Merge branch 'master' of github.com:lemire/Code-used-on-Daniel-Lemire…

…-s-blog
lemire · Dec 17, 2014 · c61bc08 · c61bc08
2 parents c37b8f3 + 0c2f14e
commit c61bc08
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Showing 6 changed files with 104 additions and 5 deletions.
diff --git a/2014/12/17/Benchmark.java b/2014/12/17/Benchmark.java
@@ -2,22 +2,35 @@ public class Benchmark {
 
     public static void main(String[] args) {
         int N = 10000000;
+        ReverseFastSummer refs = new ReverseFastSummer(N);
         FastSummer fs = new FastSummer(N);
         BasicSummer gs = new BasicSummer(new NaiveArray(N));
         SmartSummer ss = new SmartSummer(new NaiveArray(N));
+        ReverseSmartSummer ress = new ReverseSmartSummer(new NaiveArray(N));
+        SillySummer sis = new SillySummer(new NaiveArray(N));
         FixedSummer ffs = new FixedSummer(N);
+        ReverseFixedSummer reffs = new ReverseFixedSummer(N);
         int bogus = 0;
         for(int k = 0; k < 100; ++k) {
+            long t0 = System.nanoTime();
+            bogus += refs.compute();
             long t1 = System.nanoTime();
             bogus += fs.compute();
             long t2 = System.nanoTime();
             bogus += gs.compute();
             long t3 = System.nanoTime();
             bogus += ss.compute();
             long t4 = System.nanoTime();
-            bogus += ffs.compute();
+            bogus += ress.compute();
             long t5 = System.nanoTime();
-            System.out.println((t2-t1)/N+" "+(t3-t2)/N+" "+(t4-t3)/N+" "+(t5-t4)/N);
+            bogus += sis.compute();
+            long t6 = System.nanoTime();
+            bogus += ffs.compute();
+            long t7 = System.nanoTime();
+            bogus += reffs.compute();
+            long t8 = System.nanoTime();
+             System.out.println("refast fast basic smart resmart silly fixed ");
+            System.out.println((t1-t0)*1.0/N+" "+(t2-t1)*1.0/N+" "+(t3-t2)*1.0/N+" "+(t4-t3)*1.0/N+" "+(t5-t4)*1.0/N+" "+(t6-t5)*1.0/N+" "+(t7-t6)*1.0/N+" "+(t8-t7)*1.0/N);
         }
     }
-}
+}
diff --git a/2014/12/17/NaiveArray.java b/2014/12/17/NaiveArray.java
@@ -5,7 +5,6 @@ public NaiveArray(int cap) {
         array = new int[cap];
     }
 
-
     public int get(int i) {
         return array[i];
     }
@@ -17,4 +16,4 @@ public void set(int i, int x) {
     public int size() {
         return array.length;
     }
-}
+}
diff --git a/2014/12/17/ReverseFastSummer.java b/2014/12/17/ReverseFastSummer.java
@@ -0,0 +1,16 @@
+public class ReverseFastSummer {
+
+    int[] array;
+    public ReverseFastSummer(int cap) {
+        array = new int[cap];
+    }
+
+    public int compute() {
+        for(int k = array.length - 1 ; k >=0; --k) 
+          array[k] = k;
+        int sum = 0;
+        for(int k = array.length - 1 ; k >=0; --k) 
+          sum += array[k];
+        return sum;
+    }
+}
diff --git a/2014/12/17/ReverseFixedSummer.java b/2014/12/17/ReverseFixedSummer.java
@@ -0,0 +1,18 @@
+public final class ReverseFixedSummer {
+    protected final NaiveArray array;
+
+    public ReverseFixedSummer(int cap) {
+        array = new NaiveArray(cap);
+    }
+
+
+    public int compute() {
+        for(int k = array.size() - 1; k >=0 ; --k) 
+          array.set(k,k);
+        int sum = 0;
+        for(int k = array.size() - 1; k >=0 ; --k) 
+          sum += array.get(k);
+        return sum;
+    }
+
+}
diff --git a/2014/12/17/ReverseSmartSummer.java b/2014/12/17/ReverseSmartSummer.java
@@ -0,0 +1,27 @@
+public class ReverseSmartSummer {
+    protected Array array;
+
+    public ReverseSmartSummer(Array backend) {
+        array = backend;
+    }
+
+
+    public int compute() {
+        if(array instanceof NaiveArray) {
+            int[] back = ((NaiveArray) array).array;
+            for(int k = back.length - 1; k >= 0; --k) 
+               back[k] = k;
+            int sum = 0;
+            for(int k = back.length - 1; k >= 0; --k) 
+               sum += back[k];
+            return sum;
+        }
+        for(int k = array.size() - 1; k >= 0; --k) 
+          array.set(k,k);
+        int sum = 0;
+        for(int k = 0; k < array.size(); --k) 
+          sum += array.get(k);
+        return sum;
+    }
+
+}
diff --git a/2014/12/17/SillySummer.java b/2014/12/17/SillySummer.java
@@ -0,0 +1,26 @@
+public class SillySummer {
+    protected Array array;
+
+    public SillySummer(Array backend) {
+        array = backend;
+    }
+
+
+    public int compute() {
+        if(array instanceof NaiveArray) {
+             for(int k = 0; k < array.size(); ++k) 
+               array.set(k,k);
+             int sum = 0;
+             for(int k = 0; k < array.size(); ++k) 
+               sum += array.get(k);
+             return sum;
+       }
+        for(int k = 0; k < array.size(); ++k) 
+          array.set(k,k);
+        int sum = 0;
+        for(int k = 0; k < array.size(); ++k) 
+          sum += array.get(k);
+        return sum;
+    }
+
+}