Adding specialization for fast path in PInt case and correcting return type of error handler in CastToIndexNode.

Author: ppisl

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/str/StringBuiltins.java

@@ -538,8 +538,13 @@ boolean startsWith(String self, String prefix, long start, long end) {
             return doIt(self, prefix, correctIndex(start, self), correctIndex(end, self));
         }
 
-        @Specialization
+        @Specialization (rewriteOn = ArithmeticException.class)
         boolean startsWith(String self, String prefix, PInt start, @SuppressWarnings("unused") PNone end) {
+            return startsWith(self, prefix, start.intValueExact(), self.length());
+        }
+        
+        @Specialization
+        boolean startsWithPIntOvf(String self, String prefix, PInt start, @SuppressWarnings("unused") PNone end) {
             return doIt(self, prefix, correctIndex(start, self), self.length());
         }
 
@@ -563,11 +568,16 @@ boolean startsWith(String self, PTuple prefix, long start, long end) {
             return doIt(self, prefix, correctIndex(start, self), correctIndex(end, self));
         }
 
-        @Specialization
+        @Specialization (rewriteOn = ArithmeticException.class)
         boolean startsWith(String self, PTuple prefix, PInt start, @SuppressWarnings("unused") PNone end) {
+            return startsWith(self, prefix, start.intValueExact(), end);
+        }
+        
+        @Specialization
+        boolean startsWithPIntOvf(String self, PTuple prefix, PInt start, @SuppressWarnings("unused") PNone end) {
             return doIt(self, prefix, correctIndex(start, self), self.length());
         }
-
+        
         @Specialization
         boolean startsWith(String self, PTuple prefix, @SuppressWarnings("unused") PNone start, @SuppressWarnings("unused") PNone end) {
             return startsWith(self, prefix, 0, self.length());

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/util/CastToIndexNode.java

@@ -70,9 +70,9 @@ public abstract class CastToIndexNode extends PNodeWithContext {
 
     private final PythonBuiltinClassType errorType;
     private final boolean recursive;
-    private final Function<Object, Byte> typeErrorHandler;
+    private final Function<Object, Integer> typeErrorHandler;
 
-    protected CastToIndexNode(PythonBuiltinClassType errorType, boolean recursive, Function<Object, Byte> typeErrorHandler) {
+    protected CastToIndexNode(PythonBuiltinClassType errorType, boolean recursive, Function<Object, Integer> typeErrorHandler) {
         this.errorType = errorType;
         this.recursive = recursive;
         this.typeErrorHandler = typeErrorHandler;
@@ -166,7 +166,7 @@ public static CastToIndexNode createOverflow() {
         return CastToIndexNodeGen.create(OverflowError, true, null);
     }
 
-    public static CastToIndexNode create(PythonBuiltinClassType errorType, Function<Object, Byte> typeErrorHandler) {
+    public static CastToIndexNode create(PythonBuiltinClassType errorType, Function<Object, Integer> typeErrorHandler) {
         return CastToIndexNodeGen.create(errorType, true, typeErrorHandler);
     }
 }