8322589: Add Ideal transformation: (~a) & (~b) => ~(a | b)

CptGit · TobiHartmann · commit 856922747358 · 2024-01-10T07:31:56.000Z
Reviewed-by: thartmann, epeter
diff --git a/src/hotspot/share/opto/addnode.cpp b/src/hotspot/share/opto/addnode.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, 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
@@ -253,6 +253,22 @@ AddNode* AddNode::make(Node* in1, Node* in2, BasicType bt) {
   return nullptr;
 }
 
+bool AddNode::is_not(PhaseGVN* phase, Node* n, BasicType bt) {
+  return n->Opcode() == Op_Xor(bt) && phase->type(n->in(2)) == TypeInteger::minus_1(bt);
+}
+
+AddNode* AddNode::make_not(PhaseGVN* phase, Node* n, BasicType bt) {
+  switch (bt) {
+    case T_INT:
+      return new XorINode(n, phase->intcon(-1));
+    case T_LONG:
+      return new XorLNode(n, phase->longcon(-1L));
+    default:
+      fatal("Not implemented for %s", type2name(bt));
+  }
+  return nullptr;
+}
+
 //=============================================================================
 //------------------------------Idealize---------------------------------------
 Node* AddNode::IdealIL(PhaseGVN* phase, bool can_reshape, BasicType bt) {
diff --git a/src/hotspot/share/opto/addnode.hpp b/src/hotspot/share/opto/addnode.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, 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
@@ -78,6 +78,13 @@ class AddNode : public Node {
   virtual int min_opcode() const = 0;
 
   static AddNode* make(Node* in1, Node* in2, BasicType bt);
+
+  // Utility function to check if the given node is a NOT operation,
+  // i.e., n == m ^ (-1).
+  static bool is_not(PhaseGVN* phase, Node* n, BasicType bt);
+
+  // Utility function to make a NOT operation, i.e., returning n ^ (-1).
+  static AddNode* make_not(PhaseGVN* phase, Node* n, BasicType bt);
 };
 
 //------------------------------AddINode---------------------------------------
diff --git a/src/hotspot/share/opto/mulnode.cpp b/src/hotspot/share/opto/mulnode.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, 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
@@ -610,6 +610,13 @@ Node *AndINode::Ideal(PhaseGVN *phase, bool can_reshape) {
     return progress;
   }
 
+  // Convert "(~a) & (~b)" into "~(a | b)"
+  if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) {
+    Node* or_a_b = new OrINode(in(1)->in(1), in(2)->in(1));
+    Node* tn = phase->transform(or_a_b);
+    return AddNode::make_not(phase, tn, T_INT);
+  }
+
   // Special case constant AND mask
   const TypeInt *t2 = phase->type( in(2) )->isa_int();
   if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
@@ -750,6 +757,13 @@ Node *AndLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
     return progress;
   }
 
+  // Convert "(~a) & (~b)" into "~(a | b)"
+  if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) {
+    Node* or_a_b = new OrLNode(in(1)->in(1), in(2)->in(1));
+    Node* tn = phase->transform(or_a_b);
+    return AddNode::make_not(phase, tn, T_LONG);
+  }
+
   // Special case constant AND mask
   const TypeLong *t2 = phase->type( in(2) )->isa_long();
   if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
diff --git a/test/hotspot/jtreg/compiler/c2/irTests/AndINodeIdealizationTests.java b/test/hotspot/jtreg/compiler/c2/irTests/AndINodeIdealizationTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 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
@@ -38,22 +38,24 @@ public static void main(String[] args) {
         TestFramework.run();
     }
 
-    @Run(test = { "test1" })
+    @Run(test = { "test1", "test2" })
     public void runMethod() {
         int a = RunInfo.getRandom().nextInt();
+        int b = RunInfo.getRandom().nextInt();
 
         int min = Integer.MIN_VALUE;
         int max = Integer.MAX_VALUE;
 
-        assertResult(0);
-        assertResult(a);
-        assertResult(min);
-        assertResult(max);
+        assertResult(0, 0);
+        assertResult(a, b);
+        assertResult(min, min);
+        assertResult(max, max);
     }
 
     @DontCompile
-    public void assertResult(int a) {
+    public void assertResult(int a, int b) {
         Asserts.assertEQ((0 - a) & 1, test1(a));
+        Asserts.assertEQ((~a) & (~b), test2(a, b));
     }
 
     @Test
@@ -63,4 +65,13 @@ public void assertResult(int a) {
     public int test1(int x) {
         return (0 - x) & 1;
     }
+
+    @Test
+    @IR(failOn = { IRNode.AND })
+    @IR(counts = { IRNode.OR, "1",
+                   IRNode.XOR, "1" })
+    // Checks (~a) & (~b) => ~(a | b)
+    public int test2(int a, int b) {
+        return (~a) & (~b);
+    }
 }
diff --git a/test/hotspot/jtreg/compiler/c2/irTests/AndLNodeIdealizationTests.java b/test/hotspot/jtreg/compiler/c2/irTests/AndLNodeIdealizationTests.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2024, 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.
+ */
+package compiler.c2.irTests;
+
+import jdk.test.lib.Asserts;
+import compiler.lib.ir_framework.*;
+
+/*
+ * @test
+ * @bug 8322589
+ * @summary Test that Ideal transformations of AndLNode* are being performed as expected.
+ * @library /test/lib /
+ * @run driver compiler.c2.irTests.AndLNodeIdealizationTests
+ */
+public class AndLNodeIdealizationTests {
+
+    public static void main(String[] args) {
+        TestFramework.run();
+    }
+
+    @Run(test = { "test1" })
+    public void runMethod() {
+        long a = RunInfo.getRandom().nextLong();
+        long b = RunInfo.getRandom().nextLong();
+
+        long min = Long.MIN_VALUE;
+        long max = Long.MAX_VALUE;
+
+        assertResult(0, 0);
+        assertResult(a, b);
+        assertResult(min, min);
+        assertResult(max, max);
+    }
+
+    @DontCompile
+    public void assertResult(long a, long b) {
+        Asserts.assertEQ((~a) & (~b), test1(a, b));
+    }
+
+    @Test
+    @IR(failOn = { IRNode.AND })
+    @IR(counts = { IRNode.OR, "1",
+                   IRNode.XOR, "1" })
+    // Checks (~a) & (~b) => ~(a | b)
+    public long test1(long a, long b) {
+        return (~a) & (~b);
+    }
+}
diff --git a/test/hotspot/jtreg/compiler/lib/ir_framework/IRNode.java b/test/hotspot/jtreg/compiler/lib/ir_framework/IRNode.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -298,6 +298,11 @@ public class IRNode {
         optoOnly(ALLOC_ARRAY_OF, regex);
     }
 
+    public static final String OR = PREFIX + "OR" + POSTFIX;
+    static {
+        beforeMatchingNameRegex(OR, "Or(I|L)");
+    }
+
     public static final String AND = PREFIX + "AND" + POSTFIX;
     static {
         beforeMatchingNameRegex(AND, "And(I|L)");
