Created
December 21, 2017 13:44
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Performance Testing 1
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// Generate data | |
int arraySize = 32768; | |
int data[] = new int[arraySize]; | |
Random rnd = new Random(0); | |
for (int c = 0; c < arraySize; ++c) | |
data[c] = rnd.nextInt() % 256; | |
// notice !!! | |
Arrays.sort(data); | |
// Test | |
long start = System.nanoTime(); | |
long sum = 0; | |
for (int i = 0; i < 100000; ++i) | |
{ | |
// Primary loop | |
for (int c = 0; c < arraySize; ++c) | |
{ | |
if (data[c] >= 128) | |
sum += data[c]; | |
} | |
} | |
System.out.println((System.nanoTime() - start) / 1000000000.0); | |
System.out.println("sum = " + sum); |
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// Generate data | |
int arraySize = 32768; | |
int data[] = new int[arraySize]; | |
Random rnd = new Random(0); | |
for (int c = 0; c < arraySize; ++c) | |
data[c] = rnd.nextInt() % 256; | |
// notice !!! | |
Arrays.sort(data); | |
// Test | |
long start = System.nanoTime(); | |
long sum = 0; | |
for (int i = 0; i < 100000; ++i) | |
{ | |
// Primary loop | |
for (int c = 0; c < arraySize; ++c) | |
{ | |
int t = (data[c] - 128) >> 31; | |
sum += ~t & data[c]; | |
} | |
} | |
System.out.println((System.nanoTime() - start) / 1000000000.0); | |
System.out.println("sum = " + sum); |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Generate data | |
int arraySize = 32768; | |
int data[] = new int[arraySize]; | |
Random rnd = new Random(0); | |
for (int c = 0; c < arraySize; ++c) | |
data[c] = rnd.nextInt() % 256; | |
// notice !!! | |
Arrays.sort(data); | |
// Test | |
long start = System.nanoTime(); | |
long sum = 0; | |
for (int i = 0; i < 100000; ++i) | |
{ | |
// Primary loop | |
for (int c = 0; c < arraySize; ++c) | |
{ | |
// Test 3 | |
sum += data[c] >=128 ? data[c] : 0; | |
} | |
} | |
System.out.println((System.nanoTime() - start) / 1000000000.0); | |
System.out.println("sum = " + sum); |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Generate data | |
int arraySize = 32768; | |
int data[] = new int[arraySize]; | |
Random rnd = new Random(0); | |
for (int c = 0; c < arraySize; ++c) | |
data[c] = rnd.nextInt() % 256; | |
// notice !!! | |
Arrays.sort(data); | |
// Test | |
long start = System.nanoTime(); | |
long sum = 0; | |
for (int j = 0; j < arraySize; ++j) | |
{ | |
if (data[j] >= 128) | |
{ | |
sum += data[j] * 100000; | |
} | |
} | |
System.out.println((System.nanoTime() - start) / 1000000000.0); | |
System.out.println("sum = " + sum); |
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