# HG changeset patch # User kvn # Date 1281548900 25200 # Node ID 6c9cc03d87261069d902aa414372a9dd62506b15 # Parent d2ede61b7a12f82e829f55059dc969051ae83346 6973329: C2 with Zero based COOP produces code with broken anti-dependency on x86 Summary: Recompile without subsuming loads if RA try to clone a node with anti_dependence. Reviewed-by: never diff -r d2ede61b7a12 -r 6c9cc03d8726 src/share/vm/includeDB_compiler2 --- a/src/share/vm/includeDB_compiler2 Wed Aug 11 05:51:21 2010 -0700 +++ b/src/share/vm/includeDB_compiler2 Wed Aug 11 10:48:20 2010 -0700 @@ -911,6 +911,7 @@ reg_split.cpp addnode.hpp reg_split.cpp allocation.inline.hpp reg_split.cpp callnode.hpp +reg_split.cpp c2compiler.hpp reg_split.cpp cfgnode.hpp reg_split.cpp chaitin.hpp reg_split.cpp loopnode.hpp diff -r d2ede61b7a12 -r 6c9cc03d8726 src/share/vm/opto/lcm.cpp --- a/src/share/vm/opto/lcm.cpp Wed Aug 11 05:51:21 2010 -0700 +++ b/src/share/vm/opto/lcm.cpp Wed Aug 11 10:48:20 2010 -0700 @@ -113,7 +113,8 @@ if( !m->is_Mach() ) continue; MachNode *mach = m->as_Mach(); was_store = false; - switch( mach->ideal_Opcode() ) { + int iop = mach->ideal_Opcode(); + switch( iop ) { case Op_LoadB: case Op_LoadUS: case Op_LoadD: @@ -155,6 +156,12 @@ default: // Also check for embedded loads if( !mach->needs_anti_dependence_check() ) continue; // Not an memory op; skip it + if( must_clone[iop] ) { + // Do not move nodes which produce flags because + // RA will try to clone it to place near branch and + // it will cause recompilation, see clone_node(). + continue; + } { // Check that value is used in memory address in // instructions with embedded load (CmpP val1,(val2+off)). @@ -957,6 +964,8 @@ Block *sb = _succs[i]; // Clone the entire area; ignoring the edge fixup for now. for( uint j = end; j > beg; j-- ) { + // It is safe here to clone a node with anti_dependence + // since clones dominate on each path. Node *clone = _nodes[j-1]->clone(); sb->_nodes.insert( 1, clone ); bbs.map(clone->_idx,sb); diff -r d2ede61b7a12 -r 6c9cc03d8726 src/share/vm/opto/reg_split.cpp --- a/src/share/vm/opto/reg_split.cpp Wed Aug 11 05:51:21 2010 -0700 +++ b/src/share/vm/opto/reg_split.cpp Wed Aug 11 10:48:20 2010 -0700 @@ -271,6 +271,32 @@ return maxlrg; } +//------------------------------clone_node---------------------------- +// Clone node with anti dependence check. +Node* clone_node(Node* def, Block *b, Compile* C) { + if (def->needs_anti_dependence_check()) { +#ifdef ASSERT + if (Verbose) { + tty->print_cr("RA attempts to clone node with anti_dependence:"); + def->dump(-1); tty->cr(); + tty->print_cr("into block:"); + b->dump(); + } +#endif + if (C->subsume_loads() == true && !C->failing()) { + // Retry with subsume_loads == false + // If this is the first failure, the sentinel string will "stick" + // to the Compile object, and the C2Compiler will see it and retry. + C->record_failure(C2Compiler::retry_no_subsuming_loads()); + } else { + // Bailout without retry + C->record_method_not_compilable("RA Split failed: attempt to clone node with anti_dependence"); + } + return 0; + } + return def->clone(); +} + //------------------------------split_Rematerialize---------------------------- // Clone a local copy of the def. Node *PhaseChaitin::split_Rematerialize( Node *def, Block *b, uint insidx, uint &maxlrg, GrowableArray splits, int slidx, uint *lrg2reach, Node **Reachblock, bool walkThru ) { @@ -298,8 +324,8 @@ } } - Node *spill = def->clone(); - if (C->check_node_count(NodeLimitFudgeFactor, out_of_nodes)) { + Node *spill = clone_node(def, b, C); + if (spill == NULL || C->check_node_count(NodeLimitFudgeFactor, out_of_nodes)) { // Check when generating nodes return 0; } @@ -834,13 +860,13 @@ // The effect of this clone is to drop the node out of the block, // so that the allocator does not see it anymore, and therefore // does not attempt to assign it a register. - def = def->clone(); + def = clone_node(def, b, C); + if (def == NULL || C->check_node_count(NodeLimitFudgeFactor, out_of_nodes)) { + return 0; + } _names.extend(def->_idx,0); _cfg._bbs.map(def->_idx,b); n->set_req(inpidx, def); - if (C->check_node_count(NodeLimitFudgeFactor, out_of_nodes)) { - return 0; - } continue; } diff -r d2ede61b7a12 -r 6c9cc03d8726 test/compiler/6973329/Test.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/compiler/6973329/Test.java Wed Aug 11 10:48:20 2010 -0700 @@ -0,0 +1,63 @@ +/* + * Copyright (c) 2010, 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 6973329 + * @summary C2 with Zero based COOP produces code with broken anti-dependency on x86 + * + * @run main/othervm -Xbatch -Xcomp -XX:CompileOnly=Test Test + */ + +class A { + A next; + int n; + + public int get_n() { + return n+1; + } +} +public class Test { + + A a; + + void test (A new_next) { + A prev_next = a.next; + a.next = new_next; + if (prev_next == null) { + a.n = a.get_n(); + } + } + + public static void main(String args[]) { + Test t = new Test(); + t.a = new A(); + t.a.n = 1; + t.test(new A()); + if (t.a.n != 2) { + System.out.println("Wrong value: " + t.a.n + " expected: 2"); + System.exit(97); + } + } +} +