tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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cpu.c (3674B)

      1 /*
      2 * Copyright © 2018, VideoLAN and dav1d authors
      3 * Copyright © 2018, Two Orioles, LLC
      4 * All rights reserved.
      5 *
      6 * Redistribution and use in source and binary forms, with or without
      7 * modification, are permitted provided that the following conditions are met:
      8 *
      9 * 1. Redistributions of source code must retain the above copyright notice, this
     10 *    list of conditions and the following disclaimer.
     11 *
     12 * 2. Redistributions in binary form must reproduce the above copyright notice,
     13 *    this list of conditions and the following disclaimer in the documentation
     14 *    and/or other materials provided with the distribution.
     15 *
     16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
     17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     19 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
     20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26 */
     27 
     28 #include "config.h"
     29 
     30 #include <stdint.h>
     31 #include <string.h>
     32 
     33 #include "common/attributes.h"
     34 
     35 #include "src/cpu.h"
     36 #include "src/x86/cpu.h"
     37 
     38 typedef struct {
     39    uint32_t eax, ebx, edx, ecx;
     40 } CpuidRegisters;
     41 
     42 void dav1d_cpu_cpuid(CpuidRegisters *regs, unsigned leaf, unsigned subleaf);
     43 uint64_t dav1d_cpu_xgetbv(unsigned xcr);
     44 
     45 #define X(reg, mask) (((reg) & (mask)) == (mask))
     46 
     47 COLD unsigned dav1d_get_cpu_flags_x86(void) {
     48    union {
     49        CpuidRegisters r;
     50        struct {
     51            uint32_t max_leaf;
     52            char vendor[12];
     53        };
     54    } cpu;
     55    dav1d_cpu_cpuid(&cpu.r, 0, 0);
     56    unsigned flags = dav1d_get_default_cpu_flags();
     57 
     58    if (cpu.max_leaf >= 1) {
     59        CpuidRegisters r;
     60        dav1d_cpu_cpuid(&r, 1, 0);
     61        const unsigned family = ((r.eax >> 8) & 0x0f) + ((r.eax >> 20) & 0xff);
     62 
     63        if (X(r.edx, 0x06008000)) /* CMOV/SSE/SSE2 */ {
     64            flags |= DAV1D_X86_CPU_FLAG_SSE2;
     65            if (X(r.ecx, 0x00000201)) /* SSE3/SSSE3 */ {
     66                flags |= DAV1D_X86_CPU_FLAG_SSSE3;
     67                if (X(r.ecx, 0x00080000)) /* SSE4.1 */
     68                    flags |= DAV1D_X86_CPU_FLAG_SSE41;
     69            }
     70        }
     71 #if ARCH_X86_64
     72        /* We only support >128-bit SIMD on x86-64. */
     73        if (X(r.ecx, 0x18000000)) /* OSXSAVE/AVX */ {
     74            const uint64_t xcr0 = dav1d_cpu_xgetbv(0);
     75            if (X(xcr0, 0x00000006)) /* XMM/YMM */ {
     76                if (cpu.max_leaf >= 7) {
     77                    dav1d_cpu_cpuid(&r, 7, 0);
     78                    if (X(r.ebx, 0x00000128)) /* BMI1/BMI2/AVX2 */ {
     79                        flags |= DAV1D_X86_CPU_FLAG_AVX2;
     80                        if (X(xcr0, 0x000000e0)) /* ZMM/OPMASK */ {
     81                            if (X(r.ebx, 0xd0230000) && X(r.ecx, 0x00005f42))
     82                                flags |= DAV1D_X86_CPU_FLAG_AVX512ICL;
     83                        }
     84                    }
     85                }
     86            }
     87        }
     88 #endif
     89        if (!memcmp(cpu.vendor, "AuthenticAMD", sizeof(cpu.vendor))) {
     90            if ((flags & DAV1D_X86_CPU_FLAG_AVX2) && family <= 0x19) {
     91                /* Excavator, Zen, Zen+, Zen 2, Zen 3, Zen 3+, Zen 4 */
     92                flags |= DAV1D_X86_CPU_FLAG_SLOW_GATHER;
     93            }
     94        }
     95    }
     96 
     97    return flags;
     98 }