зеркало из https://github.com/mozilla/gecko-dev.git
83 строки
1.9 KiB
C
83 строки
1.9 KiB
C
/*
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* Copyright (c) 2018, Alliance for Open Media. All rights reserved
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*
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* This source code is subject to the terms of the BSD 2 Clause License and
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* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
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* was not distributed with this source code in the LICENSE file, you can
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* obtain it at www.aomedia.org/license/software. If the Alliance for Open
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* Media Patent License 1.0 was not distributed with this source code in the
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* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
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*/
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdint.h>
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#include <asm/cputable.h>
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#include <linux/auxvec.h>
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#include "config/aom_config.h"
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#include "aom_ports/ppc.h"
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#if CONFIG_RUNTIME_CPU_DETECT
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static int cpu_env_flags(int *flags) {
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char *env;
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env = getenv("AOM_SIMD_CAPS");
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if (env && *env) {
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*flags = (int)strtol(env, NULL, 0);
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return 0;
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}
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*flags = 0;
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return -1;
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}
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static int cpu_env_mask(void) {
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char *env;
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env = getenv("AOM_SIMD_CAPS_MASK");
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return env && *env ? (int)strtol(env, NULL, 0) : ~0;
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}
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int ppc_simd_caps(void) {
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int flags;
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int mask;
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int fd;
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ssize_t count;
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unsigned int i;
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uint64_t buf[64];
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// If VPX_SIMD_CAPS is set then allow only those capabilities.
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if (!cpu_env_flags(&flags)) {
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return flags;
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}
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mask = cpu_env_mask();
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fd = open("/proc/self/auxv", O_RDONLY);
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if (fd < 0) {
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return 0;
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}
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while ((count = read(fd, buf, sizeof(buf))) > 0) {
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for (i = 0; i < (count / sizeof(*buf)); i += 2) {
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if (buf[i] == AT_HWCAP) {
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#if HAVE_VSX
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if (buf[i + 1] & PPC_FEATURE_HAS_VSX) {
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flags |= HAS_VSX;
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}
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#endif // HAVE_VSX
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goto out_close;
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} else if (buf[i] == AT_NULL) {
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goto out_close;
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}
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}
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}
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out_close:
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close(fd);
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return flags & mask;
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}
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#else
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// If there is no RTCD the function pointers are not used and can not be
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// changed.
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int ppc_simd_caps(void) { return 0; }
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#endif // CONFIG_RUNTIME_CPU_DETECT
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