8288683: C2: And node gets wrong type due to not adding it back to the worklist in CCP

Reviewed-by: roland, thartmann

Author: chhagedorn

src/hotspot/share/opto/phaseX.cpp

@@ -1861,6 +1861,24 @@ void PhaseCCP::analyze() {
             }
           }
         }
+        push_and(worklist, n, m);
+      }
+    }
+  }
+}
+
+// AndI/L::Value() optimizes patterns similar to (v << 2) & 3 to zero if they are bitwise disjoint.
+// Add the AndI/L nodes back to the worklist to re-apply Value() in case the shift value changed.
+void PhaseCCP::push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const {
+  uint use_op = use->Opcode();
+  if ((use_op == Op_LShiftI || use_op == Op_LShiftL)
+      && use->in(2) == parent) { // is shift value (right-hand side of LShift)
+    for (DUIterator_Fast imax, i = use->fast_outs(imax); i < imax; i++) {
+      Node* and_node = use->fast_out(i);
+      uint and_node_op = and_node->Opcode();
+      if ((and_node_op == Op_AndI || and_node_op == Op_AndL)
+          && and_node->bottom_type() != type(and_node)) {
+        worklist.push(and_node);
       }
     }
   }

src/hotspot/share/opto/phaseX.hpp

@@ -568,6 +568,8 @@ class PhaseCCP : public PhaseIterGVN {
   // Non-recursive.  Use analysis to transform single Node.
   virtual Node *transform_once( Node *n );
 
+  void push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const;
+
 public:
   PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants
   NOT_PRODUCT( ~PhaseCCP(); )

test/hotspot/jtreg/compiler/c2/TestAndShiftZeroCCP.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8288683
+ * @library /test/lib
+ * @summary Test that And nodes are added to the CCP worklist if they have an LShift as input.
+ * @run main/othervm -Xbatch compiler.c2.TestAndShiftZeroCCP
+ */
+package compiler.c2;
+
+import jdk.test.lib.Asserts;
+
+public class TestAndShiftZeroCCP {
+    static int iFld = 0xfffff;
+
+    public static void main(String[] strArr) {
+        for (int i = 0; i < 10000; i++) {
+            Asserts.assertEQ(testAndI(), 224);
+            Asserts.assertEQ(testAndL(), 224L);
+            Asserts.assertEQ(testAndLConvI2L(), 224L);
+        }
+    }
+
+    static int testAndI() {
+        int x = 10;
+        int y = iFld;
+        int z = 3;
+        int q;
+        for (int i = 62; i < 70; ++i) {
+            q = y << i;
+            for (int j = 0; j < 8; j++) {
+                z += i;
+            }
+            z = q & 0xff;
+        }
+        return z;
+    }
+
+    static long testAndL() {
+        long x = 10;
+        long y = iFld;
+        long z = 3;
+        long q;
+        for (int i = 62; i < 70; ++i) {
+            q = y << i;
+            for (int j = 0; j < 8; j++) {
+                z += i;
+            }
+            z = q & 0xff;
+        }
+        return z;
+    }
+
+    static long testAndLConvI2L() {
+        long x = 10;
+        long y = iFld;
+        long z = 3;
+        long q;
+        for (int i = 62; i < 70; ++i) {
+            q = y << i;
+            for (int j = 0; j < 8; j++) {
+                z += i;
+            }
+            z = q & 0xff;
+        }
+        return z;
+    }
+}