src/share/vm/opto/macroArrayCopy.cpp
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src/share/vm/opto/macroArrayCopy.cpp

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rev 7687 : 6912521: System.arraycopy works slower than the simple loop for little lengths
Summary: convert small array copies to series of loads and stores
Reviewed-by:


 502     // further to JVM_ArrayCopy on the first per-oop check that fails.
 503     // (Actually, we don't move raw bits only; the GC requires card marks.)
 504 
 505     // Get the klass* for both src and dest
 506     Node* src_klass  = ac->in(ArrayCopyNode::SrcKlass);
 507     Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
 508 
 509     assert(src_klass != NULL && dest_klass != NULL, "should have klasses");
 510 
 511     // Generate the subtype check.
 512     // This might fold up statically, or then again it might not.
 513     //
 514     // Non-static example:  Copying List<String>.elements to a new String[].
 515     // The backing store for a List<String> is always an Object[],
 516     // but its elements are always type String, if the generic types
 517     // are correct at the source level.
 518     //
 519     // Test S[] against D[], not S against D, because (probably)
 520     // the secondary supertype cache is less busy for S[] than S.
 521     // This usually only matters when D is an interface.
 522     Node* not_subtype_ctrl = ac->is_arraycopy_validated() ? top() :
 523       Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, &_igvn);
 524     // Plug failing path into checked_oop_disjoint_arraycopy
 525     if (not_subtype_ctrl != top()) {
 526       Node* local_ctrl = not_subtype_ctrl;
 527       MergeMemNode* local_mem = MergeMemNode::make(mem);
 528       transform_later(local_mem);
 529 
 530       // (At this point we can assume disjoint_bases, since types differ.)
 531       int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
 532       Node* p1 = basic_plus_adr(dest_klass, ek_offset);
 533       Node* n1 = LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
 534       Node* dest_elem_klass = transform_later(n1);
 535       Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
 536                                               adr_type,
 537                                               dest_elem_klass,
 538                                               src, src_offset, dest, dest_offset,
 539                                               ConvI2X(copy_length), dest_uninitialized);
 540       if (cv == NULL)  cv = intcon(-1);  // failure (no stub available)
 541       checked_control = local_ctrl;
 542       checked_i_o     = *io;




 502     // further to JVM_ArrayCopy on the first per-oop check that fails.
 503     // (Actually, we don't move raw bits only; the GC requires card marks.)
 504 
 505     // Get the klass* for both src and dest
 506     Node* src_klass  = ac->in(ArrayCopyNode::SrcKlass);
 507     Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
 508 
 509     assert(src_klass != NULL && dest_klass != NULL, "should have klasses");
 510 
 511     // Generate the subtype check.
 512     // This might fold up statically, or then again it might not.
 513     //
 514     // Non-static example:  Copying List<String>.elements to a new String[].
 515     // The backing store for a List<String> is always an Object[],
 516     // but its elements are always type String, if the generic types
 517     // are correct at the source level.
 518     //
 519     // Test S[] against D[], not S against D, because (probably)
 520     // the secondary supertype cache is less busy for S[] than S.
 521     // This usually only matters when D is an interface.
 522     Node* not_subtype_ctrl = (ac->is_arraycopy_validated() || ac->is_copyof_validated() || ac->is_copyofrange_validated()) ? top() :
 523       Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, &_igvn);
 524     // Plug failing path into checked_oop_disjoint_arraycopy
 525     if (not_subtype_ctrl != top()) {
 526       Node* local_ctrl = not_subtype_ctrl;
 527       MergeMemNode* local_mem = MergeMemNode::make(mem);
 528       transform_later(local_mem);
 529 
 530       // (At this point we can assume disjoint_bases, since types differ.)
 531       int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
 532       Node* p1 = basic_plus_adr(dest_klass, ek_offset);
 533       Node* n1 = LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
 534       Node* dest_elem_klass = transform_later(n1);
 535       Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
 536                                               adr_type,
 537                                               dest_elem_klass,
 538                                               src, src_offset, dest, dest_offset,
 539                                               ConvI2X(copy_length), dest_uninitialized);
 540       if (cv == NULL)  cv = intcon(-1);  // failure (no stub available)
 541       checked_control = local_ctrl;
 542       checked_i_o     = *io;


src/share/vm/opto/macroArrayCopy.cpp
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