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comparison src/share/vm/opto/memnode.cpp @ 11198:1e6d5dec4a4e

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Merge.
author Christian Humer <christian.humer@gmail.com>
date Mon, 05 Aug 2013 13:20:06 +0200
parents 3aa636f2a743
children edb5ab0f3fe5 7944aba7ba41
comparison
equal deleted inserted replaced
11197:3479ab380552 11198:1e6d5dec4a4e
2928 // Return a node which is more "ideal" than the current node. Strip out 2928 // Return a node which is more "ideal" than the current node. Strip out
2929 // control copies 2929 // control copies
2930 Node *MemBarNode::Ideal(PhaseGVN *phase, bool can_reshape) { 2930 Node *MemBarNode::Ideal(PhaseGVN *phase, bool can_reshape) {
2931 if (remove_dead_region(phase, can_reshape)) return this; 2931 if (remove_dead_region(phase, can_reshape)) return this;
2932 // Don't bother trying to transform a dead node 2932 // Don't bother trying to transform a dead node
2933 if (in(0) && in(0)->is_top()) return NULL; 2933 if (in(0) && in(0)->is_top()) {
2934 return NULL;
2935 }
2934 2936
2935 // Eliminate volatile MemBars for scalar replaced objects. 2937 // Eliminate volatile MemBars for scalar replaced objects.
2936 if (can_reshape && req() == (Precedent+1)) { 2938 if (can_reshape && req() == (Precedent+1)) {
2937 bool eliminate = false; 2939 bool eliminate = false;
2938 int opc = Opcode(); 2940 int opc = Opcode();
2939 if ((opc == Op_MemBarAcquire || opc == Op_MemBarVolatile)) { 2941 if ((opc == Op_MemBarAcquire || opc == Op_MemBarVolatile)) {
2940 // Volatile field loads and stores. 2942 // Volatile field loads and stores.
2941 Node* my_mem = in(MemBarNode::Precedent); 2943 Node* my_mem = in(MemBarNode::Precedent);
2944 // The MembarAquire may keep an unused LoadNode alive through the Precedent edge
2945 if ((my_mem != NULL) && (opc == Op_MemBarAcquire) && (my_mem->outcnt() == 1)) {
2946 // if the Precedent is a decodeN and its input (a Load) is used at more than one place,
2947 // replace this Precedent (decodeN) with the Load instead.
2948 if ((my_mem->Opcode() == Op_DecodeN) && (my_mem->in(1)->outcnt() > 1)) {
2949 Node* load_node = my_mem->in(1);
2950 set_req(MemBarNode::Precedent, load_node);
2951 phase->is_IterGVN()->_worklist.push(my_mem);
2952 my_mem = load_node;
2953 } else {
2954 assert(my_mem->unique_out() == this, "sanity");
2955 del_req(Precedent);
2956 phase->is_IterGVN()->_worklist.push(my_mem); // remove dead node later
2957 my_mem = NULL;
2958 }
2959 }
2942 if (my_mem != NULL && my_mem->is_Mem()) { 2960 if (my_mem != NULL && my_mem->is_Mem()) {
2943 const TypeOopPtr* t_oop = my_mem->in(MemNode::Address)->bottom_type()->isa_oopptr(); 2961 const TypeOopPtr* t_oop = my_mem->in(MemNode::Address)->bottom_type()->isa_oopptr();
2944 // Check for scalar replaced object reference. 2962 // Check for scalar replaced object reference.
2945 if( t_oop != NULL && t_oop->is_known_instance_field() && 2963 if( t_oop != NULL && t_oop->is_known_instance_field() &&
2946 t_oop->offset() != Type::OffsetBot && 2964 t_oop->offset() != Type::OffsetBot &&
4382 } 4400 }
4383 assert(expected_wide_mem, "expected narrow slice replacement"); 4401 assert(expected_wide_mem, "expected narrow slice replacement");
4384 } 4402 }
4385 } 4403 }
4386 #else // !ASSERT 4404 #else // !ASSERT
4387 #define verify_memory_slice(m,i,n) (0) // PRODUCT version is no-op 4405 #define verify_memory_slice(m,i,n) (void)(0) // PRODUCT version is no-op
4388 #endif 4406 #endif
4389 4407
4390 4408
4391 //-----------------------------memory_at--------------------------------------- 4409 //-----------------------------memory_at---------------------------------------
4392 Node* MergeMemNode::memory_at(uint alias_idx) const { 4410 Node* MergeMemNode::memory_at(uint alias_idx) const {