Automatic merge of jdk:master into master

duke · duke · commit 2805c054982d · 2025-09-12T12:06:39.000Z
diff --git a/src/hotspot/share/opto/phaseX.cpp b/src/hotspot/share/opto/phaseX.cpp
@@ -2645,7 +2645,11 @@ void PhaseIterGVN::add_users_of_use_to_worklist(Node* n, Node* use, Unique_Node_
       worklist.push(cmp);
     }
   }
-  if (use->Opcode() == Op_AddX) {
+
+  // From CastX2PNode::Ideal
+  // CastX2P(AddX(x, y))
+  // CastX2P(SubX(x, y))
+  if (use->Opcode() == Op_AddX || use->Opcode() == Op_SubX) {
     for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
       Node* u = use->fast_out(i2);
       if (u->Opcode() == Op_CastX2P) {
diff --git a/test/hotspot/jtreg/compiler/igvn/MissedOptimizationWithCastX2PSubX.java b/test/hotspot/jtreg/compiler/igvn/MissedOptimizationWithCastX2PSubX.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2025, 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 8367483
+ * @summary Missed worklist notification during IGVN for CastX2P(SubX(x, y)) pattern,
+ *          leads to missed optimization.
+ * @run main/othervm
+ *           -XX:CompileCommand=compileonly,compiler.igvn.MissedOptimizationWithCastX2PSubX::test
+ *           -XX:-TieredCompilation
+ *           -XX:+IgnoreUnrecognizedVMOptions
+ *           -XX:VerifyIterativeGVN=1110
+ *           compiler.igvn.MissedOptimizationWithCastX2PSubX
+ * @run main compiler.igvn.MissedOptimizationWithCastX2PSubX
+ */
+
+package compiler.igvn;
+
+import java.lang.foreign.*;
+
+public class MissedOptimizationWithCastX2PSubX {
+    public static void main(String[] args) {
+        MemorySegment a  = Arena.ofAuto().allocate(74660);
+        MemorySegment b  = Arena.ofAuto().allocate(74660);
+
+        for (int i = 0; i < 1_000; i++) {
+            test(a, 69830/2 - 100, b, -10_000, 0, 1_000);
+        }
+    }
+
+    public static void test(MemorySegment a, long invarA, MemorySegment b, long invarB, long ivLo, long ivHi) {
+        for (long i = ivHi-1; i >= ivLo; i-=1) {
+            a.set(ValueLayout.JAVA_CHAR_UNALIGNED, 69830L + 2L * i + -2L * invarA, (char)42);
+            b.set(ValueLayout.JAVA_FLOAT_UNALIGNED, 9071L + -4L * i + -4L * invarB, 42);
+        }
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -2645,7 +2645,11 @@ void PhaseIterGVN::add_users_of_use_to_worklist(Node* n, Node* use, Unique_Node_`
`2645`	`2645`	`worklist.push(cmp);`
`2646`	`2646`	`}`
`2647`	`2647`	`}`
`2648`		`- if (use->Opcode() == Op_AddX) {`
	`2648`	`+`
	`2649`	`+ // From CastX2PNode::Ideal`
	`2650`	`+ // CastX2P(AddX(x, y))`
	`2651`	`+ // CastX2P(SubX(x, y))`
	`2652`	`+ if (use->Opcode() == Op_AddX \|\| use->Opcode() == Op_SubX) {`
`2649`	`2653`	`for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {`
`2650`	`2654`	`Node* u = use->fast_out(i2);`
`2651`	`2655`	`if (u->Opcode() == Op_CastX2P) {`