[SYSTEMDS-3785] Fix rewrite test for simplify bushy binary ops

This patch resolves a remaining FIXME after improved rewrite code
coverage by fixing the expressions and other rewrite configs so the
test actually triggers the existing rewrite.

src/main/java/org/apache/sysds/hops/OptimizerUtils.java

@@ -195,6 +195,7 @@ public enum MemoryManager {
 	 * all sum-product related rewrites.
 	 */
 	public static boolean ALLOW_SUM_PRODUCT_REWRITES = true;
+	public static boolean ALLOW_SUM_PRODUCT_REWRITES2 = true;
 
 	/**
 	 * Enables additional mmchain optimizations. in the future, this might be merged with

src/main/java/org/apache/sysds/hops/rewrite/ProgramRewriter.java

@@ -126,7 +126,8 @@ public ProgramRewriter(boolean staticRewrites, boolean dynamicRewrites)
 			}
 			if ( OptimizerUtils.ALLOW_SUM_PRODUCT_REWRITES) {
 				_dagRuleSet.add( new RewriteMatrixMultChainOptimization()         ); //dependency: cse
-				_dagRuleSet.add( new RewriteElementwiseMultChainOptimization()    ); //dependency: cse
+				if( OptimizerUtils.ALLOW_SUM_PRODUCT_REWRITES2 )
+					_dagRuleSet.add( new RewriteElementwiseMultChainOptimization()); //dependency: cse
 			}
 			if(OptimizerUtils.ALLOW_ADVANCED_MMCHAIN_REWRITES){
 				_dagRuleSet.add( new RewriteMatrixMultChainOptimizationTranspose()      ); //dependency: cse

src/main/java/org/apache/sysds/hops/rewrite/RewriteAlgebraicSimplificationStatic.java

@@ -855,8 +855,8 @@ private static Hop simplifyDistributiveBinaryOperation( Hop parent, Hop hi, int
 	}
 
 	/**
-	 * (X*(Y*(Z%*%v))) -> (X*Y)*(Z%*%v)
-	 * (X+(Y+(Z%*%v))) -> (X+Y)+(Z%*%v)
+	 * t(Z)%*%(X*(Y*(Z%*%v))) -> t(Z)%*%(X*Y)*(Z%*%v)
+	 * t(Z)%*%(X+(Y+(Z%*%v))) -> t(Z)%*%((X+Y)+(Z%*%v))
 	 * 
 	 * Note: Restriction ba() at leaf and root instead of data at leaf to not reorganize too
 	 * eagerly, which would loose additional rewrite potential. This rewrite has two goals

src/test/java/org/apache/sysds/test/functions/rewrite/RewriteSimplifyBushyBinaryOperationTest.java

@@ -25,6 +25,7 @@
 import org.apache.sysds.test.AutomatedTestBase;
 import org.apache.sysds.test.TestConfiguration;
 import org.apache.sysds.test.TestUtils;
+import org.junit.Assert;
 import org.junit.Test;
 
 import java.util.HashMap;
@@ -37,7 +38,7 @@ public class RewriteSimplifyBushyBinaryOperationTest extends AutomatedTestBase {
 		TEST_DIR + RewriteSimplifyBushyBinaryOperationTest.class.getSimpleName() + "/";
 
 	private static final int rows = 500;
-	private static final int cols = 500;
+	private static final int cols = 100;
 	private static final double eps = Math.pow(10, -10);
 
 	@Override
@@ -46,28 +47,28 @@ public void setUp() {
 		addTestConfiguration(TEST_NAME, new TestConfiguration(TEST_CLASS_DIR, TEST_NAME, new String[] {"R"}));
 	}
 
+	//pattern: t(Z)%*%(X*(Y*(Z%*%v))) -> t(Z)%*%((X*Y)*(Z%*%v))
 	@Test
 	public void testBushyBinaryOperationMultNoRewrite() {
 		testSimplifyBushyBinaryOperation(1, false);
 	}
 
 	@Test
-	public void testBushyBinaryOperationMultRewrite() {	//pattern: (X*(Y*(Z%*%v))) -> (X*Y)*(Z%*%v)
+	public void testBushyBinaryOperationMultRewrite() { 
 		testSimplifyBushyBinaryOperation(1, true);
 	}
 
+	//pattern: t(Z)%*%(X+(Y+(Z%*%v))) -> t(Z)%*%((X+Y)+(Z%*%v))
 	@Test
 	public void testBushyBinaryOperationAddNoRewrite() {
 		testSimplifyBushyBinaryOperation(2, false);
 	}
 
 	@Test
-	public void testBushyBinaryOperationAddtRewrite() {	//pattern: (X+(Y+(Z%*%v))) -> (X+Y)+(Z%*%v)
+	public void testBushyBinaryOperationAddtRewrite() { 
 		testSimplifyBushyBinaryOperation(2, true);
 	}
 
-
-
 	private void testSimplifyBushyBinaryOperation(int ID, boolean rewrites) {
 		boolean oldFlag = OptimizerUtils.ALLOW_ALGEBRAIC_SIMPLIFICATION;
 		try {
@@ -76,19 +77,21 @@ private void testSimplifyBushyBinaryOperation(int ID, boolean rewrites) {
 
 			String HOME = SCRIPT_DIR + TEST_DIR;
 			fullDMLScriptName = HOME + TEST_NAME + ".dml";
-			programArgs = new String[] {"-stats", "-args", input("X"), input("Y"), input("Z"), input("v"), String.valueOf(ID), output("R")};
+			programArgs = new String[] {"-stats", "-explain", "-args", 
+				input("X"), input("Y"), input("Z"), input("v"), String.valueOf(ID), output("R")};
 			fullRScriptName = HOME + TEST_NAME + ".R";
 			rCmd = getRCmd(inputDir(), String.valueOf(ID), expectedDir());
 
 			OptimizerUtils.ALLOW_ALGEBRAIC_SIMPLIFICATION = rewrites;
-			//OptimizerUtils.ALLOW_OPERATOR_FUSION = rewrites;
-			//OptimizerUtils.ALLOW_SUM_PRODUCT_REWRITES = rewrites;
-
+			OptimizerUtils.ALLOW_SUM_PRODUCT_REWRITES2 = false; //disable nary mult
+			OptimizerUtils.ALLOW_OPERATOR_FUSION = false; //disable emult reordering
+			//TODO improved phase ordering 
+
 			//create matrices
-			double[][] X = getRandomMatrix(rows, cols, -1, 1, 0.60d, 3);
-			double[][] Y = getRandomMatrix(rows, cols, -1, 1, 0.60d, 5);
+			double[][] X = getRandomMatrix(rows, 1, -1, 1, 0.60d, 3);
+			double[][] Y = getRandomMatrix(rows, 1, -1, 1, 0.60d, 5);
 			double[][] Z = getRandomMatrix(rows, cols, -1, 1, 0.60d, 6);
-			double[][] v = getRandomMatrix(rows, cols, -1, 1, 0.60d, 8);
+			double[][] v = getRandomMatrix(cols, 1, -1, 1, 0.60d, 8);
 			writeInputMatrixWithMTD("X", X, true);
 			writeInputMatrixWithMTD("Y", Y, true);
 			writeInputMatrixWithMTD("Z", Z, true);
@@ -101,15 +104,14 @@ private void testSimplifyBushyBinaryOperation(int ID, boolean rewrites) {
 			HashMap<MatrixValue.CellIndex, Double> dmlfile = readDMLMatrixFromOutputDir("R");
 			HashMap<MatrixValue.CellIndex, Double> rfile = readRMatrixFromExpectedDir("R");
 			TestUtils.compareMatrices(dmlfile, rfile, eps, "Stat-DML", "Stat-R");
-
-			/**
-			 * The rewrite in RewriteAlgebraicSimplificationStatic is not entered. Hence, we fail
-			 * the assertions for this rewrite so that we can revisit this issue later.
-			 */
-			//FIXME
+
+			if( ID == 1 && rewrites ) //check mmchain, enabled by bushy join 
+				Assert.assertTrue(heavyHittersContainsString("mmchain"));
 		}
 		finally {
 			OptimizerUtils.ALLOW_ALGEBRAIC_SIMPLIFICATION = oldFlag;
+			OptimizerUtils.ALLOW_OPERATOR_FUSION = true;
+			OptimizerUtils.ALLOW_SUM_PRODUCT_REWRITES2 = true;
 			Recompiler.reinitRecompiler();
 		}
 	}