tests/checkasm/checkasm.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Assembly testing and benchmarking tool
  * Copyright (c) 2015 Henrik Gramner
  * Copyright (c) 2008 Loren Merritt
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */

 #include "config.h"

 #if CONFIG_LINUX_PERF
 # ifndef _GNU_SOURCE
 #  define _GNU_SOURCE // for syscall (performance monitoring API)
 # endif
 #endif

 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include "checkasm.h"
 #include "libavutil/common.h"
 #include "libavutil/cpu.h"
 #include "libavutil/intfloat.h"
 #include "libavutil/random_seed.h"

 #if HAVE_IO_H
 #include <io.h>
 #endif

 #if HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
 #include <windows.h>
 #define COLOR_RED    FOREGROUND_RED
 #define COLOR_GREEN  FOREGROUND_GREEN
 #define COLOR_YELLOW (FOREGROUND_RED|FOREGROUND_GREEN)
 #else
 #define COLOR_RED    1
 #define COLOR_GREEN  2
 #define COLOR_YELLOW 3
 #endif

 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 #if !HAVE_ISATTY
 #define isatty(fd) 1
 #endif

 #if ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
 #include "libavutil/arm/cpu.h"

 void (*checkasm_checked_call)(void *func, int dummy, ...) = checkasm_checked_call_novfp;
 #endif

 /* List of tests to invoke */
 static const struct {
     const char *name;
     void (*func)(void);
 } tests[] = {
 #if CONFIG_AVCODEC
     #if CONFIG_AAC_DECODER
         { "aacpsdsp", checkasm_check_aacpsdsp },
         { "sbrdsp",   checkasm_check_sbrdsp },
     #endif
     #if CONFIG_ALAC_DECODER
         { "alacdsp", checkasm_check_alacdsp },
     #endif
     #if CONFIG_AUDIODSP
         { "audiodsp", checkasm_check_audiodsp },
     #endif
     #if CONFIG_BLOCKDSP
         { "blockdsp", checkasm_check_blockdsp },
     #endif
     #if CONFIG_BSWAPDSP
         { "bswapdsp", checkasm_check_bswapdsp },
     #endif
     #if CONFIG_DCA_DECODER
         { "synth_filter", checkasm_check_synth_filter },
     #endif
     #if CONFIG_EXR_DECODER
         { "exrdsp", checkasm_check_exrdsp },
     #endif
     #if CONFIG_FLACDSP
         { "flacdsp", checkasm_check_flacdsp },
     #endif
     #if CONFIG_FMTCONVERT
         { "fmtconvert", checkasm_check_fmtconvert },
     #endif
     #if CONFIG_G722DSP
         { "g722dsp", checkasm_check_g722dsp },
     #endif
     #if CONFIG_H264DSP
         { "h264dsp", checkasm_check_h264dsp },
     #endif
     #if CONFIG_H264PRED
         { "h264pred", checkasm_check_h264pred },
     #endif
     #if CONFIG_H264QPEL
         { "h264qpel", checkasm_check_h264qpel },
     #endif
     #if CONFIG_HEVC_DECODER
         { "hevc_add_res", checkasm_check_hevc_add_res },
         { "hevc_idct", checkasm_check_hevc_idct },
         { "hevc_sao", checkasm_check_hevc_sao },
     #endif
     #if CONFIG_HUFFYUV_DECODER
         { "huffyuvdsp", checkasm_check_huffyuvdsp },
     #endif
     #if CONFIG_JPEG2000_DECODER
         { "jpeg2000dsp", checkasm_check_jpeg2000dsp },
     #endif
     #if CONFIG_HUFFYUVDSP
         { "llviddsp", checkasm_check_llviddsp },
     #endif
     #if CONFIG_LLVIDENCDSP
         { "llviddspenc", checkasm_check_llviddspenc },
     #endif
     #if CONFIG_OPUS_DECODER
         { "opusdsp", checkasm_check_opusdsp },
     #endif
     #if CONFIG_PIXBLOCKDSP
         { "pixblockdsp", checkasm_check_pixblockdsp },
     #endif
     #if CONFIG_UTVIDEO_DECODER
         { "utvideodsp", checkasm_check_utvideodsp },
     #endif
     #if CONFIG_V210_DECODER
         { "v210dec", checkasm_check_v210dec },
     #endif
     #if CONFIG_V210_ENCODER
         { "v210enc", checkasm_check_v210enc },
     #endif
     #if CONFIG_VP8DSP
         { "vp8dsp", checkasm_check_vp8dsp },
     #endif
     #if CONFIG_VP9_DECODER
         { "vp9dsp", checkasm_check_vp9dsp },
     #endif
     #if CONFIG_VIDEODSP
         { "videodsp", checkasm_check_videodsp },
     #endif
 #endif
 #if CONFIG_AVFILTER
     #if CONFIG_AFIR_FILTER
         { "af_afir", checkasm_check_afir },
     #endif
     #if CONFIG_BLEND_FILTER
         { "vf_blend", checkasm_check_blend },
     #endif
     #if CONFIG_COLORSPACE_FILTER
         { "vf_colorspace", checkasm_check_colorspace },
     #endif
     #if CONFIG_EQ_FILTER
         { "vf_eq", checkasm_check_vf_eq },
     #endif
     #if CONFIG_GBLUR_FILTER
         { "vf_gblur", checkasm_check_vf_gblur },
     #endif
     #if CONFIG_HFLIP_FILTER
         { "vf_hflip", checkasm_check_vf_hflip },
     #endif
     #if CONFIG_NLMEANS_FILTER
         { "vf_nlmeans", checkasm_check_nlmeans },
     #endif
     #if CONFIG_THRESHOLD_FILTER
         { "vf_threshold", checkasm_check_vf_threshold },
     #endif
 #endif
 #if CONFIG_SWSCALE
     { "sw_rgb", checkasm_check_sw_rgb },
     { "sw_scale", checkasm_check_sw_scale },
 #endif
 #if CONFIG_AVUTIL
         { "fixed_dsp", checkasm_check_fixed_dsp },
         { "float_dsp", checkasm_check_float_dsp },
 #endif
     { NULL }
 };

 /* List of cpu flags to check */
 static const struct {
     const char *name;
     const char *suffix;
     int flag;
 } cpus[] = {
 #if   ARCH_AARCH64
     { "ARMV8",    "armv8",    AV_CPU_FLAG_ARMV8 },
     { "NEON",     "neon",     AV_CPU_FLAG_NEON },
 #elif ARCH_ARM
     { "ARMV5TE",  "armv5te",  AV_CPU_FLAG_ARMV5TE },
     { "ARMV6",    "armv6",    AV_CPU_FLAG_ARMV6 },
     { "ARMV6T2",  "armv6t2",  AV_CPU_FLAG_ARMV6T2 },
     { "VFP",      "vfp",      AV_CPU_FLAG_VFP },
     { "VFP_VM",   "vfp_vm",   AV_CPU_FLAG_VFP_VM },
     { "VFPV3",    "vfp3",     AV_CPU_FLAG_VFPV3 },
     { "NEON",     "neon",     AV_CPU_FLAG_NEON },
 #elif ARCH_PPC
     { "ALTIVEC",  "altivec",  AV_CPU_FLAG_ALTIVEC },
     { "VSX",      "vsx",      AV_CPU_FLAG_VSX },
     { "POWER8",   "power8",   AV_CPU_FLAG_POWER8 },
 #elif ARCH_MIPS
     { "MMI",      "mmi",      AV_CPU_FLAG_MMI },
     { "MSA",      "msa",      AV_CPU_FLAG_MSA },
 #elif ARCH_X86
     { "MMX",      "mmx",      AV_CPU_FLAG_MMX|AV_CPU_FLAG_CMOV },
     { "MMXEXT",   "mmxext",   AV_CPU_FLAG_MMXEXT },
     { "3DNOW",    "3dnow",    AV_CPU_FLAG_3DNOW },
     { "3DNOWEXT", "3dnowext", AV_CPU_FLAG_3DNOWEXT },
     { "SSE",      "sse",      AV_CPU_FLAG_SSE },
     { "SSE2",     "sse2",     AV_CPU_FLAG_SSE2|AV_CPU_FLAG_SSE2SLOW },
     { "SSE3",     "sse3",     AV_CPU_FLAG_SSE3|AV_CPU_FLAG_SSE3SLOW },
     { "SSSE3",    "ssse3",    AV_CPU_FLAG_SSSE3|AV_CPU_FLAG_ATOM },
     { "SSE4.1",   "sse4",     AV_CPU_FLAG_SSE4 },
     { "SSE4.2",   "sse42",    AV_CPU_FLAG_SSE42 },
     { "AES-NI",   "aesni",    AV_CPU_FLAG_AESNI },
     { "AVX",      "avx",      AV_CPU_FLAG_AVX },
     { "XOP",      "xop",      AV_CPU_FLAG_XOP },
     { "FMA3",     "fma3",     AV_CPU_FLAG_FMA3 },
     { "FMA4",     "fma4",     AV_CPU_FLAG_FMA4 },
     { "AVX2",     "avx2",     AV_CPU_FLAG_AVX2 },
     { "AVX-512",  "avx512",   AV_CPU_FLAG_AVX512 },
 #endif
     { NULL }
 };

 typedef struct CheckasmFuncVersion {
     struct CheckasmFuncVersion *next;
     void *func;
     int ok;
     int cpu;
     CheckasmPerf perf;
 } CheckasmFuncVersion;

 /* Binary search tree node */
 typedef struct CheckasmFunc {
     struct CheckasmFunc *child[2];
     CheckasmFuncVersion versions;
     uint8_t color; /* 0 = red, 1 = black */
     char name[1];
 } CheckasmFunc;

 /* Internal state */
 static struct {
     CheckasmFunc *funcs;
     CheckasmFunc *current_func;
     CheckasmFuncVersion *current_func_ver;
     const char *current_test_name;
     const char *bench_pattern;
     int bench_pattern_len;
     int num_checked;
     int num_failed;

     /* perf */
     int nop_time;
     int sysfd;

     int cpu_flag;
     const char *cpu_flag_name;
     const char *test_name;
     int verbose;
 } state;

 /* PRNG state */
 AVLFG checkasm_lfg;

 /* float compare support code */
 static int is_negative(union av_intfloat32 u)
 {
     return u.i >> 31;
 }

 int float_near_ulp(float a, float b, unsigned max_ulp)
 {
     union av_intfloat32 x, y;

     x.f = a;
     y.f = b;

     if (is_negative(x) != is_negative(y)) {
         // handle -0.0 == +0.0
         return a == b;
     }

     if (llabs((int64_t)x.i - y.i) <= max_ulp)
         return 1;

     return 0;
 }

 int float_near_ulp_array(const float *a, const float *b, unsigned max_ulp,
                          unsigned len)
 {
     unsigned i;

     for (i = 0; i < len; i++) {
         if (!float_near_ulp(a[i], b[i], max_ulp))
             return 0;
     }
     return 1;
 }

 int float_near_abs_eps(float a, float b, float eps)
 {
     float abs_diff = fabsf(a - b);
     if (abs_diff < eps)
         return 1;

     fprintf(stderr, "test failed comparing %g with %g (abs diff=%g with EPS=%g)\n", a, b, abs_diff, eps);

     return 0;
 }

 int float_near_abs_eps_array(const float *a, const float *b, float eps,
                          unsigned len)
 {
     unsigned i;

     for (i = 0; i < len; i++) {
         if (!float_near_abs_eps(a[i], b[i], eps))
             return 0;
     }
     return 1;
 }

 int float_near_abs_eps_ulp(float a, float b, float eps, unsigned max_ulp)
 {
     return float_near_ulp(a, b, max_ulp) || float_near_abs_eps(a, b, eps);
 }

 int float_near_abs_eps_array_ulp(const float *a, const float *b, float eps,
                          unsigned max_ulp, unsigned len)
 {
     unsigned i;

     for (i = 0; i < len; i++) {
         if (!float_near_abs_eps_ulp(a[i], b[i], eps, max_ulp))
             return 0;
     }
     return 1;
 }

 int double_near_abs_eps(double a, double b, double eps)
 {
     double abs_diff = fabs(a - b);

     return abs_diff < eps;
 }

 int double_near_abs_eps_array(const double *a, const double *b, double eps,
                               unsigned len)
 {
     unsigned i;

     for (i = 0; i < len; i++) {
         if (!double_near_abs_eps(a[i], b[i], eps))
             return 0;
     }
     return 1;
 }

 /* Print colored text to stderr if the terminal supports it */
 static void color_printf(int color, const char *fmt, ...)
 {
     static int use_color = -1;
     va_list arg;

 #if HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
     static HANDLE con;
     static WORD org_attributes;

     if (use_color < 0) {
         CONSOLE_SCREEN_BUFFER_INFO con_info;
         con = GetStdHandle(STD_ERROR_HANDLE);
         if (con && con != INVALID_HANDLE_VALUE && GetConsoleScreenBufferInfo(con, &con_info)) {
             org_attributes = con_info.wAttributes;
             use_color = 1;
         } else
             use_color = 0;
     }
     if (use_color)
         SetConsoleTextAttribute(con, (org_attributes & 0xfff0) | (color & 0x0f));
 #else
     if (use_color < 0) {
         const char *term = getenv("TERM");
         use_color = term && strcmp(term, "dumb") && isatty(2);
     }
     if (use_color)
         fprintf(stderr, "\x1b[%d;3%dm", (color & 0x08) >> 3, color & 0x07);
 #endif

     va_start(arg, fmt);
     vfprintf(stderr, fmt, arg);
     va_end(arg);

     if (use_color) {
 #if HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
         SetConsoleTextAttribute(con, org_attributes);
 #else
         fprintf(stderr, "\x1b[0m");
 #endif
     }
 }

 /* Deallocate a tree */
 static void destroy_func_tree(CheckasmFunc *f)
 {
     if (f) {
         CheckasmFuncVersion *v = f->versions.next;
         while (v) {
             CheckasmFuncVersion *next = v->next;
             free(v);
             v = next;
         }

         destroy_func_tree(f->child[0]);
         destroy_func_tree(f->child[1]);
         free(f);
     }
 }

 /* Allocate a zero-initialized block, clean up and exit on failure */
 static void *checkasm_malloc(size_t size)
 {
     void *ptr = calloc(1, size);
     if (!ptr) {
         fprintf(stderr, "checkasm: malloc failed\n");
         destroy_func_tree(state.funcs);
         exit(1);
     }
     return ptr;
 }

 /* Get the suffix of the specified cpu flag */
 static const char *cpu_suffix(int cpu)
 {
     int i = FF_ARRAY_ELEMS(cpus);

     while (--i >= 0)
         if (cpu & cpus[i].flag)
             return cpus[i].suffix;

     return "c";
 }

 static int cmp_nop(const void *a, const void *b)
 {
     return *(const uint16_t*)a - *(const uint16_t*)b;
 }

 /* Measure the overhead of the timing code (in decicycles) */
 static int measure_nop_time(void)
 {
     uint16_t nops[10000];
     int i, nop_sum = 0;
     av_unused const int sysfd = state.sysfd;

     uint64_t t = 0;
     for (i = 0; i < 10000; i++) {
         PERF_START(t);
         PERF_STOP(t);
         nops[i] = t;
     }

     qsort(nops, 10000, sizeof(uint16_t), cmp_nop);
     for (i = 2500; i < 7500; i++)
         nop_sum += nops[i];

     return nop_sum / 500;
 }

 /* Print benchmark results */
 static void print_benchs(CheckasmFunc *f)
 {
     if (f) {
         print_benchs(f->child[0]);

         /* Only print functions with at least one assembly version */
         if (f->versions.cpu || f->versions.next) {
             CheckasmFuncVersion *v = &f->versions;
             do {
                 CheckasmPerf *p = &v->perf;
                 if (p->iterations) {
                     int decicycles = (10*p->cycles/p->iterations - state.nop_time) / 4;
                     printf("%s_%s: %d.%d\n", f->name, cpu_suffix(v->cpu), decicycles/10, decicycles%10);
                 }
             } while ((v = v->next));
         }

         print_benchs(f->child[1]);
     }
 }

 /* ASCIIbetical sort except preserving natural order for numbers */
 static int cmp_func_names(const char *a, const char *b)
 {
     const char *start = a;
     int ascii_diff, digit_diff;

     for (; !(ascii_diff = *(const unsigned char*)a - *(const unsigned char*)b) && *a; a++, b++);
     for (; av_isdigit(*a) && av_isdigit(*b); a++, b++);

     if (a > start && av_isdigit(a[-1]) && (digit_diff = av_isdigit(*a) - av_isdigit(*b)))
         return digit_diff;

     return ascii_diff;
 }

 /* Perform a tree rotation in the specified direction and return the new root */
 static CheckasmFunc *rotate_tree(CheckasmFunc *f, int dir)
 {
     CheckasmFunc *r = f->child[dir^1];
     f->child[dir^1] = r->child[dir];
     r->child[dir] = f;
     r->color = f->color;
     f->color = 0;
     return r;
 }

 #define is_red(f) ((f) && !(f)->color)

 /* Balance a left-leaning red-black tree at the specified node */
 static void balance_tree(CheckasmFunc **root)
 {
     CheckasmFunc *f = *root;

     if (is_red(f->child[0]) && is_red(f->child[1])) {
         f->color ^= 1;
         f->child[0]->color = f->child[1]->color = 1;
     }

     if (!is_red(f->child[0]) && is_red(f->child[1]))
         *root = rotate_tree(f, 0); /* Rotate left */
     else if (is_red(f->child[0]) && is_red(f->child[0]->child[0]))
         *root = rotate_tree(f, 1); /* Rotate right */
 }

 /* Get a node with the specified name, creating it if it doesn't exist */
 static CheckasmFunc *get_func(CheckasmFunc **root, const char *name)
 {
     CheckasmFunc *f = *root;

     if (f) {
         /* Search the tree for a matching node */
         int cmp = cmp_func_names(name, f->name);
         if (cmp) {
             f = get_func(&f->child[cmp > 0], name);

             /* Rebalance the tree on the way up if a new node was inserted */
             if (!f->versions.func)
                 balance_tree(root);
         }
     } else {
         /* Allocate and insert a new node into the tree */
         int name_length = strlen(name);
         f = *root = checkasm_malloc(sizeof(CheckasmFunc) + name_length);
         memcpy(f->name, name, name_length + 1);
     }

     return f;
 }

 /* Perform tests and benchmarks for the specified cpu flag if supported by the host */
 static void check_cpu_flag(const char *name, int flag)
 {
     int old_cpu_flag = state.cpu_flag;

     flag |= old_cpu_flag;
     av_force_cpu_flags(-1);
     state.cpu_flag = flag & av_get_cpu_flags();
     av_force_cpu_flags(state.cpu_flag);

     if (!flag || state.cpu_flag != old_cpu_flag) {
         int i;

         state.cpu_flag_name = name;
         for (i = 0; tests[i].func; i++) {
             if (state.test_name && strcmp(tests[i].name, state.test_name))
                 continue;
             state.current_test_name = tests[i].name;
             tests[i].func();
         }
     }
 }

 /* Print the name of the current CPU flag, but only do it once */
 static void print_cpu_name(void)
 {
     if (state.cpu_flag_name) {
         color_printf(COLOR_YELLOW, "%s:\n", state.cpu_flag_name);
         state.cpu_flag_name = NULL;
     }
 }

 #if CONFIG_LINUX_PERF
 static int bench_init_linux(void)
 {
     struct perf_event_attr attr = {
         .type           = PERF_TYPE_HARDWARE,
         .size           = sizeof(struct perf_event_attr),
         .config         = PERF_COUNT_HW_CPU_CYCLES,
         .disabled       = 1, // start counting only on demand
         .exclude_kernel = 1,
         .exclude_hv     = 1,
     };

     printf("benchmarking with Linux Perf Monitoring API\n");

     state.sysfd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
     if (state.sysfd == -1) {
         perror("syscall");
         return -1;
     }
     return 0;
 }
 #endif

 #if !CONFIG_LINUX_PERF
 static int bench_init_ffmpeg(void)
 {
 #ifdef AV_READ_TIME
     printf("benchmarking with native FFmpeg timers\n");
     return 0;
 #else
     fprintf(stderr, "checkasm: --bench is not supported on your system\n");
     return -1;
 #endif
 }
 #endif

 static int bench_init(void)
 {
 #if CONFIG_LINUX_PERF
     int ret = bench_init_linux();
 #else
     int ret = bench_init_ffmpeg();
 #endif
     if (ret < 0)
         return ret;

     state.nop_time = measure_nop_time();
     printf("nop: %d.%d\n", state.nop_time/10, state.nop_time%10);
     return 0;
 }

 static void bench_uninit(void)
 {
 #if CONFIG_LINUX_PERF
     if (state.sysfd > 0)
         close(state.sysfd);
 #endif
 }

 int main(int argc, char *argv[])
 {
     unsigned int seed = av_get_random_seed();
     int i, ret = 0;

 #if ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
     if (have_vfp(av_get_cpu_flags()) || have_neon(av_get_cpu_flags()))
         checkasm_checked_call = checkasm_checked_call_vfp;
 #endif

     if (!tests[0].func || !cpus[0].flag) {
         fprintf(stderr, "checkasm: no tests to perform\n");
         return 0;
     }

     while (argc > 1) {
         if (!strncmp(argv[1], "--bench", 7)) {
             if (bench_init() < 0)
                 return 1;
             if (argv[1][7] == '=') {
                 state.bench_pattern = argv[1] + 8;
                 state.bench_pattern_len = strlen(state.bench_pattern);
             } else
                 state.bench_pattern = "";
         } else if (!strncmp(argv[1], "--test=", 7)) {
             state.test_name = argv[1] + 7;
         } else if (!strcmp(argv[1], "--verbose") || !strcmp(argv[1], "-v")) {
             state.verbose = 1;
         } else {
             seed = strtoul(argv[1], NULL, 10);
         }

         argc--;
         argv++;
     }

     fprintf(stderr, "checkasm: using random seed %u\n", seed);
     av_lfg_init(&checkasm_lfg, seed);

     check_cpu_flag(NULL, 0);
     for (i = 0; cpus[i].flag; i++)
         check_cpu_flag(cpus[i].name, cpus[i].flag);

     if (state.num_failed) {
         fprintf(stderr, "checkasm: %d of %d tests have failed\n", state.num_failed, state.num_checked);
         ret = 1;
     } else {
         fprintf(stderr, "checkasm: all %d tests passed\n", state.num_checked);
         if (state.bench_pattern) {
             print_benchs(state.funcs);
         }
     }

     destroy_func_tree(state.funcs);
     bench_uninit();
     return ret;
 }

 /* Decide whether or not the specified function needs to be tested and
  * allocate/initialize data structures if needed. Returns a pointer to a
  * reference function if the function should be tested, otherwise NULL */
 void *checkasm_check_func(void *func, const char *name, ...)
 {
     char name_buf[256];
     void *ref = func;
     CheckasmFuncVersion *v;
     int name_length;
     va_list arg;

     va_start(arg, name);
     name_length = vsnprintf(name_buf, sizeof(name_buf), name, arg);
     va_end(arg);

     if (!func || name_length <= 0 || name_length >= sizeof(name_buf))
         return NULL;

     state.current_func = get_func(&state.funcs, name_buf);
     state.funcs->color = 1;
     v = &state.current_func->versions;

     if (v->func) {
         CheckasmFuncVersion *prev;
         do {
             /* Only test functions that haven't already been tested */
             if (v->func == func)
                 return NULL;

             if (v->ok)
                 ref = v->func;

             prev = v;
         } while ((v = v->next));

         v = prev->next = checkasm_malloc(sizeof(CheckasmFuncVersion));
     }

     v->func = func;
     v->ok = 1;
     v->cpu = state.cpu_flag;
     state.current_func_ver = v;

     if (state.cpu_flag)
         state.num_checked++;

     return ref;
 }

 /* Decide whether or not the current function needs to be benchmarked */
 int checkasm_bench_func(void)
 {
     return !state.num_failed && state.bench_pattern &&
            !strncmp(state.current_func->name, state.bench_pattern, state.bench_pattern_len);
 }

 /* Indicate that the current test has failed */
 void checkasm_fail_func(const char *msg, ...)
 {
     if (state.current_func_ver->cpu && state.current_func_ver->ok) {
         va_list arg;

         print_cpu_name();
         fprintf(stderr, "   %s_%s (", state.current_func->name, cpu_suffix(state.current_func_ver->cpu));
         va_start(arg, msg);
         vfprintf(stderr, msg, arg);
         va_end(arg);
         fprintf(stderr, ")\n");

         state.current_func_ver->ok = 0;
         state.num_failed++;
     }
 }

 /* Get the benchmark context of the current function */
 CheckasmPerf *checkasm_get_perf_context(void)
 {
     CheckasmPerf *perf = &state.current_func_ver->perf;
     memset(perf, 0, sizeof(*perf));
     perf->sysfd = state.sysfd;
     return perf;
 }

 /* Print the outcome of all tests performed since the last time this function was called */
 void checkasm_report(const char *name, ...)
 {
     static int prev_checked, prev_failed, max_length;

     if (state.num_checked > prev_checked) {
         int pad_length = max_length + 4;
         va_list arg;

         print_cpu_name();
         pad_length -= fprintf(stderr, " - %s.", state.current_test_name);
         va_start(arg, name);
         pad_length -= vfprintf(stderr, name, arg);
         va_end(arg);
         fprintf(stderr, "%*c", FFMAX(pad_length, 0) + 2, '[');

         if (state.num_failed == prev_failed)
             color_printf(COLOR_GREEN, "OK");
         else
             color_printf(COLOR_RED, "FAILED");
         fprintf(stderr, "]\n");

         prev_checked = state.num_checked;
         prev_failed  = state.num_failed;
     } else if (!state.cpu_flag) {
         /* Calculate the amount of padding required to make the output vertically aligned */
         int length = strlen(state.current_test_name);
         va_list arg;

         va_start(arg, name);
         length += vsnprintf(NULL, 0, name, arg);
         va_end(arg);

         if (length > max_length)
             max_length = length;
     }
 }

 #define DEF_CHECKASM_CHECK_FUNC(type, fmt) \
 int checkasm_check_##type(const char *const file, const int line, \
                           const type *buf1, ptrdiff_t stride1, \
                           const type *buf2, ptrdiff_t stride2, \
                           const int w, int h, const char *const name) \
 { \
     int y = 0; \
     stride1 /= sizeof(*buf1); \
     stride2 /= sizeof(*buf2); \
     for (y = 0; y < h; y++) \
         if (memcmp(&buf1[y*stride1], &buf2[y*stride2], w*sizeof(*buf1))) \
             break; \
     if (y == h) \
         return 0; \
     checkasm_fail_func("%s:%d", file, line); \
     if (!state.verbose) \
         return 1; \
     fprintf(stderr, "%s:\n", name); \
     while (h--) { \
         for (int x = 0; x < w; x++) \
             fprintf(stderr, " " fmt, buf1[x]); \
         fprintf(stderr, "    "); \
         for (int x = 0; x < w; x++) \
             fprintf(stderr, " " fmt, buf2[x]); \
         fprintf(stderr, "    "); \
         for (int x = 0; x < w; x++) \
             fprintf(stderr, "%c", buf1[x] != buf2[x] ? 'x' : '.'); \
         buf1 += stride1; \
         buf2 += stride2; \
         fprintf(stderr, "\n"); \
     } \
     return 1; \
 }

 DEF_CHECKASM_CHECK_FUNC(uint8_t,  "%02x")
 DEF_CHECKASM_CHECK_FUNC(uint16_t, "%04x")
 DEF_CHECKASM_CHECK_FUNC(int16_t,  "%6d")
 DEF_CHECKASM_CHECK_FUNC(int32_t,  "%9d")
	/*
	* Assembly testing and benchmarking tool
	* Copyright (c) 2015 Henrik Gramner
	* Copyright (c) 2008 Loren Merritt
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with FFmpeg; if not, write to the Free Software Foundation, Inc.,
	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	*/

	#include "config.h"

	#if CONFIG_LINUX_PERF
	# ifndef _GNU_SOURCE
	# define _GNU_SOURCE // for syscall (performance monitoring API)
	# endif
	#endif

	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include "checkasm.h"
	#include "libavutil/common.h"
	#include "libavutil/cpu.h"
	#include "libavutil/intfloat.h"
	#include "libavutil/random_seed.h"

	#if HAVE_IO_H
	#include <io.h>
	#endif

	#if HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
	#include <windows.h>
	#define COLOR_RED FOREGROUND_RED
	#define COLOR_GREEN FOREGROUND_GREEN
	#define COLOR_YELLOW (FOREGROUND_RED\|FOREGROUND_GREEN)
	#else
	#define COLOR_RED 1
	#define COLOR_GREEN 2
	#define COLOR_YELLOW 3
	#endif

	#if HAVE_UNISTD_H
	#include <unistd.h>
	#endif

	#if !HAVE_ISATTY
	#define isatty(fd) 1
	#endif

	#if ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
	#include "libavutil/arm/cpu.h"

	void (checkasm_checked_call)(void func, int dummy, ...) = checkasm_checked_call_novfp;
	#endif

	/* List of tests to invoke */
	static const struct {
	const char *name;
	void (*func)(void);
	} tests[] = {
	#if CONFIG_AVCODEC
	#if CONFIG_AAC_DECODER
	{ "aacpsdsp", checkasm_check_aacpsdsp },
	{ "sbrdsp", checkasm_check_sbrdsp },
	#endif
	#if CONFIG_ALAC_DECODER
	{ "alacdsp", checkasm_check_alacdsp },
	#endif
	#if CONFIG_AUDIODSP
	{ "audiodsp", checkasm_check_audiodsp },
	#endif
	#if CONFIG_BLOCKDSP
	{ "blockdsp", checkasm_check_blockdsp },
	#endif
	#if CONFIG_BSWAPDSP
	{ "bswapdsp", checkasm_check_bswapdsp },
	#endif
	#if CONFIG_DCA_DECODER
	{ "synth_filter", checkasm_check_synth_filter },
	#endif
	#if CONFIG_EXR_DECODER
	{ "exrdsp", checkasm_check_exrdsp },
	#endif
	#if CONFIG_FLACDSP
	{ "flacdsp", checkasm_check_flacdsp },
	#endif
	#if CONFIG_FMTCONVERT
	{ "fmtconvert", checkasm_check_fmtconvert },
	#endif
	#if CONFIG_G722DSP
	{ "g722dsp", checkasm_check_g722dsp },
	#endif
	#if CONFIG_H264DSP
	{ "h264dsp", checkasm_check_h264dsp },
	#endif
	#if CONFIG_H264PRED
	{ "h264pred", checkasm_check_h264pred },
	#endif
	#if CONFIG_H264QPEL
	{ "h264qpel", checkasm_check_h264qpel },
	#endif
	#if CONFIG_HEVC_DECODER
	{ "hevc_add_res", checkasm_check_hevc_add_res },
	{ "hevc_idct", checkasm_check_hevc_idct },
	{ "hevc_sao", checkasm_check_hevc_sao },
	#endif
	#if CONFIG_HUFFYUV_DECODER
	{ "huffyuvdsp", checkasm_check_huffyuvdsp },
	#endif
	#if CONFIG_JPEG2000_DECODER
	{ "jpeg2000dsp", checkasm_check_jpeg2000dsp },
	#endif
	#if CONFIG_HUFFYUVDSP
	{ "llviddsp", checkasm_check_llviddsp },
	#endif
	#if CONFIG_LLVIDENCDSP
	{ "llviddspenc", checkasm_check_llviddspenc },
	#endif
	#if CONFIG_OPUS_DECODER
	{ "opusdsp", checkasm_check_opusdsp },
	#endif
	#if CONFIG_PIXBLOCKDSP
	{ "pixblockdsp", checkasm_check_pixblockdsp },
	#endif
	#if CONFIG_UTVIDEO_DECODER
	{ "utvideodsp", checkasm_check_utvideodsp },
	#endif
	#if CONFIG_V210_DECODER
	{ "v210dec", checkasm_check_v210dec },
	#endif
	#if CONFIG_V210_ENCODER
	{ "v210enc", checkasm_check_v210enc },
	#endif
	#if CONFIG_VP8DSP
	{ "vp8dsp", checkasm_check_vp8dsp },
	#endif
	#if CONFIG_VP9_DECODER
	{ "vp9dsp", checkasm_check_vp9dsp },
	#endif
	#if CONFIG_VIDEODSP
	{ "videodsp", checkasm_check_videodsp },
	#endif
	#endif
	#if CONFIG_AVFILTER
	#if CONFIG_AFIR_FILTER
	{ "af_afir", checkasm_check_afir },
	#endif
	#if CONFIG_BLEND_FILTER
	{ "vf_blend", checkasm_check_blend },
	#endif
	#if CONFIG_COLORSPACE_FILTER
	{ "vf_colorspace", checkasm_check_colorspace },
	#endif
	#if CONFIG_EQ_FILTER
	{ "vf_eq", checkasm_check_vf_eq },
	#endif
	#if CONFIG_GBLUR_FILTER
	{ "vf_gblur", checkasm_check_vf_gblur },
	#endif
	#if CONFIG_HFLIP_FILTER
	{ "vf_hflip", checkasm_check_vf_hflip },
	#endif
	#if CONFIG_NLMEANS_FILTER
	{ "vf_nlmeans", checkasm_check_nlmeans },
	#endif
	#if CONFIG_THRESHOLD_FILTER
	{ "vf_threshold", checkasm_check_vf_threshold },
	#endif
	#endif
	#if CONFIG_SWSCALE
	{ "sw_rgb", checkasm_check_sw_rgb },
	{ "sw_scale", checkasm_check_sw_scale },
	#endif
	#if CONFIG_AVUTIL
	{ "fixed_dsp", checkasm_check_fixed_dsp },
	{ "float_dsp", checkasm_check_float_dsp },
	#endif
	{ NULL }
	};

	/* List of cpu flags to check */
	static const struct {
	const char *name;
	const char *suffix;
	int flag;
	} cpus[] = {
	#if ARCH_AARCH64
	{ "ARMV8", "armv8", AV_CPU_FLAG_ARMV8 },
	{ "NEON", "neon", AV_CPU_FLAG_NEON },
	#elif ARCH_ARM
	{ "ARMV5TE", "armv5te", AV_CPU_FLAG_ARMV5TE },
	{ "ARMV6", "armv6", AV_CPU_FLAG_ARMV6 },
	{ "ARMV6T2", "armv6t2", AV_CPU_FLAG_ARMV6T2 },
	{ "VFP", "vfp", AV_CPU_FLAG_VFP },
	{ "VFP_VM", "vfp_vm", AV_CPU_FLAG_VFP_VM },
	{ "VFPV3", "vfp3", AV_CPU_FLAG_VFPV3 },
	{ "NEON", "neon", AV_CPU_FLAG_NEON },
	#elif ARCH_PPC
	{ "ALTIVEC", "altivec", AV_CPU_FLAG_ALTIVEC },
	{ "VSX", "vsx", AV_CPU_FLAG_VSX },
	{ "POWER8", "power8", AV_CPU_FLAG_POWER8 },
	#elif ARCH_MIPS
	{ "MMI", "mmi", AV_CPU_FLAG_MMI },
	{ "MSA", "msa", AV_CPU_FLAG_MSA },
	#elif ARCH_X86
	{ "MMX", "mmx", AV_CPU_FLAG_MMX\|AV_CPU_FLAG_CMOV },
	{ "MMXEXT", "mmxext", AV_CPU_FLAG_MMXEXT },
	{ "3DNOW", "3dnow", AV_CPU_FLAG_3DNOW },
	{ "3DNOWEXT", "3dnowext", AV_CPU_FLAG_3DNOWEXT },
	{ "SSE", "sse", AV_CPU_FLAG_SSE },
	{ "SSE2", "sse2", AV_CPU_FLAG_SSE2\|AV_CPU_FLAG_SSE2SLOW },
	{ "SSE3", "sse3", AV_CPU_FLAG_SSE3\|AV_CPU_FLAG_SSE3SLOW },
	{ "SSSE3", "ssse3", AV_CPU_FLAG_SSSE3\|AV_CPU_FLAG_ATOM },
	{ "SSE4.1", "sse4", AV_CPU_FLAG_SSE4 },
	{ "SSE4.2", "sse42", AV_CPU_FLAG_SSE42 },
	{ "AES-NI", "aesni", AV_CPU_FLAG_AESNI },
	{ "AVX", "avx", AV_CPU_FLAG_AVX },
	{ "XOP", "xop", AV_CPU_FLAG_XOP },
	{ "FMA3", "fma3", AV_CPU_FLAG_FMA3 },
	{ "FMA4", "fma4", AV_CPU_FLAG_FMA4 },
	{ "AVX2", "avx2", AV_CPU_FLAG_AVX2 },
	{ "AVX-512", "avx512", AV_CPU_FLAG_AVX512 },
	#endif
	{ NULL }
	};

	typedef struct CheckasmFuncVersion {
	struct CheckasmFuncVersion *next;
	void *func;
	int ok;
	int cpu;
	CheckasmPerf perf;
	} CheckasmFuncVersion;

	/* Binary search tree node */
	typedef struct CheckasmFunc {
	struct CheckasmFunc *child[2];
	CheckasmFuncVersion versions;
	uint8_t color; /* 0 = red, 1 = black */
	char name[1];
	} CheckasmFunc;

	/* Internal state */
	static struct {
	CheckasmFunc *funcs;
	CheckasmFunc *current_func;
	CheckasmFuncVersion *current_func_ver;
	const char *current_test_name;
	const char *bench_pattern;
	int bench_pattern_len;
	int num_checked;
	int num_failed;

	/* perf */
	int nop_time;
	int sysfd;

	int cpu_flag;
	const char *cpu_flag_name;
	const char *test_name;
	int verbose;
	} state;

	/* PRNG state */
	AVLFG checkasm_lfg;

	/* float compare support code */
	static int is_negative(union av_intfloat32 u)
	{
	return u.i >> 31;
	}

	int float_near_ulp(float a, float b, unsigned max_ulp)
	{
	union av_intfloat32 x, y;

	x.f = a;
	y.f = b;

	if (is_negative(x) != is_negative(y)) {
	// handle -0.0 == +0.0
	return a == b;
	}

	if (llabs((int64_t)x.i - y.i) <= max_ulp)
	return 1;

	return 0;
	}

	int float_near_ulp_array(const float a, const float b, unsigned max_ulp,
	unsigned len)
	{
	unsigned i;

	for (i = 0; i < len; i++) {
	if (!float_near_ulp(a[i], b[i], max_ulp))
	return 0;
	}
	return 1;
	}

	int float_near_abs_eps(float a, float b, float eps)
	{
	float abs_diff = fabsf(a - b);
	if (abs_diff < eps)
	return 1;

	fprintf(stderr, "test failed comparing %g with %g (abs diff=%g with EPS=%g)\n", a, b, abs_diff, eps);

	return 0;
	}

	int float_near_abs_eps_array(const float a, const float b, float eps,
	unsigned len)
	{
	unsigned i;

	for (i = 0; i < len; i++) {
	if (!float_near_abs_eps(a[i], b[i], eps))
	return 0;
	}
	return 1;
	}

	int float_near_abs_eps_ulp(float a, float b, float eps, unsigned max_ulp)
	{
	return float_near_ulp(a, b, max_ulp) \|\| float_near_abs_eps(a, b, eps);
	}

	int float_near_abs_eps_array_ulp(const float a, const float b, float eps,
	unsigned max_ulp, unsigned len)
	{
	unsigned i;

	for (i = 0; i < len; i++) {
	if (!float_near_abs_eps_ulp(a[i], b[i], eps, max_ulp))
	return 0;
	}
	return 1;
	}

	int double_near_abs_eps(double a, double b, double eps)
	{
	double abs_diff = fabs(a - b);

	return abs_diff < eps;
	}

	int double_near_abs_eps_array(const double a, const double b, double eps,
	unsigned len)
	{
	unsigned i;

	for (i = 0; i < len; i++) {
	if (!double_near_abs_eps(a[i], b[i], eps))
	return 0;
	}
	return 1;
	}

	/* Print colored text to stderr if the terminal supports it */
	static void color_printf(int color, const char *fmt, ...)
	{
	static int use_color = -1;
	va_list arg;

	#if HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
	static HANDLE con;
	static WORD org_attributes;

	if (use_color < 0) {
	CONSOLE_SCREEN_BUFFER_INFO con_info;
	con = GetStdHandle(STD_ERROR_HANDLE);
	if (con && con != INVALID_HANDLE_VALUE && GetConsoleScreenBufferInfo(con, &con_info)) {
	org_attributes = con_info.wAttributes;
	use_color = 1;
	} else
	use_color = 0;
	}
	if (use_color)
	SetConsoleTextAttribute(con, (org_attributes & 0xfff0) \| (color & 0x0f));
	#else
	if (use_color < 0) {
	const char *term = getenv("TERM");
	use_color = term && strcmp(term, "dumb") && isatty(2);
	}
	if (use_color)
	fprintf(stderr, "\x1b[%d;3%dm", (color & 0x08) >> 3, color & 0x07);
	#endif

	va_start(arg, fmt);
	vfprintf(stderr, fmt, arg);
	va_end(arg);

	if (use_color) {
	#if HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
	SetConsoleTextAttribute(con, org_attributes);
	#else
	fprintf(stderr, "\x1b[0m");
	#endif
	}
	}

	/* Deallocate a tree */
	static void destroy_func_tree(CheckasmFunc *f)
	{
	if (f) {
	CheckasmFuncVersion *v = f->versions.next;
	while (v) {
	CheckasmFuncVersion *next = v->next;
	free(v);
	v = next;
	}

	destroy_func_tree(f->child[0]);
	destroy_func_tree(f->child[1]);
	free(f);
	}
	}

	/* Allocate a zero-initialized block, clean up and exit on failure */
	static void *checkasm_malloc(size_t size)
	{
	void *ptr = calloc(1, size);
	if (!ptr) {
	fprintf(stderr, "checkasm: malloc failed\n");
	destroy_func_tree(state.funcs);
	exit(1);
	}
	return ptr;
	}

	/* Get the suffix of the specified cpu flag */
	static const char *cpu_suffix(int cpu)
	{
	int i = FF_ARRAY_ELEMS(cpus);

	while (--i >= 0)
	if (cpu & cpus[i].flag)
	return cpus[i].suffix;

	return "c";
	}

	static int cmp_nop(const void a, const void b)
	{
	return (const uint16_t)a - (const uint16_t)b;
	}

	/* Measure the overhead of the timing code (in decicycles) */
	static int measure_nop_time(void)
	{
	uint16_t nops[10000];
	int i, nop_sum = 0;
	av_unused const int sysfd = state.sysfd;

	uint64_t t = 0;
	for (i = 0; i < 10000; i++) {
	PERF_START(t);
	PERF_STOP(t);
	nops[i] = t;
	}

	qsort(nops, 10000, sizeof(uint16_t), cmp_nop);
	for (i = 2500; i < 7500; i++)
	nop_sum += nops[i];

	return nop_sum / 500;
	}

	/* Print benchmark results */
	static void print_benchs(CheckasmFunc *f)
	{
	if (f) {
	print_benchs(f->child[0]);

	/* Only print functions with at least one assembly version */
	if (f->versions.cpu \|\| f->versions.next) {
	CheckasmFuncVersion *v = &f->versions;
	do {
	CheckasmPerf *p = &v->perf;
	if (p->iterations) {
	int decicycles = (10*p->cycles/p->iterations - state.nop_time) / 4;
	printf("%s_%s: %d.%d\n", f->name, cpu_suffix(v->cpu), decicycles/10, decicycles%10);
	}
	} while ((v = v->next));
	}

	print_benchs(f->child[1]);
	}
	}

	/* ASCIIbetical sort except preserving natural order for numbers */
	static int cmp_func_names(const char a, const char b)
	{
	const char *start = a;
	int ascii_diff, digit_diff;

	for (; !(ascii_diff = (const unsigned char)a - (const unsigned char)b) && *a; a++, b++);
	for (; av_isdigit(a) && av_isdigit(b); a++, b++);

	if (a > start && av_isdigit(a[-1]) && (digit_diff = av_isdigit(a) - av_isdigit(b)))
	return digit_diff;

	return ascii_diff;
	}

	/* Perform a tree rotation in the specified direction and return the new root */
	static CheckasmFunc rotate_tree(CheckasmFunc f, int dir)
	{
	CheckasmFunc *r = f->child[dir^1];
	f->child[dir^1] = r->child[dir];
	r->child[dir] = f;
	r->color = f->color;
	f->color = 0;
	return r;
	}

	#define is_red(f) ((f) && !(f)->color)

	/* Balance a left-leaning red-black tree at the specified node */
	static void balance_tree(CheckasmFunc **root)
	{
	CheckasmFunc f = root;

	if (is_red(f->child[0]) && is_red(f->child[1])) {
	f->color ^= 1;
	f->child[0]->color = f->child[1]->color = 1;
	}

	if (!is_red(f->child[0]) && is_red(f->child[1]))
	root = rotate_tree(f, 0); / Rotate left */
	else if (is_red(f->child[0]) && is_red(f->child[0]->child[0]))
	root = rotate_tree(f, 1); / Rotate right */
	}

	/* Get a node with the specified name, creating it if it doesn't exist */
	static CheckasmFunc get_func(CheckasmFunc root, const char name)
	{
	CheckasmFunc f = root;

	if (f) {
	/* Search the tree for a matching node */
	int cmp = cmp_func_names(name, f->name);
	if (cmp) {
	f = get_func(&f->child[cmp > 0], name);

	/* Rebalance the tree on the way up if a new node was inserted */
	if (!f->versions.func)
	balance_tree(root);
	}
	} else {
	/* Allocate and insert a new node into the tree */
	int name_length = strlen(name);
	f = *root = checkasm_malloc(sizeof(CheckasmFunc) + name_length);
	memcpy(f->name, name, name_length + 1);
	}

	return f;
	}

	/* Perform tests and benchmarks for the specified cpu flag if supported by the host */
	static void check_cpu_flag(const char *name, int flag)
	{
	int old_cpu_flag = state.cpu_flag;

	flag \|= old_cpu_flag;
	av_force_cpu_flags(-1);
	state.cpu_flag = flag & av_get_cpu_flags();
	av_force_cpu_flags(state.cpu_flag);

	if (!flag \|\| state.cpu_flag != old_cpu_flag) {
	int i;

	state.cpu_flag_name = name;
	for (i = 0; tests[i].func; i++) {
	if (state.test_name && strcmp(tests[i].name, state.test_name))
	continue;
	state.current_test_name = tests[i].name;
	tests[i].func();
	}
	}
	}

	/* Print the name of the current CPU flag, but only do it once */
	static void print_cpu_name(void)
	{
	if (state.cpu_flag_name) {
	color_printf(COLOR_YELLOW, "%s:\n", state.cpu_flag_name);
	state.cpu_flag_name = NULL;
	}
	}

	#if CONFIG_LINUX_PERF
	static int bench_init_linux(void)
	{
	struct perf_event_attr attr = {
	.type = PERF_TYPE_HARDWARE,
	.size = sizeof(struct perf_event_attr),
	.config = PERF_COUNT_HW_CPU_CYCLES,
	.disabled = 1, // start counting only on demand
	.exclude_kernel = 1,
	.exclude_hv = 1,
	};

	printf("benchmarking with Linux Perf Monitoring API\n");

	state.sysfd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
	if (state.sysfd == -1) {
	perror("syscall");
	return -1;
	}
	return 0;
	}
	#endif

	#if !CONFIG_LINUX_PERF
	static int bench_init_ffmpeg(void)
	{
	#ifdef AV_READ_TIME
	printf("benchmarking with native FFmpeg timers\n");
	return 0;
	#else
	fprintf(stderr, "checkasm: --bench is not supported on your system\n");
	return -1;
	#endif
	}
	#endif

	static int bench_init(void)
	{
	#if CONFIG_LINUX_PERF
	int ret = bench_init_linux();
	#else
	int ret = bench_init_ffmpeg();
	#endif
	if (ret < 0)
	return ret;

	state.nop_time = measure_nop_time();
	printf("nop: %d.%d\n", state.nop_time/10, state.nop_time%10);
	return 0;
	}

	static void bench_uninit(void)
	{
	#if CONFIG_LINUX_PERF
	if (state.sysfd > 0)
	close(state.sysfd);
	#endif
	}

	int main(int argc, char *argv[])
	{
	unsigned int seed = av_get_random_seed();
	int i, ret = 0;

	#if ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
	if (have_vfp(av_get_cpu_flags()) \|\| have_neon(av_get_cpu_flags()))
	checkasm_checked_call = checkasm_checked_call_vfp;
	#endif

	if (!tests[0].func \|\| !cpus[0].flag) {
	fprintf(stderr, "checkasm: no tests to perform\n");
	return 0;
	}

	while (argc > 1) {
	if (!strncmp(argv[1], "--bench", 7)) {
	if (bench_init() < 0)
	return 1;
	if (argv[1][7] == '=') {
	state.bench_pattern = argv[1] + 8;
	state.bench_pattern_len = strlen(state.bench_pattern);
	} else
	state.bench_pattern = "";
	} else if (!strncmp(argv[1], "--test=", 7)) {
	state.test_name = argv[1] + 7;
	} else if (!strcmp(argv[1], "--verbose") \|\| !strcmp(argv[1], "-v")) {
	state.verbose = 1;
	} else {
	seed = strtoul(argv[1], NULL, 10);
	}

	argc--;
	argv++;
	}

	fprintf(stderr, "checkasm: using random seed %u\n", seed);
	av_lfg_init(&checkasm_lfg, seed);

	check_cpu_flag(NULL, 0);
	for (i = 0; cpus[i].flag; i++)
	check_cpu_flag(cpus[i].name, cpus[i].flag);

	if (state.num_failed) {
	fprintf(stderr, "checkasm: %d of %d tests have failed\n", state.num_failed, state.num_checked);
	ret = 1;
	} else {
	fprintf(stderr, "checkasm: all %d tests passed\n", state.num_checked);
	if (state.bench_pattern) {
	print_benchs(state.funcs);
	}
	}

	destroy_func_tree(state.funcs);
	bench_uninit();
	return ret;
	}

	/* Decide whether or not the specified function needs to be tested and
	* allocate/initialize data structures if needed. Returns a pointer to a
	* reference function if the function should be tested, otherwise NULL */
	void checkasm_check_func(void func, const char *name, ...)
	{
	char name_buf[256];
	void *ref = func;
	CheckasmFuncVersion *v;
	int name_length;
	va_list arg;

	va_start(arg, name);
	name_length = vsnprintf(name_buf, sizeof(name_buf), name, arg);
	va_end(arg);

	if (!func \|\| name_length <= 0 \|\| name_length >= sizeof(name_buf))
	return NULL;

	state.current_func = get_func(&state.funcs, name_buf);
	state.funcs->color = 1;
	v = &state.current_func->versions;

	if (v->func) {
	CheckasmFuncVersion *prev;
	do {
	/* Only test functions that haven't already been tested */
	if (v->func == func)
	return NULL;

	if (v->ok)
	ref = v->func;

	prev = v;
	} while ((v = v->next));

	v = prev->next = checkasm_malloc(sizeof(CheckasmFuncVersion));
	}

	v->func = func;
	v->ok = 1;
	v->cpu = state.cpu_flag;
	state.current_func_ver = v;

	if (state.cpu_flag)
	state.num_checked++;

	return ref;
	}

	/* Decide whether or not the current function needs to be benchmarked */
	int checkasm_bench_func(void)
	{
	return !state.num_failed && state.bench_pattern &&
	!strncmp(state.current_func->name, state.bench_pattern, state.bench_pattern_len);
	}

	/* Indicate that the current test has failed */
	void checkasm_fail_func(const char *msg, ...)
	{
	if (state.current_func_ver->cpu && state.current_func_ver->ok) {
	va_list arg;

	print_cpu_name();
	fprintf(stderr, " %s_%s (", state.current_func->name, cpu_suffix(state.current_func_ver->cpu));
	va_start(arg, msg);
	vfprintf(stderr, msg, arg);
	va_end(arg);
	fprintf(stderr, ")\n");

	state.current_func_ver->ok = 0;
	state.num_failed++;
	}
	}

	/* Get the benchmark context of the current function */
	CheckasmPerf *checkasm_get_perf_context(void)
	{
	CheckasmPerf *perf = &state.current_func_ver->perf;
	memset(perf, 0, sizeof(*perf));
	perf->sysfd = state.sysfd;
	return perf;
	}

	/* Print the outcome of all tests performed since the last time this function was called */
	void checkasm_report(const char *name, ...)
	{
	static int prev_checked, prev_failed, max_length;

	if (state.num_checked > prev_checked) {
	int pad_length = max_length + 4;
	va_list arg;

	print_cpu_name();
	pad_length -= fprintf(stderr, " - %s.", state.current_test_name);
	va_start(arg, name);
	pad_length -= vfprintf(stderr, name, arg);
	va_end(arg);
	fprintf(stderr, "%*c", FFMAX(pad_length, 0) + 2, '[');

	if (state.num_failed == prev_failed)
	color_printf(COLOR_GREEN, "OK");
	else
	color_printf(COLOR_RED, "FAILED");
	fprintf(stderr, "]\n");

	prev_checked = state.num_checked;
	prev_failed = state.num_failed;
	} else if (!state.cpu_flag) {
	/* Calculate the amount of padding required to make the output vertically aligned */
	int length = strlen(state.current_test_name);
	va_list arg;

	va_start(arg, name);
	length += vsnprintf(NULL, 0, name, arg);
	va_end(arg);

	if (length > max_length)
	max_length = length;
	}
	}

	#define DEF_CHECKASM_CHECK_FUNC(type, fmt) \
	int checkasm_check_##type(const char *const file, const int line, \
	const type *buf1, ptrdiff_t stride1, \
	const type *buf2, ptrdiff_t stride2, \
	const int w, int h, const char *const name) \
	{ \
	int y = 0; \
	stride1 /= sizeof(*buf1); \
	stride2 /= sizeof(*buf2); \
	for (y = 0; y < h; y++) \
	if (memcmp(&buf1[ystride1], &buf2[ystride2], wsizeof(buf1))) \
	break; \
	if (y == h) \
	return 0; \
	checkasm_fail_func("%s:%d", file, line); \
	if (!state.verbose) \
	return 1; \
	fprintf(stderr, "%s:\n", name); \
	while (h--) { \
	for (int x = 0; x < w; x++) \
	fprintf(stderr, " " fmt, buf1[x]); \
	fprintf(stderr, " "); \
	for (int x = 0; x < w; x++) \
	fprintf(stderr, " " fmt, buf2[x]); \
	fprintf(stderr, " "); \
	for (int x = 0; x < w; x++) \
	fprintf(stderr, "%c", buf1[x] != buf2[x] ? 'x' : '.'); \
	buf1 += stride1; \
	buf2 += stride2; \
	fprintf(stderr, "\n"); \
	} \
	return 1; \
	}

	DEF_CHECKASM_CHECK_FUNC(uint8_t, "%02x")
	DEF_CHECKASM_CHECK_FUNC(uint16_t, "%04x")
	DEF_CHECKASM_CHECK_FUNC(int16_t, "%6d")
	DEF_CHECKASM_CHECK_FUNC(int32_t, "%9d")