small fixes and performance improvments

Makefile

@@ -6,7 +6,7 @@ OPENMPFLAGS=  -fopenmp=libomp
 	#CLFLAGS= -D CL_TARGET_OPENCL_VERSION=100  -lOpenCL
 
 
-CFLAGS := $(CFLAGS) -O3 -mavx -march=native
+CFLAGS := $(CFLAGS) -Ofast -mavx -march=native
 CFLAGS := $(CFLAGS) $(OPENMPFLAGS) $(WARNING_FLAGS)
 LDLIBS = $(shell pkg-config --libs sdl2 SDL2_ttf SDL2_image)
 DEBUG_FLAGS = -g -DDEBUG -pg -O0 

src/mandelbrot.c

@@ -31,46 +31,42 @@
  *      3.1 x86intrin.h DONE
 */
 
-int
-mandelbrot_avx(Complex c, unsigned max_iterations)
-{
-    __m256 cr = _mm256_set1_pd(c.real);
-    __m256 ci = _mm256_set1_pd(c.imag);
-
-    __m256 zr = cr;
-    __m256 zi = ci;
-
-    __m256 threshold = _mm256_set1_pd(4); 
-
-    unsigned int k = 1;
-
-    __m256 mk = _mm256_set1_pd(k);
-    __m256 one = _mm256_set1_pd(1);
-    while (++k < max_iterations){
-        /* Compute z1 from z0 */
-        __m256 zr2 = _mm256_mul_pd(zr, zr);
-        __m256 zi2 = _mm256_mul_pd(zi, zi);
-        __m256 zrzi = _mm256_mul_pd(zr, zi);
+int mandelbrot_avx(Complex c, unsigned max_iterations) {
+    __m256d cr = _mm256_set1_pd(c.real);
+    __m256d ci = _mm256_set1_pd(c.imag);
+    
+    __m256d zr = cr;
+    __m256d zi = ci;
+    
+    __m256d threshold = _mm256_set1_pd(4.0);
+    __m256d one = _mm256_set1_pd(1.0);
+    
+    int k = 1;
+    __m256d mk = _mm256_set1_pd(k);
+    
+    while (k < max_iterations) {
+        // Compute z = z^2 + c
+        __m256d zr2 = _mm256_mul_pd(zr, zr);
+        __m256d zi2 = _mm256_mul_pd(zi, zi);
+        __m256d zrzi = _mm256_mul_pd(zr, zi);
         /* zr1 = zr0 * zr0 - zi0 * zi0 + cr */
-        /* zi1 = zr0 * zi0 + zr0 * zi0 + ci */
+        /* zi1 = zr0 * zi0 + zr0 * zi0 + ci */ 
         zr = _mm256_add_pd(_mm256_sub_pd(zr2, zi2), cr);
         zi = _mm256_add_pd(_mm256_add_pd(zrzi, zrzi), ci);
-
-        /* Increment k */
-        zr2 = _mm256_mul_pd(zr, zr);
-        zi2 = _mm256_mul_pd(zi, zi);
-        __m256 mag2 = _mm256_add_pd(zr2, zi2);
-        __m256 mask = _mm256_cmp_pd(mag2, threshold, _CMP_LT_OS);
+        
+        // Check for escape
+        __m256d mag2 = _mm256_add_pd(zr2, zi2);
+        __m256d mask = _mm256_cmp_pd(mag2, threshold, _CMP_LT_OS);
         mk = _mm256_add_pd(_mm256_and_pd(mask, one), mk);
-
-        /* Early bailout? */
-        if (_mm256_testz_pd(mask, _mm256_set1_pd(-1)))
+        
+        if (_mm256_testz_pd(mask, _mm256_set1_pd(-1))) {
             break;
+        }
+        k++;
     }
     return k;
 }
 
-
 int 
 mandelbrot(Complex c, unsigned int max_iterations) {
     Complex z = {0.0, 0.0};
@@ -100,16 +96,36 @@ typedef struct {
     int size;
 }Array;
 
-void
-calculate_set(Array *arr, int height, int width, ViewInfo view, short unsigned use_avx, unsigned int max_iterations)
+Color
+calculate_color(unsigned int iterations, unsigned int max_iterations)
 {
-    int (*mandelbrot_func)(Complex C, unsigned);
+    Color cl;
+    if (iterations == max_iterations){
+        cl.r = 0;
+        cl.g = 0;
+        cl.b = 0;
+        cl.a = 0;
+    } else {
+        double t = (double)iterations / max_iterations;
+        t = 0.5 + 0.5 * tan(log(t + 0.0001) * 3.0);
+        cl.r = 255 * t * 0.5;
+        cl.g = 255 * t * 0.4;
+        cl.b = 255 * t * 0.3;
+        cl.a = 255;
+    }
+    return cl;
+}
+
 
-    if (use_avx == 0)
-        mandelbrot_func = mandelbrot;
-    else
-        mandelbrot_func = mandelbrot_avx;
+void
+calculate_set(Array *arr, int height, int width, ViewInfo view, short unsigned use_avx, short unsigned use_omp, unsigned int max_iterations)
+{
+    int (*mandelbrot_func)(Complex, unsigned) = use_avx == 0 ? mandelbrot : mandelbrot_avx;
+    
+    if (use_omp == 0)
+        goto no_omp;
 
+    #pragma omp parallel for schedule(static, 16)
     for (int y = 0; y < height; y++) {
         for (int x = 0; x < width; x++) {
             long double real = view.x_min + (x * (view.x_max - view.x_min)) / width;
@@ -118,35 +134,12 @@ calculate_set(Array *arr, int height, int width, ViewInfo view, short unsigned u
             
             unsigned int iterations = mandelbrot_func(c, max_iterations);
 
-            if (iterations == max_iterations){
-                arr->pointer[y * width + x].r = 0;
-                arr->pointer[y * width + x].g = 0;
-                arr->pointer[y * width + x].b = 0;
-                arr->pointer[y * width + x].a = 0;
-            } else {
-                double t = (double)iterations / max_iterations;
-                t = 0.5 + 0.5 * tan(log(t + 0.0001) * 3.0);
-
-                arr->pointer[y * width + x].r = 255 * t * 0.5;
-                arr->pointer[y * width + x].g = 255 * t * 0.4;
-                arr->pointer[y * width + x].b = 255 * t;
-                arr->pointer[y * width + x].a = 255;
-            }
+            arr->pointer[y * width + x] = calculate_color(iterations, max_iterations);
         }
     }
-}
+    return;
 
-void
-calculate_set_omp(Array *arr, int height, int width, ViewInfo view, short unsigned use_avx, unsigned int max_iterations)
-{
-    int (*mandelbrot_func)(Complex, unsigned);
-
-    if (use_avx == 0)
-        mandelbrot_func = mandelbrot;
-    else
-        mandelbrot_func = mandelbrot_avx;
-
-    #pragma omp parallel for schedule(guided)
+    no_omp:
     for (int y = 0; y < height; y++) {
         for (int x = 0; x < width; x++) {
             long double real = view.x_min + (x * (view.x_max - view.x_min)) / width;
@@ -154,21 +147,8 @@ calculate_set_omp(Array *arr, int height, int width, ViewInfo view, short unsign
             Complex c = {real, imag};
             
             unsigned int iterations = mandelbrot_func(c, max_iterations);
-
-            if (iterations == max_iterations){
-                arr->pointer[y * width + x].r = 0;
-                arr->pointer[y * width + x].g = 0;
-                arr->pointer[y * width + x].b = 0;
-                arr->pointer[y * width + x].a = 0;
-            } else {
-                double t = (double)iterations / max_iterations;
-                t = 0.5 + 0.5 * tan(log(t + 0.0001) * 3.0);
-
-                arr->pointer[y * width + x].r = 255 * t * 0.5;
-                arr->pointer[y * width + x].g = 255 * t * 0.4;
-                arr->pointer[y * width + x].b = 255 * t;
-                arr->pointer[y * width + x].a = 255;
-            }
+            
+            arr->pointer[y * width + x] = calculate_color(iterations, max_iterations);
         }
     }
 }
@@ -284,14 +264,11 @@ parse_opt (int key, char *arg, struct argp_state *state)
 
 static struct argp argp = {options, parse_opt, NULL, NULL, NULL, NULL, NULL};
 
+
 void 
 render_cl(Array *arr, SDL_Texture *texture, SDL_Renderer *renderer, int width, int height, ViewInfo *view, 
         short unsigned use_avx, short unsigned use_omp, short unsigned *needs_recalc, unsigned int max_iterations) {
     
-    void (*calculate_set_func)(Array *arr, int height, int width, 
-            ViewInfo view, short unsigned use_avx, unsigned max_iterations);
-    
-    calculate_set_func = use_omp ? calculate_set_omp : calculate_set;
 
     SDL_SetRenderDrawColor(renderer, 0, 0, 50, 255);
     SDL_RenderClear(renderer);
@@ -301,7 +278,7 @@ render_cl(Array *arr, SDL_Texture *texture, SDL_Renderer *renderer, int width, i
         arr->size = height * width * sizeof(Color);
     }
     if (*needs_recalc){
-            calculate_set_func(arr, height, width, *view, use_avx, max_iterations); 
+            calculate_set(arr, height, width, *view, use_avx, use_omp, max_iterations); 
             *needs_recalc = 0;
     }
     
@@ -417,6 +394,11 @@ main(int argc, char **argv)
     
 
     int running = 1;
+    // draw the first frame
+    
+    render_cl(&screen, app.texture, app.renderer, app.win_width, app.win_height, &view, args.use_avx, args.use_omp,
+            &app.needs_recalc, args.max_iterations);
+    SDL_RenderPresent(app.renderer); 
 
     while (running)
     {