Support split non-AST-able join condition for BroadcastNestedLoopJoin

integration_tests/src/main/python/join_test.py

@@ -14,7 +14,7 @@
 
 import pytest
 from _pytest.mark.structures import ParameterSet
-from pyspark.sql.functions import broadcast, col
+from pyspark.sql.functions import array_contains, broadcast, col
 from pyspark.sql.types import *
 from asserts import assert_gpu_and_cpu_are_equal_collect, assert_gpu_fallback_collect, assert_cpu_and_gpu_are_equal_collect_with_capture
 from conftest import is_databricks_runtime, is_emr_runtime
@@ -397,17 +397,47 @@ def do_join(spark):
         return left.join(broadcast(right), left.a > f.log(right.r_a), join_type)
     assert_gpu_and_cpu_are_equal_collect(do_join)
 
+@ignore_order(local=True)
+@pytest.mark.parametrize('data_gen', [IntegerGen(), LongGen(), pytest.param(FloatGen(), marks=[incompat]), pytest.param(DoubleGen(), marks=[incompat])], ids=idfn)
+@pytest.mark.parametrize('join_type', ['Cross', 'Left', 'LeftSemi', 'LeftAnti'], ids=idfn)
+def test_broadcast_nested_loop_join_with_condition(data_gen, join_type):
+    def do_join(spark):
+        left, right = create_df(spark, data_gen, 50, 25)
+        # AST does not support cast or logarithm yet which is supposed to be extracted into child
+        # nodes. And this test doesn't cover other join types due to:
+        #    (1) build right are not supported for Right
+        #    (2) FullOuter: currently is not supported
+        # Those fallback reasons are not due to AST. Additionally, this test case changes test_broadcast_nested_loop_join_with_condition_fallback:
+        #    (1) adapt double to integer since AST current doesn't support it.
+        #    (2) switch to right side build to pass checks of 'Left', 'LeftSemi', 'LeftAnti' join types
+        return left.join(broadcast(right), f.round(left.a).cast('integer') > f.round(f.log(right.r_a).cast('integer')), join_type)
+    assert_gpu_and_cpu_are_equal_collect(do_join, conf={"spark.rapids.sql.castFloatToIntegralTypes.enabled": True})
+
 @allow_non_gpu('BroadcastExchangeExec', 'BroadcastNestedLoopJoinExec', 'Cast', 'GreaterThan', 'Log')
 @ignore_order(local=True)
 @pytest.mark.parametrize('data_gen', [IntegerGen(), LongGen(), pytest.param(FloatGen(), marks=[incompat]), pytest.param(DoubleGen(), marks=[incompat])], ids=idfn)
 @pytest.mark.parametrize('join_type', ['Left', 'Right', 'FullOuter', 'LeftSemi', 'LeftAnti'], ids=idfn)
 def test_broadcast_nested_loop_join_with_condition_fallback(data_gen, join_type):
     def do_join(spark):
         left, right = create_df(spark, data_gen, 50, 25)
-        # AST does not support cast or logarithm yet
+        # AST does not support double type which is not split-able into child nodes.
         return broadcast(left).join(right, left.a > f.log(right.r_a), join_type)
     assert_gpu_fallback_collect(do_join, 'BroadcastNestedLoopJoinExec')
 
+@ignore_order(local=True)
+@pytest.mark.parametrize('data_gen', [byte_gen, short_gen, int_gen, long_gen,
+                                      float_gen, double_gen,
+                                      string_gen, boolean_gen, date_gen, timestamp_gen], ids=idfn)
+@pytest.mark.parametrize('join_type', ['Left', 'Right', 'FullOuter', 'LeftSemi', 'LeftAnti'], ids=idfn)
+def test_broadcast_nested_loop_join_with_array_contains(data_gen, join_type):
+    arr_gen = ArrayGen(data_gen)
+    literal = with_cpu_session(lambda spark: gen_scalar(data_gen))
+    def do_join(spark):
+        left, right = create_df(spark, arr_gen, 50, 25)
+        # Array_contains will be pushed down into project child nodes
+        return broadcast(left).join(right, array_contains(left.a, literal.cast(data_gen.data_type)) < array_contains(right.r_a, literal.cast(data_gen.data_type)))
+    assert_gpu_and_cpu_are_equal_collect(do_join)
+
 @ignore_order(local=True)
 @pytest.mark.parametrize('data_gen', all_gen, ids=idfn)
 @pytest.mark.parametrize('join_type', ['Left', 'LeftSemi', 'LeftAnti'], ids=idfn)

sql-plugin/src/main/scala/com/nvidia/spark/rapids/AstUtil.scala

@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2023, NVIDIA CORPORATION.
+ *
+ * Licensed 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.
+ */
+
+package com.nvidia.spark.rapids
+
+import scala.collection.mutable
+import scala.collection.mutable.ListBuffer
+
+import org.apache.spark.sql.catalyst.expressions.{AttributeSeq, Expression, ExprId, NamedExpression}
+import org.apache.spark.sql.rapids.catalyst.expressions.{GpuEquivalentExpressions, GpuExpressionEquals}
+
+
+object AstUtil {
+
+  /**
+   * Check whether it can be split into non-ast sub-expression if needed
+   *
+   * @return true when: 1) If all ast-able in expr; 2) all non-ast-able tree nodes don't contain
+   *         attributes from both join sides. In such case, it's not able
+   *         to push down into single child.
+   */
+  def canExtractNonAstConditionIfNeed(expr: BaseExprMeta[_], left: Seq[ExprId],
+      right: Seq[ExprId]): Boolean = {
+    if (!expr.canSelfBeAst) {
+      // It needs to be split since not ast-able. Check itself and childerns to ensure
+      // pushing-down can be made, which doesn't need attributions from both sides.
+      val exprRef = expr.wrapped.asInstanceOf[Expression]
+      val leftTree = exprRef.references.exists(r => left.contains(r.exprId))
+      val rightTree = exprRef.references.exists(r => right.contains(r.exprId))
+      // Can't extract a condition involving columns from both sides
+      !(rightTree && leftTree)
+    } else {
+      // Check whether any child contains the case not able to split
+      expr.childExprs.isEmpty || expr.childExprs.forall(
+        canExtractNonAstConditionIfNeed(_, left, right))
+    }
+  }
+
+  /**
+   * Extract non-AST functions from join conditions and update the original join condition. Based
+   * on the attributes, it decides which side the split condition belongs to. The replaced
+   * condition is wrapped with GpuAlias with new intermediate attributes.
+   *
+   * @param condition to be split if needed
+   * @param left attributions from left child
+   * @param right attributions from right child
+   * @param skipCheck whether skip split-able check
+   * @return a tuple of [[Expression]] for remained expressions, List of [[NamedExpression]] for
+   *         left child if any, List of [[NamedExpression]] for right child if any
+   */
+  def extractNonAstFromJoinCond(condition: Option[BaseExprMeta[_]],
+      left: AttributeSeq, right: AttributeSeq, skipCheck: Boolean):
+  (Option[Expression], List[NamedExpression], List[NamedExpression]) = {
+    // Choose side with smaller key size. Use expr ID to check the side which project expr
+    // belonging to.
+    val (exprIds, isLeft) = if (left.attrs.size < right.attrs.size) {
+      (left.attrs.map(_.exprId), true)
+    } else {
+      (right.attrs.map(_.exprId), false)
+    }
+    // List of expression pushing down to left side child
+    val leftExprs: ListBuffer[NamedExpression] = ListBuffer.empty
+    // List of expression pushing down to right side child
+    val rightExprs: ListBuffer[NamedExpression] = ListBuffer.empty
+    // Substitution map used to replace targeted expressions based on semantic equality
+    val substitutionMap = mutable.HashMap.empty[GpuExpressionEquals, Expression]
+
+    // 1st step to construct 1) left expr list; 2) right expr list; 3) substitutionMap
+    // No need to consider common sub-expressions here since project node will use tiered execution
+    condition.foreach(c =>
+      if (skipCheck || canExtractNonAstConditionIfNeed(c, left.attrs.map(_.exprId), right.attrs
+          .map(_.exprId))) {
+        splitNonAstInternal(c, exprIds, leftExprs, rightExprs, substitutionMap, isLeft)
+      })
+
+    // 2nd step to replace expression pushing down to child plans in depth first fashion
+    (condition.map(
+      _.convertToGpu().mapChildren(
+        GpuEquivalentExpressions.replaceWithSemanticCommonRef(_,
+          substitutionMap))), leftExprs.toList, rightExprs.toList)
+  }
+
+  private[this] def splitNonAstInternal(condition: BaseExprMeta[_], childAtt: Seq[ExprId],
+      left: ListBuffer[NamedExpression], right: ListBuffer[NamedExpression],
+      substitutionMap: mutable.HashMap[GpuExpressionEquals, Expression], isLeft: Boolean): Unit = {
+    for (child <- condition.childExprs) {
+      if (!child.canSelfBeAst) {
+        val exprRef = child.wrapped.asInstanceOf[Expression]
+        val gpuProj = child.convertToGpu()
+        val alias = substitutionMap.get(GpuExpressionEquals(gpuProj)) match {
+          case Some(_) => None
+          case None =>
+            if (exprRef.references.exists(r => childAtt.contains(r.exprId)) ^ isLeft) {
+              val alias = GpuAlias(gpuProj, s"_agpu_non_ast_r_${left.size}")()
+              right += alias
+              Some(alias)
+            } else {
+              val alias = GpuAlias(gpuProj, s"_agpu_non_ast_l_${left.size}")()
+              left += alias
+              Some(alias)
+            }
+        }
+        alias.foreach(a => substitutionMap.put(GpuExpressionEquals(gpuProj), a.toAttribute))
+      } else {
+        splitNonAstInternal(child, childAtt, left, right, substitutionMap, isLeft)
+      }
+    }
+  }
+}

sql-plugin/src/main/scala/com/nvidia/spark/rapids/RapidsMeta.scala

@@ -1115,6 +1115,15 @@ abstract class BaseExprMeta[INPUT <: Expression](
     childExprs.forall(_.canThisBeAst) && cannotBeAstReasons.isEmpty
   }
 
+  /**
+   * Check whether this node itself can be converted to AST. It will not recursively check its
+   * children. It's used to check join condition AST-ability in top-down fashion.
+   */
+  lazy val canSelfBeAst = {
+    tagForAst()
+    cannotBeAstReasons.isEmpty
+  }
+
   final def requireAstForGpu(): Unit = {
     tagForAst()
     cannotBeAstReasons.foreach { reason =>

sql-plugin/src/main/scala/org/apache/spark/sql/rapids/catalyst/expressions/GpuEquivalentExpressions.scala

@@ -240,6 +240,22 @@ class GpuEquivalentExpressions {
 }
 
 object GpuEquivalentExpressions {
+  /**
+   * Recursively replaces semantic equal expression with its proxy expression in `substitutionMap`.
+   */
+  def replaceWithSemanticCommonRef(
+      expr: Expression,
+      substitutionMap: mutable.HashMap[GpuExpressionEquals, Expression]): Expression = {
+    expr match {
+      case e: AttributeReference => e
+      case _ =>
+        substitutionMap.get(GpuExpressionEquals(expr)) match {
+          case Some(attr) => attr
+          case None => expr.mapChildren(replaceWithSemanticCommonRef(_, substitutionMap))
+        }
+    }
+  }
+
   /**
    * Recursively replaces expression with its proxy expression in `substitutionMap`.
    */