init for #4: 0.67ms

customers/issue4_getsubpixelvalue/.gitignore

@@ -0,0 +1,2 @@
+.cache/
+build/

customers/issue4_getsubpixelvalue/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.18)
+
+if (NOT CMAKE_BUILD_TYPE)
+    set(CMAKE_BUILD_TYPE Release)
+endif()
+set(CMAKE_CXX_STANDARD 20)
+
+project(main LANGUAGES CXX)
+
+add_executable(main main.cpp)

customers/issue4_getsubpixelvalue/main.cpp

@@ -0,0 +1,96 @@
+// 以下是项目中的一段热点代码
+// 会调用这个函数很多次，用来计算亚像素的像素值，方法是插值（具体算法可以不用管），里头的具体魔数我改了一下，因为是公司的代码，而且跟优化没有关系
+
+double GetSubPixelValue(const double* preCaculatedParameter, int width, int height, double X, double Y)
+{
+	int xIndex[6], yIndex[6];
+	xIndex[0] = int(X + 0.5) - 2;
+	yIndex[0] = int(Y + 0.5) - 2;
+	for (int i = 1; i < 5; i++)
+	{
+		xIndex[i] = xIndex[i - 1] + 1;
+		yIndex[i] = yIndex[i - 1] + 1;
+	}
+
+	double xWeight[5];
+	{
+		double w = X - (double)xIndex[2];
+		double w2 = w * w;
+		double w3 = w * w2;
+		double w4 = w2 * w2;
+		xWeight[0] = 0.111 * w4 - w3 / 22.0 + 0.233 * w2 - 0.344 * w + 0.345;
+		xWeight[1] = -0.333 * w4 + 0.333 * w3 + 0.444 * w2 - 0.555 * w + 0.0666;
+		xWeight[2] = 0.15 *w4 - 0.222 * w2 + 0.0777;
+		xWeight[3] = -0.333 * w4 - 0.333 * w3 + 0.444 * w2 + 0.555 * w + 0.0666;
+		xWeight[4] = 0.111 * w4 + w3 / 22.0 + 0.233 * w2 + 0.344 * w + 0.345;
+	}
+
+	// 下面这个计算方法和上面是一样的
+	double yWeight[5];
+	{
+		double w = Y - (double)yIndex[2];
+		double w2 = w * w;
+		double w3 = w * w2;
+		double w4 = w2 * w2;
+		yWeight[0] = 0.111 * w4 - w3 / 22.0 + 0.233 * w2 - 0.344 * w + 0.345;
+		yWeight[1] = -0.333 * w4 + 0.333 * w3 + 0.444 * w2 - 0.555 * w + 0.0666;
+		yWeight[2] = 0.15 *w4 - 0.222 * w2 + 0.0777;
+		yWeight[3] = -0.333 * w4 - 0.333 * w3 + 0.444 * w2 + 0.555 * w + 0.0666;
+		yWeight[4] = 0.111 * w4 + w3 / 22.0 + 0.233 * w2 + 0.344 * w + 0.345;
+	}
+
+	int width2 = 2 * width - 2;
+	int height2 = 2 * height - 2;
+	for (int i = 0; i < 5; i++)
+	{
+		xIndex[i] = (xIndex[i] < 0) ? (-xIndex[i] - width2 * ((-xIndex[i]) / width2)) : (xIndex[i] - width2 * (xIndex[i] / width2));
+		if (width <= xIndex[i])
+			xIndex[i] = width2 - xIndex[i];
+
+		yIndex[i] = (yIndex[i] < 0) ? (-yIndex[i] - height2 * ((-yIndex[i]) / height2)) : (yIndex[i] - height2 * (yIndex[i] / height2));
+		if (height <= yIndex[i])
+			yIndex[i] = height2 - yIndex[i];
+	}
+
+	double result = 0;
+	for (int i = 0; i < 5; i++)
+	{
+		for (int j = 0; j < 5; j++)
+		{
+			result += ((*(preCaculatedParameter + width * yIndex[i] + xIndex[j])) * xWeight[j] * yWeight[i]);
+		}
+	}
+	return result;
+}
+
+#include <vector>
+#include <chrono>
+#include <iostream>
+
+#define TICK(x) auto bench_##x = std::chrono::steady_clock::now();
+#define TOCK(x) std::cerr<<#x ": "<<std::chrono::duration_cast<std::chrono::duration<double>>(std::chrono::steady_clock::now()-bench_##x).count();std::cerr<<"秒\n";
+
+
+#define TEST_NUM 10000000
+int main() {
+	int width = 2048;
+	int height = 2048;
+	std::vector<double> preCaculatedParameter(width * height, 0.123); // 里面是预计算的数字
+	std::vector<double> xs(TEST_NUM);
+	std::vector<double> ys(TEST_NUM);
+	for (size_t i = 0; i < xs.size(); i++)
+	{
+		xs[i] = rand() % 2048;
+		ys[i] = rand() % 2048;
+	}
+	std::vector<double> result(1);
+
+	TICK(t);
+	for (int i = 0; i < TEST_NUM; i++)
+	{
+		result[0] = GetSubPixelValue(preCaculatedParameter.data(), width, height, xs[i], ys[i]);
+	}
+	TOCK(t);
+
+	return 0;
+}

foundation/main.cpp

@@ -9,10 +9,7 @@
 #include "dispatch_kernel.h"
 #include "ScopeProfiler.h"
 #include "simd_print.h"
-#include "kernel_hashrng.h"
-#include "kernel_rgba2rgb.h"
 
-#if 0
 #define _MM_SHUFFLER(w, x, y, z) _MM_SHUFFLE(z, y, x, w)
 
 int main() {
@@ -76,4 +73,3 @@ int main() {
         print(b);
     }
 }
-#endif