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1 /*
2  *  Copyright (c) 2010 The WebM 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 #ifndef VPX_VPX_PORTS_X86_H_
12 #define VPX_VPX_PORTS_X86_H_
13 #include <stdlib.h>
14 
15 #if defined(_MSC_VER)
16 #include <intrin.h> /* For __cpuidex, __rdtsc */
17 #endif
18 
19 #include "vpx_config.h"
20 #include "vpx/vpx_integer.h"
21 
22 #ifdef __cplusplus
23 extern "C" {
24 #endif
25 
26 typedef enum {
27   VPX_CPU_UNKNOWN = -1,
28   VPX_CPU_AMD,
29   VPX_CPU_AMD_OLD,
30   VPX_CPU_CENTAUR,
31   VPX_CPU_CYRIX,
32   VPX_CPU_INTEL,
33   VPX_CPU_NEXGEN,
34   VPX_CPU_NSC,
35   VPX_CPU_RISE,
36   VPX_CPU_SIS,
37   VPX_CPU_TRANSMETA,
38   VPX_CPU_TRANSMETA_OLD,
39   VPX_CPU_UMC,
40   VPX_CPU_VIA,
41 
42   VPX_CPU_LAST
43 } vpx_cpu_t;
44 
45 #if defined(__GNUC__) && __GNUC__ || defined(__ANDROID__)
46 #if ARCH_X86_64
47 #define cpuid(func, func2, ax, bx, cx, dx)                      \
48   __asm__ __volatile__("cpuid           \n\t"                   \
49                        : "=a"(ax), "=b"(bx), "=c"(cx), "=d"(dx) \
50                        : "a"(func), "c"(func2));
51 #else
52 #define cpuid(func, func2, ax, bx, cx, dx)     \
53   __asm__ __volatile__(                        \
54       "mov %%ebx, %%edi   \n\t"                \
55       "cpuid              \n\t"                \
56       "xchg %%edi, %%ebx  \n\t"                \
57       : "=a"(ax), "=D"(bx), "=c"(cx), "=d"(dx) \
58       : "a"(func), "c"(func2));
59 #endif
60 #elif defined(__SUNPRO_C) || \
61     defined(__SUNPRO_CC) /* end __GNUC__ or __ANDROID__*/
62 #if ARCH_X86_64
63 #define cpuid(func, func2, ax, bx, cx, dx)     \
64   asm volatile(                                \
65       "xchg %rsi, %rbx \n\t"                   \
66       "cpuid           \n\t"                   \
67       "movl %ebx, %edi \n\t"                   \
68       "xchg %rsi, %rbx \n\t"                   \
69       : "=a"(ax), "=D"(bx), "=c"(cx), "=d"(dx) \
70       : "a"(func), "c"(func2));
71 #else
72 #define cpuid(func, func2, ax, bx, cx, dx)     \
73   asm volatile(                                \
74       "pushl %ebx       \n\t"                  \
75       "cpuid            \n\t"                  \
76       "movl %ebx, %edi  \n\t"                  \
77       "popl %ebx        \n\t"                  \
78       : "=a"(ax), "=D"(bx), "=c"(cx), "=d"(dx) \
79       : "a"(func), "c"(func2));
80 #endif
81 #else /* end __SUNPRO__ */
82 #if ARCH_X86_64
83 #if defined(_MSC_VER) && _MSC_VER > 1500
84 #define cpuid(func, func2, a, b, c, d) \
85   do {                                 \
86     int regs[4];                       \
87     __cpuidex(regs, func, func2);      \
88     a = regs[0];                       \
89     b = regs[1];                       \
90     c = regs[2];                       \
91     d = regs[3];                       \
92   } while (0)
93 #else
94 #define cpuid(func, func2, a, b, c, d) \
95   do {                                 \
96     int regs[4];                       \
97     __cpuid(regs, func);               \
98     a = regs[0];                       \
99     b = regs[1];                       \
100     c = regs[2];                       \
101     d = regs[3];                       \
102   } while (0)
103 #endif
104 #else
105 #define cpuid(func, func2, a, b, c, d)                              \
106   __asm mov eax, func __asm mov ecx, func2 __asm cpuid __asm mov a, \
107       eax __asm mov b, ebx __asm mov c, ecx __asm mov d, edx
108 #endif
109 #endif /* end others */
110 
111 // NaCl has no support for xgetbv or the raw opcode.
112 #if !defined(__native_client__) && (defined(__i386__) || defined(__x86_64__))
xgetbv(void)113 static INLINE uint64_t xgetbv(void) {
114   const uint32_t ecx = 0;
115   uint32_t eax, edx;
116   // Use the raw opcode for xgetbv for compatibility with older toolchains.
117   __asm__ volatile(".byte 0x0f, 0x01, 0xd0\n"
118                    : "=a"(eax), "=d"(edx)
119                    : "c"(ecx));
120   return ((uint64_t)edx << 32) | eax;
121 }
122 #elif (defined(_M_X64) || defined(_M_IX86)) && defined(_MSC_FULL_VER) && \
123     _MSC_FULL_VER >= 160040219  // >= VS2010 SP1
124 #include <immintrin.h>
125 #define xgetbv() _xgetbv(0)
126 #elif defined(_MSC_VER) && defined(_M_IX86)
xgetbv(void)127 static INLINE uint64_t xgetbv(void) {
128   uint32_t eax_, edx_;
129   __asm {
130     xor ecx, ecx  // ecx = 0
131     // Use the raw opcode for xgetbv for compatibility with older toolchains.
132     __asm _emit 0x0f __asm _emit 0x01 __asm _emit 0xd0
133     mov eax_, eax
134     mov edx_, edx
135   }
136   return ((uint64_t)edx_ << 32) | eax_;
137 }
138 #else
139 #define xgetbv() 0U  // no AVX for older x64 or unrecognized toolchains.
140 #endif
141 
142 #if defined(_MSC_VER) && _MSC_VER >= 1700
143 #undef NOMINMAX
144 #define NOMINMAX
145 #ifndef WIN32_LEAN_AND_MEAN
146 #define WIN32_LEAN_AND_MEAN
147 #endif
148 #include <windows.h>
149 #if WINAPI_FAMILY_PARTITION(WINAPI_FAMILY_APP)
150 #define getenv(x) NULL
151 #endif
152 #endif
153 
154 #define HAS_MMX 0x001
155 #define HAS_SSE 0x002
156 #define HAS_SSE2 0x004
157 #define HAS_SSE3 0x008
158 #define HAS_SSSE3 0x010
159 #define HAS_SSE4_1 0x020
160 #define HAS_AVX 0x040
161 #define HAS_AVX2 0x080
162 #define HAS_AVX512 0x100
163 #ifndef BIT
164 #define BIT(n) (1u << n)
165 #endif
166 
x86_simd_caps(void)167 static INLINE int x86_simd_caps(void) {
168   unsigned int flags = 0;
169   unsigned int mask = ~0;
170   unsigned int max_cpuid_val, reg_eax, reg_ebx, reg_ecx, reg_edx;
171   char *env;
172   (void)reg_ebx;
173 
174   /* See if the CPU capabilities are being overridden by the environment */
175   env = getenv("VPX_SIMD_CAPS");
176 
177   if (env && *env) return (int)strtol(env, NULL, 0);
178 
179   env = getenv("VPX_SIMD_CAPS_MASK");
180 
181   if (env && *env) mask = (unsigned int)strtoul(env, NULL, 0);
182 
183   /* Ensure that the CPUID instruction supports extended features */
184   cpuid(0, 0, max_cpuid_val, reg_ebx, reg_ecx, reg_edx);
185 
186   if (max_cpuid_val < 1) return 0;
187 
188   /* Get the standard feature flags */
189   cpuid(1, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
190 
191   if (reg_edx & BIT(23)) flags |= HAS_MMX;
192 
193   if (reg_edx & BIT(25)) flags |= HAS_SSE; /* aka xmm */
194 
195   if (reg_edx & BIT(26)) flags |= HAS_SSE2; /* aka wmt */
196 
197   if (reg_ecx & BIT(0)) flags |= HAS_SSE3;
198 
199   if (reg_ecx & BIT(9)) flags |= HAS_SSSE3;
200 
201   if (reg_ecx & BIT(19)) flags |= HAS_SSE4_1;
202 
203   // bits 27 (OSXSAVE) & 28 (256-bit AVX)
204   if ((reg_ecx & (BIT(27) | BIT(28))) == (BIT(27) | BIT(28))) {
205     if ((xgetbv() & 0x6) == 0x6) {
206       flags |= HAS_AVX;
207 
208       if (max_cpuid_val >= 7) {
209         /* Get the leaf 7 feature flags. Needed to check for AVX2 support */
210         cpuid(7, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
211 
212         if (reg_ebx & BIT(5)) flags |= HAS_AVX2;
213 
214         // bits 16 (AVX-512F) & 17 (AVX-512DQ) & 28 (AVX-512CD) &
215         // 30 (AVX-512BW) & 32 (AVX-512VL)
216         if ((reg_ebx & (BIT(16) | BIT(17) | BIT(28) | BIT(30) | BIT(31))) ==
217             (BIT(16) | BIT(17) | BIT(28) | BIT(30) | BIT(31)))
218           flags |= HAS_AVX512;
219       }
220     }
221   }
222 
223   return flags & mask;
224 }
225 
226 // Fine-Grain Measurement Functions
227 //
228 // If you are timing a small region of code, access the timestamp counter
229 // (TSC) via:
230 //
231 // unsigned int start = x86_tsc_start();
232 //   ...
233 // unsigned int end = x86_tsc_end();
234 // unsigned int diff = end - start;
235 //
236 // The start/end functions introduce a few more instructions than using
237 // x86_readtsc directly, but prevent the CPU's out-of-order execution from
238 // affecting the measurement (by having earlier/later instructions be evaluated
239 // in the time interval). See the white paper, "How to Benchmark Code
240 // Execution Times on Intel® IA-32 and IA-64 Instruction Set Architectures" by
241 // Gabriele Paoloni for more information.
242 //
243 // If you are timing a large function (CPU time > a couple of seconds), use
244 // x86_readtsc64 to read the timestamp counter in a 64-bit integer. The
245 // out-of-order leakage that can occur is minimal compared to total runtime.
x86_readtsc(void)246 static INLINE unsigned int x86_readtsc(void) {
247 #if defined(__GNUC__) && __GNUC__
248   unsigned int tsc;
249   __asm__ __volatile__("rdtsc\n\t" : "=a"(tsc) :);
250   return tsc;
251 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
252   unsigned int tsc;
253   asm volatile("rdtsc\n\t" : "=a"(tsc) :);
254   return tsc;
255 #else
256 #if ARCH_X86_64
257   return (unsigned int)__rdtsc();
258 #else
259   __asm rdtsc;
260 #endif
261 #endif
262 }
263 // 64-bit CPU cycle counter
x86_readtsc64(void)264 static INLINE uint64_t x86_readtsc64(void) {
265 #if defined(__GNUC__) && __GNUC__
266   uint32_t hi, lo;
267   __asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
268   return ((uint64_t)hi << 32) | lo;
269 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
270   uint_t hi, lo;
271   asm volatile("rdtsc\n\t" : "=a"(lo), "=d"(hi));
272   return ((uint64_t)hi << 32) | lo;
273 #else
274 #if ARCH_X86_64
275   return (uint64_t)__rdtsc();
276 #else
277   __asm rdtsc;
278 #endif
279 #endif
280 }
281 
282 // 32-bit CPU cycle counter with a partial fence against out-of-order execution.
x86_readtscp(void)283 static INLINE unsigned int x86_readtscp(void) {
284 #if defined(__GNUC__) && __GNUC__
285   unsigned int tscp;
286   __asm__ __volatile__("rdtscp\n\t" : "=a"(tscp) :);
287   return tscp;
288 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
289   unsigned int tscp;
290   asm volatile("rdtscp\n\t" : "=a"(tscp) :);
291   return tscp;
292 #elif defined(_MSC_VER)
293   unsigned int ui;
294   return (unsigned int)__rdtscp(&ui);
295 #else
296 #if ARCH_X86_64
297   return (unsigned int)__rdtscp();
298 #else
299   __asm rdtscp;
300 #endif
301 #endif
302 }
303 
x86_tsc_start(void)304 static INLINE unsigned int x86_tsc_start(void) {
305   unsigned int reg_eax, reg_ebx, reg_ecx, reg_edx;
306   cpuid(0, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
307   return x86_readtsc();
308 }
309 
x86_tsc_end(void)310 static INLINE unsigned int x86_tsc_end(void) {
311   uint32_t v = x86_readtscp();
312   unsigned int reg_eax, reg_ebx, reg_ecx, reg_edx;
313   cpuid(0, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
314   return v;
315 }
316 
317 #if defined(__GNUC__) && __GNUC__
318 #define x86_pause_hint() __asm__ __volatile__("pause \n\t")
319 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
320 #define x86_pause_hint() asm volatile("pause \n\t")
321 #else
322 #if ARCH_X86_64
323 #define x86_pause_hint() _mm_pause();
324 #else
325 #define x86_pause_hint() __asm pause
326 #endif
327 #endif
328 
329 #if defined(__GNUC__) && __GNUC__
x87_set_control_word(unsigned short mode)330 static void x87_set_control_word(unsigned short mode) {
331   __asm__ __volatile__("fldcw %0" : : "m"(*&mode));
332 }
x87_get_control_word(void)333 static unsigned short x87_get_control_word(void) {
334   unsigned short mode;
335   __asm__ __volatile__("fstcw %0\n\t" : "=m"(*&mode) :);
336   return mode;
337 }
338 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
x87_set_control_word(unsigned short mode)339 static void x87_set_control_word(unsigned short mode) {
340   asm volatile("fldcw %0" : : "m"(*&mode));
341 }
x87_get_control_word(void)342 static unsigned short x87_get_control_word(void) {
343   unsigned short mode;
344   asm volatile("fstcw %0\n\t" : "=m"(*&mode) :);
345   return mode;
346 }
347 #elif ARCH_X86_64
348 /* No fldcw intrinsics on Windows x64, punt to external asm */
349 extern void vpx_winx64_fldcw(unsigned short mode);
350 extern unsigned short vpx_winx64_fstcw(void);
351 #define x87_set_control_word vpx_winx64_fldcw
352 #define x87_get_control_word vpx_winx64_fstcw
353 #else
x87_set_control_word(unsigned short mode)354 static void x87_set_control_word(unsigned short mode) {
355   __asm { fldcw mode }
356 }
x87_get_control_word(void)357 static unsigned short x87_get_control_word(void) {
358   unsigned short mode;
359   __asm { fstcw mode }
360   return mode;
361 }
362 #endif
363 
x87_set_double_precision(void)364 static INLINE unsigned int x87_set_double_precision(void) {
365   unsigned int mode = x87_get_control_word();
366   // Intel 64 and IA-32 Architectures Developer's Manual: Vol. 1
367   // https://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-1-manual.pdf
368   // 8.1.5.2 Precision Control Field
369   // Bits 8 and 9 (0x300) of the x87 FPU Control Word ("Precision Control")
370   // determine the number of bits used in floating point calculations. To match
371   // later SSE instructions restrict x87 operations to Double Precision (0x200).
372   // Precision                     PC Field
373   // Single Precision (24-Bits)    00B
374   // Reserved                      01B
375   // Double Precision (53-Bits)    10B
376   // Extended Precision (64-Bits)  11B
377   x87_set_control_word((mode & ~0x300) | 0x200);
378   return mode;
379 }
380 
381 #ifdef __cplusplus
382 }  // extern "C"
383 #endif
384 
385 #endif  // VPX_VPX_PORTS_X86_H_
386