diff --git a/src/hotspot/share/opto/gcm.cpp b/src/hotspot/share/opto/gcm.cpp index 4646e1bb9c7..0c7c3ec30c6 100644 --- a/src/hotspot/share/opto/gcm.cpp +++ b/src/hotspot/share/opto/gcm.cpp @@ -746,6 +746,21 @@ Block* PhaseCFG::insert_anti_dependences(Block* LCA, Node* load, bool verify) { // The anti-dependence constraints apply only to the fringe of this tree. Node* initial_mem = load->in(MemNode::Memory); + + // We don't optimize the memory graph for pinned loads, so we may need to raise the + // root of our search tree through the corresponding slices of MergeMem nodes to + // get to the node that really creates the memory state for this slice. + if (load_alias_idx >= Compile::AliasIdxRaw) { + while (initial_mem->is_MergeMem()) { + MergeMemNode* mm = initial_mem->as_MergeMem(); + Node* p = mm->memory_at(load_alias_idx); + if (p != mm->base_memory()) { + initial_mem = p; + } else { + break; + } + } + } worklist_def_use_mem_states.push(nullptr, initial_mem); while (worklist_def_use_mem_states.is_nonempty()) { // Examine a nearby store to see if it might interfere with our load. diff --git a/test/hotspot/jtreg/compiler/controldependency/TestAntiDependencyForPinnedLoads.java b/test/hotspot/jtreg/compiler/controldependency/TestAntiDependencyForPinnedLoads.java new file mode 100644 index 00000000000..05673015ebe --- /dev/null +++ b/test/hotspot/jtreg/compiler/controldependency/TestAntiDependencyForPinnedLoads.java @@ -0,0 +1,44 @@ +/* + * 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. + */ + +/** + * @test + * @bug 8337066 + * @summary Test that MergeMem is skipped when looking for stores + * @run main/othervm -Xbatch -XX:-TieredCompilation + * -XX:CompileCommand=compileonly,java.lang.StringUTF16::reverse + * compiler.controldependency.TestAntiDependencyForPinnedLoads + */ + +package compiler.controldependency; + +public class TestAntiDependencyForPinnedLoads { + public static void main(String[] args) { + for(int i = 0; i < 50_000; i++) { + String str = "YYYY年MM月DD日"; + StringBuffer strBuffer = new StringBuffer(str); + String revStr = strBuffer.reverse().toString(); + if (!revStr.equals("日DD月MM年YYYY")) throw new InternalError("FAIL"); + } + } +}