Mercurial > hg > truffle
diff src/share/vm/opto/memnode.cpp @ 64:b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
Summary: Avoid an infinite generation of instance's field values Phi nodes.
Reviewed-by: never
author | kvn |
---|---|
date | Thu, 13 Mar 2008 16:31:32 -0700 |
parents | d821d920b465 |
children | daf38130e60d |
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--- a/src/share/vm/opto/memnode.cpp Thu Mar 13 16:06:34 2008 -0700 +++ b/src/share/vm/opto/memnode.cpp Thu Mar 13 16:31:32 2008 -0700 @@ -87,6 +87,58 @@ #endif +static Node *step_through_mergemem(PhaseGVN *phase, MergeMemNode *mmem, const TypePtr *tp, const TypePtr *adr_check, outputStream *st) { + uint alias_idx = phase->C->get_alias_index(tp); + Node *mem = mmem; +#ifdef ASSERT + { + // Check that current type is consistent with the alias index used during graph construction + assert(alias_idx >= Compile::AliasIdxRaw, "must not be a bad alias_idx"); + bool consistent = adr_check == NULL || adr_check->empty() || + phase->C->must_alias(adr_check, alias_idx ); + // Sometimes dead array references collapse to a[-1], a[-2], or a[-3] + if( !consistent && adr_check != NULL && !adr_check->empty() && + tp->isa_aryptr() && tp->offset() == Type::OffsetBot && + adr_check->isa_aryptr() && adr_check->offset() != Type::OffsetBot && + ( adr_check->offset() == arrayOopDesc::length_offset_in_bytes() || + adr_check->offset() == oopDesc::klass_offset_in_bytes() || + adr_check->offset() == oopDesc::mark_offset_in_bytes() ) ) { + // don't assert if it is dead code. + consistent = true; + } + if( !consistent ) { + st->print("alias_idx==%d, adr_check==", alias_idx); + if( adr_check == NULL ) { + st->print("NULL"); + } else { + adr_check->dump(); + } + st->cr(); + print_alias_types(); + assert(consistent, "adr_check must match alias idx"); + } + } +#endif + // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally + // means an array I have not precisely typed yet. Do not do any + // alias stuff with it any time soon. + const TypeOopPtr *tinst = tp->isa_oopptr(); + if( tp->base() != Type::AnyPtr && + !(tinst && + tinst->klass()->is_java_lang_Object() && + tinst->offset() == Type::OffsetBot) ) { + // compress paths and change unreachable cycles to TOP + // If not, we can update the input infinitely along a MergeMem cycle + // Equivalent code in PhiNode::Ideal + Node* m = phase->transform(mmem); + // If tranformed to a MergeMem, get the desired slice + // Otherwise the returned node represents memory for every slice + mem = (m->is_MergeMem())? m->as_MergeMem()->memory_at(alias_idx) : m; + // Update input if it is progress over what we have now + } + return mem; +} + //--------------------------Ideal_common--------------------------------------- // Look for degenerate control and memory inputs. Bypass MergeMem inputs. // Unhook non-raw memories from complete (macro-expanded) initializations. @@ -119,48 +171,8 @@ if (mem->is_MergeMem()) { MergeMemNode* mmem = mem->as_MergeMem(); const TypePtr *tp = t_adr->is_ptr(); - uint alias_idx = phase->C->get_alias_index(tp); -#ifdef ASSERT - { - // Check that current type is consistent with the alias index used during graph construction - assert(alias_idx >= Compile::AliasIdxRaw, "must not be a bad alias_idx"); - const TypePtr *adr_t = adr_type(); - bool consistent = adr_t == NULL || adr_t->empty() || phase->C->must_alias(adr_t, alias_idx ); - // Sometimes dead array references collapse to a[-1], a[-2], or a[-3] - if( !consistent && adr_t != NULL && !adr_t->empty() && - tp->isa_aryptr() && tp->offset() == Type::OffsetBot && - adr_t->isa_aryptr() && adr_t->offset() != Type::OffsetBot && - ( adr_t->offset() == arrayOopDesc::length_offset_in_bytes() || - adr_t->offset() == oopDesc::klass_offset_in_bytes() || - adr_t->offset() == oopDesc::mark_offset_in_bytes() ) ) { - // don't assert if it is dead code. - consistent = true; - } - if( !consistent ) { - tty->print("alias_idx==%d, adr_type()==", alias_idx); if( adr_t == NULL ) { tty->print("NULL"); } else { adr_t->dump(); } - tty->cr(); - print_alias_types(); - assert(consistent, "adr_type must match alias idx"); - } - } -#endif - // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally - // means an array I have not precisely typed yet. Do not do any - // alias stuff with it any time soon. - const TypeInstPtr *tinst = tp->isa_instptr(); - if( tp->base() != Type::AnyPtr && - !(tinst && - tinst->klass()->is_java_lang_Object() && - tinst->offset() == Type::OffsetBot) ) { - // compress paths and change unreachable cycles to TOP - // If not, we can update the input infinitely along a MergeMem cycle - // Equivalent code in PhiNode::Ideal - Node* m = phase->transform(mmem); - // If tranformed to a MergeMem, get the desired slice - // Otherwise the returned node represents memory for every slice - mem = (m->is_MergeMem())? m->as_MergeMem()->memory_at(alias_idx) : m; - // Update input if it is progress over what we have now - } + + mem = step_through_mergemem(phase, mmem, tp, adr_type(), tty); } if (mem != old_mem) { @@ -534,7 +546,10 @@ const Node* call = adr->in(0); if (call->is_CallStaticJava()) { const CallStaticJavaNode* call_java = call->as_CallStaticJava(); - assert(call_java && call_java->method() == NULL, "must be runtime call"); + const TypeTuple *r = call_java->tf()->range(); + assert(r->cnt() > TypeFunc::Parms, "must return value"); + const Type* ret_type = r->field_at(TypeFunc::Parms); + assert(ret_type && ret_type->isa_ptr(), "must return pointer"); // We further presume that this is one of // new_instance_Java, new_array_Java, or // the like, but do not assert for this. @@ -732,6 +747,21 @@ return NULL; } +//----------------------is_instance_field_load_with_local_phi------------------ +bool LoadNode::is_instance_field_load_with_local_phi(Node* ctrl) { + if( in(MemNode::Memory)->is_Phi() && in(MemNode::Memory)->in(0) == ctrl && + in(MemNode::Address)->is_AddP() ) { + const TypeOopPtr* t_oop = in(MemNode::Address)->bottom_type()->isa_oopptr(); + // Only instances. + if( t_oop != NULL && t_oop->is_instance_field() && + t_oop->offset() != Type::OffsetBot && + t_oop->offset() != Type::OffsetTop) { + return true; + } + } + return false; +} + //------------------------------Identity--------------------------------------- // Loads are identity if previous store is to same address Node *LoadNode::Identity( PhaseTransform *phase ) { @@ -754,6 +784,25 @@ // usually runs first, producing the singleton type of the Con.) return value; } + + // Search for an existing data phi which was generated before for the same + // instance's field to avoid infinite genertion of phis in a loop. + Node *region = mem->in(0); + if (is_instance_field_load_with_local_phi(region)) { + const TypePtr *addr_t = in(MemNode::Address)->bottom_type()->isa_ptr(); + int this_index = phase->C->get_alias_index(addr_t); + int this_offset = addr_t->offset(); + int this_id = addr_t->is_oopptr()->instance_id(); + const Type* this_type = bottom_type(); + for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { + Node* phi = region->fast_out(i); + if (phi->is_Phi() && phi != mem && + phi->as_Phi()->is_same_inst_field(this_type, this_id, this_index, this_offset)) { + return phi; + } + } + } + return this; } @@ -1189,6 +1238,17 @@ return value->bottom_type(); } + const TypeOopPtr *tinst = tp->isa_oopptr(); + if (tinst != NULL && tinst->is_instance_field()) { + // If we have an instance type and our memory input is the + // programs's initial memory state, there is no matching store, + // so just return a zero of the appropriate type + Node *mem = in(MemNode::Memory); + if (mem->is_Parm() && mem->in(0)->is_Start()) { + assert(mem->as_Parm()->_con == TypeFunc::Memory, "must be memory Parm"); + return Type::get_zero_type(_type->basic_type()); + } + } return _type; } @@ -1712,7 +1772,7 @@ const TypeOopPtr *adr_oop = phase->type(adr)->isa_oopptr(); if (adr_oop == NULL) return false; - if (!adr_oop->is_instance()) + if (!adr_oop->is_instance_field()) return false; // if not a distinct instance, there may be aliases of the address for (DUIterator_Fast imax, i = adr->fast_outs(imax); i < imax; i++) { Node *use = adr->fast_out(i); @@ -3244,7 +3304,7 @@ } } - assert(verify_sparse(), "please, no dups of base"); + assert(progress || verify_sparse(), "please, no dups of base"); return progress; }