[GR-66619] Set cfg loops to null after invalidation.

PullRequest: graal/21274

Author: rmosaner

compiler/src/jdk.graal.compiler.test/src/jdk/graal/compiler/core/test/MemoryScheduleTest.java

@@ -715,7 +715,7 @@ private ScheduleResult getFinalSchedule(final String snippet, final TestMode mod
                 if (graph.hasLoops() && graph.isLastCFGValid()) {
                     // CFGLoops are computed differently after FSA, see CFGLoop#getLoopExits(). The
                     // cached cfg needs to have its loop information invalidated.
-                    graph.getLastCFG().invalidateLoopInformation();
+                    graph.getLastCFG().resetLoopInformation();
                 }
             }
             debug.dump(DebugContext.BASIC_LEVEL, graph, "after removal of framestates");

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/cfg/ControlFlowGraph.java

@@ -1255,7 +1255,7 @@ public void invalidateFrequencies() {
         }
     }
 
-    public void invalidateLoopInformation() {
+    public void resetLoopInformation() {
         if (buildConfig.loopsComputed) {
             buildConfig.loopsComputed = false;
             /*
@@ -1265,6 +1265,7 @@ public void invalidateLoopInformation() {
             for (HIRBlock b : getBlocks()) {
                 b.loop = null;
             }
+            loops = null;
         }
     }
 

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/phases/common/FrameStateAssignmentPhase.java

@@ -148,7 +148,7 @@ protected void run(StructuredGraph graph) {
         GraphUtil.killAllWithUnusedFloatingInputs(graph.getNodes(FrameState.TYPE).filter(state -> state.hasNoUsages()), false);
         if (graph.hasLoops() && graph.isLastCFGValid()) {
             // CFGLoops are computed differently after FSA, see CFGLoop#getLoopExits().
-            graph.getLastCFG().invalidateLoopInformation();
+            graph.getLastCFG().resetLoopInformation();
         }
     }