8327381: Refactor type-improving transformations in BoolNode::Ideal to BoolNode::Value

Reviewed-by: chagedorn, thartmann, jkarthikeyan, epeter

src/hotspot/share/opto/subnode.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
@@ -1623,25 +1623,8 @@ Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
     return new BoolNode( ncmp, _test.negate() );
   }
 
-  // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
-  // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
-  if (cop == Op_CmpU &&
-      cmp1_op == Op_AndI) {
-    Node* bound = nullptr;
-    if (_test._test == BoolTest::le) {
-      bound = cmp2;
-    } else if (_test._test == BoolTest::lt &&
-               cmp2->Opcode() == Op_AddI &&
-               cmp2->in(2)->find_int_con(0) == 1) {
-      bound = cmp2->in(1);
-    }
-    if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
-      return ConINode::make(1);
-    }
-  }
-
   // Change ((x & (m - 1)) u< m) into (m > 0)
-  // This is the off-by-one variant of the above
+  // This is the off-by-one variant of ((x & m) u<= m)
   if (cop == Op_CmpU &&
       _test._test == BoolTest::lt &&
       cmp1_op == Op_AndI) {
@@ -1827,9 +1810,39 @@ Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 }
 
 //------------------------------Value------------------------------------------
+// Change ((x & m) u<= m) or ((m & x) u<= m) to always true
+// Same with ((x & m) u< m+1) and ((m & x) u< m+1)
+const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const {
+  Node* cmp = in(1);
+  if (cmp != nullptr && cmp->Opcode() == Op_CmpU) {
+    Node* cmp1 = cmp->in(1);
+    Node* cmp2 = cmp->in(2);
+
+    if (cmp1->Opcode() == Op_AndI) {
+      Node* bound = nullptr;
+      if (_test._test == BoolTest::le) {
+        bound = cmp2;
+      } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) {
+        bound = cmp2->in(1);
+      }
+
+      if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
+        return TypeInt::ONE;
+      }
+    }
+  }
+
+  return nullptr;
+}
+
 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
 // based on local information.   If the input is constant, do it.
 const Type* BoolNode::Value(PhaseGVN* phase) const {
+  const Type* t = Value_cmpu_and_mask(phase);
+  if (t != nullptr) {
+    return t;
+  }
+
   return _test.cc2logical( phase->type( in(1) ) );
 }
 

src/hotspot/share/opto/subnode.hpp

@@ -347,6 +347,7 @@ public:
   BoolNode* negate(PhaseGVN* phase);
   virtual int Opcode() const;
   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
+  const Type* Value_cmpu_and_mask(PhaseValues* phase) const;
   virtual const Type* Value(PhaseGVN* phase) const;
   virtual const Type *bottom_type() const { return TypeInt::BOOL; }
   uint match_edge(uint idx) const { return 0; }

test/hotspot/jtreg/compiler/c2/gvn/TestBoolNodeGVN.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2024 Red Hat 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.gvn;
+
+import compiler.lib.ir_framework.*;
+
+import java.util.Random;
+
+/**
+ * @test
+ * @bug 8327381
+ * @summary Refactor boolean node tautology transformations
+ * @library /test/lib /
+ * @run driver compiler.c2.gvn.TestBoolNodeGVN
+ */
+public class TestBoolNodeGVN {
+    public static void main(String[] args) {
+        TestFramework.run();
+        testCorrectness();
+    }
+
+    /**
+     * Test changing ((x & m) u<= m) or ((m & x) u<= m) to always true, same with ((x & m) u< m+1) and ((m & x) u< m+1)
+     * The test is only applicable to x64, aarch64 and riscv64 for having <code>Integer.compareUnsigned</code>
+     * intrinsified.
+     */
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(failOn = IRNode.CMP_U,
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldReplaceCpmUCase1(int x, int m) {
+        return !(Integer.compareUnsigned((x & m), m) > 0); // assert in inversions to generates the pattern looking for
+    }
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(failOn = IRNode.CMP_U,
+            phase = CompilePhase.AFTER_PARSING,
+            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldReplaceCpmUCase2(int x, int m) {
+        return !(Integer.compareUnsigned((m & x), m) > 0);
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(failOn = IRNode.CMP_U,
+            phase = CompilePhase.AFTER_PARSING,
+            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldReplaceCpmUCase3(int x, int m) {
+        return Integer.compareUnsigned((x & m), m + 1) < 0;
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(failOn = IRNode.CMP_U,
+            phase = CompilePhase.AFTER_PARSING,
+            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldReplaceCpmUCase4(int x, int m) {
+        return Integer.compareUnsigned((m & x), m + 1) < 0;
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(counts = {IRNode.CMP_U, "1"},
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldHaveCpmUCase1(int x, int m) {
+        return !(Integer.compareUnsigned((x & m), m - 1) > 0);
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(counts = {IRNode.CMP_U, "1"},
+            phase = CompilePhase.AFTER_PARSING,
+            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldHaveCpmUCase2(int x, int m) {
+        return !(Integer.compareUnsigned((m & x), m - 1) > 0);
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(counts = {IRNode.CMP_U, "1"},
+            phase = CompilePhase.AFTER_PARSING,
+            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldHaveCpmUCase3(int x, int m) {
+        return Integer.compareUnsigned((x & m), m + 2) < 0;
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(counts = {IRNode.CMP_U, "1"},
+            phase = CompilePhase.AFTER_PARSING,
+            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldHaveCpmUCase4(int x, int m) {
+        return Integer.compareUnsigned((m & x), m + 2) < 0;
+    }
+
+    private static void testCorrectness() {
+        int[] values = {
+                0, 1, 5, 8, 16, 42, 100, new Random().nextInt(0, Integer.MAX_VALUE), Integer.MAX_VALUE
+        };
+
+        for (int x : values) {
+            for (int m : values) {
+                if (!testShouldReplaceCpmUCase1(x, m) |
+                    !testShouldReplaceCpmUCase2(x, m) |
+                    !testShouldReplaceCpmUCase3(x, m) |
+                    !testShouldReplaceCpmUCase4(x, m)) {
+                    throw new RuntimeException("Bad result for x = " + x + " and m = " + m + ", expected always true");
+                }
+            }
+        }
+    }
+}

test/hotspot/jtreg/compiler/lib/ir_framework/IRNode.java

@@ -439,7 +439,7 @@ public class IRNode {
 
     public static final String CMP_U = PREFIX + "CMP_U" + POSTFIX;
     static {
-        beforeMatchingNameRegex(CMP_U, "CmpU");
+        beforeMatchingNameRegex(CMP_U, "CmpU\\b");
     }
 
     public static final String CMP_U3 = PREFIX + "CMP_U3" + POSTFIX;