no exit safepoint if end safepoints are disabled

Author: davleopo

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/java/BytecodeParser.java

@@ -3861,6 +3861,7 @@ private LoopBeginNode appendLoopBegin(FixedWithNextNode fixedWithNext, int start
             if (disableLoopSafepoint()) {
                 loopBegin.disableSafepoint(SafepointState.MUST_NEVER_SAFEPOINT);
                 loopBegin.disableGuestSafepoint(SafepointState.MUST_NEVER_SAFEPOINT);
+                loopBegin.disableLoopExitSafepoint(SafepointState.MUST_NEVER_SAFEPOINT);
             }
             fixedWithNext.setNext(preLoopEnd);
             // Add the single non-loop predecessor of the loop header.

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/phases/SubstrateSafepointInsertionPhase.java

@@ -64,20 +64,34 @@ public static boolean needSafepointCheck(ResolvedJavaMethod method) {
         return true;
     }
 
-    @Override
-    protected void run(StructuredGraph graph, MidTierContext context) {
+    /**
+     * Determines if this (potentially special) method needs safepoint checks.
+     */
+    public static boolean needsSafepointCheck(StructuredGraph graph) {
         SharedMethod method = (SharedMethod) graph.method();
-        if (!method.needSafepointCheck()) {
-            return;
-        }
+        return method.needSafepointCheck();
+    }
 
+    /**
+     * Insert SVM specific safepoints at the method end if necessary.
+     */
+    public static void insertMethodEndSafepoints(StructuredGraph graph, MidTierContext context) {
+        SharedMethod method = (SharedMethod) graph.method();
         if (!((SubstrateBackend) context.getTargetProvider()).safepointCheckedInEpilogue(method)) {
             /* Insert method-end safepoints. */
             for (ReturnNode returnNode : graph.getNodes(ReturnNode.TYPE)) {
                 SafepointNode safepointNode = graph.add(new SafepointNode());
                 graph.addBeforeFixed(returnNode, safepointNode);
             }
         }
+    }
+
+    @Override
+    protected void run(StructuredGraph graph, MidTierContext context) {
+        if (!needsSafepointCheck(graph)) {
+            return;
+        }
+        insertMethodEndSafepoints(graph, context);
 
         /* Insert loop safepoints. */
         super.run(graph, context);