From 19d99e3d9239cabdb2767b10281596f994f6dad2 Mon Sep 17 00:00:00 2001 From: Martin Doerr Date: Wed, 24 Apr 2013 14:48:43 -0700 Subject: [PATCH] 8012715: G1: GraphKit accesses PtrQueue::_index as int but is size_t In graphKit INT operations were generated to access PtrQueue::_index which has type size_t. This is 64 bit on 64-bit machines. No problems occur on little endian machines as long as the index fits into 32 bit, but on big endian machines the upper part is read, which is zero. This leads to unnecessary branches to the slow path in the runtime. Reviewed-by: twisti, johnc --- hotspot/src/share/vm/opto/graphKit.cpp | 40 +++++++++++--------------- 1 file changed, 16 insertions(+), 24 deletions(-) diff --git a/hotspot/src/share/vm/opto/graphKit.cpp b/hotspot/src/share/vm/opto/graphKit.cpp index 028020f51de..e2285916ce5 100644 --- a/hotspot/src/share/vm/opto/graphKit.cpp +++ b/hotspot/src/share/vm/opto/graphKit.cpp @@ -3564,7 +3564,8 @@ void GraphKit::g1_write_barrier_pre(bool do_load, Node* no_ctrl = NULL; Node* no_base = __ top(); - Node* zero = __ ConI(0); + Node* zero = __ ConI(0); + Node* zeroX = __ ConX(0); float likely = PROB_LIKELY(0.999); float unlikely = PROB_UNLIKELY(0.999); @@ -3590,7 +3591,9 @@ void GraphKit::g1_write_barrier_pre(bool do_load, // if (!marking) __ if_then(marking, BoolTest::ne, zero); { - Node* index = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw); + BasicType index_bt = TypeX_X->basic_type(); + assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size."); + Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw); if (do_load) { // load original value @@ -3603,22 +3606,16 @@ void GraphKit::g1_write_barrier_pre(bool do_load, Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); // is the queue for this thread full? - __ if_then(index, BoolTest::ne, zero, likely); { + __ if_then(index, BoolTest::ne, zeroX, likely); { // decrement the index - Node* next_index = __ SubI(index, __ ConI(sizeof(intptr_t))); - Node* next_indexX = next_index; -#ifdef _LP64 - // We could refine the type for what it's worth - // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue); - next_indexX = _gvn.transform( new (C) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) ); -#endif + Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t)))); // Now get the buffer location we will log the previous value into and store it - Node *log_addr = __ AddP(no_base, buffer, next_indexX); + Node *log_addr = __ AddP(no_base, buffer, next_index); __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw); // update the index - __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw); + __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw); } __ else_(); { @@ -3645,26 +3642,21 @@ void GraphKit::g1_mark_card(IdealKit& ideal, Node* buffer, const TypeFunc* tf) { - Node* zero = __ ConI(0); + Node* zero = __ ConI(0); + Node* zeroX = __ ConX(0); Node* no_base = __ top(); BasicType card_bt = T_BYTE; // Smash zero into card. MUST BE ORDERED WRT TO STORE __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw); // Now do the queue work - __ if_then(index, BoolTest::ne, zero); { + __ if_then(index, BoolTest::ne, zeroX); { - Node* next_index = __ SubI(index, __ ConI(sizeof(intptr_t))); - Node* next_indexX = next_index; -#ifdef _LP64 - // We could refine the type for what it's worth - // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue); - next_indexX = _gvn.transform( new (C) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) ); -#endif // _LP64 - Node* log_addr = __ AddP(no_base, buffer, next_indexX); + Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t)))); + Node* log_addr = __ AddP(no_base, buffer, next_index); __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw); - __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw); + __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw); } __ else_(); { __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread()); @@ -3725,7 +3717,7 @@ void GraphKit::g1_write_barrier_post(Node* oop_store, // Now some values // Use ctrl to avoid hoisting these values past a safepoint, which could // potentially reset these fields in the JavaThread. - Node* index = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw); + Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw); Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); // Convert the store obj pointer to an int prior to doing math on it