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src/hotspot/share/opto/compile.cpp

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1673     idx = _num_alias_types++;
1674     _alias_types[idx]->Init(idx, flat);
1675     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1676     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1677     if (flat->isa_instptr()) {
1678       if (flat->offset() == java_lang_Class::klass_offset()
1679           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1680         alias_type(idx)->set_rewritable(false);
1681     }
1682     if (flat->isa_aryptr()) {
1683 #ifdef ASSERT
1684       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1685       // (T_BYTE has the weakest alignment and size restrictions...)
1686       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1687 #endif
1688       if (flat->offset() == TypePtr::OffsetBot) {
1689         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1690       }
1691     }
1692     if (flat->isa_klassptr()) {




1693       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1694         alias_type(idx)->set_rewritable(false);
1695       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1696         alias_type(idx)->set_rewritable(false);
1697       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1698         alias_type(idx)->set_rewritable(false);
1699       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1700         alias_type(idx)->set_rewritable(false);
1701       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1702         alias_type(idx)->set_rewritable(false);
1703     }
1704     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1705     // but the base pointer type is not distinctive enough to identify
1706     // references into JavaThread.)
1707 
1708     // Check for final fields.
1709     const TypeInstPtr* tinst = flat->isa_instptr();
1710     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1711       ciField* field;
1712       if (tinst->const_oop() != nullptr &&

1673     idx = _num_alias_types++;
1674     _alias_types[idx]->Init(idx, flat);
1675     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1676     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1677     if (flat->isa_instptr()) {
1678       if (flat->offset() == java_lang_Class::klass_offset()
1679           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1680         alias_type(idx)->set_rewritable(false);
1681     }
1682     if (flat->isa_aryptr()) {
1683 #ifdef ASSERT
1684       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1685       // (T_BYTE has the weakest alignment and size restrictions...)
1686       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1687 #endif
1688       if (flat->offset() == TypePtr::OffsetBot) {
1689         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1690       }
1691     }
1692     if (flat->isa_klassptr()) {
1693       if (UseCompactObjectHeaders) {
1694         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1695           alias_type(idx)->set_rewritable(false);
1696       }
1697       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1698         alias_type(idx)->set_rewritable(false);
1699       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1700         alias_type(idx)->set_rewritable(false);
1701       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1702         alias_type(idx)->set_rewritable(false);
1703       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1704         alias_type(idx)->set_rewritable(false);
1705       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1706         alias_type(idx)->set_rewritable(false);
1707     }
1708     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1709     // but the base pointer type is not distinctive enough to identify
1710     // references into JavaThread.)
1711 
1712     // Check for final fields.
1713     const TypeInstPtr* tinst = flat->isa_instptr();
1714     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1715       ciField* field;
1716       if (tinst->const_oop() != nullptr &&
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