text: /*
   * jsimd_arm64.c
   *
   * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
   * Copyright (C) 2009-2011, 2013-2014, 2016, D. R. Commander.
   * Copyright (C) 2015-2016, Matthieu Darbois.
   *
   * Based on the x86 SIMD extension for IJG JPEG library,
   * Copyright (C) 1999-2006, MIYASAKA Masaru.
   * For conditions of distribution and use, see copyright notice in jsimdext.inc
   *
   * This file contains the interface between the "normal" portions
   * of the library and the SIMD implementations when running on a
   * 64-bit ARM architecture.
   */
  
  #define JPEG_INTERNALS
  #include "../jinclude.h"
  #include "../jpeglib.h"
  #include "../jsimd.h"
  #include "../jdct.h"
  #include "../jsimddct.h"
  #include "jsimd.h"
  
  #include <stdio.h>
  #include <string.h>
  #include <ctype.h>
  
  #define JSIMD_FASTLD3 1
  #define JSIMD_FASTST3 2
  #define JSIMD_FASTTBL 4
  
  static unsigned int simd_support = ~0;
  static unsigned int simd_huffman = 1;
  static unsigned int simd_features = JSIMD_FASTLD3 | JSIMD_FASTST3 |
                                      JSIMD_FASTTBL;
  
  #if (defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)) && !defined(AVOID_CPUINFO_CHECK)
  
  #define SOMEWHAT_SANE_PROC_CPUINFO_SIZE_LIMIT (1024 * 1024)
  
  LOCAL(int)
  check_cpuinfo (char *buffer, const char *field, char *value)
  {
    char *p;
    if (*value == 0)
      return 0;
    if (strncmp(buffer, field, strlen(field)) != 0)
      return 0;
    buffer += strlen(field);
    while (isspace(*buffer))
      buffer++;
  
    /* Check if 'value' is present in the buffer as a separate word */
    while ((p = strstr(buffer, value))) {
      if (p > buffer && !isspace(*(p - 1))) {
        buffer++;
        continue;
      }
      p += strlen(value);
      if (*p != 0 && !isspace(*p)) {
        buffer++;
        continue;
      }
      return 1;
    }
    return 0;
  }
  
  LOCAL(int)
  parse_proc_cpuinfo (int bufsize)
  {
    char *buffer = (char *)malloc(bufsize);
    FILE *fd;
  
    if (!buffer)
      return 0;
  
    fd = fopen("/proc/cpuinfo", "r");
    if (fd) {
      while (fgets(buffer, bufsize, fd)) {
        if (!strchr(buffer, '\n') && !feof(fd)) {
          /* "impossible" happened - insufficient size of the buffer! */
          fclose(fd);
          free(buffer);
          return 0;
        }
        if (check_cpuinfo(buffer, "CPU part", "0xd03") ||
            check_cpuinfo(buffer, "CPU part", "0xd07"))
          /* The Cortex-A53 has a slow tbl implementation.  We can gain a few
             percent speedup by disabling the use of that instruction.  The
             speedup on Cortex-A57 is more subtle but still measurable. */
          simd_features &= ~JSIMD_FASTTBL;
        else if (check_cpuinfo(buffer, "CPU part", "0x0a1"))
          /* The SIMD version of Huffman encoding is slower than the C version on
             Cavium ThunderX.  Also, ld3 and st3 are abyssmally slow on that
             CPU. */
          simd_huffman = simd_features = 0;
      }
      fclose(fd);
    }
    free(buffer);
    return 1;
  }
  
  #endif
  
  /*
   * Check what SIMD accelerations are supported.
   *
   * FIXME: This code is racy under a multi-threaded environment.
   */
  
  /*
   * ARMv8 architectures support NEON extensions by default.
   * It is no longer optional as it was with ARMv7.
   */
  
  
  LOCAL(void)
  init_simd (void)
  {
    char *env = NULL;
  #if defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)
    int bufsize = 1024; /* an initial guess for the line buffer size limit */
  #endif
  
    if (simd_support != ~0U)
      return;
  
    simd_support = 0;
  
    simd_support |= JSIMD_ARM_NEON;
  #if (defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)) && !defined(AVOID_CPUINFO_CHECK)
    while (!parse_proc_cpuinfo(bufsize)) {
      bufsize *= 2;
      if (bufsize > SOMEWHAT_SANE_PROC_CPUINFO_SIZE_LIMIT)
        break;
    }
  #elif defined(AVOID_CPUINFO_CHECK)
    #if defined(TARGET_IS_CORTEX_A53)
      /*
      The Cortex-A53 has a slow tbl implementation.  We can gain a few
      percent speedup by disabling the use of that instruction.
      */
      simd_features &= ~JSIMD_FASTTBL;
    #endif
  #endif
  
    /* Force different settings through environment variables */
    env = getenv("JSIMD_FORCENEON");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_support = JSIMD_ARM_NEON;
    env = getenv("JSIMD_FORCENONE");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_support = 0;
    env = getenv("JSIMD_NOHUFFENC");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_huffman = 0;
    env = getenv("JSIMD_FASTLD3");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_features |= JSIMD_FASTLD3;
    if ((env != NULL) && (strcmp(env, "0") == 0))
      simd_features &= ~JSIMD_FASTLD3;
    env = getenv("JSIMD_FASTST3");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_features |= JSIMD_FASTST3;
    if ((env != NULL) && (strcmp(env, "0") == 0))
      simd_features &= ~JSIMD_FASTST3;
  }
  
  GLOBAL(int)
  jsimd_can_rgb_ycc (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_rgb_gray (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_ycc_rgb (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_ycc_rgb565 (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_rgb_ycc_convert (j_compress_ptr cinfo,
                         JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
                         JDIMENSION output_row, int num_rows)
  {
    void (*neonfct)(JDIMENSION, JSAMPARRAY, JSAMPIMAGE, JDIMENSION, int);
  
    switch(cinfo->in_color_space) {
      case JCS_EXT_RGB:
        if (simd_features & JSIMD_FASTLD3)
          neonfct=jsimd_extrgb_ycc_convert_neon;
        else
          neonfct=jsimd_extrgb_ycc_convert_neon_slowld3;
        break;
      case JCS_EXT_RGBX:
      case JCS_EXT_RGBA:
        neonfct=jsimd_extrgbx_ycc_convert_neon;
        break;
      case JCS_EXT_BGR:
        if (simd_features & JSIMD_FASTLD3)
          neonfct=jsimd_extbgr_ycc_convert_neon;
        else
          neonfct=jsimd_extbgr_ycc_convert_neon_slowld3;
        break;
      case JCS_EXT_BGRX:
      case JCS_EXT_BGRA:
        neonfct=jsimd_extbgrx_ycc_convert_neon;
        break;
      case JCS_EXT_XBGR:
      case JCS_EXT_ABGR:
        neonfct=jsimd_extxbgr_ycc_convert_neon;
        break;
      case JCS_EXT_XRGB:
      case JCS_EXT_ARGB:
        neonfct=jsimd_extxrgb_ycc_convert_neon;
        break;
      default:
        if (simd_features & JSIMD_FASTLD3)
          neonfct=jsimd_extrgb_ycc_convert_neon;
        else
          neonfct=jsimd_extrgb_ycc_convert_neon_slowld3;
        break;
    }
  
    neonfct(cinfo->image_width, input_buf, output_buf, output_row, num_rows);
  }
  
  GLOBAL(void)
  jsimd_rgb_gray_convert (j_compress_ptr cinfo,
                          JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
                          JDIMENSION output_row, int num_rows)
  {
  }
  
  GLOBAL(void)
  jsimd_ycc_rgb_convert (j_decompress_ptr cinfo,
                         JSAMPIMAGE input_buf, JDIMENSION input_row,
                         JSAMPARRAY output_buf, int num_rows)
  {
    void (*neonfct)(JDIMENSION, JSAMPIMAGE, JDIMENSION, JSAMPARRAY, int);
  
    switch(cinfo->out_color_space) {
      case JCS_EXT_RGB:
        if (simd_features & JSIMD_FASTST3)
          neonfct=jsimd_ycc_extrgb_convert_neon;
        else
          neonfct=jsimd_ycc_extrgb_convert_neon_slowst3;
        break;
      case JCS_EXT_RGBX:
      case JCS_EXT_RGBA:
        neonfct=jsimd_ycc_extrgbx_convert_neon;
        break;
      case JCS_EXT_BGR:
        if (simd_features & JSIMD_FASTST3)
          neonfct=jsimd_ycc_extbgr_convert_neon;
        else
          neonfct=jsimd_ycc_extbgr_convert_neon_slowst3;
        break;
      case JCS_EXT_BGRX:
      case JCS_EXT_BGRA:
        neonfct=jsimd_ycc_extbgrx_convert_neon;
        break;
      case JCS_EXT_XBGR:
      case JCS_EXT_ABGR:
        neonfct=jsimd_ycc_extxbgr_convert_neon;
        break;
      case JCS_EXT_XRGB:
      case JCS_EXT_ARGB:
        neonfct=jsimd_ycc_extxrgb_convert_neon;
        break;
      default:
        if (simd_features & JSIMD_FASTST3)
          neonfct=jsimd_ycc_extrgb_convert_neon;
        else
          neonfct=jsimd_ycc_extrgb_convert_neon_slowst3;
        break;
    }
  
    neonfct(cinfo->output_width, input_buf, input_row, output_buf, num_rows);
  }
  
  GLOBAL(void)
  jsimd_ycc_rgb565_convert (j_decompress_ptr cinfo,
                            JSAMPIMAGE input_buf, JDIMENSION input_row,
                            JSAMPARRAY output_buf, int num_rows)
  {
    jsimd_ycc_rgb565_convert_neon(cinfo->output_width, input_buf, input_row,
                                  output_buf, num_rows);
  }
  
  GLOBAL(int)
  jsimd_can_h2v2_downsample (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_h2v1_downsample (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr,
                         JSAMPARRAY input_data, JSAMPARRAY output_data)
  {
    jsimd_h2v2_downsample_neon(cinfo->image_width, cinfo->max_v_samp_factor,
                               compptr->v_samp_factor, compptr->width_in_blocks,
                               input_data, output_data);
  }
  
  GLOBAL(void)
  jsimd_h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr,
                         JSAMPARRAY input_data, JSAMPARRAY output_data)
  {
    jsimd_h2v1_downsample_neon(cinfo->image_width, cinfo->max_v_samp_factor,
                               compptr->v_samp_factor, compptr->width_in_blocks,
                               input_data, output_data);
  }
  
  GLOBAL(int)
  jsimd_can_h2v2_upsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_h2v1_upsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_h2v2_upsample (j_decompress_ptr cinfo,
                       jpeg_component_info *compptr,
                       JSAMPARRAY input_data,
                       JSAMPARRAY *output_data_ptr)
  {
  }
  
  GLOBAL(void)
  jsimd_h2v1_upsample (j_decompress_ptr cinfo,
                       jpeg_component_info *compptr,
                       JSAMPARRAY input_data,
                       JSAMPARRAY *output_data_ptr)
  {
  }
  
  GLOBAL(int)
  jsimd_can_h2v2_fancy_upsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_h2v1_fancy_upsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_h2v2_fancy_upsample (j_decompress_ptr cinfo,
                             jpeg_component_info *compptr,
                             JSAMPARRAY input_data,
                             JSAMPARRAY *output_data_ptr)
  {
  }
  
  GLOBAL(void)
  jsimd_h2v1_fancy_upsample (j_decompress_ptr cinfo,
                             jpeg_component_info *compptr,
                             JSAMPARRAY input_data,
                             JSAMPARRAY *output_data_ptr)
  {
  }
  
  GLOBAL(int)
  jsimd_can_h2v2_merged_upsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_h2v1_merged_upsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_h2v2_merged_upsample (j_decompress_ptr cinfo,
                              JSAMPIMAGE input_buf,
                              JDIMENSION in_row_group_ctr,
                              JSAMPARRAY output_buf)
  {
  }
  
  GLOBAL(void)
  jsimd_h2v1_merged_upsample (j_decompress_ptr cinfo,
                              JSAMPIMAGE input_buf,
                              JDIMENSION in_row_group_ctr,
                              JSAMPARRAY output_buf)
  {
  }
  
  GLOBAL(int)
  jsimd_can_convsamp (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if (sizeof(DCTELEM) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_convsamp_float (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_convsamp (JSAMPARRAY sample_data, JDIMENSION start_col,
                  DCTELEM *workspace)
  {
    jsimd_convsamp_neon(sample_data, start_col, workspace);
  }
  
  GLOBAL(void)
  jsimd_convsamp_float (JSAMPARRAY sample_data, JDIMENSION start_col,
                        FAST_FLOAT *workspace)
  {
  }
  
  GLOBAL(int)
  jsimd_can_fdct_islow (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(DCTELEM) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_fdct_ifast (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(DCTELEM) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_fdct_float (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_fdct_islow (DCTELEM *data)
  {
    jsimd_fdct_islow_neon(data);
  }
  
  GLOBAL(void)
  jsimd_fdct_ifast (DCTELEM *data)
  {
    jsimd_fdct_ifast_neon(data);
  }
  
  GLOBAL(void)
  jsimd_fdct_float (FAST_FLOAT *data)
  {
  }
  
  GLOBAL(int)
  jsimd_can_quantize (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JCOEF) != 2)
      return 0;
    if (sizeof(DCTELEM) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_quantize_float (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_quantize (JCOEFPTR coef_block, DCTELEM *divisors,
                  DCTELEM *workspace)
  {
    jsimd_quantize_neon(coef_block, divisors, workspace);
  }
  
  GLOBAL(void)
  jsimd_quantize_float (JCOEFPTR coef_block, FAST_FLOAT *divisors,
                        FAST_FLOAT *workspace)
  {
  }
  
  GLOBAL(int)
  jsimd_can_idct_2x2 (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JCOEF) != 2)
      return 0;
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if (sizeof(ISLOW_MULT_TYPE) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_idct_4x4 (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JCOEF) != 2)
      return 0;
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if (sizeof(ISLOW_MULT_TYPE) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info *compptr,
                  JCOEFPTR coef_block, JSAMPARRAY output_buf,
                  JDIMENSION output_col)
  {
    jsimd_idct_2x2_neon(compptr->dct_table, coef_block, output_buf,
                        output_col);
  }
  
  GLOBAL(void)
  jsimd_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info *compptr,
                  JCOEFPTR coef_block, JSAMPARRAY output_buf,
                  JDIMENSION output_col)
  {
    jsimd_idct_4x4_neon(compptr->dct_table, coef_block, output_buf,
                        output_col);
  }
  
  GLOBAL(int)
  jsimd_can_idct_islow (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JCOEF) != 2)
      return 0;
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if (sizeof(ISLOW_MULT_TYPE) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_idct_ifast (void)
  {
    init_simd();
  
    /* The code is optimised for these values only */
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JCOEF) != 2)
      return 0;
    if (BITS_IN_JSAMPLE != 8)
      return 0;
    if (sizeof(JDIMENSION) != 4)
      return 0;
    if (sizeof(IFAST_MULT_TYPE) != 2)
      return 0;
    if (IFAST_SCALE_BITS != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON)
      return 1;
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_idct_float (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_idct_islow (j_decompress_ptr cinfo, jpeg_component_info *compptr,
                    JCOEFPTR coef_block, JSAMPARRAY output_buf,
                    JDIMENSION output_col)
  {
    jsimd_idct_islow_neon(compptr->dct_table, coef_block, output_buf,
                          output_col);
  }
  
  GLOBAL(void)
  jsimd_idct_ifast (j_decompress_ptr cinfo, jpeg_component_info *compptr,
                    JCOEFPTR coef_block, JSAMPARRAY output_buf,
                    JDIMENSION output_col)
  {
    jsimd_idct_ifast_neon(compptr->dct_table, coef_block, output_buf,
                          output_col);
  }
  
  GLOBAL(void)
  jsimd_idct_float (j_decompress_ptr cinfo, jpeg_component_info *compptr,
                    JCOEFPTR coef_block, JSAMPARRAY output_buf,
                    JDIMENSION output_col)
  {
  }
  
  GLOBAL(int)
  jsimd_can_huff_encode_one_block (void)
  {
    init_simd();
  
    if (DCTSIZE != 8)
      return 0;
    if (sizeof(JCOEF) != 2)
      return 0;
  
    if (simd_support & JSIMD_ARM_NEON && simd_huffman)
      return 1;
  
    return 0;
  }
  
  GLOBAL(JOCTET*)
  jsimd_huff_encode_one_block (void *state, JOCTET *buffer, JCOEFPTR block,
                               int last_dc_val, c_derived_tbl *dctbl,
                               c_derived_tbl *actbl)
  {
    if (simd_features & JSIMD_FASTTBL)
      return jsimd_huff_encode_one_block_neon(state, buffer, block, last_dc_val,
                                              dctbl, actbl);
    else
      return jsimd_huff_encode_one_block_neon_slowtbl(state, buffer, block,
                                                      last_dc_val, dctbl, actbl);
  }
  