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comparison src/share/vm/opto/cfgnode.cpp @ 899:55cb84cd1247

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6865031: Application gives bad result (throws bad exception) with compressed oops Summary: Produce narrow type for new Phi from the original Phi type. Reviewed-by: cfang
author kvn
date Fri, 31 Jul 2009 12:04:07 -0700
parents 433f394ab509
children 15bbd3f505c0
comparison
equal deleted inserted replaced
898:60fea60a6db5 899:55cb84cd1247
1790 // Push DecodeN down through phi. 1790 // Push DecodeN down through phi.
1791 // The rest of phi graph will transform by split EncodeP node though phis up. 1791 // The rest of phi graph will transform by split EncodeP node though phis up.
1792 if (UseCompressedOops && can_reshape && progress == NULL) { 1792 if (UseCompressedOops && can_reshape && progress == NULL) {
1793 bool may_push = true; 1793 bool may_push = true;
1794 bool has_decodeN = false; 1794 bool has_decodeN = false;
1795 Node* in_decodeN = NULL;
1796 for (uint i=1; i<req(); ++i) {// For all paths in 1795 for (uint i=1; i<req(); ++i) {// For all paths in
1797 Node *ii = in(i); 1796 Node *ii = in(i);
1798 if (ii->is_DecodeN() && ii->bottom_type() == bottom_type()) { 1797 if (ii->is_DecodeN() && ii->bottom_type() == bottom_type()) {
1799 // Note: in_decodeN is used only to define the type of new phi. 1798 // Do optimization if a non dead path exist.
1800 // Find a non dead path otherwise phi type will be wrong.
1801 if (ii->in(1)->bottom_type() != Type::TOP) { 1799 if (ii->in(1)->bottom_type() != Type::TOP) {
1802 has_decodeN = true; 1800 has_decodeN = true;
1803 in_decodeN = ii->in(1);
1804 } 1801 }
1805 } else if (!ii->is_Phi()) { 1802 } else if (!ii->is_Phi()) {
1806 may_push = false; 1803 may_push = false;
1807 } 1804 }
1808 } 1805 }
1809 1806
1810 if (has_decodeN && may_push) { 1807 if (has_decodeN && may_push) {
1811 PhaseIterGVN *igvn = phase->is_IterGVN(); 1808 PhaseIterGVN *igvn = phase->is_IterGVN();
1812 PhiNode *new_phi = PhiNode::make_blank(in(0), in_decodeN); 1809 // Make narrow type for new phi.
1810 const Type* narrow_t = TypeNarrowOop::make(this->bottom_type()->is_ptr());
1811 PhiNode* new_phi = new (phase->C, r->req()) PhiNode(r, narrow_t);
1813 uint orig_cnt = req(); 1812 uint orig_cnt = req();
1814 for (uint i=1; i<req(); ++i) {// For all paths in 1813 for (uint i=1; i<req(); ++i) {// For all paths in
1815 Node *ii = in(i); 1814 Node *ii = in(i);
1816 Node* new_ii = NULL; 1815 Node* new_ii = NULL;
1817 if (ii->is_DecodeN()) { 1816 if (ii->is_DecodeN()) {
1820 } else { 1819 } else {
1821 assert(ii->is_Phi(), "sanity"); 1820 assert(ii->is_Phi(), "sanity");
1822 if (ii->as_Phi() == this) { 1821 if (ii->as_Phi() == this) {
1823 new_ii = new_phi; 1822 new_ii = new_phi;
1824 } else { 1823 } else {
1825 new_ii = new (phase->C, 2) EncodePNode(ii, in_decodeN->bottom_type()); 1824 new_ii = new (phase->C, 2) EncodePNode(ii, narrow_t);
1826 igvn->register_new_node_with_optimizer(new_ii); 1825 igvn->register_new_node_with_optimizer(new_ii);
1827 } 1826 }
1828 } 1827 }
1829 new_phi->set_req(i, new_ii); 1828 new_phi->set_req(i, new_ii);
1830 } 1829 }