[SYSTEMDS-3868] Fix new hoisting of function calls from if statements

This patch fixes a compilation issue, where certain if-branches were
lost during hoisting of function calls from if statements. The issue
did not show up, because for test instances of function calls in
if statements triggered rewrites of predicate constant folding and
branch removal. Now, we also resolved all remaining FIXMEs in the new
 ampute() builtin function.

Author: mboehm7

scripts/builtin/ampute.dml

@@ -91,9 +91,6 @@ u_validateInputs = function(Matrix[Double] X, Double prop, Matrix[Double] freq,
 return (Matrix[Double] freq, Matrix[Double] patterns, Matrix[Double] weights) {
 
   errors = list()
-  freqProvided = !u_isEmpty(freq) # FIX ME
-  patternsProvided = !u_isEmpty(patterns) # FIX ME
-  weightsProvided = !u_isEmpty(weights) # FIX ME
 
   # About the input dataset:
   if (max(is.na(X)) == 1) {
@@ -107,7 +104,7 @@ return (Matrix[Double] freq, Matrix[Double] patterns, Matrix[Double] weights) {
   if (mech != "MAR" & mech != "MCAR" & mech != "MNAR") {
     errors = append(errors, "Invalid option provided for mech: " + mech + ".")
   }
-  else if (weightsProvided & mech == "MCAR") {
+  else if (!u_isEmpty(weights) & mech == "MCAR") {
     print("ampute warning: User-provided weights will be ignored when mechanism MCAR is chosen.")
   }
 
@@ -190,11 +187,10 @@ return (Matrix[Double] freq, Matrix[Double] patterns, Matrix[Double] weights) {
 
   # Weights: Various defaults based on chosen missingness mechanism:
   numPatterns = nrow(patterns)
-  empty = u_isEmpty(weights) # FIX ME
   if (mech == "MCAR") {
     weights = matrix(0, rows=numPatterns, cols=numFeatures) # MCAR: All 0's (weights don't matter). Overrides any provided weights.
   }
-  else if (empty) { # FIX ME
+  else if (u_isEmpty(weights)) {
     if (mech == "MAR") {
       weights = patterns # MAR: Missing features weighted with 0.
     }

src/main/java/org/apache/sysds/parser/StatementBlock.java

@@ -520,7 +520,7 @@ else if (current instanceof IfStatementBlock) {
 				istmt.setElseBody(tmp2);
 			}
 			if( !tmpPred.isEmpty() )
-				return createStatementBlocks(current, tmpPred);
+				return createStatementBlocks(current, tmpPred, true);
 		}
 		else if (current instanceof ForStatementBlock) { //incl parfor
 			ForStatementBlock fsb = (ForStatementBlock) current;
@@ -659,6 +659,12 @@ private static DataIdentifier copy(DataIdentifier di) {
 	}
 
 	private static List<StatementBlock> createStatementBlocks(StatementBlock sb, List<Statement> stmts) {
+		return createStatementBlocks(sb, stmts, false);
+	}
+	
+	private static List<StatementBlock> createStatementBlocks(
+		StatementBlock sb, List<Statement> stmts, boolean includeSb)
+	{
 		List<StatementBlock> ret = new ArrayList<>();
 		StatementBlock current = new StatementBlock(sb);
 		for(Statement stmt : stmts) {
@@ -679,6 +685,8 @@ private static List<StatementBlock> createStatementBlocks(StatementBlock sb, Lis
 		}
 		if( current.getNumStatements() > 0 )
 			ret.add(current);
+		if( includeSb ) // e.g., if block
+			ret.add(sb);
 		return ret;
 	}
 

src/test/java/org/apache/sysds/test/functions/misc/FunctionPotpourriTest.java

@@ -63,6 +63,7 @@ public class FunctionPotpourriTest extends AutomatedTestBase
 		"FunPotpourriParforEvalBuiltin",
 		"FunPotpourriParforEvalSpark",
 		"FunPotpourriEvalNamespace3",
+		"FunPotpourriDefaultParams",
 	};
 
 	private final static String TEST_DIR = "functions/misc/";
@@ -277,6 +278,11 @@ public void testFunctionEvalNamespace3() {
 		runFunctionTest( TEST_NAMES[29], null, false );
 	}
 
+	@Test
+	public void testFunctionDefaultParams() {
+		runFunctionTest( TEST_NAMES[30], null, false );
+	}
+	
 	private void runFunctionTest(String testName, Class<?> error) {
 		runFunctionTest(testName, error, false);
 	}

src/test/scripts/functions/misc/FunPotpourriDefaultParams.dml

@@ -0,0 +1,45 @@
+#-------------------------------------------------------------
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+#-------------------------------------------------------------
+
+foo = function(Matrix[Double] X, Matrix[Double] h=matrix(0,0,0))
+  return (Matrix[Double] X2)
+{
+  print(nrow(h)+" "+ncol(h)+" "+length(h));
+  #if( length(h)==0 ) # worked
+  if( isEmpty(h) ) # didn't work
+    h = 2 * X;
+  X2 = h - X;
+}
+
+isEmpty = function(Matrix[Double] h)
+  return (boolean R)
+{
+  R = (length(h) == 0);
+}
+
+
+X = rand(rows=100, cols=100, seed=7)
+
+X2 = foo(X=X);
+
+if( sum((X-X2)>1e-10)>0 )
+  stop("Incorrect results: "+sum(X)+" "+sum(X2))
+