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8155643: Java crash with assert in Xcomp mode and disabled ReduceInitialCardMarks

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We should not emit a subtype check for CloneOop arraycopy.

Reviewed-by: kvn
This commit is contained in:
Tobias Hartmann 2016-05-12 08:23:25 +02:00
parent 536db8741f
commit cf5a61530f
2 changed files with 81 additions and 37 deletions
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78
hotspot/src/share/vm/opto/macroArrayCopy.cpp
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@ -503,46 +503,50 @@ Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode*
// further to JVM_ArrayCopy on the first per-oop check that fails.
// (Actually, we don't move raw bits only; the GC requires card marks.)
// Get the klass* for both src and dest
Node* src_klass = ac->in(ArrayCopyNode::SrcKlass);
Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
// We don't need a subtype check for validated copies and Object[].clone()
bool skip_subtype_check = ac->is_arraycopy_validated() || ac->is_copyof_validated() ||
ac->is_copyofrange_validated() || ac->is_cloneoop();
if (!skip_subtype_check) {
// Get the klass* for both src and dest
Node* src_klass = ac->in(ArrayCopyNode::SrcKlass);
Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
assert(src_klass != NULL && dest_klass != NULL, "should have klasses");
assert(src_klass != NULL && dest_klass != NULL, "should have klasses");
// Generate the subtype check.
// This might fold up statically, or then again it might not.
//
// Non-static example: Copying List<String>.elements to a new String[].
// The backing store for a List<String> is always an Object[],
// but its elements are always type String, if the generic types
// are correct at the source level.
//
// Test S[] against D[], not S against D, because (probably)
// the secondary supertype cache is less busy for S[] than S.
// This usually only matters when D is an interface.
Node* not_subtype_ctrl = (ac->is_arraycopy_validated() || ac->is_copyof_validated() || ac->is_copyofrange_validated()) ? top() :
Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, &_igvn);
// Plug failing path into checked_oop_disjoint_arraycopy
if (not_subtype_ctrl != top()) {
Node* local_ctrl = not_subtype_ctrl;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
// Generate the subtype check.
// This might fold up statically, or then again it might not.
//
// Non-static example: Copying List<String>.elements to a new String[].
// The backing store for a List<String> is always an Object[],
// but its elements are always type String, if the generic types
// are correct at the source level.
//
// Test S[] against D[], not S against D, because (probably)
// the secondary supertype cache is less busy for S[] than S.
// This usually only matters when D is an interface.
Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, &_igvn);
// Plug failing path into checked_oop_disjoint_arraycopy
if (not_subtype_ctrl != top()) {
Node* local_ctrl = not_subtype_ctrl;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
// (At this point we can assume disjoint_bases, since types differ.)
int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
Node* p1 = basic_plus_adr(dest_klass, ek_offset);
Node* n1 = LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
Node* dest_elem_klass = transform_later(n1);
Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
adr_type,
dest_elem_klass,
src, src_offset, dest, dest_offset,
ConvI2X(copy_length), dest_uninitialized);
if (cv == NULL) cv = intcon(-1); // failure (no stub available)
checked_control = local_ctrl;
checked_i_o = *io;
checked_mem = local_mem->memory_at(alias_idx);
checked_value = cv;
// (At this point we can assume disjoint_bases, since types differ.)
int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
Node* p1 = basic_plus_adr(dest_klass, ek_offset);
Node* n1 = LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
Node* dest_elem_klass = transform_later(n1);
Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
adr_type,
dest_elem_klass,
src, src_offset, dest, dest_offset,
ConvI2X(copy_length), dest_uninitialized);
if (cv == NULL) cv = intcon(-1); // failure (no stub available)
checked_control = local_ctrl;
checked_i_o = *io;
checked_mem = local_mem->memory_at(alias_idx);
checked_value = cv;
}
}
// At this point we know we do not need type checks on oop stores.

40
hotspot/test/compiler/arraycopy/TestObjectArrayClone.java Normal file
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@ -0,0 +1,40 @@
/*
* Copyright (c) 2016, 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 8155643
* @summary Test Object.clone() intrinsic if ReduceInitialCardMarks is disabled.
* @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xcomp -XX:CompileOnly=TestObjectArrayClone.test -XX:-ReduceInitialCardMarks TestObjectArrayClone
*/
public class TestObjectArrayClone {
public static TestObjectArrayClone[] test(TestObjectArrayClone[] arr) {
return arr.clone();
}
public static void main(String[] args) {
test(new TestObjectArrayClone[42]);
}
}