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  1. #include <iostream>
  2. #include <cmath>
  3. #include <random>
  4. #include <time.h> 
  5. using namespace std;
  6.  
  7. const double PI = 3.141592653589793;
  8. const double PI2 = 2.0 * 3.141592653589793;
  9. const double PI4 = 4.0 * 3.141592653589793;
  10. const float PIf = 3.141592653589793;
  11. const float PI2f = 2.0 * 3.141592653589793;
  12. const float PI4f = 4.0 * 3.141592653589793;
  13.  
  14. const int N = 14400;
  15. const int HALF_N = N >> 1;
  16. const double STEP = 4.0 * PI / (double)N; 
  17. const double INV_STEP = 1.0 / STEP;
  18. static double LUT[N * 2];
  19.  
  20. const int Nsm = 90;
  21. const int HALF_Nsm = Nsm >> 1;
  22. const float STEPsm = 4.0 * PIf / (float)Nsm;
  23. const float INV_STEPsm = 1.0 / STEPsm;
  24. static float LUTsm[Nsm * 2];
  25.  
  26. int seed = (int)clock();
  27.  
  28. void benchLUT() {
  29. 	cout << "LUT (double)" << endl;
  30. 	srand(seed);
  31. 	double result = 0.0;
  32. 	clock_t t;
  33. 	t = clock();
  34. 	for(int x = 0; x < 100000; x++) {
  35. 		double r = PI4 * ((double)rand() / RAND_MAX) - PI2;
  36. 		int index = (int)((r * INV_STEP) + HALF_N) << 1;
  37. 		result += LUT[index] + LUT[index + 1];
  38. 	}
  39. 	t = clock() - t;
  40. 	cout << "Sum : " << result << endl;
  41. 	cout << "Time : " << t << " : " << ((float)t)/CLOCKS_PER_SEC << endl;
  42. }
  43. void benchSinCos() {
  44. 	cout << "CMATH (float)" << endl;
  45. 	srand(seed);
  46. 	float result = 0.0;
  47. 	clock_t t;
  48. 	t = clock();
  49. 	for(int x = 0; x < 100000; x++) {
  50. 		float r = (float)(PI4f * ((float)rand() / RAND_MAX) - PI2f);
  51. 		result += sin(r) + cos(r);
  52. 	}
  53. 	t = clock() - t;
  54. 	cout << "Sum : " << result << endl;
  55. 	cout << "Time : " << t << " : " << ((float)t)/CLOCKS_PER_SEC << endl;
  56. }
  57. void benchPoly() {
  58. 	cout << "Poly (float)" << endl;
  59. 	srand(seed);
  60. 	float result = 0.0;
  61. 	clock_t t;
  62. 	t = clock();
  63. 	for(int x = 0; x < 100000; x++) {
  64. 		float r = (float)(PI4f * ((float)rand() / RAND_MAX) - PI2f);
  65. 		// wrap
  66. 		if (r < -3.14159265) {
  67. 			r += 6.28318531;
  68. 		} else if (r > 3.14159265) {
  69. 			r -= 6.28318531;
  70. 		}
  71. 		// sin
  72. 		if (r < 0) {
  73. 			result += 1.27323954 * r + 0.405284735 * r * r;
  74. 		} else {
  75. 			result += 1.27323954 * r - 0.405284735 * r * r;
  76. 		}
  77. 		// cos
  78. 		r += 1.57079632;
  79. 		if (r > 3.14159265) {
  80.     		r -= 6.28318531;
  81. 		}
  82. 		if (r < 0) {
  83.     		result += 1.27323954 * r + 0.405284735 * r * r;
  84. 		} else {
  85.     		result += 1.27323954 * r - 0.405284735 * r * r;
  86. 		}
  87. 		//result = sin(r) + cos(r);
  88. 	}
  89. 	t = clock() - t;
  90. 	cout << "Sum : " << result << endl;
  91. 	cout << "Time : " << t << " : " << ((float)t)/CLOCKS_PER_SEC << endl;
  92. }
  93. void benchInterp() {
  94. 	cout << "Small LUT Interp (float)" << endl;
  95. 	srand(seed);
  96. 	float result = 0.0;
  97. 	clock_t t;
  98. 	t = clock();
  99. 	for(int x = 0; x < 100000; x++) {
  100. 		float r = PI4f * ((float)rand() / RAND_MAX) - PI2f;
  101. 		int index = (int)((r * INV_STEPsm) + HALF_Nsm) << 1;
  102. 		result += LUTsm[index] + LUTsm[index + 1];
  103. 	}
  104. 	t = clock() - t;
  105. 	cout << "Sum : " << result << endl;
  106. 	cout << "Time : " << t << " : " << ((float)t)/CLOCKS_PER_SEC << endl;
  107. }
  108.  
  109. int main() {
  110. 	// build LUT
  111. 	int i = 0;
  112. 	double r = -2.0 * PI;
  113. 	for(i=0; i < N; i++, r += STEP) {
  114.     	LUT[(i << 1)] = sin(r);
  115.     	LUT[(i << 1) + 1] = cos(r);
  116. 	}
  117. 	// build small LUT
  118. 	r = -2.0 * PIf;
  119. 	for(i=0; i < Nsm; i++, r += STEPsm) {
  120.     	LUTsm[(i << 1)] = sin(r);
  121.     	LUTsm[(i << 1) + 1] = cos(r);
  122. 	}
  123.  
  124. 	benchLUT();
  125. 	benchSinCos();
  126. 	benchPoly();
  127. 	benchInterp();
  128. 	benchLUT();
  129. 	benchSinCos();
  130. 	benchPoly();
  131. 	benchInterp();
  132. 	return 0;
  133. }
Success #stdin #stdout 0.06s 3640KB
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stdin
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stdout
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LUT (double)
Sum : 125.021
Time : 5692 : 0.005692
CMATH (float)
Sum : 125.014
Time : 13911 : 0.013911
Poly (float)
Sum : 138.512
Time : 7846 : 0.007846
Small LUT Interp (float)
Sum : 120.153
Time : 5019 : 0.005019
LUT (double)
Sum : 125.021
Time : 6123 : 0.006123
CMATH (float)
Sum : 125.014
Time : 13029 : 0.013029
Poly (float)
Sum : 138.512
Time : 7528 : 0.007528
Small LUT Interp (float)
Sum : 120.153
Time : 4647 : 0.004647
https://ideone.com/SGrFVG
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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