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src/hotspot/share/opto/compile.cpp

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1675     idx = _num_alias_types++;
1676     _alias_types[idx]->Init(idx, flat);
1677     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1678     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1679     if (flat->isa_instptr()) {
1680       if (flat->offset() == java_lang_Class::klass_offset()
1681           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1682         alias_type(idx)->set_rewritable(false);
1683     }
1684     if (flat->isa_aryptr()) {
1685 #ifdef ASSERT
1686       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1687       // (T_BYTE has the weakest alignment and size restrictions...)
1688       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1689 #endif
1690       if (flat->offset() == TypePtr::OffsetBot) {
1691         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1692       }
1693     }
1694     if (flat->isa_klassptr()) {




1695       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1696         alias_type(idx)->set_rewritable(false);
1697       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1698         alias_type(idx)->set_rewritable(false);
1699       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1700         alias_type(idx)->set_rewritable(false);
1701       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1702         alias_type(idx)->set_rewritable(false);
1703       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1704         alias_type(idx)->set_rewritable(false);
1705     }
1706     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1707     // but the base pointer type is not distinctive enough to identify
1708     // references into JavaThread.)
1709 
1710     // Check for final fields.
1711     const TypeInstPtr* tinst = flat->isa_instptr();
1712     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1713       ciField* field;
1714       if (tinst->const_oop() != nullptr &&

1675     idx = _num_alias_types++;
1676     _alias_types[idx]->Init(idx, flat);
1677     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1678     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1679     if (flat->isa_instptr()) {
1680       if (flat->offset() == java_lang_Class::klass_offset()
1681           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1682         alias_type(idx)->set_rewritable(false);
1683     }
1684     if (flat->isa_aryptr()) {
1685 #ifdef ASSERT
1686       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1687       // (T_BYTE has the weakest alignment and size restrictions...)
1688       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1689 #endif
1690       if (flat->offset() == TypePtr::OffsetBot) {
1691         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1692       }
1693     }
1694     if (flat->isa_klassptr()) {
1695       if (UseCompactObjectHeaders) {
1696         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1697           alias_type(idx)->set_rewritable(false);
1698       }
1699       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1700         alias_type(idx)->set_rewritable(false);
1701       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1702         alias_type(idx)->set_rewritable(false);
1703       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1704         alias_type(idx)->set_rewritable(false);
1705       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1706         alias_type(idx)->set_rewritable(false);
1707       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1708         alias_type(idx)->set_rewritable(false);
1709     }
1710     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1711     // but the base pointer type is not distinctive enough to identify
1712     // references into JavaThread.)
1713 
1714     // Check for final fields.
1715     const TypeInstPtr* tinst = flat->isa_instptr();
1716     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1717       ciField* field;
1718       if (tinst->const_oop() != nullptr &&
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