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8027751: C1 crashes in Weblogic with G1 enabled

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Keep T_OBJECT operands in registers for logical operations on x64

Reviewed-by: kvn, roland
This commit is contained in:
Igor Veresov 2013-11-05 00:59:30 -08:00
parent c8757a5edd
commit 7899a729a9
2 changed files with 49 additions and 2 deletions
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6
hotspot/src/share/vm/c1/c1_LinearScan.cpp
View File

@ -1138,8 +1138,10 @@ IntervalUseKind LinearScan::use_kind_of_input_operand(LIR_Op* op, LIR_Opr opr) {
}
}
}
} else if (opr_type != T_LONG) {
// We want to sometimes use logical operations on pointers, in particular in GC barriers.
// Since 64bit logical operations do not current support operands on stack, we have to make sure
// T_OBJECT doesn't get spilled along with T_LONG.
} else if (opr_type != T_LONG LP64_ONLY(&& opr_type != T_OBJECT)) {
// integer instruction (note: long operands must always be in register)
switch (op->code()) {
case lir_cmp:

45
hotspot/test/compiler/regalloc/C1ObjectSpillInLogicOp.java Normal file
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@ -0,0 +1,45 @@
/*
* Copyright (c) 2013, 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 8027751
* @summary C1 crashes generating G1 post-barrier in Unsafe.getAndSetObject() intrinsic because of the new value spill
* @run main/othervm -XX:+UseG1GC C1ObjectSpillInLogicOp
*
* G1 barriers use logical operators (xor) on T_OBJECT mixed with T_LONG or T_INT.
* The current implementation of logical operations on x86 in C1 doesn't allow for long operands to be on stack.
* There is a special code in the register allocator that forces long arguments in registers on x86. However T_OBJECT
* can be spilled just fine, and in that case the xor emission will fail.
*/
import java.util.concurrent.atomic.*;
class C1ObjectSpillInLogicOp {
static public void main(String[] args) {
AtomicReferenceArray<Integer> x = new AtomicReferenceArray(128);
Integer y = new Integer(0);
for (int i = 0; i < 50000; i++) {
x.getAndSet(i % x.length(), y);
}
}
}