assert no gvn is done after fixing reads

Author: davleopo

compiler/src/jdk.internal.vm.compiler/src/org/graalvm/compiler/core/phases/LowTier.java

@@ -58,19 +58,20 @@ static class Options {
     }
 
     private final CanonicalizerPhase canonicalizerWithoutGVN;
+    private final CanonicalizerPhase canonicalizerWithGVN;
 
     @SuppressWarnings("this-escape")
     public LowTier(OptionValues options) {
-        CanonicalizerPhase canonicalizer = CanonicalizerPhase.create();
-        this.canonicalizerWithoutGVN = canonicalizer.copyWithoutGVN();
+        this.canonicalizerWithGVN = CanonicalizerPhase.create();
+        this.canonicalizerWithoutGVN = canonicalizerWithGVN.copyWithoutGVN();
 
         if (Options.ProfileCompiledMethods.getValue(options)) {
             appendPhase(new ProfileCompiledMethodsPhase());
         }
 
-        appendPhase(new LowTierLoweringPhase(canonicalizer));
+        appendPhase(new LowTierLoweringPhase(canonicalizerWithGVN));
 
-        appendPhase(new ExpandLogicPhase(canonicalizer));
+        appendPhase(new ExpandLogicPhase(canonicalizerWithGVN));
 
         appendPhase(new FixReadsPhase(true,
                         new SchedulePhase(GraalOptions.StressTestEarlyReads.getValue(options) ? SchedulingStrategy.EARLIEST : SchedulingStrategy.LATEST_OUT_OF_LOOPS_IMPLICIT_NULL_CHECKS)));
@@ -95,7 +96,11 @@ public LowTier(OptionValues options) {
         appendPhase(new SchedulePhase(SchedulePhase.SchedulingStrategy.LATEST_OUT_OF_LOOPS));
     }
 
-    public CanonicalizerPhase getCanonicalizerWithoutGVN() {
+    public final CanonicalizerPhase getCanonicalizerWithoutGVN() {
         return canonicalizerWithoutGVN;
     }
+
+    public final CanonicalizerPhase getCanonicalizer() {
+        return canonicalizerWithGVN;
+    }
 }

compiler/src/jdk.internal.vm.compiler/src/org/graalvm/compiler/phases/common/CanonicalizerPhase.java

@@ -527,6 +527,7 @@ public static boolean gvn(Node node, NodeClass<?> nodeClass) {
     }
 
     public boolean tryGlobalValueNumbering(Node node, NodeClass<?> nodeClass) {
+        assert ((StructuredGraph) node.graph()).getGraphState().isBeforeStage(StageFlag.FIXED_READS) : "GVN must not occur after fixing reads, trying to gvn " + node + " for graph " + node.graph();
         return gvn(node, nodeClass);
     }
 

compiler/src/jdk.internal.vm.compiler/src/org/graalvm/compiler/virtual/phases/ea/ReadEliminationBlockState.java

@@ -204,20 +204,19 @@ public void killReadCache(LocationIdentity identity, ValueNode index, ValueNode
                 }
             }
             return;
-        } else {
-            Iterator<CacheEntry<?>> iterator = readCache.getKeys().iterator();
-            while (iterator.hasNext()) {
-                CacheEntry<?> entry = iterator.next();
-                /*
-                 * We cover multiple cases here but in general index and array can only be !=null
-                 * for indexed nodes thus the location identity of other accesses (field and object
-                 * locations) will never be the same and will never alias with array accesses.
-                 *
-                 * Unsafe accesses will alias if they are writing to any location.
-                 */
-                if (entry.conflicts(identity, index, array)) {
-                    iterator.remove();
-                }
+        }
+        Iterator<CacheEntry<?>> iterator = readCache.getKeys().iterator();
+        while (iterator.hasNext()) {
+            CacheEntry<?> entry = iterator.next();
+            /*
+             * We cover multiple cases here but in general index and array can only be !=null for
+             * indexed nodes thus the location identity of other accesses (field and object
+             * locations) will never be the same and will never alias with array accesses.
+             *
+             * Unsafe accesses will alias if they are writing to any location.
+             */
+            if (entry.conflicts(identity, index, array)) {
+                iterator.remove();
             }
         }
     }