1x speedup

inf2440/hw3/Main.java

@@ -35,6 +35,7 @@ class Main {
 		a = s.sort(a);
 		t.end();
 		new MultiRadix().testSort(a);
+
 		return t;
 	} // end doIt
 }

inf2440/hw3/MultiRadix.java

@@ -17,9 +17,11 @@ class MultiRadix{
 		int [] bit ;
 
 		// a) finn max verdi i a[]
+		//Timer ta = new Timer().start();
 		for (int i = 1 ; i < n ; i++)
 			if (a[i] > max) max = a[i];
 		while (max >= (1L<<numBit) )numBit++; // antall binaere siffer i max
+		//System.out.println("A: "+ta.end().prettyTime());
 
 		// bestem antall bit i numBits sifre
 		numDigits = Math.max(1, numBit/NUM_BIT);
@@ -57,16 +59,20 @@ class MultiRadix{
 		int [] count = new int [mask+1];
 
 		// b) count=the frequency of each radix value in a
+		//Timer tb = new Timer().start();
 		for (int i = 0; i < n; i++) {
 			count[(a[i]>>> shift) & mask]++;
 		}
+		//System.out.println("B: "+tb.end().prettyTime());
 
 		// c) Add up in 'count' - accumulated values
+		//Timer tc = new Timer().start();
 		for (int i = 0; i <= mask; i++) {
 			j = count[i];
 			count[i] = acumVal;
 			acumVal += j;
 		}
+		//System.out.println("C: "+tc.end().prettyTime());
 
 		// d) move numbers in sorted order a to b
 		Timer t = new Timer().start();
@@ -74,7 +80,7 @@ class MultiRadix{
 			b[count[(a[i]>>>shift) & mask]++] = a[i];
 		}
 		t.end();
-		System.out.println("seq D from "+0+" to "+n+": "+t.prettyTime());
+		System.out.println("seq D: "+t.prettyTime());
 
 	}// end radixSort
 

inf2440/hw3/MultiRadixPar.java

@@ -15,9 +15,11 @@ class MultiRadixPar{
 		int [] bit ;
 
 		// a) finn max verdi i a[]
+		//Timer ta = new Timer().start();
 		for (int i = 1 ; i < n ; i++)
 			if (a[i] > max) max = a[i];
 		while (max >= (1L<<numBit) )numBit++; // antall binaere siffer i max
+		//System.out.println("A: "+ta.end().prettyTime());
 
 		// bestem antall bit i numBits sifre
 		numDigits = Math.max(1, numBit/NUM_BIT);
@@ -40,34 +42,30 @@ class MultiRadixPar{
 			a = b;
 			b = t;
 		}
-		if (bit.length%2 != 0 ) {
-			// et odde antall sifre, kopier innhold tilbake til original a[] (nå b)
-			System.arraycopy (a,0,b,0,a.length);
-		}
 
 		return a;
 	} // end radixMulti
 
 	class Worker implements Runnable {
-		int[] a, b, count;
 		int start, end, shift, mask;
-		int id;
+		int[] a, b, count;
 
-		Worker(int[] a, int[] b, int[] count, int start, int end, int shift, int mask) {
-			this.a = a;
-			this.b = b;
-			this.count = count; //Arrays.copyOf(count, count.length);
+		Worker(int start, int end, int[] a, int[] b, int[] count, int shift, int mask) {
 			this.start = start;
 			this.end = end;
+			this.a = a;
+			this.b = b;
+			this.count = count;
 			this.shift = shift;
 			this.mask = mask;
 		}
 
 		public void run() {
-
-			// d) move numbers in sorted order a to b
-			for (int i = start; i < end - 1; i++) {
-				b[count[(a[i]>>>shift) & mask]++] = a[i];
+			for (int i = 0; i < a.length; i++) {
+				int var = (a[i] >>> shift) & mask;
+				if (var >= start && var < end) {
+					b[count[var]++] = a[i];
+				}
 			}
 		}
 	}
@@ -79,11 +77,15 @@ class MultiRadixPar{
 		int [] count = new int [mask+1];
 
 		// b) count=the frequency of each radix value in a
+		//Timer tb = new Timer().start();
 		for (int i = 0; i < n; i++) {
-			count[(a[i]>>> shift) & mask]++;
+			int var = (a[i]>>>shift) & mask;
+			count[var]++;
 		}
+		//System.out.println("B: "+tb.end().prettyTime());
 
 		// c) Add up in 'count' - accumulated values
+		//Timer tc = new Timer().start();
 		int j = 0;
 		int acumVal = 0;
 		for (int i = 0; i <= mask; i++) {
@@ -91,25 +93,26 @@ class MultiRadixPar{
 			count[i] = acumVal;
 			acumVal += j;
 		}
+		//System.out.println("C: "+tc.end().prettyTime());
 
-		// Parallel
 		Timer td = new Timer().start();
 		int d = n / nThreads;
 		Thread[] threads = new Thread[nThreads];
-		Worker[] workers = new Worker[nThreads];
 		for (int i = 0; i < nThreads; ++i) {
 			int start = d * i;
-			int end = i == nThreads - 1 ? n : d * (i + 1);
+			int end = i == nThreads - 1 ? n + 1 : d * (i + 1);
 
-			Worker w = workers[i] = new Worker(a, b, count, start, end, shift, mask);
+			Worker w = new Worker(start, end, a, b, count, shift, mask);
 			Thread t = threads[i] = new Thread(w);
 			t.start();
 		}
+
 		for (Thread t: threads) {
 			try { t.join(); } catch (InterruptedException ex) {}
 		}
 		System.out.println("par D: "+td.end().prettyTime());
 
+		//System.out.println("");
 	}// end radixSort
 
 	void testSort(int [] a){