Revert accidental changes to MatrixBlockDictionary.java

This file was accidentally modified in a prior commit. Restoring the
original vectorized SIMD implementation.

Author: kubraaksux

src/main/java/org/apache/sysds/runtime/compress/colgroup/dictionary/MatrixBlockDictionary.java

@@ -67,6 +67,8 @@ public class MatrixBlockDictionary extends ADictionary {
 
 	final private MatrixBlock _data;
 
+	static final VectorSpecies<Double> SPECIES = DoubleVector.SPECIES_PREFERRED;
+
 	/**
 	 * Unsafe private constructor that does not check the data validity. USE WITH CAUTION.
 	 * 
@@ -2125,6 +2127,9 @@ private void preaggValuesFromDenseDictDenseAggRangeRange(final int numVals, fina
 
 	private static void preaggValuesFromDenseDictBlockedIKJ(double[] a, double[] b, double[] ret, int bi, int bk, int bj,
 		int bie, int bke, int cz, int az, int ls, int cut, int sOffT, int eOffT) {
+		final int vLen = SPECIES.length();
+		final DoubleVector vVec = DoubleVector.zero(SPECIES);
+		final int leftover = (eOffT - sOffT) % vLen; // leftover not vectorized
 		for(int i = bi; i < bie; i++) {
 			final int offI = i * cz;
 			final int offOutT = i * az + bj;
@@ -2133,14 +2138,27 @@ private static void preaggValuesFromDenseDictBlockedIKJ(double[] a, double[] b,
 				final int sOff = sOffT + idb;
 				final int eOff = eOffT + idb;
 				final double v = a[offI + k];
-				int offOut = offOutT;
-				for(int j = sOff; j < eOff; j++, offOut++) {
-					ret[offOut] += v * b[j];
-				}
+				vecInnerLoop(v, b, ret, offOutT, eOff, sOff, leftover, vLen, vVec);
 			}
 		}
 	}
 
+	private static void vecInnerLoop(final double v, final double[] b, final double[] ret, final int offOutT,
+		final int eOff, final int sOff, final int leftover, final int vLen, DoubleVector vVec) {
+		int offOut = offOutT;
+		vVec = vVec.broadcast(v);
+		final int end = eOff - leftover;
+		for(int j = sOff; j < end; j += vLen, offOut += vLen) {
+			DoubleVector res = DoubleVector.fromArray(SPECIES, ret, offOut);
+			DoubleVector bVec = DoubleVector.fromArray(SPECIES, b, j);
+			vVec.fma(bVec, res).intoArray(ret, offOut);
+		}
+		for(int j = end; j < eOff; j++, offOut++) {
+			ret[offOut] += v * b[j];
+		}
+
+	}
+
 	private void preaggValuesFromDenseDictDenseAggRangeGeneric(final int numVals, final IColIndex colIndexes,
 		final int s, final int e, final double[] b, final int cut, final double[] ret) {
 		final int cz = colIndexes.size();