16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/castnode.hpp"
33 #include "opto/connode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/divnode.hpp"
36 #include "opto/loopnode.hpp"
37 #include "opto/matcher.hpp"
38 #include "opto/mulnode.hpp"
39 #include "opto/movenode.hpp"
40 #include "opto/opaquenode.hpp"
41 #include "opto/rootnode.hpp"
42 #include "opto/subnode.hpp"
43 #include "opto/subtypenode.hpp"
44 #include "utilities/macros.hpp"
45
46 //=============================================================================
47 //------------------------------split_thru_phi---------------------------------
48 // Split Node 'n' through merge point if there is enough win.
49 Node* PhaseIdealLoop::split_thru_phi(Node* n, Node* region, int policy) {
50 if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) {
51 // ConvI2L may have type information on it which is unsafe to push up
52 // so disable this for now
53 return NULL;
54 }
55
56 // Splitting range check CastIIs through a loop induction Phi can
57 // cause new Phis to be created that are left unrelated to the loop
58 // induction Phi and prevent optimizations (vectorization)
59 if (n->Opcode() == Op_CastII && region->is_CountedLoop() &&
60 n->in(1) == region->as_CountedLoop()->phi()) {
61 return NULL;
62 }
63
64 // Bail out if 'n' is a Div or Mod node whose zero check was removed earlier (i.e. control is NULL) and its divisor is an induction variable
65 // phi p of a trip-counted (integer) loop whose inputs could be zero (include zero in their type range). p could have a more precise type
66 // range that does not necessarily include all values of its inputs. Since each of these inputs will be a divisor of the newly cloned nodes
67 // of 'n', we need to bail out of one of these divisors could be zero (zero in its type range).
68 if ((n->Opcode() == Op_DivI || n->Opcode() == Op_ModI) && n->in(0) == NULL
69 && region->is_CountedLoop() && n->in(2) == region->as_CountedLoop()->phi()) {
70 Node* phi = region->as_CountedLoop()->phi();
71 for (uint i = 1; i < phi->req(); i++) {
72 if (_igvn.type(phi->in(i))->filter_speculative(TypeInt::ZERO) != Type::TOP) {
73 // Zero could be a possible value but we already removed the zero check. Bail out to avoid a possible division by zero at a later point.
74 return NULL;
75 }
76 }
77 }
78
79 int wins = 0;
80 assert(!n->is_CFG(), "");
81 assert(region->is_Region(), "");
82
83 const Type* type = n->bottom_type();
977 assert(get_loop(lca)->_nest < n_loop->_nest || lca->in(0)->Opcode() == Op_NeverBranch, "must not be moved into inner loop");
978
979 // Move store out of the loop
980 _igvn.replace_node(hook, n->in(MemNode::Memory));
981 _igvn.replace_input_of(n, 0, lca);
982 set_ctrl_and_loop(n, lca);
983
984 // Disconnect the phi now. An empty phi can confuse other
985 // optimizations in this pass of loop opts..
986 if (phi->in(LoopNode::LoopBackControl) == phi) {
987 _igvn.replace_node(phi, phi->in(LoopNode::EntryControl));
988 n_loop->_body.yank(phi);
989 }
990 }
991 }
992 }
993 }
994 }
995 }
996
997 //------------------------------split_if_with_blocks_pre-----------------------
998 // Do the real work in a non-recursive function. Data nodes want to be
999 // cloned in the pre-order so they can feed each other nicely.
1000 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
1001 // Cloning these guys is unlikely to win
1002 int n_op = n->Opcode();
1003 if (n_op == Op_MergeMem) {
1004 return n;
1005 }
1006 if (n->is_Proj()) {
1007 return n;
1008 }
1009 // Do not clone-up CmpFXXX variations, as these are always
1010 // followed by a CmpI
1011 if (n->is_Cmp()) {
1012 return n;
1013 }
1014 // Attempt to use a conditional move instead of a phi/branch
1015 if (ConditionalMoveLimit > 0 && n_op == Op_Region) {
1016 Node *cmov = conditional_move( n );
1017 if (cmov) {
1018 return cmov;
1019 }
1020 }
1021 if (n->is_CFG() || n->is_LoadStore()) {
1022 return n;
1023 }
1024 if (n->is_Opaque1() || // Opaque nodes cannot be mod'd
1025 n_op == Op_Opaque2) {
1026 if (!C->major_progress()) { // If chance of no more loop opts...
1027 _igvn._worklist.push(n); // maybe we'll remove them
1028 }
1262
1263 return true;
1264 }
1265
1266 // Detect if the node is the inner strip-mined loop
1267 // Return: NULL if it's not the case, or the exit of outer strip-mined loop
1268 static Node* is_inner_of_stripmined_loop(const Node* out) {
1269 Node* out_le = NULL;
1270
1271 if (out->is_CountedLoopEnd()) {
1272 const CountedLoopNode* loop = out->as_CountedLoopEnd()->loopnode();
1273
1274 if (loop != NULL && loop->is_strip_mined()) {
1275 out_le = loop->in(LoopNode::EntryControl)->as_OuterStripMinedLoop()->outer_loop_exit();
1276 }
1277 }
1278
1279 return out_le;
1280 }
1281
1282 //------------------------------split_if_with_blocks_post----------------------
1283 // Do the real work in a non-recursive function. CFG hackery wants to be
1284 // in the post-order, so it can dirty the I-DOM info and not use the dirtied
1285 // info.
1286 void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
1287
1288 // Cloning Cmp through Phi's involves the split-if transform.
1289 // FastLock is not used by an If
1290 if (n->is_Cmp() && !n->is_FastLock()) {
1291 Node *n_ctrl = get_ctrl(n);
1292 // Determine if the Node has inputs from some local Phi.
1293 // Returns the block to clone thru.
1294 Node *n_blk = has_local_phi_input(n);
1295 if (n_blk != n_ctrl) {
1296 return;
1297 }
1298
1299 if (!can_split_if(n_ctrl)) {
1300 return;
1301 }
1302
1303 if (n->outcnt() != 1) {
1304 return; // Multiple bool's from 1 compare?
1305 }
1306 Node *bol = n->unique_out();
1307 assert(bol->is_Bool(), "expect a bool here");
1403 }
1404 // Replace the dominated test with an obvious true or false.
1405 // Place it on the IGVN worklist for later cleanup.
1406 C->set_major_progress();
1407 dominated_by(prevdom->as_IfProj(), n->as_If(), false, true);
1408 #ifndef PRODUCT
1409 if( VerifyLoopOptimizations ) verify();
1410 #endif
1411 return;
1412 }
1413 prevdom = dom;
1414 dom = idom(prevdom);
1415 }
1416 }
1417 }
1418
1419 try_sink_out_of_loop(n);
1420
1421 try_move_store_after_loop(n);
1422
1423 // Check for Opaque2's who's loop has disappeared - who's input is in the
1424 // same loop nest as their output. Remove 'em, they are no longer useful.
1425 if( n_op == Op_Opaque2 &&
1426 n->in(1) != NULL &&
1427 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {
1428 _igvn.replace_node( n, n->in(1) );
1429 }
1430 }
1431
1432 // Tranform:
1433 //
1434 // if (some_condition) {
1435 // // body 1
1436 // } else {
1437 // // body 2
1438 // }
1439 // if (some_condition) {
1440 // // body 3
1441 // } else {
1442 // // body 4
1842 uint i;
1843 for (i = 1; i < phi->req(); i++) {
1844 Node *b = phi->in(i);
1845 if (b->is_Phi()) {
1846 _igvn.replace_input_of(phi, i, clone_iff(b->as_Phi(), loop));
1847 } else {
1848 assert(b->is_Bool() || b->Opcode() == Op_Opaque4, "");
1849 }
1850 }
1851
1852 Node* n = phi->in(1);
1853 Node* sample_opaque = NULL;
1854 Node *sample_bool = NULL;
1855 if (n->Opcode() == Op_Opaque4) {
1856 sample_opaque = n;
1857 sample_bool = n->in(1);
1858 assert(sample_bool->is_Bool(), "wrong type");
1859 } else {
1860 sample_bool = n;
1861 }
1862 Node *sample_cmp = sample_bool->in(1);
1863
1864 // Make Phis to merge the Cmp's inputs.
1865 PhiNode *phi1 = new PhiNode(phi->in(0), Type::TOP);
1866 PhiNode *phi2 = new PhiNode(phi->in(0), Type::TOP);
1867 for (i = 1; i < phi->req(); i++) {
1868 Node *n1 = sample_opaque == NULL ? phi->in(i)->in(1)->in(1) : phi->in(i)->in(1)->in(1)->in(1);
1869 Node *n2 = sample_opaque == NULL ? phi->in(i)->in(1)->in(2) : phi->in(i)->in(1)->in(1)->in(2);
1870 phi1->set_req(i, n1);
1871 phi2->set_req(i, n2);
1872 phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
1873 phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
1874 }
1875 // See if these Phis have been made before.
1876 // Register with optimizer
1877 Node *hit1 = _igvn.hash_find_insert(phi1);
1878 if (hit1) { // Hit, toss just made Phi
1879 _igvn.remove_dead_node(phi1); // Remove new phi
1880 assert(hit1->is_Phi(), "" );
1881 phi1 = (PhiNode*)hit1; // Use existing phi
1882 } else { // Miss
1883 _igvn.register_new_node_with_optimizer(phi1);
1884 }
1885 Node *hit2 = _igvn.hash_find_insert(phi2);
|
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/castnode.hpp"
33 #include "opto/connode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/divnode.hpp"
36 #include "opto/inlinetypenode.hpp"
37 #include "opto/loopnode.hpp"
38 #include "opto/matcher.hpp"
39 #include "opto/mulnode.hpp"
40 #include "opto/movenode.hpp"
41 #include "opto/opaquenode.hpp"
42 #include "opto/rootnode.hpp"
43 #include "opto/subnode.hpp"
44 #include "opto/subtypenode.hpp"
45 #include "utilities/macros.hpp"
46
47 //=============================================================================
48 //------------------------------split_thru_phi---------------------------------
49 // Split Node 'n' through merge point if there is enough win.
50 Node* PhaseIdealLoop::split_thru_phi(Node* n, Node* region, int policy) {
51 if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) {
52 // ConvI2L may have type information on it which is unsafe to push up
53 // so disable this for now
54 return NULL;
55 }
56
57 // Splitting range check CastIIs through a loop induction Phi can
58 // cause new Phis to be created that are left unrelated to the loop
59 // induction Phi and prevent optimizations (vectorization)
60 if (n->Opcode() == Op_CastII && region->is_CountedLoop() &&
61 n->in(1) == region->as_CountedLoop()->phi()) {
62 return NULL;
63 }
64
65 // Inline types should not be split through Phis because they cannot be merged
66 // through Phi nodes but each value input needs to be merged individually.
67 if (n->is_InlineType()) {
68 return NULL;
69 }
70
71 // Bail out if 'n' is a Div or Mod node whose zero check was removed earlier (i.e. control is NULL) and its divisor is an induction variable
72 // phi p of a trip-counted (integer) loop whose inputs could be zero (include zero in their type range). p could have a more precise type
73 // range that does not necessarily include all values of its inputs. Since each of these inputs will be a divisor of the newly cloned nodes
74 // of 'n', we need to bail out of one of these divisors could be zero (zero in its type range).
75 if ((n->Opcode() == Op_DivI || n->Opcode() == Op_ModI) && n->in(0) == NULL
76 && region->is_CountedLoop() && n->in(2) == region->as_CountedLoop()->phi()) {
77 Node* phi = region->as_CountedLoop()->phi();
78 for (uint i = 1; i < phi->req(); i++) {
79 if (_igvn.type(phi->in(i))->filter_speculative(TypeInt::ZERO) != Type::TOP) {
80 // Zero could be a possible value but we already removed the zero check. Bail out to avoid a possible division by zero at a later point.
81 return NULL;
82 }
83 }
84 }
85
86 int wins = 0;
87 assert(!n->is_CFG(), "");
88 assert(region->is_Region(), "");
89
90 const Type* type = n->bottom_type();
984 assert(get_loop(lca)->_nest < n_loop->_nest || lca->in(0)->Opcode() == Op_NeverBranch, "must not be moved into inner loop");
985
986 // Move store out of the loop
987 _igvn.replace_node(hook, n->in(MemNode::Memory));
988 _igvn.replace_input_of(n, 0, lca);
989 set_ctrl_and_loop(n, lca);
990
991 // Disconnect the phi now. An empty phi can confuse other
992 // optimizations in this pass of loop opts..
993 if (phi->in(LoopNode::LoopBackControl) == phi) {
994 _igvn.replace_node(phi, phi->in(LoopNode::EntryControl));
995 n_loop->_body.yank(phi);
996 }
997 }
998 }
999 }
1000 }
1001 }
1002 }
1003
1004 // If UseArrayMarkWordCheck is enabled, we can't use immutable memory for the flat array check
1005 // because we are loading the mark word which is mutable. Although the bits we are interested in
1006 // are immutable (we check for markWord::unlocked_value), we need to use raw memory to not break
1007 // anti dependency analysis. Below code will attempt to still move flat array checks out of loops,
1008 // mainly to enable loop unswitching.
1009 void PhaseIdealLoop::move_flat_array_check_out_of_loop(Node* n) {
1010 // Skip checks for more than one array
1011 if (n->req() > 3) {
1012 return;
1013 }
1014 Node* mem = n->in(FlatArrayCheckNode::Memory);
1015 Node* array = n->in(FlatArrayCheckNode::ArrayOrKlass)->uncast();
1016 IdealLoopTree* check_loop = get_loop(get_ctrl(n));
1017 IdealLoopTree* ary_loop = get_loop(get_ctrl(array));
1018
1019 // Check if array is loop invariant
1020 if (!check_loop->is_member(ary_loop)) {
1021 // Walk up memory graph from the check until we leave the loop
1022 VectorSet wq;
1023 wq.set(mem->_idx);
1024 while (check_loop->is_member(get_loop(ctrl_or_self(mem)))) {
1025 if (mem->is_Phi()) {
1026 mem = mem->in(1);
1027 } else if (mem->is_MergeMem()) {
1028 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1029 } else if (mem->is_Proj()) {
1030 mem = mem->in(0);
1031 } else if (mem->is_MemBar() || mem->is_SafePoint()) {
1032 mem = mem->in(TypeFunc::Memory);
1033 } else if (mem->is_Store() || mem->is_LoadStore() || mem->is_ClearArray()) {
1034 mem = mem->in(MemNode::Memory);
1035 } else {
1036 #ifdef ASSERT
1037 mem->dump();
1038 #endif
1039 ShouldNotReachHere();
1040 }
1041 if (wq.test_set(mem->_idx)) {
1042 return;
1043 }
1044 }
1045 // Replace memory input and re-compute ctrl to move the check out of the loop
1046 _igvn.replace_input_of(n, 1, mem);
1047 set_ctrl_and_loop(n, get_early_ctrl(n));
1048 Node* bol = n->unique_out();
1049 set_ctrl_and_loop(bol, get_early_ctrl(bol));
1050 }
1051 }
1052
1053 //------------------------------split_if_with_blocks_pre-----------------------
1054 // Do the real work in a non-recursive function. Data nodes want to be
1055 // cloned in the pre-order so they can feed each other nicely.
1056 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
1057 // Cloning these guys is unlikely to win
1058 int n_op = n->Opcode();
1059 if (n_op == Op_MergeMem) {
1060 return n;
1061 }
1062 if (n->is_Proj()) {
1063 return n;
1064 }
1065
1066 if (UseArrayMarkWordCheck && n->isa_FlatArrayCheck()) {
1067 move_flat_array_check_out_of_loop(n);
1068 return n;
1069 }
1070
1071 // Do not clone-up CmpFXXX variations, as these are always
1072 // followed by a CmpI
1073 if (n->is_Cmp()) {
1074 return n;
1075 }
1076 // Attempt to use a conditional move instead of a phi/branch
1077 if (ConditionalMoveLimit > 0 && n_op == Op_Region) {
1078 Node *cmov = conditional_move( n );
1079 if (cmov) {
1080 return cmov;
1081 }
1082 }
1083 if (n->is_CFG() || n->is_LoadStore()) {
1084 return n;
1085 }
1086 if (n->is_Opaque1() || // Opaque nodes cannot be mod'd
1087 n_op == Op_Opaque2) {
1088 if (!C->major_progress()) { // If chance of no more loop opts...
1089 _igvn._worklist.push(n); // maybe we'll remove them
1090 }
1324
1325 return true;
1326 }
1327
1328 // Detect if the node is the inner strip-mined loop
1329 // Return: NULL if it's not the case, or the exit of outer strip-mined loop
1330 static Node* is_inner_of_stripmined_loop(const Node* out) {
1331 Node* out_le = NULL;
1332
1333 if (out->is_CountedLoopEnd()) {
1334 const CountedLoopNode* loop = out->as_CountedLoopEnd()->loopnode();
1335
1336 if (loop != NULL && loop->is_strip_mined()) {
1337 out_le = loop->in(LoopNode::EntryControl)->as_OuterStripMinedLoop()->outer_loop_exit();
1338 }
1339 }
1340
1341 return out_le;
1342 }
1343
1344 bool PhaseIdealLoop::flatten_array_element_type_check(Node *n) {
1345 // If the CmpP is a subtype check for a value that has just been
1346 // loaded from an array, the subtype check guarantees the value
1347 // can't be stored in a flattened array and the load of the value
1348 // happens with a flattened array check then: push the type check
1349 // through the phi of the flattened array check. This needs special
1350 // logic because the subtype check's input is not a phi but a
1351 // LoadKlass that must first be cloned through the phi.
1352 if (n->Opcode() != Op_CmpP) {
1353 return false;
1354 }
1355
1356 Node* klassptr = n->in(1);
1357 Node* klasscon = n->in(2);
1358
1359 if (klassptr->is_DecodeNarrowPtr()) {
1360 klassptr = klassptr->in(1);
1361 }
1362
1363 if (klassptr->Opcode() != Op_LoadKlass && klassptr->Opcode() != Op_LoadNKlass) {
1364 return false;
1365 }
1366
1367 if (!klasscon->is_Con()) {
1368 return false;
1369 }
1370
1371 Node* addr = klassptr->in(MemNode::Address);
1372
1373 if (!addr->is_AddP()) {
1374 return false;
1375 }
1376
1377 intptr_t offset;
1378 Node* obj = AddPNode::Ideal_base_and_offset(addr, &_igvn, offset);
1379
1380 if (obj == NULL) {
1381 return false;
1382 }
1383
1384 assert(obj != NULL && addr->in(AddPNode::Base) == addr->in(AddPNode::Address), "malformed AddP?");
1385 if (obj->Opcode() == Op_CastPP) {
1386 obj = obj->in(1);
1387 }
1388
1389 if (!obj->is_Phi()) {
1390 return false;
1391 }
1392
1393 Node* region = obj->in(0);
1394
1395 Node* phi = PhiNode::make_blank(region, n->in(1));
1396 for (uint i = 1; i < region->req(); i++) {
1397 Node* in = obj->in(i);
1398 Node* ctrl = region->in(i);
1399 if (addr->in(AddPNode::Base) != obj) {
1400 Node* cast = addr->in(AddPNode::Base);
1401 assert(cast->Opcode() == Op_CastPP && cast->in(0) != NULL, "inconsistent subgraph");
1402 Node* cast_clone = cast->clone();
1403 cast_clone->set_req(0, ctrl);
1404 cast_clone->set_req(1, in);
1405 register_new_node(cast_clone, ctrl);
1406 _igvn.set_type(cast_clone, cast_clone->Value(&_igvn));
1407 in = cast_clone;
1408 }
1409 Node* addr_clone = addr->clone();
1410 addr_clone->set_req(AddPNode::Base, in);
1411 addr_clone->set_req(AddPNode::Address, in);
1412 register_new_node(addr_clone, ctrl);
1413 _igvn.set_type(addr_clone, addr_clone->Value(&_igvn));
1414 Node* klassptr_clone = klassptr->clone();
1415 klassptr_clone->set_req(2, addr_clone);
1416 register_new_node(klassptr_clone, ctrl);
1417 _igvn.set_type(klassptr_clone, klassptr_clone->Value(&_igvn));
1418 if (klassptr != n->in(1)) {
1419 Node* decode = n->in(1);
1420 assert(decode->is_DecodeNarrowPtr(), "inconsistent subgraph");
1421 Node* decode_clone = decode->clone();
1422 decode_clone->set_req(1, klassptr_clone);
1423 register_new_node(decode_clone, ctrl);
1424 _igvn.set_type(decode_clone, decode_clone->Value(&_igvn));
1425 klassptr_clone = decode_clone;
1426 }
1427 phi->set_req(i, klassptr_clone);
1428 }
1429 register_new_node(phi, region);
1430 Node* orig = n->in(1);
1431 _igvn.replace_input_of(n, 1, phi);
1432 split_if_with_blocks_post(n);
1433 if (n->outcnt() != 0) {
1434 _igvn.replace_input_of(n, 1, orig);
1435 _igvn.remove_dead_node(phi);
1436 }
1437 return true;
1438 }
1439
1440 //------------------------------split_if_with_blocks_post----------------------
1441 // Do the real work in a non-recursive function. CFG hackery wants to be
1442 // in the post-order, so it can dirty the I-DOM info and not use the dirtied
1443 // info.
1444 void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
1445
1446 if (flatten_array_element_type_check(n)) {
1447 return;
1448 }
1449
1450 // Cloning Cmp through Phi's involves the split-if transform.
1451 // FastLock is not used by an If
1452 if (n->is_Cmp() && !n->is_FastLock()) {
1453 Node *n_ctrl = get_ctrl(n);
1454 // Determine if the Node has inputs from some local Phi.
1455 // Returns the block to clone thru.
1456 Node *n_blk = has_local_phi_input(n);
1457 if (n_blk != n_ctrl) {
1458 return;
1459 }
1460
1461 if (!can_split_if(n_ctrl)) {
1462 return;
1463 }
1464
1465 if (n->outcnt() != 1) {
1466 return; // Multiple bool's from 1 compare?
1467 }
1468 Node *bol = n->unique_out();
1469 assert(bol->is_Bool(), "expect a bool here");
1565 }
1566 // Replace the dominated test with an obvious true or false.
1567 // Place it on the IGVN worklist for later cleanup.
1568 C->set_major_progress();
1569 dominated_by(prevdom->as_IfProj(), n->as_If(), false, true);
1570 #ifndef PRODUCT
1571 if( VerifyLoopOptimizations ) verify();
1572 #endif
1573 return;
1574 }
1575 prevdom = dom;
1576 dom = idom(prevdom);
1577 }
1578 }
1579 }
1580
1581 try_sink_out_of_loop(n);
1582
1583 try_move_store_after_loop(n);
1584
1585 // Remove multiple allocations of the same inline type
1586 if (n->is_InlineType()) {
1587 n->as_InlineType()->remove_redundant_allocations(&_igvn, this);
1588 }
1589
1590 // Check for Opaque2's who's loop has disappeared - who's input is in the
1591 // same loop nest as their output. Remove 'em, they are no longer useful.
1592 if( n_op == Op_Opaque2 &&
1593 n->in(1) != NULL &&
1594 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {
1595 _igvn.replace_node( n, n->in(1) );
1596 }
1597 }
1598
1599 // Tranform:
1600 //
1601 // if (some_condition) {
1602 // // body 1
1603 // } else {
1604 // // body 2
1605 // }
1606 // if (some_condition) {
1607 // // body 3
1608 // } else {
1609 // // body 4
2009 uint i;
2010 for (i = 1; i < phi->req(); i++) {
2011 Node *b = phi->in(i);
2012 if (b->is_Phi()) {
2013 _igvn.replace_input_of(phi, i, clone_iff(b->as_Phi(), loop));
2014 } else {
2015 assert(b->is_Bool() || b->Opcode() == Op_Opaque4, "");
2016 }
2017 }
2018
2019 Node* n = phi->in(1);
2020 Node* sample_opaque = NULL;
2021 Node *sample_bool = NULL;
2022 if (n->Opcode() == Op_Opaque4) {
2023 sample_opaque = n;
2024 sample_bool = n->in(1);
2025 assert(sample_bool->is_Bool(), "wrong type");
2026 } else {
2027 sample_bool = n;
2028 }
2029 Node* sample_cmp = sample_bool->in(1);
2030 const Type* t = Type::TOP;
2031 const TypePtr* at = NULL;
2032 if (sample_cmp->is_FlatArrayCheck()) {
2033 // Left input of a FlatArrayCheckNode is memory, set the (adr) type of the phi accordingly
2034 assert(sample_cmp->in(1)->bottom_type() == Type::MEMORY, "unexpected input type");
2035 t = Type::MEMORY;
2036 at = TypeRawPtr::BOTTOM;
2037 }
2038
2039 // Make Phis to merge the Cmp's inputs.
2040 PhiNode *phi1 = new PhiNode(phi->in(0), t, at);
2041 PhiNode *phi2 = new PhiNode(phi->in(0), Type::TOP);
2042 for (i = 1; i < phi->req(); i++) {
2043 Node *n1 = sample_opaque == NULL ? phi->in(i)->in(1)->in(1) : phi->in(i)->in(1)->in(1)->in(1);
2044 Node *n2 = sample_opaque == NULL ? phi->in(i)->in(1)->in(2) : phi->in(i)->in(1)->in(1)->in(2);
2045 phi1->set_req(i, n1);
2046 phi2->set_req(i, n2);
2047 phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
2048 phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
2049 }
2050 // See if these Phis have been made before.
2051 // Register with optimizer
2052 Node *hit1 = _igvn.hash_find_insert(phi1);
2053 if (hit1) { // Hit, toss just made Phi
2054 _igvn.remove_dead_node(phi1); // Remove new phi
2055 assert(hit1->is_Phi(), "" );
2056 phi1 = (PhiNode*)hit1; // Use existing phi
2057 } else { // Miss
2058 _igvn.register_new_node_with_optimizer(phi1);
2059 }
2060 Node *hit2 = _igvn.hash_find_insert(phi2);
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