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();
979 assert(get_loop(lca)->_nest < n_loop->_nest || lca->in(0)->Opcode() == Op_NeverBranch, "must not be moved into inner loop");
980
981 // Move store out of the loop
982 _igvn.replace_node(hook, n->in(MemNode::Memory));
983 _igvn.replace_input_of(n, 0, lca);
984 set_ctrl_and_loop(n, lca);
985
986 // Disconnect the phi now. An empty phi can confuse other
987 // optimizations in this pass of loop opts..
988 if (phi->in(LoopNode::LoopBackControl) == phi) {
989 _igvn.replace_node(phi, phi->in(LoopNode::EntryControl));
990 n_loop->_body.yank(phi);
991 }
992 }
993 }
994 }
995 }
996 }
997 }
998
999 //------------------------------split_if_with_blocks_pre-----------------------
1000 // Do the real work in a non-recursive function. Data nodes want to be
1001 // cloned in the pre-order so they can feed each other nicely.
1002 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
1003 // Cloning these guys is unlikely to win
1004 int n_op = n->Opcode();
1005 if (n_op == Op_MergeMem) {
1006 return n;
1007 }
1008 if (n->is_Proj()) {
1009 return n;
1010 }
1011 // Do not clone-up CmpFXXX variations, as these are always
1012 // followed by a CmpI
1013 if (n->is_Cmp()) {
1014 return n;
1015 }
1016 // Attempt to use a conditional move instead of a phi/branch
1017 if (ConditionalMoveLimit > 0 && n_op == Op_Region) {
1018 Node *cmov = conditional_move( n );
1019 if (cmov) {
1020 return cmov;
1021 }
1022 }
1023 if (n->is_CFG() || n->is_LoadStore()) {
1024 return n;
1025 }
1026 if (n->is_Opaque1() || // Opaque nodes cannot be mod'd
1027 n_op == Op_Opaque2) {
1028 if (!C->major_progress()) { // If chance of no more loop opts...
1029 _igvn._worklist.push(n); // maybe we'll remove them
1030 }
1269
1270 return true;
1271 }
1272
1273 // Detect if the node is the inner strip-mined loop
1274 // Return: NULL if it's not the case, or the exit of outer strip-mined loop
1275 static Node* is_inner_of_stripmined_loop(const Node* out) {
1276 Node* out_le = NULL;
1277
1278 if (out->is_CountedLoopEnd()) {
1279 const CountedLoopNode* loop = out->as_CountedLoopEnd()->loopnode();
1280
1281 if (loop != NULL && loop->is_strip_mined()) {
1282 out_le = loop->in(LoopNode::EntryControl)->as_OuterStripMinedLoop()->outer_loop_exit();
1283 }
1284 }
1285
1286 return out_le;
1287 }
1288
1289 //------------------------------split_if_with_blocks_post----------------------
1290 // Do the real work in a non-recursive function. CFG hackery wants to be
1291 // in the post-order, so it can dirty the I-DOM info and not use the dirtied
1292 // info.
1293 void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
1294
1295 // Cloning Cmp through Phi's involves the split-if transform.
1296 // FastLock is not used by an If
1297 if (n->is_Cmp() && !n->is_FastLock()) {
1298 Node *n_ctrl = get_ctrl(n);
1299 // Determine if the Node has inputs from some local Phi.
1300 // Returns the block to clone thru.
1301 Node *n_blk = has_local_phi_input(n);
1302 if (n_blk != n_ctrl) {
1303 return;
1304 }
1305
1306 if (!can_split_if(n_ctrl)) {
1307 return;
1308 }
1309
1310 if (n->outcnt() != 1) {
1311 return; // Multiple bool's from 1 compare?
1312 }
1313 Node *bol = n->unique_out();
1314 assert(bol->is_Bool(), "expect a bool here");
1410 }
1411 // Replace the dominated test with an obvious true or false.
1412 // Place it on the IGVN worklist for later cleanup.
1413 C->set_major_progress();
1414 dominated_by(prevdom->as_IfProj(), n->as_If(), false, true);
1415 #ifndef PRODUCT
1416 if( VerifyLoopOptimizations ) verify();
1417 #endif
1418 return;
1419 }
1420 prevdom = dom;
1421 dom = idom(prevdom);
1422 }
1423 }
1424 }
1425
1426 try_sink_out_of_loop(n);
1427
1428 try_move_store_after_loop(n);
1429
1430 // Check for Opaque2's who's loop has disappeared - who's input is in the
1431 // same loop nest as their output. Remove 'em, they are no longer useful.
1432 if( n_op == Op_Opaque2 &&
1433 n->in(1) != NULL &&
1434 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {
1435 _igvn.replace_node( n, n->in(1) );
1436 }
1437 }
1438
1439 // Transform:
1440 //
1441 // if (some_condition) {
1442 // // body 1
1443 // } else {
1444 // // body 2
1445 // }
1446 // if (some_condition) {
1447 // // body 3
1448 // } else {
1449 // // body 4
1848 uint i;
1849 for (i = 1; i < phi->req(); i++) {
1850 Node *b = phi->in(i);
1851 if (b->is_Phi()) {
1852 _igvn.replace_input_of(phi, i, clone_iff(b->as_Phi()));
1853 } else {
1854 assert(b->is_Bool() || b->Opcode() == Op_Opaque4, "");
1855 }
1856 }
1857
1858 Node* n = phi->in(1);
1859 Node* sample_opaque = NULL;
1860 Node *sample_bool = NULL;
1861 if (n->Opcode() == Op_Opaque4) {
1862 sample_opaque = n;
1863 sample_bool = n->in(1);
1864 assert(sample_bool->is_Bool(), "wrong type");
1865 } else {
1866 sample_bool = n;
1867 }
1868 Node *sample_cmp = sample_bool->in(1);
1869
1870 // Make Phis to merge the Cmp's inputs.
1871 PhiNode *phi1 = new PhiNode(phi->in(0), Type::TOP);
1872 PhiNode *phi2 = new PhiNode(phi->in(0), Type::TOP);
1873 for (i = 1; i < phi->req(); i++) {
1874 Node *n1 = sample_opaque == NULL ? phi->in(i)->in(1)->in(1) : phi->in(i)->in(1)->in(1)->in(1);
1875 Node *n2 = sample_opaque == NULL ? phi->in(i)->in(1)->in(2) : phi->in(i)->in(1)->in(1)->in(2);
1876 phi1->set_req(i, n1);
1877 phi2->set_req(i, n2);
1878 phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
1879 phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
1880 }
1881 // See if these Phis have been made before.
1882 // Register with optimizer
1883 Node *hit1 = _igvn.hash_find_insert(phi1);
1884 if (hit1) { // Hit, toss just made Phi
1885 _igvn.remove_dead_node(phi1); // Remove new phi
1886 assert(hit1->is_Phi(), "" );
1887 phi1 = (PhiNode*)hit1; // Use existing phi
1888 } else { // Miss
1889 _igvn.register_new_node_with_optimizer(phi1);
1890 }
1891 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();
986 assert(get_loop(lca)->_nest < n_loop->_nest || lca->in(0)->Opcode() == Op_NeverBranch, "must not be moved into inner loop");
987
988 // Move store out of the loop
989 _igvn.replace_node(hook, n->in(MemNode::Memory));
990 _igvn.replace_input_of(n, 0, lca);
991 set_ctrl_and_loop(n, lca);
992
993 // Disconnect the phi now. An empty phi can confuse other
994 // optimizations in this pass of loop opts..
995 if (phi->in(LoopNode::LoopBackControl) == phi) {
996 _igvn.replace_node(phi, phi->in(LoopNode::EntryControl));
997 n_loop->_body.yank(phi);
998 }
999 }
1000 }
1001 }
1002 }
1003 }
1004 }
1005
1006 // If UseArrayMarkWordCheck is enabled, we can't use immutable memory for the flat array check
1007 // because we are loading the mark word which is mutable. Although the bits we are interested in
1008 // are immutable (we check for markWord::unlocked_value), we need to use raw memory to not break
1009 // anti dependency analysis. Below code will attempt to still move flat array checks out of loops,
1010 // mainly to enable loop unswitching.
1011 void PhaseIdealLoop::move_flat_array_check_out_of_loop(Node* n) {
1012 // Skip checks for more than one array
1013 if (n->req() > 3) {
1014 return;
1015 }
1016 Node* mem = n->in(FlatArrayCheckNode::Memory);
1017 Node* array = n->in(FlatArrayCheckNode::ArrayOrKlass)->uncast();
1018 IdealLoopTree* check_loop = get_loop(get_ctrl(n));
1019 IdealLoopTree* ary_loop = get_loop(get_ctrl(array));
1020
1021 // Check if array is loop invariant
1022 if (!check_loop->is_member(ary_loop)) {
1023 // Walk up memory graph from the check until we leave the loop
1024 VectorSet wq;
1025 wq.set(mem->_idx);
1026 while (check_loop->is_member(get_loop(ctrl_or_self(mem)))) {
1027 if (mem->is_Phi()) {
1028 mem = mem->in(1);
1029 } else if (mem->is_MergeMem()) {
1030 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1031 } else if (mem->is_Proj()) {
1032 mem = mem->in(0);
1033 } else if (mem->is_MemBar() || mem->is_SafePoint()) {
1034 mem = mem->in(TypeFunc::Memory);
1035 } else if (mem->is_Store() || mem->is_LoadStore() || mem->is_ClearArray()) {
1036 mem = mem->in(MemNode::Memory);
1037 } else {
1038 #ifdef ASSERT
1039 mem->dump();
1040 #endif
1041 ShouldNotReachHere();
1042 }
1043 if (wq.test_set(mem->_idx)) {
1044 return;
1045 }
1046 }
1047 // Replace memory input and re-compute ctrl to move the check out of the loop
1048 _igvn.replace_input_of(n, 1, mem);
1049 set_ctrl_and_loop(n, get_early_ctrl(n));
1050 Node* bol = n->unique_out();
1051 set_ctrl_and_loop(bol, get_early_ctrl(bol));
1052 }
1053 }
1054
1055 //------------------------------split_if_with_blocks_pre-----------------------
1056 // Do the real work in a non-recursive function. Data nodes want to be
1057 // cloned in the pre-order so they can feed each other nicely.
1058 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
1059 // Cloning these guys is unlikely to win
1060 int n_op = n->Opcode();
1061 if (n_op == Op_MergeMem) {
1062 return n;
1063 }
1064 if (n->is_Proj()) {
1065 return n;
1066 }
1067
1068 if (UseArrayMarkWordCheck && n->isa_FlatArrayCheck()) {
1069 move_flat_array_check_out_of_loop(n);
1070 return n;
1071 }
1072
1073 // Do not clone-up CmpFXXX variations, as these are always
1074 // followed by a CmpI
1075 if (n->is_Cmp()) {
1076 return n;
1077 }
1078 // Attempt to use a conditional move instead of a phi/branch
1079 if (ConditionalMoveLimit > 0 && n_op == Op_Region) {
1080 Node *cmov = conditional_move( n );
1081 if (cmov) {
1082 return cmov;
1083 }
1084 }
1085 if (n->is_CFG() || n->is_LoadStore()) {
1086 return n;
1087 }
1088 if (n->is_Opaque1() || // Opaque nodes cannot be mod'd
1089 n_op == Op_Opaque2) {
1090 if (!C->major_progress()) { // If chance of no more loop opts...
1091 _igvn._worklist.push(n); // maybe we'll remove them
1092 }
1331
1332 return true;
1333 }
1334
1335 // Detect if the node is the inner strip-mined loop
1336 // Return: NULL if it's not the case, or the exit of outer strip-mined loop
1337 static Node* is_inner_of_stripmined_loop(const Node* out) {
1338 Node* out_le = NULL;
1339
1340 if (out->is_CountedLoopEnd()) {
1341 const CountedLoopNode* loop = out->as_CountedLoopEnd()->loopnode();
1342
1343 if (loop != NULL && loop->is_strip_mined()) {
1344 out_le = loop->in(LoopNode::EntryControl)->as_OuterStripMinedLoop()->outer_loop_exit();
1345 }
1346 }
1347
1348 return out_le;
1349 }
1350
1351 bool PhaseIdealLoop::flatten_array_element_type_check(Node *n) {
1352 // If the CmpP is a subtype check for a value that has just been
1353 // loaded from an array, the subtype check guarantees the value
1354 // can't be stored in a flattened array and the load of the value
1355 // happens with a flattened array check then: push the type check
1356 // through the phi of the flattened array check. This needs special
1357 // logic because the subtype check's input is not a phi but a
1358 // LoadKlass that must first be cloned through the phi.
1359 if (n->Opcode() != Op_CmpP) {
1360 return false;
1361 }
1362
1363 Node* klassptr = n->in(1);
1364 Node* klasscon = n->in(2);
1365
1366 if (klassptr->is_DecodeNarrowPtr()) {
1367 klassptr = klassptr->in(1);
1368 }
1369
1370 if (klassptr->Opcode() != Op_LoadKlass && klassptr->Opcode() != Op_LoadNKlass) {
1371 return false;
1372 }
1373
1374 if (!klasscon->is_Con()) {
1375 return false;
1376 }
1377
1378 Node* addr = klassptr->in(MemNode::Address);
1379
1380 if (!addr->is_AddP()) {
1381 return false;
1382 }
1383
1384 intptr_t offset;
1385 Node* obj = AddPNode::Ideal_base_and_offset(addr, &_igvn, offset);
1386
1387 if (obj == NULL) {
1388 return false;
1389 }
1390
1391 assert(obj != NULL && addr->in(AddPNode::Base) == addr->in(AddPNode::Address), "malformed AddP?");
1392 if (obj->Opcode() == Op_CastPP) {
1393 obj = obj->in(1);
1394 }
1395
1396 if (!obj->is_Phi()) {
1397 return false;
1398 }
1399
1400 Node* region = obj->in(0);
1401
1402 Node* phi = PhiNode::make_blank(region, n->in(1));
1403 for (uint i = 1; i < region->req(); i++) {
1404 Node* in = obj->in(i);
1405 Node* ctrl = region->in(i);
1406 if (addr->in(AddPNode::Base) != obj) {
1407 Node* cast = addr->in(AddPNode::Base);
1408 assert(cast->Opcode() == Op_CastPP && cast->in(0) != NULL, "inconsistent subgraph");
1409 Node* cast_clone = cast->clone();
1410 cast_clone->set_req(0, ctrl);
1411 cast_clone->set_req(1, in);
1412 register_new_node(cast_clone, ctrl);
1413 _igvn.set_type(cast_clone, cast_clone->Value(&_igvn));
1414 in = cast_clone;
1415 }
1416 Node* addr_clone = addr->clone();
1417 addr_clone->set_req(AddPNode::Base, in);
1418 addr_clone->set_req(AddPNode::Address, in);
1419 register_new_node(addr_clone, ctrl);
1420 _igvn.set_type(addr_clone, addr_clone->Value(&_igvn));
1421 Node* klassptr_clone = klassptr->clone();
1422 klassptr_clone->set_req(2, addr_clone);
1423 register_new_node(klassptr_clone, ctrl);
1424 _igvn.set_type(klassptr_clone, klassptr_clone->Value(&_igvn));
1425 if (klassptr != n->in(1)) {
1426 Node* decode = n->in(1);
1427 assert(decode->is_DecodeNarrowPtr(), "inconsistent subgraph");
1428 Node* decode_clone = decode->clone();
1429 decode_clone->set_req(1, klassptr_clone);
1430 register_new_node(decode_clone, ctrl);
1431 _igvn.set_type(decode_clone, decode_clone->Value(&_igvn));
1432 klassptr_clone = decode_clone;
1433 }
1434 phi->set_req(i, klassptr_clone);
1435 }
1436 register_new_node(phi, region);
1437 Node* orig = n->in(1);
1438 _igvn.replace_input_of(n, 1, phi);
1439 split_if_with_blocks_post(n);
1440 if (n->outcnt() != 0) {
1441 _igvn.replace_input_of(n, 1, orig);
1442 _igvn.remove_dead_node(phi);
1443 }
1444 return true;
1445 }
1446
1447 //------------------------------split_if_with_blocks_post----------------------
1448 // Do the real work in a non-recursive function. CFG hackery wants to be
1449 // in the post-order, so it can dirty the I-DOM info and not use the dirtied
1450 // info.
1451 void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
1452
1453 if (flatten_array_element_type_check(n)) {
1454 return;
1455 }
1456
1457 // Cloning Cmp through Phi's involves the split-if transform.
1458 // FastLock is not used by an If
1459 if (n->is_Cmp() && !n->is_FastLock()) {
1460 Node *n_ctrl = get_ctrl(n);
1461 // Determine if the Node has inputs from some local Phi.
1462 // Returns the block to clone thru.
1463 Node *n_blk = has_local_phi_input(n);
1464 if (n_blk != n_ctrl) {
1465 return;
1466 }
1467
1468 if (!can_split_if(n_ctrl)) {
1469 return;
1470 }
1471
1472 if (n->outcnt() != 1) {
1473 return; // Multiple bool's from 1 compare?
1474 }
1475 Node *bol = n->unique_out();
1476 assert(bol->is_Bool(), "expect a bool here");
1572 }
1573 // Replace the dominated test with an obvious true or false.
1574 // Place it on the IGVN worklist for later cleanup.
1575 C->set_major_progress();
1576 dominated_by(prevdom->as_IfProj(), n->as_If(), false, true);
1577 #ifndef PRODUCT
1578 if( VerifyLoopOptimizations ) verify();
1579 #endif
1580 return;
1581 }
1582 prevdom = dom;
1583 dom = idom(prevdom);
1584 }
1585 }
1586 }
1587
1588 try_sink_out_of_loop(n);
1589
1590 try_move_store_after_loop(n);
1591
1592 // Remove multiple allocations of the same inline type
1593 if (n->is_InlineType()) {
1594 n->as_InlineType()->remove_redundant_allocations(&_igvn, this);
1595 }
1596
1597 // Check for Opaque2's who's loop has disappeared - who's input is in the
1598 // same loop nest as their output. Remove 'em, they are no longer useful.
1599 if( n_op == Op_Opaque2 &&
1600 n->in(1) != NULL &&
1601 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {
1602 _igvn.replace_node( n, n->in(1) );
1603 }
1604 }
1605
1606 // Transform:
1607 //
1608 // if (some_condition) {
1609 // // body 1
1610 // } else {
1611 // // body 2
1612 // }
1613 // if (some_condition) {
1614 // // body 3
1615 // } else {
1616 // // body 4
2015 uint i;
2016 for (i = 1; i < phi->req(); i++) {
2017 Node *b = phi->in(i);
2018 if (b->is_Phi()) {
2019 _igvn.replace_input_of(phi, i, clone_iff(b->as_Phi()));
2020 } else {
2021 assert(b->is_Bool() || b->Opcode() == Op_Opaque4, "");
2022 }
2023 }
2024
2025 Node* n = phi->in(1);
2026 Node* sample_opaque = NULL;
2027 Node *sample_bool = NULL;
2028 if (n->Opcode() == Op_Opaque4) {
2029 sample_opaque = n;
2030 sample_bool = n->in(1);
2031 assert(sample_bool->is_Bool(), "wrong type");
2032 } else {
2033 sample_bool = n;
2034 }
2035 Node* sample_cmp = sample_bool->in(1);
2036 const Type* t = Type::TOP;
2037 const TypePtr* at = NULL;
2038 if (sample_cmp->is_FlatArrayCheck()) {
2039 // Left input of a FlatArrayCheckNode is memory, set the (adr) type of the phi accordingly
2040 assert(sample_cmp->in(1)->bottom_type() == Type::MEMORY, "unexpected input type");
2041 t = Type::MEMORY;
2042 at = TypeRawPtr::BOTTOM;
2043 }
2044
2045 // Make Phis to merge the Cmp's inputs.
2046 PhiNode *phi1 = new PhiNode(phi->in(0), t, at);
2047 PhiNode *phi2 = new PhiNode(phi->in(0), Type::TOP);
2048 for (i = 1; i < phi->req(); i++) {
2049 Node *n1 = sample_opaque == NULL ? phi->in(i)->in(1)->in(1) : phi->in(i)->in(1)->in(1)->in(1);
2050 Node *n2 = sample_opaque == NULL ? phi->in(i)->in(1)->in(2) : phi->in(i)->in(1)->in(1)->in(2);
2051 phi1->set_req(i, n1);
2052 phi2->set_req(i, n2);
2053 phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
2054 phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
2055 }
2056 // See if these Phis have been made before.
2057 // Register with optimizer
2058 Node *hit1 = _igvn.hash_find_insert(phi1);
2059 if (hit1) { // Hit, toss just made Phi
2060 _igvn.remove_dead_node(phi1); // Remove new phi
2061 assert(hit1->is_Phi(), "" );
2062 phi1 = (PhiNode*)hit1; // Use existing phi
2063 } else { // Miss
2064 _igvn.register_new_node_with_optimizer(phi1);
2065 }
2066 Node *hit2 = _igvn.hash_find_insert(phi2);
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