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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 // For ArmCpuCaps() but unittested on all platforms
23 #include <stdio.h>  // For fopen()
24 #include <string.h>
25 
26 #ifdef __cplusplus
27 namespace libyuv {
28 extern "C" {
29 #endif
30 
31 // For functions that use the stack and have runtime checks for overflow,
32 // use SAFEBUFFERS to avoid additional check.
33 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) && \
34     !defined(__clang__)
35 #define SAFEBUFFERS __declspec(safebuffers)
36 #else
37 #define SAFEBUFFERS
38 #endif
39 
40 // cpu_info_ variable for SIMD instruction sets detected.
41 LIBYUV_API int cpu_info_ = 0;
42 
43 // TODO(fbarchard): Consider using int for cpuid so casting is not needed.
44 // Low level cpuid for X86.
45 #if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \
46      defined(__x86_64__)) &&                                     \
47     !defined(__pnacl__) && !defined(__CLR_VER)
48 LIBYUV_API
CpuId(int info_eax,int info_ecx,int * cpu_info)49 void CpuId(int info_eax, int info_ecx, int* cpu_info) {
50 #if defined(_MSC_VER)
51 // Visual C version uses intrinsic or inline x86 assembly.
52 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
53   __cpuidex(cpu_info, info_eax, info_ecx);
54 #elif defined(_M_IX86)
55   __asm {
56     mov        eax, info_eax
57     mov        ecx, info_ecx
58     mov        edi, cpu_info
59     cpuid
60     mov        [edi], eax
61     mov        [edi + 4], ebx
62     mov        [edi + 8], ecx
63     mov        [edi + 12], edx
64   }
65 #else  // Visual C but not x86
66   if (info_ecx == 0) {
67     __cpuid(cpu_info, info_eax);
68   } else {
69     cpu_info[3] = cpu_info[2] = cpu_info[1] = cpu_info[0] = 0u;
70   }
71 #endif
72 // GCC version uses inline x86 assembly.
73 #else  // defined(_MSC_VER)
74   int info_ebx, info_edx;
75   asm volatile(
76 #if defined(__i386__) && defined(__PIC__)
77       // Preserve ebx for fpic 32 bit.
78       "mov         %%ebx, %%edi                  \n"
79       "cpuid                                     \n"
80       "xchg        %%edi, %%ebx                  \n"
81       : "=D"(info_ebx),
82 #else
83       "cpuid                                     \n"
84       : "=b"(info_ebx),
85 #endif  //  defined( __i386__) && defined(__PIC__)
86         "+a"(info_eax), "+c"(info_ecx), "=d"(info_edx));
87   cpu_info[0] = info_eax;
88   cpu_info[1] = info_ebx;
89   cpu_info[2] = info_ecx;
90   cpu_info[3] = info_edx;
91 #endif  // defined(_MSC_VER)
92 }
93 #else  // (defined(_M_IX86) || defined(_M_X64) ...
94 LIBYUV_API
CpuId(int eax,int ecx,int * cpu_info)95 void CpuId(int eax, int ecx, int* cpu_info) {
96   (void)eax;
97   (void)ecx;
98   cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0;
99 }
100 #endif
101 
102 // For VS2010 and earlier emit can be used:
103 //   _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0  // For VS2010 and earlier.
104 //  __asm {
105 //    xor        ecx, ecx    // xcr 0
106 //    xgetbv
107 //    mov        xcr0, eax
108 //  }
109 // For VS2013 and earlier 32 bit, the _xgetbv(0) optimizer produces bad code.
110 // https://code.google.com/p/libyuv/issues/detail?id=529
111 #if defined(_M_IX86) && (_MSC_VER < 1900)
112 #pragma optimize("g", off)
113 #endif
114 #if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \
115      defined(__x86_64__)) &&                                     \
116     !defined(__pnacl__) && !defined(__CLR_VER) && !defined(__native_client__)
117 // X86 CPUs have xgetbv to detect OS saves high parts of ymm registers.
GetXCR0()118 int GetXCR0() {
119   int xcr0 = 0;
120 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
121   xcr0 = (int)_xgetbv(0);  // VS2010 SP1 required.  NOLINT
122 #elif defined(__i386__) || defined(__x86_64__)
123   asm(".byte 0x0f, 0x01, 0xd0" : "=a"(xcr0) : "c"(0) : "%edx");
124 #endif  // defined(__i386__) || defined(__x86_64__)
125   return xcr0;
126 }
127 #else
128 // xgetbv unavailable to query for OSSave support.  Return 0.
129 #define GetXCR0() 0
130 #endif  // defined(_M_IX86) || defined(_M_X64) ..
131 // Return optimization to previous setting.
132 #if defined(_M_IX86) && (_MSC_VER < 1900)
133 #pragma optimize("g", on)
134 #endif
135 
136 // Based on libvpx arm_cpudetect.c
137 // For Arm, but public to allow testing on any CPU
ArmCpuCaps(const char * cpuinfo_name)138 LIBYUV_API SAFEBUFFERS int ArmCpuCaps(const char* cpuinfo_name) {
139   char cpuinfo_line[512];
140   FILE* f = fopen(cpuinfo_name, "r");
141   if (!f) {
142     // Assume Neon if /proc/cpuinfo is unavailable.
143     // This will occur for Chrome sandbox for Pepper or Render process.
144     return kCpuHasNEON;
145   }
146   while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) {
147     if (memcmp(cpuinfo_line, "Features", 8) == 0) {
148       char* p = strstr(cpuinfo_line, " neon");
149       if (p && (p[5] == ' ' || p[5] == '\n')) {
150         fclose(f);
151         return kCpuHasNEON;
152       }
153       // aarch64 uses asimd for Neon.
154       p = strstr(cpuinfo_line, " asimd");
155       if (p) {
156         fclose(f);
157         return kCpuHasNEON;
158       }
159     }
160   }
161   fclose(f);
162   return 0;
163 }
164 
165 // TODO(fbarchard): Consider read_msa_ir().
MipsCpuCaps(const char * cpuinfo_name)166 LIBYUV_API SAFEBUFFERS int MipsCpuCaps(const char* cpuinfo_name) {
167   char cpuinfo_line[512];
168   int flag = 0x0;
169   FILE* f = fopen(cpuinfo_name, "r");
170   if (!f) {
171     // Assume nothing if /proc/cpuinfo is unavailable.
172     // This will occur for Chrome sandbox for Pepper or Render process.
173     return 0;
174   }
175   while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) {
176     if (memcmp(cpuinfo_line, "cpu model", 9) == 0) {
177       // Workaround early kernel without MSA in ASEs line.
178       if (strstr(cpuinfo_line, "Loongson-2K")) {
179         flag |= kCpuHasMSA;
180       }
181     }
182     if (memcmp(cpuinfo_line, "ASEs implemented", 16) == 0) {
183       if (strstr(cpuinfo_line, "msa")) {
184         flag |= kCpuHasMSA;
185       }
186       // ASEs is the last line, so we can break here.
187       break;
188     }
189   }
190   fclose(f);
191   return flag;
192 }
193 
194 // TODO(fbarchard): Consider read_loongarch_ir().
195 #define LOONGARCH_CFG2 0x2
196 #define LOONGARCH_CFG2_LSX (1 << 6)
197 #define LOONGARCH_CFG2_LASX (1 << 7)
198 
199 #if defined(__loongarch__)
LoongarchCpuCaps(void)200 LIBYUV_API SAFEBUFFERS int LoongarchCpuCaps(void) {
201   int flag = 0x0;
202   uint32_t cfg2 = 0;
203 
204   __asm__ volatile("cpucfg %0, %1 \n\t" : "+&r"(cfg2) : "r"(LOONGARCH_CFG2));
205 
206   if (cfg2 & LOONGARCH_CFG2_LSX)
207     flag |= kCpuHasLSX;
208 
209   if (cfg2 & LOONGARCH_CFG2_LASX)
210     flag |= kCpuHasLASX;
211   return flag;
212 }
213 #endif
214 
GetCpuFlags(void)215 static SAFEBUFFERS int GetCpuFlags(void) {
216   int cpu_info = 0;
217 #if !defined(__pnacl__) && !defined(__CLR_VER) &&                   \
218     (defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || \
219      defined(_M_IX86))
220   int cpu_info0[4] = {0, 0, 0, 0};
221   int cpu_info1[4] = {0, 0, 0, 0};
222   int cpu_info7[4] = {0, 0, 0, 0};
223   CpuId(0, 0, cpu_info0);
224   CpuId(1, 0, cpu_info1);
225   if (cpu_info0[0] >= 7) {
226     CpuId(7, 0, cpu_info7);
227   }
228   cpu_info = kCpuHasX86 | ((cpu_info1[3] & 0x04000000) ? kCpuHasSSE2 : 0) |
229              ((cpu_info1[2] & 0x00000200) ? kCpuHasSSSE3 : 0) |
230              ((cpu_info1[2] & 0x00080000) ? kCpuHasSSE41 : 0) |
231              ((cpu_info1[2] & 0x00100000) ? kCpuHasSSE42 : 0) |
232              ((cpu_info7[1] & 0x00000200) ? kCpuHasERMS : 0);
233 
234   // AVX requires OS saves YMM registers.
235   if (((cpu_info1[2] & 0x1c000000) == 0x1c000000) &&  // AVX and OSXSave
236       ((GetXCR0() & 6) == 6)) {  // Test OS saves YMM registers
237     cpu_info |= kCpuHasAVX | ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) |
238                 ((cpu_info1[2] & 0x00001000) ? kCpuHasFMA3 : 0) |
239                 ((cpu_info1[2] & 0x20000000) ? kCpuHasF16C : 0);
240 
241     // Detect AVX512bw
242     if ((GetXCR0() & 0xe0) == 0xe0) {
243       cpu_info |= (cpu_info7[1] & 0x40000000) ? kCpuHasAVX512BW : 0;
244       cpu_info |= (cpu_info7[1] & 0x80000000) ? kCpuHasAVX512VL : 0;
245       cpu_info |= (cpu_info7[2] & 0x00000002) ? kCpuHasAVX512VBMI : 0;
246       cpu_info |= (cpu_info7[2] & 0x00000040) ? kCpuHasAVX512VBMI2 : 0;
247       cpu_info |= (cpu_info7[2] & 0x00000800) ? kCpuHasAVX512VNNI : 0;
248       cpu_info |= (cpu_info7[2] & 0x00001000) ? kCpuHasAVX512VBITALG : 0;
249       cpu_info |= (cpu_info7[2] & 0x00004000) ? kCpuHasAVX512VPOPCNTDQ : 0;
250       cpu_info |= (cpu_info7[2] & 0x00000100) ? kCpuHasGFNI : 0;
251     }
252   }
253 #endif
254 #if defined(__mips__) && defined(__linux__)
255   cpu_info = MipsCpuCaps("/proc/cpuinfo");
256   cpu_info |= kCpuHasMIPS;
257 #endif
258 #if defined(__loongarch__) && defined(__linux__)
259   cpu_info = LoongarchCpuCaps();
260   cpu_info |= kCpuHasLOONGARCH;
261 #endif
262 #if defined(__arm__) || defined(__aarch64__)
263 // gcc -mfpu=neon defines __ARM_NEON__
264 // __ARM_NEON__ generates code that requires Neon.  NaCL also requires Neon.
265 // For Linux, /proc/cpuinfo can be tested but without that assume Neon.
266 #if defined(__ARM_NEON__) || defined(__native_client__) || !defined(__linux__)
267   cpu_info = kCpuHasNEON;
268 // For aarch64(arm64), /proc/cpuinfo's feature is not complete, e.g. no neon
269 // flag in it.
270 // So for aarch64, neon enabling is hard coded here.
271 #endif
272 #if defined(__aarch64__)
273   cpu_info = kCpuHasNEON;
274 #else
275   // Linux arm parse text file for neon detect.
276   cpu_info = ArmCpuCaps("/proc/cpuinfo");
277 #endif
278   cpu_info |= kCpuHasARM;
279 #endif  // __arm__
280   cpu_info |= kCpuInitialized;
281   return cpu_info;
282 }
283 
284 // Note that use of this function is not thread safe.
285 LIBYUV_API
MaskCpuFlags(int enable_flags)286 int MaskCpuFlags(int enable_flags) {
287   int cpu_info = GetCpuFlags() & enable_flags;
288   SetCpuFlags(cpu_info);
289   return cpu_info;
290 }
291 
292 LIBYUV_API
InitCpuFlags(void)293 int InitCpuFlags(void) {
294   return MaskCpuFlags(-1);
295 }
296 
297 #ifdef __cplusplus
298 }  // extern "C"
299 }  // namespace libyuv
300 #endif
301