1317 // Slot 0 of constants is not really a Control.
1318 if( control && m->in(0) && control != m->in(0) ) {
1319
1320 // Actually, we can live with the most conservative control we
1321 // find, if it post-dominates the others. This allows us to
1322 // pick up load/op/store trees where the load can float a little
1323 // above the store.
1324 Node *x = control;
1325 const uint max_scan = 6; // Arbitrary scan cutoff
1326 uint j;
1327 for( j=0; j<max_scan; j++ ) {
1328 if( x->is_Region() ) // Bail out at merge points
1329 return true;
1330 x = x->in(0);
1331 if( x == m->in(0) ) // Does 'control' post-dominate
1332 break; // m->in(0)? If so, we can use it
1333 }
1334 if( j == max_scan ) // No post-domination before scan end?
1335 return true; // Then break the match tree up
1336 }
1337 if (m->is_DecodeN() && Matcher::clone_shift_expressions) {
1338 // These are commonly used in address expressions and can
1339 // efficiently fold into them on X64 in some cases.
1340 return false;
1341 }
1342 }
1343
1344 // Not forceable cloning. If shared, put it into a register.
1345 return shared;
1346 }
1347
1348
1349 //------------------------------Instruction Selection--------------------------
1350 // Label method walks a "tree" of nodes, using the ADLC generated DFA to match
1351 // ideal nodes to machine instructions. Trees are delimited by shared Nodes,
1352 // things the Matcher does not match (e.g., Memory), and things with different
1353 // Controls (hence forced into different blocks). We pass in the Control
1354 // selected for this entire State tree.
1355
1356 // The Matcher works on Trees, but an Intel add-to-memory requires a DAG: the
1357 // Store and the Load must have identical Memories (as well as identical
2093 if (ct == TypePtr::NULL_PTR ||
2094 (opc == Op_CmpN && ct == TypeNarrowOop::NULL_PTR)) {
2095
2096 bool push_it = false;
2097 if( proj->Opcode() == Op_IfTrue ) {
2098 extern int all_null_checks_found;
2099 all_null_checks_found++;
2100 if( b->_test._test == BoolTest::ne ) {
2101 push_it = true;
2102 }
2103 } else {
2104 assert( proj->Opcode() == Op_IfFalse, "" );
2105 if( b->_test._test == BoolTest::eq ) {
2106 push_it = true;
2107 }
2108 }
2109 if( push_it ) {
2110 _null_check_tests.push(proj);
2111 Node* val = cmp->in(1);
2112 #ifdef _LP64
2113 if (UseCompressedOops && !Matcher::clone_shift_expressions &&
2114 val->bottom_type()->isa_narrowoop()) {
2115 //
2116 // Look for DecodeN node which should be pinned to orig_proj.
2117 // On platforms (Sparc) which can not handle 2 adds
2118 // in addressing mode we have to keep a DecodeN node and
2119 // use it to do implicit NULL check in address.
2120 //
2121 // DecodeN node was pinned to non-null path (orig_proj) during
2122 // CastPP transformation in final_graph_reshaping_impl().
2123 //
2124 uint cnt = orig_proj->outcnt();
2125 for (uint i = 0; i < orig_proj->outcnt(); i++) {
2126 Node* d = orig_proj->raw_out(i);
2127 if (d->is_DecodeN() && d->in(1) == val) {
2128 val = d;
2129 val->set_req(0, NULL); // Unpin now.
2130 break;
2131 }
2132 }
2133 }
2134 #endif
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1317 // Slot 0 of constants is not really a Control.
1318 if( control && m->in(0) && control != m->in(0) ) {
1319
1320 // Actually, we can live with the most conservative control we
1321 // find, if it post-dominates the others. This allows us to
1322 // pick up load/op/store trees where the load can float a little
1323 // above the store.
1324 Node *x = control;
1325 const uint max_scan = 6; // Arbitrary scan cutoff
1326 uint j;
1327 for( j=0; j<max_scan; j++ ) {
1328 if( x->is_Region() ) // Bail out at merge points
1329 return true;
1330 x = x->in(0);
1331 if( x == m->in(0) ) // Does 'control' post-dominate
1332 break; // m->in(0)? If so, we can use it
1333 }
1334 if( j == max_scan ) // No post-domination before scan end?
1335 return true; // Then break the match tree up
1336 }
1337 if (m->is_DecodeN() && Matcher::narrow_oop_use_complex_address()) {
1338 // These are commonly used in address expressions and can
1339 // efficiently fold into them on X64 in some cases.
1340 return false;
1341 }
1342 }
1343
1344 // Not forceable cloning. If shared, put it into a register.
1345 return shared;
1346 }
1347
1348
1349 //------------------------------Instruction Selection--------------------------
1350 // Label method walks a "tree" of nodes, using the ADLC generated DFA to match
1351 // ideal nodes to machine instructions. Trees are delimited by shared Nodes,
1352 // things the Matcher does not match (e.g., Memory), and things with different
1353 // Controls (hence forced into different blocks). We pass in the Control
1354 // selected for this entire State tree.
1355
1356 // The Matcher works on Trees, but an Intel add-to-memory requires a DAG: the
1357 // Store and the Load must have identical Memories (as well as identical
2093 if (ct == TypePtr::NULL_PTR ||
2094 (opc == Op_CmpN && ct == TypeNarrowOop::NULL_PTR)) {
2095
2096 bool push_it = false;
2097 if( proj->Opcode() == Op_IfTrue ) {
2098 extern int all_null_checks_found;
2099 all_null_checks_found++;
2100 if( b->_test._test == BoolTest::ne ) {
2101 push_it = true;
2102 }
2103 } else {
2104 assert( proj->Opcode() == Op_IfFalse, "" );
2105 if( b->_test._test == BoolTest::eq ) {
2106 push_it = true;
2107 }
2108 }
2109 if( push_it ) {
2110 _null_check_tests.push(proj);
2111 Node* val = cmp->in(1);
2112 #ifdef _LP64
2113 if (val->bottom_type()->isa_narrowoop() &&
2114 !Matcher::narrow_oop_use_complex_address()) {
2115 //
2116 // Look for DecodeN node which should be pinned to orig_proj.
2117 // On platforms (Sparc) which can not handle 2 adds
2118 // in addressing mode we have to keep a DecodeN node and
2119 // use it to do implicit NULL check in address.
2120 //
2121 // DecodeN node was pinned to non-null path (orig_proj) during
2122 // CastPP transformation in final_graph_reshaping_impl().
2123 //
2124 uint cnt = orig_proj->outcnt();
2125 for (uint i = 0; i < orig_proj->outcnt(); i++) {
2126 Node* d = orig_proj->raw_out(i);
2127 if (d->is_DecodeN() && d->in(1) == val) {
2128 val = d;
2129 val->set_req(0, NULL); // Unpin now.
2130 break;
2131 }
2132 }
2133 }
2134 #endif
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