From 92dd60e7a309c9ce46e03cd3e5c06f177fdd39a2 Mon Sep 17 00:00:00 2001
From: David Kaufmann <astra@fsinf.at>
Date: Tue, 17 Jan 2012 22:02:28 +0100
Subject: [PATCH] fixed hillis algorithm

---
 openmp/prefix/hillis.c | 10 +++++-----
 openmp/prefix/prefix.c | 21 +++++++++++----------
 openmp/prefix/prefix.h |  1 +
 3 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/openmp/prefix/hillis.c b/openmp/prefix/hillis.c
index a9ba133..6b9b4f0 100644
--- a/openmp/prefix/hillis.c
+++ b/openmp/prefix/hillis.c
@@ -9,12 +9,12 @@ void algorithm (numtype x[], unsigned long size, unsigned int ops[]) {
 	unsigned long i;
 
 	printf ("hillis.\n");
-	for(k=1; k < size; k <<=1){
-printf ("hier.%li\n", k);
-		for(i = k; i < size; i++){
-printf ("  da.%li\n",i);
-			x[i] = x[i-k] + x[i];
+	for(k=2; k <= size; k <<=1){
+		for(i = (k-1); i < size; i+=k){
+			//printf ("x[%2li] = x[%2li] + x[%2li]; // {i:%li, k:%li}\n", i, i-k, i, i, k);
+			x[i] = x[i-(k/2)] + x[i];
 		}
+		//arrayState(x, size);
 		//barrier;
 	}
 
diff --git a/openmp/prefix/prefix.c b/openmp/prefix/prefix.c
index 076e8f3..bc4790a 100644
--- a/openmp/prefix/prefix.c
+++ b/openmp/prefix/prefix.c
@@ -5,6 +5,15 @@
 /* TODO: Replace with file read. */
 #define NUMBERS 16
 
+void array_contents(numtype array[], unsigned long size) {
+	printf ("[%li", array[0]);
+	for (unsigned long i = 1; i < size; i++) {
+		printf (", %li", array[i]);
+	}
+	printf ("]\n");
+}
+
+
 int main (int argc, char* argv[]) {
 	numtype numarray[NUMBERS];
 	unsigned long size;
@@ -18,11 +27,7 @@ int main (int argc, char* argv[]) {
 	}
 
 	/* might want to comment this out, if numarray is big */
-	printf ("array details\n[%li", numarray[0]);
-	for (unsigned long i = 1; i < size; i++) {
-		printf (", %li", numarray[i]);
-	}
-	printf ("]\n");
+	array_contents(numarray, size);
 
 	printf("init done starting algorithm. size: %li\n", size);
 	startTime = omp_get_wtime();
@@ -31,11 +36,7 @@ int main (int argc, char* argv[]) {
 	printf ("result: %li\n", numarray[(size-1)]);
 
 	/* might want to comment this out, if numarray is big */
-	printf ("array details\n[%li", numarray[0]);
-	for (unsigned long i = 1; i < size; i++) {
-		printf (", %li", numarray[i]);
-	}
-	printf ("]\n");
+	array_contents(numarray, size);
 
 	return 0;
 }
diff --git a/openmp/prefix/prefix.h b/openmp/prefix/prefix.h
index 27cb99d..fd1b5a8 100644
--- a/openmp/prefix/prefix.h
+++ b/openmp/prefix/prefix.h
@@ -6,6 +6,7 @@
 #define _prefix_h_
 
 typedef unsigned long numtype;
+void array_contents(numtype array[], unsigned long size);
 void algorithm (numtype in[], unsigned long size, unsigned int ops[]);
 
 #endif
-- 
2.43.0