Added more comments

This commit is contained in:
Nikola
2026-07-19 19:06:27 +02:00
parent 193c1f20ad
commit 748d0521bc
3 changed files with 73 additions and 18 deletions
+23 -5
View File
@@ -32,7 +32,7 @@ void tricorn(float complex start, size_t width, ssize_t height, float res, unsig
__m128 minus_two = _mm_set1_ps(-2.0f);
float c_imag = c_start_imag;
__m128 c_imag_vector = _mm_set1_ps(c_imag);
__m128 c_imag_vector = _mm_set1_ps(c_imag); // Initialize imagiinary vector which will be acumulated
float four_res = 4 * res;
@@ -41,26 +41,33 @@ void tricorn(float complex start, size_t width, ssize_t height, float res, unsig
for(ssize_t y = 0; y < actual_height;y++) {
size_t x = 0;
// Initialize real vector which will be accumulated
__m128 c_real_vector = _mm_setr_ps(c_start_real,c_start_real + 1.0f*res,c_start_real + 2.0f*res, c_start_real + 3.0f*res);
for(; x < simd_width;x += 4) { //SIMD Loop
// Initialize start values for the calculation
__m128 real = _mm_setzero_ps();
__m128 imag = _mm_setzero_ps();
__m128i iterations = _mm_setzero_si128();
__m128i active_mask = _mm_set1_epi32(-1);
__m128i active_mask = _mm_set1_epi32(-1); // Active mask will track which pixels have digerved - 0 for diverged, 1 - for contained, at start 0xFFFF
for(unsigned i = 0; i < n;i++) {
// Calculate squared values of real and imaginary
__m128 real2 = _mm_mul_ps(real,real);
__m128 imag2 = _mm_mul_ps(imag,imag);
// Detect which have diverged
__m128 unbounded = _mm_cmple_ps(_mm_add_ps(real2,imag2),four);
__m128i unbounded_i = _mm_castps_si128(unbounded);
// Update the active mask
active_mask = _mm_and_si128(active_mask,unbounded_i);
// If all have diverged break
if(_mm_test_all_zeros(active_mask,active_mask)) {
break;
}
// Add the iterations for each pixel only if it hasn't diverged
iterations = _mm_sub_epi32(iterations,active_mask);
imag = _mm_add_ps(c_imag_vector,_mm_mul_ps(minus_two, _mm_mul_ps(real,imag)));
@@ -68,33 +75,43 @@ void tricorn(float complex start, size_t width, ssize_t height, float res, unsig
}
__m128i mod64 = _mm_and_si128(iterations, _mm_set1_epi32(63));
__m128i times4 = _mm_slli_epi32(mod64, 2);
__m128i values = _mm_sub_epi32(_mm_set1_epi32(255), times4);
// Calculate the value for the pixel
// value = 255 - 4 * (i % 64)
__m128i mod64 = _mm_and_si128(iterations, _mm_set1_epi32(63)); // mod is realised with a bitmask
__m128i times4 = _mm_slli_epi32(mod64, 2); // then multiplication by 4 is shift by 2
__m128i values = _mm_sub_epi32(_mm_set1_epi32(255), times4); // subtraction from 255
// pixels which have not escaped need to be colored black so value = 0
__m128i max_iter = _mm_set1_epi32(n);
__m128i is_max = _mm_cmpeq_epi32(iterations, max_iter);
values = _mm_andnot_si128(is_max, values);
// Convert vector to an array of ints
unsigned int value_array[4];
_mm_storeu_si128((__m128i*)value_array,values);
// Write the 4 values in the image buffer
for(unsigned i = 0 ; i < 4;i++) {
unsigned int value = value_array[i];
size_t position = (y*width + (x+i)) * bytesPerColor;
// If grayscale just take value
if(!color) {
img[position] = value;
}
else {
// If colored use the lookup table to get the RGB values
img[position] = color_lookup_table[value][0];
img[position + 1] = color_lookup_table[value][1];
img[position + 2] = color_lookup_table[value][2];
}
}
// Accumulate the real part
c_real_vector = _mm_add_ps(c_real_vector,_mm_set1_ps(four_res));
}
// Follow up loop for the remaining pixels
// Calculates them scalarly
for(;x < width; x++) {
float c_real = c_start_real + (x*res);
unsigned int value = converge(c_real,c_imag,n);
@@ -110,6 +127,7 @@ void tricorn(float complex start, size_t width, ssize_t height, float res, unsig
img[position + 2] = ((value*5) % 255);
}
}
// Accumulate the imaginary part
c_imag += vertical_step;
c_imag_vector = _mm_add_ps(c_imag_vector,vertical_step_vector);
}
+27 -7
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@@ -28,62 +28,80 @@ void tricorn_V2(float complex start, size_t width, ssize_t height, float res, un
float c_start_real = creal(start);
float c_start_imag = height > 0 ? cimag(start) : cimag(start) + (actual_height - 1) * res;
// Prepared vectors for later
__m128 four = _mm_set1_ps(4.0f);
__m128 minus_two = _mm_set1_ps(-2.0f);
for(ssize_t y = 0; y < actual_height;y++) {
// Calculate the imaginary part once per row and create a vector from it
float c_imag = c_start_imag + (y * imag_direction) * res;
__m128 c_imag_vector = _mm_set1_ps(c_imag);
size_t x = 0;
for(; x < simd_width;x += 4) { //SIMD Loop
// Calculate real part for the first pixel and then create vector for the group of for pixels
float c_real = c_start_real + (x*res);
__m128 c_real_vector = _mm_setr_ps(c_real,c_real+1.0f*res,c_real+2.0f*res,c_real+3.0f*res);
// Initialize start values for the calculation
__m128 real = _mm_setzero_ps();
__m128 imag = _mm_setzero_ps();
__m128i iterations = _mm_setzero_si128();
__m128i active_mask = _mm_set1_epi32(-1);
__m128i active_mask = _mm_set1_epi32(-1); // Active mask will track which pixels have digerved - 0 for diverged, 1 - for contained, at start 0xFFFF
for(unsigned i = 0; i < n;i++) {
// Calculate squared values of real and imaginary
__m128 real2 = _mm_mul_ps(real,real);
__m128 imag2 = _mm_mul_ps(imag,imag);
__m128 unbounded = _mm_cmple_ps(_mm_add_ps(real2,imag2),four);
__m128i unbounded_i = _mm_castps_si128(unbounded);
// Detect which have diverged
__m128 unbounded = _mm_cmple_ps(_mm_add_ps(real2,imag2),four);
__m128i unbounded_i = _mm_castps_si128(unbounded); // Cast to __m128i
// Update the active mask
active_mask = _mm_and_si128(active_mask,unbounded_i);
// If all have diverged break
if(_mm_test_all_zeros(active_mask,active_mask)) {
break;
}
// Add the iterations for each pixel only if it hasn't diverged
iterations = _mm_sub_epi32(iterations,active_mask);
imag = _mm_add_ps(c_imag_vector,_mm_mul_ps(minus_two, _mm_mul_ps(real,imag)));
real = _mm_add_ps(_mm_sub_ps(real2,imag2),c_real_vector);
}
// Calculate the value for the pixel
// value = 255 - 4 * (i % 64)
__m128i mod64 = _mm_and_si128(iterations, _mm_set1_epi32(63)); // mod is realised with a bitmask
__m128i times4 = _mm_slli_epi32(mod64, 2); // then multiplication by 4 is shift by 2
__m128i values = _mm_sub_epi32(_mm_set1_epi32(255), times4); // subtraction from 255
__m128i mod64 = _mm_and_si128(iterations, _mm_set1_epi32(63));
__m128i times4 = _mm_slli_epi32(mod64, 2);
__m128i values = _mm_sub_epi32(_mm_set1_epi32(255), times4);
// pixels which have not escaped need to be colored black so value = 0
__m128i max_iter = _mm_set1_epi32(n);
__m128i is_max = _mm_cmpeq_epi32(iterations, max_iter);
values = _mm_andnot_si128(is_max, values);
// Convert vector to an array of ints
unsigned int value_array[4];
_mm_storeu_si128((__m128i*)value_array,values);
// Write the 4 values in the image buffer
for(unsigned i = 0 ; i < 4;i++) {
unsigned int value = value_array[i];
size_t position = (y*width + (x+i)) * bytesPerColor;
// If grayscale just take value
if(!color) {
img[position] = value;
}
else {
// If colored use the lookup table to get the RGB values
img[position] = color_lookup_table[value][0];
img[position + 1] = color_lookup_table[value][1];
img[position + 2] = color_lookup_table[value][2];
@@ -91,6 +109,8 @@ void tricorn_V2(float complex start, size_t width, ssize_t height, float res, un
}
}
// Follow up loop for the remaining pixels
// Calculates them scalarly
for(;x < width; x++) {
float c_real = c_start_real + (x*res);
unsigned int value = converge(c_real,c_imag,n);
+23 -6
View File
@@ -101,7 +101,7 @@ static void* compute(void * vargs){
__m128 minus_two = _mm_set1_ps(-2.0f);
float c_imag = args->start_i;
__m128 c_imag_vector = _mm_set1_ps(c_imag);
__m128 c_imag_vector = _mm_set1_ps(c_imag); // Initialize imagiinary vector which will be acumulated
float four_res = 4 * c->res;
float vertical_step = (c->flipped? -1.0f: 1.0f) * c->res;
@@ -109,60 +109,76 @@ static void* compute(void * vargs){
for(size_t y = args->start_row; y < args->stop_row;y++) {
size_t x = 0;
// Initialize real vector which will be accumulated
__m128 c_real_vector = _mm_setr_ps(c_start_real,c_start_real + 1.0f*c->res,c_start_real + 2.0f*c->res, c_start_real + 3.0f*c->res);
for(; x < simd_width;x += 4) { //SIMD Loop
// Initialize start values for the calculation
__m128 real = _mm_setzero_ps();
__m128 imag = _mm_setzero_ps();
__m128i iterations = _mm_setzero_si128();
__m128i active_mask = _mm_set1_epi32(-1);
__m128i active_mask = _mm_set1_epi32(-1); // Active mask will track which pixels have digerved - 0 for diverged, 1 - for contained, at start 0xFFFF
for(unsigned i = 0; i < c->n;i++) {
// Calculate squared values of real and imaginary
__m128 real2 = _mm_mul_ps(real,real);
__m128 imag2 = _mm_mul_ps(imag,imag);
// Detect which have diverged
__m128 unbounded = _mm_cmple_ps(_mm_add_ps(real2,imag2),four);
__m128i unbounded_i = _mm_castps_si128(unbounded);
// Update the active mask
active_mask = _mm_and_si128(active_mask,unbounded_i);
// If all have diverged break
if(_mm_test_all_zeros(active_mask,active_mask)) {
break;
}
// Add the iterations for each pixel only if it hasn't diverged
iterations = _mm_sub_epi32(iterations,active_mask);
imag = _mm_add_ps(c_imag_vector,_mm_mul_ps(minus_two, _mm_mul_ps(real,imag)));
real = _mm_add_ps(_mm_sub_ps(real2,imag2),c_real_vector);
}
// Calculate the value for the pixel
// value = 255 - 4 * (i % 64)
__m128i mod64 = _mm_and_si128(iterations, _mm_set1_epi32(63)); // mod is realised with a bitmask
__m128i times4 = _mm_slli_epi32(mod64, 2); // then multiplication by 4 is shift by 2
__m128i values = _mm_sub_epi32(_mm_set1_epi32(255), times4); // subtraction from 255
__m128i mod64 = _mm_and_si128(iterations, _mm_set1_epi32(63));
__m128i times4 = _mm_slli_epi32(mod64, 2);
__m128i values = _mm_sub_epi32(_mm_set1_epi32(255), times4);
// pixels which have not escaped need to be colored black so value = 0
__m128i max_iter = _mm_set1_epi32(c->n);
__m128i is_max = _mm_cmpeq_epi32(iterations, max_iter);
values = _mm_andnot_si128(is_max, values);
// Convert vector to an array of ints
unsigned int value_array[4];
_mm_storeu_si128((__m128i*)value_array,values);
// Write the 4 values in the image buffer
for(unsigned i = 0 ; i < 4;i++) {
unsigned int value = value_array[i];
size_t position = (y*c->width + (x+i)) * bytes_per_color;
if(!c->color) {
// If grayscale just take value
c->img[position] = value;
}
else {
// If colored use the lookup table to get the RGB values
c->img[position] = color_lookup_table[value][0];
c->img[position + 1] = color_lookup_table[value][1];
c->img[position + 2] = color_lookup_table[value][2];
}
}
// Accumulate the real part
c_real_vector = _mm_add_ps(c_real_vector,_mm_set1_ps(four_res));
}
// Follow up loop for the remaining pixels
// Calculates them scalarly
for(;x < c->width; x++) {
float c_real = c_start_real + (x*c->res);
unsigned int value = converge(c_real,c_imag,c->n);
@@ -178,6 +194,7 @@ static void* compute(void * vargs){
c->img[position + 2] = color_lookup_table[value][2];
}
}
// Accumulate the imaginary part
c_imag += vertical_step;
c_imag_vector = _mm_add_ps(c_imag_vector,vertical_step_vector);
}