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8182036: Load from initializing arraycopy uses wrong memory state

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Reviewed-by: kvn
This commit is contained in:
Roland Westrelin 2017-07-03 14:33:00 +02:00
parent 7c8c0a97fc
commit a6490b0abc
3 changed files with 71 additions and 8 deletions
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21
hotspot/src/share/vm/opto/macroArrayCopy.cpp
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@ -892,16 +892,22 @@ bool PhaseMacroExpand::generate_block_arraycopy(Node** ctrl, MergeMemNode** mem,
((src_off ^ dest_off) & (BytesPerLong-1)) == 0) {
Node* sptr = basic_plus_adr(src, src_off);
Node* dptr = basic_plus_adr(dest, dest_off);
uint alias_idx = C->get_alias_index(adr_type);
const TypePtr* s_adr_type = _igvn.type(sptr)->is_ptr();
assert(s_adr_type->isa_aryptr(), "impossible slice");
uint s_alias_idx = C->get_alias_index(s_adr_type);
uint d_alias_idx = C->get_alias_index(adr_type);
bool is_mismatched = (basic_elem_type != T_INT);
Node* sval = transform_later(
LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(alias_idx), sptr, adr_type,
LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(s_alias_idx), sptr, s_adr_type,
TypeInt::INT, T_INT, MemNode::unordered, LoadNode::DependsOnlyOnTest,
false /*unaligned*/, is_mismatched));
Node* st = transform_later(
StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(alias_idx), dptr, adr_type,
StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(d_alias_idx), dptr, adr_type,
sval, T_INT, MemNode::unordered));
(*mem)->set_memory_at(alias_idx, st);
if (is_mismatched) {
st->as_Store()->set_mismatched_access();
}
(*mem)->set_memory_at(d_alias_idx, st);
src_off += BytesPerInt;
dest_off += BytesPerInt;
} else {
@ -1275,12 +1281,11 @@ void PhaseMacroExpand::expand_arraycopy_node(ArrayCopyNode *ac) {
// The generate_arraycopy subroutine checks this.
}
// This is where the memory effects are placed:
const TypePtr* adr_type = TypeAryPtr::get_array_body_type(dest_elem);
const TypePtr* adr_type = NULL;
if (ac->_dest_type != TypeOopPtr::BOTTOM) {
adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
}
if (ac->_src_type != ac->_dest_type) {
adr_type = TypeRawPtr::BOTTOM;
} else {
adr_type = TypeAryPtr::get_array_body_type(dest_elem);
}
generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,