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8017065: C2 allows safepoint checks to leak into G1 pre-barriers

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Make all raw loads strictly respect control dependencies, make sure RCE doesn't move raw loads, add verification of G1 pre-barriers.

Reviewed-by: kvn, roland
This commit is contained in:
Igor Veresov 2013-11-05 01:57:18 -08:00
parent 7899a729a9
commit c342a79faf
4 changed files with 82 additions and 21 deletions
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31
hotspot/src/share/vm/opto/memnode.hpp
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@ -204,6 +204,17 @@ public:
protected:
const Type* load_array_final_field(const TypeKlassPtr *tkls,
ciKlass* klass) const;
// depends_only_on_test is almost always true, and needs to be almost always
// true to enable key hoisting & commoning optimizations. However, for the
// special case of RawPtr loads from TLS top & end, and other loads performed by
// GC barriers, the control edge carries the dependence preventing hoisting past
// a Safepoint instead of the memory edge. (An unfortunate consequence of having
// Safepoints not set Raw Memory; itself an unfortunate consequence of having Nodes
// which produce results (new raw memory state) inside of loops preventing all
// manner of other optimizations). Basically, it's ugly but so is the alternative.
// See comment in macro.cpp, around line 125 expand_allocate_common().
virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
};
//------------------------------LoadBNode--------------------------------------
@ -370,16 +381,6 @@ public:
virtual uint ideal_reg() const { return Op_RegP; }
virtual int store_Opcode() const { return Op_StoreP; }
virtual BasicType memory_type() const { return T_ADDRESS; }
// depends_only_on_test is almost always true, and needs to be almost always
// true to enable key hoisting & commoning optimizations. However, for the
// special case of RawPtr loads from TLS top & end, the control edge carries
// the dependence preventing hoisting past a Safepoint instead of the memory
// edge. (An unfortunate consequence of having Safepoints not set Raw
// Memory; itself an unfortunate consequence of having Nodes which produce
// results (new raw memory state) inside of loops preventing all manner of
// other optimizations). Basically, it's ugly but so is the alternative.
// See comment in macro.cpp, around line 125 expand_allocate_common().
virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
};
@ -393,16 +394,6 @@ public:
virtual uint ideal_reg() const { return Op_RegN; }
virtual int store_Opcode() const { return Op_StoreN; }
virtual BasicType memory_type() const { return T_NARROWOOP; }
// depends_only_on_test is almost always true, and needs to be almost always
// true to enable key hoisting & commoning optimizations. However, for the
// special case of RawPtr loads from TLS top & end, the control edge carries
// the dependence preventing hoisting past a Safepoint instead of the memory
// edge. (An unfortunate consequence of having Safepoints not set Raw
// Memory; itself an unfortunate consequence of having Nodes which produce
// results (new raw memory state) inside of loops preventing all manner of
// other optimizations). Basically, it's ugly but so is the alternative.
// See comment in macro.cpp, around line 125 expand_allocate_common().
virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
};
//------------------------------LoadKlassNode----------------------------------