C++ vs. C ; R5G6B5 color pixel transform battle source (1)

C++ vs. C ; R5G6B5 color pixel transform battle source (1)

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README.md

Article

http://usagi.hatenablog.jp/entry/2012/12/23/181513

build eg.

$ cc master.c -o master_c.O0 -O0
$ cc master_macro.c -o master_macro_c.O0 -O0
$ g++ -std=c++11 master_fixed.cxx -o master_fixed_cxx.O0 -O0

dependency

• master_fixed_cxx: boost (it can replace std)

Copyrights and Licenses

A PART OF MASTER SOURCE

(C) 2012 池田 公平. Allrights reserved.

ANOTHER PARTS

(C) 2012 Usagi Ito / Wonder Rabbit Project.

To the extent possible under law, Usagi Ito has waived all copyright and related or neighboring rights to this work. This work is published from: 日本.

master.c

#include <malloc.h>
#include <stdint.h>
#include <time.h>
#include <stdio.h>

#define IMAGE_HEIGHT      1920
#define IMAGE_WIDTH       1080

// NOTE: THERE ARE BAD DEFINE USAGE.
#define short uint16_t
#define int   unsigned

// BEGIN OF MASTER SOURCE
int get_r(short x) { return ((x >> 8) & 0xf8); }
int get_g(short x) { return ((x >> 3) & 0xfc); }
int get_b(short x) { return ((x << 3) & 0xff); }

short to_rgb(int r, int g, int b) {
  return (short)(((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | (b >> 3));
}

void test_bitmap_color_transform_pure_c(short* buffer) {
  short* p = buffer;
  int n;
  for (n = 0; n < IMAGE_HEIGHT * IMAGE_WIDTH; ++n, ++p) {
    int r = get_r(*p);
    int g = get_g(*p);
    int b = get_b(*p);
    *p = to_rgb(g, b, r);
  }
}
// END OF MASTER SOURCE

// NOTE: UNDEFINE BAD DEFINES.
#undef int
#undef short

#define NUM_OF_LOOP 1000

int main(){

  uint16_t* pixels = calloc(
    IMAGE_WIDTH * IMAGE_HEIGHT,
    sizeof( uint16_t )
  );

  unsigned n;
  clock_t t, tt;
  
  setvbuf(stdout, NULL, _IONBF, 0);
  puts("last:");

  for(n = NUM_OF_LOOP, tt = 0; n; --n){
    t = clock();
    test_bitmap_color_transform_pure_c( pixels );
    tt += clock() - t;
    printf("\x1b[12D  %08X", n);
  }
  puts("\x1b[12D  FINISHED\n");

  free(pixels);

  printf(
    "result: %.3e [sec/function]\n",
    (double)tt / CLOCKS_PER_SEC / NUM_OF_LOOP
  );

  return 0;
}

master_fixed.cxx

#include <vector>
#include <boost/range/algorithm/for_each.hpp>
#include <chrono>
#include <iostream>
#include <iomanip>

using namespace std;
using namespace boost;

// BEGIN OF MASTER SOURCE
template <int PixelBits>
struct pixel_t {};
template <>
struct pixel_t<16> {
 uint16_t value_;
 pixel_t() : value_(0) {}
 pixel_t(int r, int g, int b)
   : value_(static_cast<uint16_t>(((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | (b >> 3)))
 {}
 int get_r() const { return (value_ >> 8) & 0xf8; }
 int get_g() const { return (value_ >> 3) & 0xfc; }
 int get_b() const { return (value_ << 3) & 0xff; }
};
struct transcolor {
 template <typename Pixel>
 void operator () (Pixel& px) {
   px = Pixel(px.get_g(), px.get_b(), px.get_r());
 }
};
 
void test_bitmap_color_transform_cpp(vector< pixel_t<16> >& buffer){
 for_each(buffer, transcolor());
}
// END OF MASTER SOURCE

namespace{
  constexpr size_t image_width  = 1920;
  constexpr size_t image_height = 1080;
  constexpr auto num_of_loop = 1000ull;
}

int main(){
  vector<pixel_t<16>> pixels;
  pixels.resize(image_width * image_height);
  
  using c = chrono::high_resolution_clock;
  c::duration tt;

  cout << "last:\n";

  for(auto n = num_of_loop; n; --n){
    auto t = c::now();
    test_bitmap_color_transform_cpp(pixels);
    tt += c::now() - t;
    cout
      << "\x1b[12D  "
      << hex
      << setw(8)
      << setfill('0')
      << n
      << flush
      ;
  }
  cout
    << "\x1b[12D  FINISHED"
    << endl;

  cout
    << "result: "
    << scientific
    << setprecision(3)
    << chrono::duration_cast<chrono::duration<double>>(tt).count() / num_of_loop
    << endl;
}

master_macro.c

#include <malloc.h>
#include <stdint.h>
#include <time.h>
#include <stdio.h>

#define IMAGE_HEIGHT      1920
#define IMAGE_WIDTH       1080

// NOTE: THERE ARE BAD DEFINE USAGE.
#define short uint16_t
#define int   unsigned

// BEGIN OF MASTER SOURCE
#define GET_R(x) ((x >> 8) & 0xf8)
#define GET_G(x) ((x >> 3) & 0xfc)
#define GET_B(x) ((x << 3) & 0xff)
#define TO_RGB(r, g, b) (((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | (b >> 3))

void test_bitmap_color_transform_macro_c(short* buffer) {
  short* p = buffer;
  int n;
  for (n = 0; n < IMAGE_HEIGHT * IMAGE_WIDTH; ++n, ++p) {
      int r = GET_R(*p);
      int g = GET_G(*p);
      int b = GET_B(*p);
      *p = (short)TO_RGB(g, b, r);
  }
}
// END OF MASTER SOURCE

// NOTE: UNDEFINE BAD DEFINES.
#undef int
#undef short

#define NUM_OF_LOOP 1000

int main(){

  uint16_t* pixels = calloc(
    IMAGE_WIDTH * IMAGE_HEIGHT,
    sizeof( uint16_t )
  );

  unsigned n;
  clock_t t, tt;
  
  setvbuf(stdout, NULL, _IONBF, 0);
  puts("last:");

  for(n = NUM_OF_LOOP, tt = 0; n; --n){
    t = clock();
    test_bitmap_color_transform_macro_c( pixels );
    tt += clock() - t;
    printf("\x1b[12D  %08X", n);
  }
  puts("\x1b[12D  FINISHED\n");

  free(pixels);

  printf(
    "result: %.3e [sec/function]\n",
    (double)tt / CLOCKS_PER_SEC / NUM_OF_LOOP
  );

  return 0;
}