif // defined(_M_IX86) || defined(_M_X64) ..
133 // Return optimization to previous setting.
134 #if defined(_M_IX86) && (_MSC_VER < 1900)
135 #pragma optimize("g", on)
136 #endif
137
138 // based on libvpx arm_cpudetect.c
139 // For Arm, but public to allow testing on any CPU
ArmCpuCaps(const char * cpuinfo_name)140 LIBYUV_API SAFEBUFFERS int ArmCpuCaps(const char* cpuinfo_name) {
141 char cpuinfo_line[512];
142 FILE* f = fopen(cpuinfo_name, "r");
143 if (!f) {
144 // Assume Neon if /proc/cpuinfo is unavailable.
145 // This will occur for Chrome sandbox for Pepper or Render process.
146 return kCpuHasNEON;
147 }
148 while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) {
149 if (memcmp(cpuinfo_line, "Features", 8) == 0) {
150 char* p = strstr(cpuinfo_line, " neon");
151 if (p && (p[5] == ' ' || p[5] == '\n')) {
152 fclose(f);
153 return kCpuHasNEON;
154 }
155 // aarch64 uses asimd for Neon.
156 p = strstr(cpuinfo_line, " asimd");
157 if (p && (p[6] == ' ' || p[6] == '\n')) {
158 fclose(f);
159 return kCpuHasNEON;
160 }
161 }
162 }
163 fclose(f);
164 return 0;
165 }
166
MipsCpuCaps(const char * cpuinfo_name,const char ase[])167 LIBYUV_API SAFEBUFFERS int MipsCpuCaps(const char* cpuinfo_name,
168 const char ase[]) {
169 char cpuinfo_line[512];
170 int len = (int)strlen(ase);
171 FILE* f = fopen(cpuinfo_name, "r");
172 if (!f) {
173 // ase enabled if /proc/cpuinfo is unavailable.
174 if (strcmp(ase, " msa") == 0) {
175 return kCpuHasMSA;
176 }
177 return kCpuHasDSPR2;
178 }
179 while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) {
180 if (memcmp(cpuinfo_line, "ASEs implemented", 16) == 0) {
181 char* p = strstr(cpuinfo_line, ase);
182 if (p && (p[len] == ' ' || p[len] == '\n')) {
183 fclose(f);
184 if (strcmp(ase, " msa") == 0) {
185 return kCpuHasMSA;
186 }
187 return kCpuHasDSPR2;
188 }
189 }
190 }
191 fclose(f);
192 return 0;
193 }
194
195 // CPU detect function for SIMD instruction sets.
196 LIBYUV_API
197 int cpu_info_ = 0; // cpu_info is not initialized yet.
198
199 // Test environment variable for disabling CPU features. Any non-zero value
200 // to disable. Zero ignored to make it easy to set the variable on/off.
201 #if !defined(__native_client__) && !defined(_M_ARM)
202
TestEnv(const char * name)203 static LIBYUV_BOOL TestEnv(const char* name) {
204 const char* var = getenv(name);
205 if (var) {
206 if (var[0] != '0') {
207 return LIBYUV_TRUE;
208 }
209 }
210 return LIBYUV_FALSE;
211 }
212 #else // nacl does not support getenv().
TestEnv(const char *)213 static LIBYUV_BOOL TestEnv(const char*) {
214 return LIBYUV_FALSE;
215 }
216 #endif
217
InitCpuFlags(void)218 LIBYUV_API SAFEBUFFERS int InitCpuFlags(void) {
219 int cpu_info = 0;
220 #if !defined(__pnacl__) && !defined(__CLR_VER) && defined(CPU_X86)
221 uint32 cpu_info0[4] = {0, 0, 0, 0};
222 uint32 cpu_info1[4] = {0, 0, 0, 0};
223 uint32 cpu_info7[4] = {0, 0, 0, 0};
224 CpuId(0, 0, cpu_info0);
225 CpuId(1, 0, cpu_info1);
226 if (cpu_info0[0] >= 7) {
227 CpuId(7, 0, cpu_info7);
228 }
229 cpu_info = kCpuHasX86 | ((cpu_info1[3] & 0x04000000) ? kCpuHasSSE2 : 0) |
230 ((cpu_info1[2] & 0x00000200) ? kCpuHasSSSE3 : 0) |
231 ((cpu_info1[2] & 0x00080000) ? kCpuHasSSE41 : 0) |
232 ((cpu_info1[2] & 0x00100000) ? kCpuHasSSE42 : 0) |
233 ((cpu_info7[1] & 0x00000200) ? kCpuHasERMS : 0);
234
235 // AVX requires OS saves YMM registers.
236 if (((cpu_info1[2] & 0x1c000000) == 0x1c000000) && // AVX and OSXSave
237 ((GetXCR0() & 6) == 6)) { // Test OS saves YMM registers
238 cpu_info |= kCpuHasAVX | ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) |
239 ((cpu_info1[2] & 0x00001000) ? kCpuHasFMA3 : 0) |
240 ((cpu_info1[2] & 0x20000000) ? kCpuHasF16C : 0);
241
242 // Detect AVX512bw
243 if ((GetXCR0() & 0xe0) == 0xe0) {
244 cpu_info |= (cpu_info7[1] & 0x40000000) ? kCpuHasAVX3 : 0;
245 }
246 }
247
248 // Environment variable overrides for testing.
249 if (TestEnv("LIBYUV_DISABLE_X86")) {
250 cpu_info &= ~kCpuHasX86;
251 }
252 if (TestEnv("LIBYUV_DISABLE_SSE2")) {
253 cpu_info &= ~kCpuHasSSE2;
254 }
255 if (TestEnv("LIBYUV_DISABLE_SSSE3")) {
256 cpu_info &= ~kCpuHasSSSE3;
257 }
258 if (TestEnv("LIBYUV_DISABLE_SSE41")) {
259 cpu_info &= ~kCpuHasSSE41;
260 }
261 if (TestEnv("LIBYUV_DISABLE_SSE42")) {
262 cpu_info &= ~kCpuHasSSE42;
263 }
264 if (TestEnv("LIBYUV_DISABLE_AVX")) {
265 cpu_info &= ~kCpuHasAVX;
266 }
267 if (TestEnv("LIBYUV_DISABLE_AVX2")) {
268 cpu_info &= ~kCpuHasAVX2;
269 }
270 if (TestEnv("LIBYUV_DISABLE_ERMS")) {
271 cpu_info &= ~kCpuHasERMS;
272 }
273 if (TestEnv("LIBYUV_DISABLE_FMA3")) {
274 cpu_info &= ~kCpuHasFMA3;
275 }
276 if (TestEnv("LIBYUV_DISABLE_AVX3")) {
277 cpu_info &= ~kCpuHasAVX3;
278 }
279 if (TestEnv("LIBYUV_DISABLE_F16C")) {
280 cpu_info &= ~kCpuHasF16C;
281 }
282
283 #endif
284 #if defined(__mips__) && defined(__linux__)
285 #if defined(__mips_dspr2)
286 cpu_info |= kCpuHasDSPR2;
287 #endif
288 #if defined(__mips_msa)
289 cpu_info = MipsCpuCaps("/proc/cpuinfo", " msa");
290 #endif
291 cpu_info |= kCpuHasMIPS;
292 if (getenv("LIBYUV_DISABLE_DSPR2")) {
293 cpu_info &= ~kCpuHasDSPR2;
294 }
295 if (getenv("LIBYUV_DISABLE_MSA")) {
296 cpu_info &= ~kCpuHasMSA;
297 }
298 #endif
299 #if defined(__arm__) || defined(__aarch64__)
300 // gcc -mfpu=neon defines __ARM_NEON__
301 // __ARM_NEON__ generates code that requires Neon. NaCL also requires Neon.
302 // For Linux, /proc/cpuinfo can be tested but without that assume Neon.
303 #if defined(__ARM_NEON__) || defined(__native_client__) || !defined(__linux__)
304 cpu_info = kCpuHasNEON;
305 // For aarch64(arm64), /proc/cpuinfo's feature is not complete, e.g. no neon
306 // flag in it.
307 // So for aarch64, neon enabling is hard coded here.
308 #endif
309 #if defined(__aarch64__)
310 cpu_info = kCpuHasNEON;
311 #else
312 // Linux arm parse text file for neon detect.
313 cpu_info = ArmCpuCaps("/proc/cpuinfo");
314 #endif
315 cpu_info |= kCpuHasARM;
316 if (TestEnv("LIBYUV_DISABLE_NEON")) {
317 cpu_info &= ~kCpuHasNEON;
318 }
319 #endif // __arm__
320 if (TestEnv("LIBYUV_DISABLE_ASM")) {
321 cpu_info = 0;
322 }
323 cpu_info |= kCpuInitialized;
324 cpu_info_ = cpu_info;
325 return cpu_info;
326 }
327
328 // Note that use of this function is not thread safe.
329 LIBYUV_API
MaskCpuFlags(int enable_flags)330 void MaskCpuFlags(int enable_flags) {
331 cpu_info_ = InitCpuFlags() & enable_flags;
332 }
333
334 #ifdef __cplusplus
335 } // extern "C"
336 } // namespace libyuv
337 #endif
338