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8245465: Shenandoah: test_in_cset can use more efficient encoding

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Reviewed-by: rkennke, roland
This commit is contained in:
Aleksey Shipilev 2020-05-25 11:05:23 +02:00
parent 360554e41f
commit de4b15e52e
1 changed files with 13 additions and 4 deletions

17
src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp

@ -924,9 +924,16 @@ void ShenandoahBarrierC2Support::test_in_cset(Node*& ctrl, Node*& not_cset_ctrl,
Node* raw_val = new CastP2XNode(old_ctrl, val);
Node* cset_idx = new URShiftXNode(raw_val, igvn.intcon(ShenandoahHeapRegion::region_size_bytes_shift_jint()));
Node* cset_addr = igvn.makecon(TypeRawPtr::make(ShenandoahHeap::in_cset_fast_test_addr()));
Node* cset_load_addr = new AddPNode(phase->C->top(), cset_addr, cset_idx);
Node* cset_load = new LoadBNode(old_ctrl, raw_mem, cset_load_addr,
// Figure out the target cset address with raw pointer math.
// This avoids matching AddP+LoadB that would emit inefficient code.
// See JDK-8245465.
Node* cset_addr_ptr = igvn.makecon(TypeRawPtr::make(ShenandoahHeap::in_cset_fast_test_addr()));
Node* cset_addr = new CastP2XNode(old_ctrl, cset_addr_ptr);
Node* cset_load_addr = new AddXNode(cset_addr, cset_idx);
Node* cset_load_ptr = new CastX2PNode(cset_load_addr);
Node* cset_load = new LoadBNode(old_ctrl, raw_mem, cset_load_ptr,
DEBUG_ONLY(phase->C->get_adr_type(Compile::AliasIdxRaw)) NOT_DEBUG(NULL),
TypeInt::BYTE, MemNode::unordered);
Node* cset_cmp = new CmpINode(cset_load, igvn.zerocon(T_INT));
@ -941,11 +948,13 @@ void ShenandoahBarrierC2Support::test_in_cset(Node*& ctrl, Node*& not_cset_ctrl,
phase->register_control(ctrl, loop, cset_iff);
phase->register_control(not_cset_ctrl, loop, cset_iff);
phase->set_ctrl(cset_addr, phase->C->root());
phase->set_ctrl(cset_addr_ptr, phase->C->root());
phase->register_new_node(raw_val, old_ctrl);
phase->register_new_node(cset_idx, old_ctrl);
phase->register_new_node(cset_addr, old_ctrl);
phase->register_new_node(cset_load_addr, old_ctrl);
phase->register_new_node(cset_load_ptr, old_ctrl);
phase->register_new_node(cset_load, old_ctrl);
phase->register_new_node(cset_cmp, old_ctrl);
phase->register_new_node(cset_bool, old_ctrl);