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8054927: Missing MemNode::acquire ordering in some volatile Load nodes

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Fixed memory ordering parameter and added missing barriers for volatile loads.

Reviewed-by: roland, iveresov
This commit is contained in:
Vladimir Kozlov 2014-08-13 13:05:04 -07:00
parent 2a78aba488
commit ed5be50e9e
1 changed files with 14 additions and 2 deletions
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16
hotspot/src/share/vm/opto/library_call.cpp
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@ -2595,7 +2595,8 @@ bool LibraryCallKit::inline_unsafe_access(bool is_native_ptr, bool is_store, Bas
if (need_mem_bar) insert_mem_bar(Op_MemBarCPUOrder);
if (!is_store) {
Node* p = make_load(control(), adr, value_type, type, adr_type, MemNode::unordered, is_volatile);
MemNode::MemOrd mo = is_volatile ? MemNode::acquire : MemNode::unordered;
Node* p = make_load(control(), adr, value_type, type, adr_type, mo, is_volatile);
// load value
switch (type) {
case T_BOOLEAN:
@ -5096,8 +5097,19 @@ Node * LibraryCallKit::load_field_from_object(Node * fromObj, const char * field
type = Type::get_const_basic_type(bt);
}
if (support_IRIW_for_not_multiple_copy_atomic_cpu && is_vol) {
insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
}
// Build the load.
Node* loadedField = make_load(NULL, adr, type, bt, adr_type, MemNode::unordered, is_vol);
MemNode::MemOrd mo = is_vol ? MemNode::acquire : MemNode::unordered;
Node* loadedField = make_load(NULL, adr, type, bt, adr_type, mo, is_vol);
// If reference is volatile, prevent following memory ops from
// floating up past the volatile read. Also prevents commoning
// another volatile read.
if (is_vol) {
// Memory barrier includes bogus read of value to force load BEFORE membar
insert_mem_bar(Op_MemBarAcquire, loadedField);
}
return loadedField;
}