DRY up the string slicing code

Author: timfel

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

@@ -99,8 +99,8 @@
 import com.oracle.graal.python.nodes.object.GetLazyClassNode;
 import com.oracle.graal.python.nodes.object.IsBuiltinClassProfile;
 import com.oracle.graal.python.nodes.subscript.GetItemNode;
+import com.oracle.graal.python.nodes.subscript.SliceLiteralNode.CastToSliceComponentNode;
 import com.oracle.graal.python.nodes.truffle.PythonArithmeticTypes;
-import com.oracle.graal.python.nodes.util.CastToIndexNode;
 import com.oracle.graal.python.nodes.util.CastToJavaIntNode;
 import com.oracle.graal.python.nodes.util.CastToJavaStringNode;
 import com.oracle.graal.python.nodes.util.CastToJavaStringNodeGen;
@@ -444,8 +444,7 @@ static Object doAll(VirtualFrame frame, Object left, Object right,
 
     abstract static class PrefixSuffixBaseNode extends PythonQuaternaryBuiltinNode {
 
-        @Child private CastToIndexNode startNode;
-        @Child private CastToIndexNode endNode;
+        @Child private CastToSliceComponentNode castSliceComponentNode;
         @Child private GetObjectArrayNode getObjectArrayNode;
         @Child private CastToJavaStringNode castToJavaStringNode;
 
@@ -493,8 +492,8 @@ boolean doObjectPrefixGeneric(VirtualFrame frame, Object self, Object substr, Ob
                         @Cached CastToJavaStringCheckedNode castPrefixNode) {
             String selfStr = castSelfNode.cast(self, INVALID_RECEIVER, "startswith", self);
             int len = selfStr.length();
-            int istart = PGuards.isPNone(start) ? 0 : adjustStart(castStart(frame, start), len);
-            int iend = PGuards.isPNone(end) ? len : adjustEnd(castEnd(frame, end), len);
+            int istart = adjustStart(castSlicePart(frame, start), len);
+            int iend = PGuards.isPNone(end) ? len : adjustEnd(castSlicePart(frame, end), len);
             String prefixStr = castPrefixNode.cast(substr, INVALID_FIRST_ARG, "startswith", substr);
             return doIt(selfStr, prefixStr, istart, iend);
         }
@@ -504,8 +503,8 @@ boolean doTuplePrefixGeneric(VirtualFrame frame, Object self, PTuple substrs, Ob
                         @Cached CastToJavaStringCheckedNode castSelfNode) {
             String selfStr = castSelfNode.cast(self, INVALID_RECEIVER, "startswith", self);
             int len = selfStr.length();
-            int istart = PGuards.isPNone(start) ? 0 : adjustStart(castStart(frame, start), len);
-            int iend = PGuards.isPNone(end) ? len : adjustEnd(castEnd(frame, end), len);
+            int istart = adjustStart(castSlicePart(frame, start), len);
+            int iend = PGuards.isPNone(end) ? len : adjustEnd(castSlicePart(frame, end), len);
             return doIt(selfStr, substrs, istart, iend);
         }
 
@@ -553,24 +552,13 @@ static int adjustEnd(int end, int length) {
             return adjustStart(end, length);
         }
 
-        private int castStart(VirtualFrame frame, Object start) {
-            if (startNode == null) {
+        private int castSlicePart(VirtualFrame frame, Object idx) {
+            if (castSliceComponentNode == null) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
-                startNode = insert(CastToIndexNode.create(TypeError, val -> {
-                    throw raise(PythonBuiltinClassType.TypeError, "slice indices must be integers or None or have an __index__ method");
-                }));
+                // None should map to 0, overflow to the maximum integer
+                castSliceComponentNode = insert(CastToSliceComponentNode.create(0, Integer.MAX_VALUE));
             }
-            return startNode.execute(frame, start);
-        }
-
-        private int castEnd(VirtualFrame frame, Object end) {
-            if (endNode == null) {
-                CompilerDirectives.transferToInterpreterAndInvalidate();
-                endNode = insert(CastToIndexNode.create(TypeError, val -> {
-                    throw raise(PythonBuiltinClassType.TypeError, "slice indices must be integers or None or have an __index__ method");
-                }));
-            }
-            return endNode.execute(frame, end);
+            return castSliceComponentNode.execute(frame, idx);
         }
 
         private GetObjectArrayNode ensureGetObjectArrayNode() {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/subscript/SliceLiteralNode.java

@@ -33,6 +33,7 @@
 import com.oracle.graal.python.builtins.objects.ints.PInt;
 import com.oracle.graal.python.builtins.objects.object.PythonObjectLibrary;
 import com.oracle.graal.python.builtins.objects.slice.PSlice;
+import com.oracle.graal.python.nodes.PGuards;
 import com.oracle.graal.python.nodes.PNode;
 import com.oracle.graal.python.nodes.PNodeWithContext;
 import com.oracle.graal.python.nodes.PRaiseNode;
@@ -45,6 +46,7 @@
 import com.oracle.graal.python.runtime.object.PythonObjectFactory;
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.dsl.Cached.Shared;
 import com.oracle.truffle.api.dsl.Fallback;
 import com.oracle.truffle.api.dsl.ImportStatic;
 import com.oracle.truffle.api.dsl.NodeChild;
@@ -119,14 +121,10 @@ public static SliceLiteralNode create() {
         return SliceLiteralNodeGen.create(null, null, null);
     }
 
-    @ImportStatic(PythonOptions.class)
-    abstract static class CastToSliceComponentNode extends PNodeWithContext {
-
-        @Child private PRaiseNode raiseNode;
-
+    @ImportStatic({PythonOptions.class, PGuards.class})
+    public abstract static class CastToSliceComponentNode extends PNodeWithContext {
         private final int defaultValue;
         private final int overflowValue;
-        private final BranchProfile indexErrorProfile = BranchProfile.create();
 
         public CastToSliceComponentNode(int defaultValue, int overflowValue) {
             this.defaultValue = defaultValue;
@@ -155,7 +153,7 @@ int doInt(int i) {
         }
 
         @Specialization
-        int doLong(long i) {
+        int doLong(long i, @Shared("indexErrorProfile") @Cached BranchProfile indexErrorProfile) {
             try {
                 return PInt.intValueExact(i);
             } catch (ArithmeticException e) {
@@ -165,7 +163,7 @@ int doLong(long i) {
         }
 
         @Specialization
-        int doPInt(PInt i) {
+        int doPInt(PInt i, @Shared("indexErrorProfile") @Cached BranchProfile indexErrorProfile) {
             try {
                 return i.intValueExact();
             } catch (ArithmeticException e) {
@@ -174,7 +172,7 @@ int doPInt(PInt i) {
             }
         }
 
-        @Specialization(replaces = {"doBoolean", "doInt", "doLong", "doPInt"}, limit = "getCallSiteInlineCacheMaxDepth()")
+        @Specialization(guards = "!isPNone(i)", replaces = {"doBoolean", "doInt", "doLong", "doPInt"}, limit = "getCallSiteInlineCacheMaxDepth()")
         int doGeneric(VirtualFrame frame, Object i,
                         @Cached PRaiseNode raise,
                         @CachedLibrary("i") PythonObjectLibrary lib,