[SYSTEMDS-2864] Fix opcode merge conflicts and autodiff bug

* revert the bad merge of the previous sqrt_matrix modification
* fix the handling of opcodes in the autodiff program reconstruction

Author: mboehm7

src/main/java/org/apache/sysds/common/Opcodes.java

@@ -150,6 +150,7 @@ public enum Opcodes {
 	ATAN("atan", CPType.Unary),
 	SIGN("sign", CPType.Unary),
 	SQRT("sqrt", CPType.Unary),
+	SQRT_MATRIX_JAVA("sqrt_matrix_java", CPType.Unary),
 	PLOGP("plogp", CPType.Unary),
 	PRINT("print", CPType.Unary),
 	ASSERT("assert", CPType.Unary),

src/main/java/org/apache/sysds/runtime/matrix/data/LibCommonsMath.java

@@ -81,7 +81,9 @@ private LibCommonsMath() {
 	}
 
 	public static boolean isSupportedUnaryOperation( String opcode ) {
-		return ( opcode.equals(Opcodes.INVERSE.toString()) || opcode.equals(Opcodes.CHOLESKY.toString()) );
+		return opcode.equals(Opcodes.INVERSE.toString())
+			|| opcode.equals(Opcodes.CHOLESKY.toString()) 
+			|| opcode.equals(Opcodes.SQRT_MATRIX_JAVA.toString());
 	}
 
 	public static boolean isSupportedMultiReturnOperation( String opcode ) {
@@ -107,11 +109,15 @@ public static boolean isSupportedMatrixMatrixOperation( String opcode ) {
 	}
 
 	public static MatrixBlock unaryOperations(MatrixBlock inj, String opcode) {
-		Array2DRowRealMatrix matrixInput = DataConverter.convertToArray2DRowRealMatrix(inj);
-		if(opcode.equals(Opcodes.INVERSE.toString()))
-			return computeMatrixInverse(matrixInput);
-		else if (opcode.equals(Opcodes.CHOLESKY.toString()))
-			return computeCholesky(matrixInput);
+		if (opcode.equals(Opcodes.SQRT_MATRIX_JAVA.toString()))
+			return computeSqrt(inj);
+		else {
+			Array2DRowRealMatrix matrixInput = DataConverter.convertToArray2DRowRealMatrix(inj);
+			if(opcode.equals(Opcodes.INVERSE.toString()))
+				return computeMatrixInverse(matrixInput);
+			else if (opcode.equals(Opcodes.CHOLESKY.toString()))
+				return computeCholesky(matrixInput);
+		}
 		return null;
 	}
 
@@ -514,6 +520,18 @@ private static MatrixBlock[] computeSvd(MatrixBlock in) {
 		return new MatrixBlock[] { U, Sigma, V };
 	}
 
+	/**
+	 * Computes the square root of a matrix Calls Apache Commons Math EigenDecomposition.
+	 *
+	 * @param in Input matrix
+	 * @return matrix block
+	 */
+	private static MatrixBlock computeSqrt(MatrixBlock in) {
+		Array2DRowRealMatrix matrixInput = DataConverter.convertToArray2DRowRealMatrix(in);
+		EigenDecomposition ed = new EigenDecomposition(matrixInput);
+		return DataConverter.convertToMatrixBlock(ed.getSquareRoot());
+	}
+	
 	/**
 	 * Function to compute matrix inverse via matrix decomposition.
 	 * 

src/main/java/org/apache/sysds/runtime/util/AutoDiff.java

@@ -26,6 +26,7 @@
 import java.util.Stack;
 
 import org.apache.commons.lang3.mutable.MutableInt;
+import org.apache.sysds.common.Opcodes;
 import org.apache.sysds.common.Types;
 import org.apache.sysds.hops.DataGenOp;
 import org.apache.sysds.hops.DataOp;
@@ -213,7 +214,7 @@ else if(inst instanceof RandSPInstruction) {
 				break;
 			}
 			case Instruction: {
-				CPInstruction.CPType ctype = InstructionUtils.getCPTypeByOpcode(item.getOpcode());
+				CPInstruction.CPType ctype = Opcodes.getCPTypeByOpcode(item.getOpcode());
 
 				if(ctype != null) {
 					switch(ctype) {