text: /*
   * jsimd_arm.c
   *
   * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
   * Copyright 2009-2011 D. R. Commander
   * 
   * 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
   * ARM architecture.
   *
   * Based on the stubs from 'jsimd_none.c'
   */
  
  #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>
  
  static unsigned int simd_support = ~0;
  
  #if defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)
  
  #define SOMEWHAT_SANE_PROC_CPUINFO_SIZE_LIMIT (1024 * 1024)
  
  LOCAL(int)
  check_feature (char *buffer, char *feature)
  {
    char *p;
    if (*feature == 0)
      return 0;
    if (strncmp(buffer, "Features", 8) != 0)
      return 0;
    buffer += 8;
    while (isspace(*buffer))
      buffer++;
  
    /* Check if 'feature' is present in the buffer as a separate word */
    while ((p = strstr(buffer, feature))) {
      if (p > buffer && !isspace(*(p - 1))) {
        buffer++;
        continue;
      }
      p += strlen(feature);
      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;
    simd_support = 0;
  
    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_feature(buffer, "neon"))
          simd_support |= JSIMD_ARM_NEON;
      }
      fclose(fd);
    }
    free(buffer);
    return 1;
  }
  
  #endif
  
  /*
   * Check what SIMD accelerations are supported.
   *
   * FIXME: This code is racy under a multi-threaded environment.
   */
  LOCAL(void)
  init_simd (void)
  {
    char *env = NULL;
  #if !defined(__ARM_NEON__) && 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;
  
  #if defined(__ARM_NEON__)
    simd_support |= JSIMD_ARM_NEON;
  #elif defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)
    /* We still have a chance to use NEON regardless of globally used
     * -mcpu/-mfpu options passed to gcc by performing runtime detection via
     * /proc/cpuinfo parsing on linux/android */
    while (!parse_proc_cpuinfo(bufsize)) {
      bufsize *= 2;
      if (bufsize > SOMEWHAT_SANE_PROC_CPUINFO_SIZE_LIMIT)
        break;
    }
  #endif
  
    /* Force different settings through environment variables */
    env = getenv("JSIMD_FORCE_ARM_NEON");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_support &= JSIMD_ARM_NEON;
    env = getenv("JSIMD_FORCE_NO_SIMD");
    if ((env != NULL) && (strcmp(env, "1") == 0))
      simd_support = 0;
  }
  
  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(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:
        neonfct=jsimd_extrgb_ycc_convert_neon;
        break;
      case JCS_EXT_RGBX:
      case JCS_EXT_RGBA:
        neonfct=jsimd_extrgbx_ycc_convert_neon;
        break;
      case JCS_EXT_BGR:
        neonfct=jsimd_extbgr_ycc_convert_neon;
        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:
        neonfct=jsimd_extrgb_ycc_convert_neon;
        break;
    }
  
    if (simd_support & JSIMD_ARM_NEON)
      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:
        neonfct=jsimd_ycc_extrgb_convert_neon;
        break;
      case JCS_EXT_RGBX:
      case JCS_EXT_RGBA:
        neonfct=jsimd_ycc_extrgbx_convert_neon;
        break;
      case JCS_EXT_BGR:
        neonfct=jsimd_ycc_extbgr_convert_neon;
        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:
        neonfct=jsimd_ycc_extrgb_convert_neon;
        break;
    }
  
    if (simd_support & JSIMD_ARM_NEON)
      neonfct(cinfo->output_width, input_buf,
          input_row, output_buf, num_rows);
  }
  
  GLOBAL(int)
  jsimd_can_h2v2_downsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(int)
  jsimd_can_h2v1_downsample (void)
  {
    init_simd();
  
    return 0;
  }
  
  GLOBAL(void)
  jsimd_h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
                         JSAMPARRAY input_data, JSAMPARRAY output_data)
  {
  }
  
  GLOBAL(void)
  jsimd_h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
                         JSAMPARRAY input_data, JSAMPARRAY 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)
  {
    if (simd_support & JSIMD_ARM_NEON)
      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();
  
    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)
  {
  }
  
  GLOBAL(void)
  jsimd_fdct_ifast (DCTELEM * data)
  {
    if (simd_support & JSIMD_ARM_NEON)
      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)
  {
    if (simd_support & JSIMD_ARM_NEON)
      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)
  {
    if ((simd_support & JSIMD_ARM_NEON))
      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)
  {
    if ((simd_support & JSIMD_ARM_NEON))
      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)
  {
    if ((simd_support & JSIMD_ARM_NEON))
      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)
  {
    if ((simd_support & JSIMD_ARM_NEON))
      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)
  {
  }
  
  