Use explode loop limit >> depth instead of division, assert that dept is PE constant when passed as an argument

Author: steve-s

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/BuiltinFunctions.java

@@ -1043,7 +1043,7 @@ Object doObject(Object value,
      * provide the base for the recursion.
      */
     public abstract static class RecursiveBinaryCheckBaseNode extends PythonBinaryBuiltinNode {
-        static final int MAX_EXPLODE_LOOP = 16; // is also divided by recursion depth+1
+        static final int MAX_EXPLODE_LOOP = 16; // is also shifted to the left by recursion depth
         static final byte STOP_RECURSION = Byte.MAX_VALUE;
 
         @Child private SequenceStorageNodes.LenNode lenNode;
@@ -1065,7 +1065,7 @@ protected RecursiveBinaryCheckBaseNode createRecursive(@SuppressWarnings("unused
         }
 
         protected int getMaxExplodeLoop() {
-            return MAX_EXPLODE_LOOP / (depth + 1);
+            return MAX_EXPLODE_LOOP >> depth;
         }
 
         @Specialization(guards = {"depth != STOP_RECURSION", "depth < getNodeRecursionLimit()", //

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/type/TypeNodes.java

@@ -1502,7 +1502,7 @@ public static GetInstanceShape create() {
     @GenerateUncached
     @ImportStatic(PythonOptions.class)
     public abstract static class GetItemsizeNode extends Node {
-        // We cannot easily use options here
+        // We cannot easily use PythonOptions here (used on fast-path)
         static final int MAX_RECURSION_DEPTH = 4;
 
         public final long execute(Object cls) {
@@ -1522,12 +1522,13 @@ static long getItemsizeManaged(PythonBuiltinClass cls, @SuppressWarnings("unused
         }
 
         @Specialization(guards = "depth < MAX_RECURSION_DEPTH")
-        static long getItemsizeManagedRecursiveNode(PythonClass cls, @SuppressWarnings("unused") int depth,
+        static long getItemsizeManagedRecursiveNode(PythonClass cls, int depth,
                         @Shared("hasVal") @Cached ConditionProfile hasValueProfile,
                         @Shared("read") @Cached ReadAttributeFromObjectNode readNode,
                         @Shared("write") @Cached WriteAttributeToObjectNode writeNode,
                         @Shared("getBase") @Cached GetBaseClassNode getBaseNode,
                         @Cached GetItemsizeNode baseItemsizeNode) {
+            CompilerAsserts.partialEvaluationConstant(depth);
             Object itemsize = readNode.execute(cls, TYPE_ITEMSIZE);
             if (hasValueProfile.profile(itemsize != PNone.NO_VALUE)) {
                 return (long) itemsize;
@@ -1541,7 +1542,7 @@ static long getItemsizeManagedRecursiveNode(PythonClass cls, @SuppressWarnings("
         }
 
         @Specialization(guards = "depth >= MAX_RECURSION_DEPTH")
-        static long getItemsizeManagedRecursiveCall(PythonClass cls, @SuppressWarnings("unused") int depth,
+        static long getItemsizeManagedRecursiveCall(PythonClass cls, int depth,
                         @Shared("hasVal") @Cached ConditionProfile hasValueProfile,
                         @Shared("read") @Cached ReadAttributeFromObjectNode readNode,
                         @Shared("write") @Cached WriteAttributeToObjectNode writeNode,

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/classes/AbstractObjectIsSubclassNode.java

@@ -46,6 +46,7 @@
 import com.oracle.graal.python.builtins.objects.type.TypeNodes.IsSameTypeNode;
 import com.oracle.graal.python.nodes.PNodeWithContext;
 import com.oracle.graal.python.runtime.PythonOptions;
+import com.oracle.truffle.api.CompilerAsserts;
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Cached.Shared;
@@ -100,6 +101,7 @@ static boolean doSubclass(VirtualFrame frame, @SuppressWarnings("unused") Object
                     @Cached AbstractObjectGetBasesNode getBasesNode,
                     @Cached AbstractObjectIsSubclassNode isSubclassNode,
                     @Cached GetObjectArrayNode getObjectArrayNode) {
+        CompilerAsserts.partialEvaluationConstant(depth);
         PTuple bases = getBasesNode.execute(frame, cachedDerived);
         if (bases == null || isEmpty(bases, lenNode)) {
             return false;
@@ -110,7 +112,7 @@ static boolean doSubclass(VirtualFrame frame, @SuppressWarnings("unused") Object
             CompilerDirectives.transferToInterpreterAndInvalidate();
             observedSizeArray[0] = basesAry.length;
         }
-        if (observedSizeArray[0] > 0 && observedSizeArray[0] < (32 / depth) && observedSizeArray[0] == basesAry.length) {
+        if (observedSizeArray[0] > 0 && observedSizeArray[0] < (32 >> depth) && observedSizeArray[0] == basesAry.length) {
             // we observe a short constant size
             return loopBases(frame, cachedCls, basesAry, isSubclassNode, depth);
         } else if (observedSizeArray[0] > 0) {
@@ -147,6 +149,7 @@ static boolean doGeneric(VirtualFrame frame, Object derived, Object cls, int dep
                     @Cached("createRecursive(depth)") AbstractObjectIsSubclassNode isSubclassNode,
                     @Shared("isSameType") @Cached IsSameTypeNode isSameTypeNode,
                     @Cached GetObjectArrayNode getObjectArrayNode) {
+        CompilerAsserts.partialEvaluationConstant(depth);
         if (isSameMetaObject(isSameTypeNode, derived, cls)) {
             return true;
         }