Fix unreachable specializations

Author: DSouzaM

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/ctypes/CFieldBuiltins.java

@@ -161,7 +161,7 @@ static void doit(VirtualFrame frame, CFieldObject self, Object inst, Object valu
             cDataSetNode.execute(frame, dst, self.proto, self.setfunc, value, self.index, self.size, dst.b_ptr.withOffset(self.offset));
         }
 
-        @Specialization(guards = "!isNoValue(value)")
+        @Specialization(guards = "isNoValue(value)")
         @InliningCutoff
         static void doit(CFieldObject self, Object inst, Object value,
                         @Cached PRaiseNode raiseNode) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -46,13 +46,8 @@
 
 import com.oracle.graal.python.PythonLanguage;
 import com.oracle.graal.python.builtins.objects.cext.common.CExtCommonNodes.ReadUnicodeArrayNode;
-import com.oracle.graal.python.nodes.util.CastToJavaIntExactNode;
 import com.oracle.truffle.api.CompilerAsserts;
-import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.TruffleLogger;
-import com.oracle.truffle.api.interop.InteropLibrary;
-import com.oracle.truffle.api.interop.UnsupportedMessageException;
-import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.strings.TruffleString;
 import com.oracle.truffle.api.strings.TruffleString.Encoding;
 
@@ -97,17 +92,6 @@ public int length() {
         return TruffleString.CodePointLengthNode.getUncached().execute(materialize(), TS_ENCODING);
     }
 
-    int length(Node inliningTarget, InteropLibrary lib, CastToJavaIntExactNode castToJavaIntNode) {
-        try {
-            int arraySize = castToJavaIntNode.execute(inliningTarget, lib.getArraySize(ptr));
-            assert arraySize % elementSize == 0;
-            // we need to subtract the terminating null character
-            return arraySize / elementSize;
-        } catch (UnsupportedMessageException e) {
-            throw CompilerDirectives.shouldNotReachHere("pointer of NativeCharSequence is not an array");
-        }
-    }
-
     @Override
     public char charAt(int index) {
         return (char) TruffleString.CodePointAtIndexNode.getUncached().execute(materialize(), index, TS_ENCODING);

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

@@ -73,7 +73,6 @@
 import com.oracle.graal.python.nodes.object.BuiltinClassProfiles.IsBuiltinObjectProfile;
 import com.oracle.graal.python.nodes.object.GetClassNode;
 import com.oracle.graal.python.nodes.util.CannotCastException;
-import com.oracle.graal.python.nodes.util.CastToJavaIntExactNode;
 import com.oracle.graal.python.nodes.util.CastToJavaStringNode;
 import com.oracle.graal.python.nodes.util.CastToTruffleStringNode;
 import com.oracle.graal.python.runtime.PythonOptions;
@@ -95,8 +94,6 @@
 import com.oracle.truffle.api.dsl.ImportStatic;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
-import com.oracle.truffle.api.interop.InteropLibrary;
-import com.oracle.truffle.api.library.CachedLibrary;
 import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.profiles.InlinedConditionProfile;
 import com.oracle.truffle.api.strings.TruffleString;
@@ -160,27 +157,24 @@ static int doMaterialized(PString x,
             return doString(x.getMaterialized(), codePointLengthNode);
         }
 
-        @Specialization(guards = "x.isNativeCharSequence()")
-        static int doNativeCharSequence(PString x,
+        @Specialization(guards = {"x.isNativeCharSequence()", "isKnownLength(elements)"})
+        static int doNativeKnownLength(PString x,
+                        @Bind("x.getNativeCharSequence().getElements()") int elements) {
+            return elements;
+        }
+
+        @Specialization(guards = {"x.isNativeCharSequence()", "!isKnownLength(elements)"})
+        static int doNativeUnknownLength(PString x,
+                        @SuppressWarnings("unused") @Bind("x.getNativeCharSequence().getElements()") int elements,
                         @Bind("this") Node inliningTarget,
                         @Cached StringMaterializeNode materializeNode,
                         @Shared @Cached TruffleString.CodePointLengthNode codePointLengthNode) {
             return doString(materializeNode.execute(inliningTarget, x), codePointLengthNode);
         }
 
-        @Specialization(guards = {"x.isNativeCharSequence()", "x.isNativeMaterialized()"})
-        static int nativeString(PString x,
-                        @Shared @Cached TruffleString.CodePointLengthNode codePointLengthNode) {
-            return doString(x.getNativeCharSequence().getMaterialized(), codePointLengthNode);
-        }
-
-        @Specialization(guards = {"x.isNativeCharSequence()", "!x.isNativeMaterialized()"}, replaces = "nativeString", limit = "3")
-        static int nativeStringMat(@SuppressWarnings("unused") PString x,
-                        @Bind("this") Node inliningTarget,
-                        @Bind("x.getNativeCharSequence()") NativeCharSequence ncs,
-                        @CachedLibrary("ncs") InteropLibrary lib,
-                        @Cached CastToJavaIntExactNode castToJavaIntNode) {
-            return ncs.length(inliningTarget, lib, castToJavaIntNode);
+        static boolean isKnownLength(int elements) {
+            // -1 means we have to search for the null terminator to compute the length
+            return elements != -1;
         }
 
         @Specialization