| 1 | /* |
|---|---|
| 2 | * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| 13 | * accompanied this code). |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License version |
| 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 "classfile/systemDictionary.hpp" |
| 27 | #include "gc/shared/barrierSet.hpp" |
| 28 | #include "gc/shared/c2/barrierSetC2.hpp" |
| 29 | #include "memory/allocation.inline.hpp" |
| 30 | #include "memory/resourceArea.hpp" |
| 31 | #include "oops/objArrayKlass.hpp" |
| 32 | #include "opto/addnode.hpp" |
| 33 | #include "opto/castnode.hpp" |
| 34 | #include "opto/cfgnode.hpp" |
| 35 | #include "opto/connode.hpp" |
| 36 | #include "opto/convertnode.hpp" |
| 37 | #include "opto/loopnode.hpp" |
| 38 | #include "opto/machnode.hpp" |
| 39 | #include "opto/movenode.hpp" |
| 40 | #include "opto/narrowptrnode.hpp" |
| 41 | #include "opto/mulnode.hpp" |
| 42 | #include "opto/phaseX.hpp" |
| 43 | #include "opto/regmask.hpp" |
| 44 | #include "opto/runtime.hpp" |
| 45 | #include "opto/subnode.hpp" |
| 46 | #include "utilities/vmError.hpp" |
| 47 | |
| 48 | // Portions of code courtesy of Clifford Click |
| 49 | |
| 50 | // Optimization - Graph Style |
| 51 | |
| 52 | //============================================================================= |
| 53 | //------------------------------Value------------------------------------------ |
| 54 | // Compute the type of the RegionNode. |
| 55 | const Type* RegionNode::Value(PhaseGVN* phase) const { |
| 56 | for( uint i=1; i<req(); ++i ) { // For all paths in |
| 57 | Node *n = in(i); // Get Control source |
| 58 | if( !n ) continue; // Missing inputs are TOP |
| 59 | if( phase->type(n) == Type::CONTROL ) |
| 60 | return Type::CONTROL; |
| 61 | } |
| 62 | return Type::TOP; // All paths dead? Then so are we |
| 63 | } |
| 64 | |
| 65 | //------------------------------Identity--------------------------------------- |
| 66 | // Check for Region being Identity. |
| 67 | Node* RegionNode::Identity(PhaseGVN* phase) { |
| 68 | // Cannot have Region be an identity, even if it has only 1 input. |
| 69 | // Phi users cannot have their Region input folded away for them, |
| 70 | // since they need to select the proper data input |
| 71 | return this; |
| 72 | } |
| 73 | |
| 74 | //------------------------------merge_region----------------------------------- |
| 75 | // If a Region flows into a Region, merge into one big happy merge. This is |
| 76 | // hard to do if there is stuff that has to happen |
| 77 | static Node *merge_region(RegionNode *region, PhaseGVN *phase) { |
| 78 | if( region->Opcode() != Op_Region ) // Do not do to LoopNodes |
| 79 | return NULL; |
| 80 | Node *progress = NULL; // Progress flag |
| 81 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 82 | |
| 83 | uint rreq = region->req(); |
| 84 | for( uint i = 1; i < rreq; i++ ) { |
| 85 | Node *r = region->in(i); |
| 86 | if( r && r->Opcode() == Op_Region && // Found a region? |
| 87 | r->in(0) == r && // Not already collapsed? |
| 88 | r != region && // Avoid stupid situations |
| 89 | r->outcnt() == 2 ) { // Self user and 'region' user only? |
| 90 | assert(!r->as_Region()->has_phi(), "no phi users"); |
| 91 | if( !progress ) { // No progress |
| 92 | if (region->has_phi()) { |
| 93 | return NULL; // Only flatten if no Phi users |
| 94 | // igvn->hash_delete( phi ); |
| 95 | } |
| 96 | igvn->hash_delete( region ); |
| 97 | progress = region; // Making progress |
| 98 | } |
| 99 | igvn->hash_delete( r ); |
| 100 | |
| 101 | // Append inputs to 'r' onto 'region' |
| 102 | for( uint j = 1; j < r->req(); j++ ) { |
| 103 | // Move an input from 'r' to 'region' |
| 104 | region->add_req(r->in(j)); |
| 105 | r->set_req(j, phase->C->top()); |
| 106 | // Update phis of 'region' |
| 107 | //for( uint k = 0; k < max; k++ ) { |
| 108 | // Node *phi = region->out(k); |
| 109 | // if( phi->is_Phi() ) { |
| 110 | // phi->add_req(phi->in(i)); |
| 111 | // } |
| 112 | //} |
| 113 | |
| 114 | rreq++; // One more input to Region |
| 115 | } // Found a region to merge into Region |
| 116 | igvn->_worklist.push(r); |
| 117 | // Clobber pointer to the now dead 'r' |
| 118 | region->set_req(i, phase->C->top()); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | return progress; |
| 123 | } |
| 124 | |
| 125 | |
| 126 | |
| 127 | //--------------------------------has_phi-------------------------------------- |
| 128 | // Helper function: Return any PhiNode that uses this region or NULL |
| 129 | PhiNode* RegionNode::has_phi() const { |
| 130 | for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) { |
| 131 | Node* phi = fast_out(i); |
| 132 | if (phi->is_Phi()) { // Check for Phi users |
| 133 | assert(phi->in(0) == (Node*)this, "phi uses region only via in(0)"); |
| 134 | return phi->as_Phi(); // this one is good enough |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | return NULL; |
| 139 | } |
| 140 | |
| 141 | |
| 142 | //-----------------------------has_unique_phi---------------------------------- |
| 143 | // Helper function: Return the only PhiNode that uses this region or NULL |
| 144 | PhiNode* RegionNode::has_unique_phi() const { |
| 145 | // Check that only one use is a Phi |
| 146 | PhiNode* only_phi = NULL; |
| 147 | for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) { |
| 148 | Node* phi = fast_out(i); |
| 149 | if (phi->is_Phi()) { // Check for Phi users |
| 150 | assert(phi->in(0) == (Node*)this, "phi uses region only via in(0)"); |
| 151 | if (only_phi == NULL) { |
| 152 | only_phi = phi->as_Phi(); |
| 153 | } else { |
| 154 | return NULL; // multiple phis |
| 155 | } |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | return only_phi; |
| 160 | } |
| 161 | |
| 162 | |
| 163 | //------------------------------check_phi_clipping----------------------------- |
| 164 | // Helper function for RegionNode's identification of FP clipping |
| 165 | // Check inputs to the Phi |
| 166 | static bool check_phi_clipping( PhiNode *phi, ConNode * &min, uint &min_idx, ConNode * &max, uint &max_idx, Node * &val, uint &val_idx ) { |
| 167 | min = NULL; |
| 168 | max = NULL; |
| 169 | val = NULL; |
| 170 | min_idx = 0; |
| 171 | max_idx = 0; |
| 172 | val_idx = 0; |
| 173 | uint phi_max = phi->req(); |
| 174 | if( phi_max == 4 ) { |
| 175 | for( uint j = 1; j < phi_max; ++j ) { |
| 176 | Node *n = phi->in(j); |
| 177 | int opcode = n->Opcode(); |
| 178 | switch( opcode ) { |
| 179 | case Op_ConI: |
| 180 | { |
| 181 | if( min == NULL ) { |
| 182 | min = n->Opcode() == Op_ConI ? (ConNode*)n : NULL; |
| 183 | min_idx = j; |
| 184 | } else { |
| 185 | max = n->Opcode() == Op_ConI ? (ConNode*)n : NULL; |
| 186 | max_idx = j; |
| 187 | if( min->get_int() > max->get_int() ) { |
| 188 | // Swap min and max |
| 189 | ConNode *temp; |
| 190 | uint temp_idx; |
| 191 | temp = min; min = max; max = temp; |
| 192 | temp_idx = min_idx; min_idx = max_idx; max_idx = temp_idx; |
| 193 | } |
| 194 | } |
| 195 | } |
| 196 | break; |
| 197 | default: |
| 198 | { |
| 199 | val = n; |
| 200 | val_idx = j; |
| 201 | } |
| 202 | break; |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | return ( min && max && val && (min->get_int() <= 0) && (max->get_int() >=0) ); |
| 207 | } |
| 208 | |
| 209 | |
| 210 | //------------------------------check_if_clipping------------------------------ |
| 211 | // Helper function for RegionNode's identification of FP clipping |
| 212 | // Check that inputs to Region come from two IfNodes, |
| 213 | // |
| 214 | // If |
| 215 | // False True |
| 216 | // If | |
| 217 | // False True | |
| 218 | // | | | |
| 219 | // RegionNode_inputs |
| 220 | // |
| 221 | static bool check_if_clipping( const RegionNode *region, IfNode * &bot_if, IfNode * &top_if ) { |
| 222 | top_if = NULL; |
| 223 | bot_if = NULL; |
| 224 | |
| 225 | // Check control structure above RegionNode for (if ( if ) ) |
| 226 | Node *in1 = region->in(1); |
| 227 | Node *in2 = region->in(2); |
| 228 | Node *in3 = region->in(3); |
| 229 | // Check that all inputs are projections |
| 230 | if( in1->is_Proj() && in2->is_Proj() && in3->is_Proj() ) { |
| 231 | Node *in10 = in1->in(0); |
| 232 | Node *in20 = in2->in(0); |
| 233 | Node *in30 = in3->in(0); |
| 234 | // Check that #1 and #2 are ifTrue and ifFalse from same If |
| 235 | if( in10 != NULL && in10->is_If() && |
| 236 | in20 != NULL && in20->is_If() && |
| 237 | in30 != NULL && in30->is_If() && in10 == in20 && |
| 238 | (in1->Opcode() != in2->Opcode()) ) { |
| 239 | Node *in100 = in10->in(0); |
| 240 | Node *in1000 = (in100 != NULL && in100->is_Proj()) ? in100->in(0) : NULL; |
| 241 | // Check that control for in10 comes from other branch of IF from in3 |
| 242 | if( in1000 != NULL && in1000->is_If() && |
| 243 | in30 == in1000 && (in3->Opcode() != in100->Opcode()) ) { |
| 244 | // Control pattern checks |
| 245 | top_if = (IfNode*)in1000; |
| 246 | bot_if = (IfNode*)in10; |
| 247 | } |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | return (top_if != NULL); |
| 252 | } |
| 253 | |
| 254 | |
| 255 | //------------------------------check_convf2i_clipping------------------------- |
| 256 | // Helper function for RegionNode's identification of FP clipping |
| 257 | // Verify that the value input to the phi comes from "ConvF2I; LShift; RShift" |
| 258 | static bool check_convf2i_clipping( PhiNode *phi, uint idx, ConvF2INode * &convf2i, Node *min, Node *max) { |
| 259 | convf2i = NULL; |
| 260 | |
| 261 | // Check for the RShiftNode |
| 262 | Node *rshift = phi->in(idx); |
| 263 | assert( rshift, "Previous checks ensure phi input is present"); |
| 264 | if( rshift->Opcode() != Op_RShiftI ) { return false; } |
| 265 | |
| 266 | // Check for the LShiftNode |
| 267 | Node *lshift = rshift->in(1); |
| 268 | assert( lshift, "Previous checks ensure phi input is present"); |
| 269 | if( lshift->Opcode() != Op_LShiftI ) { return false; } |
| 270 | |
| 271 | // Check for the ConvF2INode |
| 272 | Node *conv = lshift->in(1); |
| 273 | if( conv->Opcode() != Op_ConvF2I ) { return false; } |
| 274 | |
| 275 | // Check that shift amounts are only to get sign bits set after F2I |
| 276 | jint max_cutoff = max->get_int(); |
| 277 | jint min_cutoff = min->get_int(); |
| 278 | jint left_shift = lshift->in(2)->get_int(); |
| 279 | jint right_shift = rshift->in(2)->get_int(); |
| 280 | jint max_post_shift = nth_bit(BitsPerJavaInteger - left_shift - 1); |
| 281 | if( left_shift != right_shift || |
| 282 | 0 > left_shift || left_shift >= BitsPerJavaInteger || |
| 283 | max_post_shift < max_cutoff || |
| 284 | max_post_shift < -min_cutoff ) { |
| 285 | // Shifts are necessary but current transformation eliminates them |
| 286 | return false; |
| 287 | } |
| 288 | |
| 289 | // OK to return the result of ConvF2I without shifting |
| 290 | convf2i = (ConvF2INode*)conv; |
| 291 | return true; |
| 292 | } |
| 293 | |
| 294 | |
| 295 | //------------------------------check_compare_clipping------------------------- |
| 296 | // Helper function for RegionNode's identification of FP clipping |
| 297 | static bool check_compare_clipping( bool less_than, IfNode *iff, ConNode *limit, Node * & input ) { |
| 298 | Node *i1 = iff->in(1); |
| 299 | if ( !i1->is_Bool() ) { return false; } |
| 300 | BoolNode *bool1 = i1->as_Bool(); |
| 301 | if( less_than && bool1->_test._test != BoolTest::le ) { return false; } |
| 302 | else if( !less_than && bool1->_test._test != BoolTest::lt ) { return false; } |
| 303 | const Node *cmpF = bool1->in(1); |
| 304 | if( cmpF->Opcode() != Op_CmpF ) { return false; } |
| 305 | // Test that the float value being compared against |
| 306 | // is equivalent to the int value used as a limit |
| 307 | Node *nodef = cmpF->in(2); |
| 308 | if( nodef->Opcode() != Op_ConF ) { return false; } |
| 309 | jfloat conf = nodef->getf(); |
| 310 | jint coni = limit->get_int(); |
| 311 | if( ((int)conf) != coni ) { return false; } |
| 312 | input = cmpF->in(1); |
| 313 | return true; |
| 314 | } |
| 315 | |
| 316 | //------------------------------is_unreachable_region-------------------------- |
| 317 | // Find if the Region node is reachable from the root. |
| 318 | bool RegionNode::is_unreachable_region(PhaseGVN *phase) const { |
| 319 | assert(req() == 2, ""); |
| 320 | |
| 321 | // First, cut the simple case of fallthrough region when NONE of |
| 322 | // region's phis references itself directly or through a data node. |
| 323 | uint max = outcnt(); |
| 324 | uint i; |
| 325 | for (i = 0; i < max; i++) { |
| 326 | Node* phi = raw_out(i); |
| 327 | if (phi != NULL && phi->is_Phi()) { |
| 328 | assert(phase->eqv(phi->in(0), this) && phi->req() == 2, ""); |
| 329 | if (phi->outcnt() == 0) |
| 330 | continue; // Safe case - no loops |
| 331 | if (phi->outcnt() == 1) { |
| 332 | Node* u = phi->raw_out(0); |
| 333 | // Skip if only one use is an other Phi or Call or Uncommon trap. |
| 334 | // It is safe to consider this case as fallthrough. |
| 335 | if (u != NULL && (u->is_Phi() || u->is_CFG())) |
| 336 | continue; |
| 337 | } |
| 338 | // Check when phi references itself directly or through an other node. |
| 339 | if (phi->as_Phi()->simple_data_loop_check(phi->in(1)) >= PhiNode::Unsafe) |
| 340 | break; // Found possible unsafe data loop. |
| 341 | } |
| 342 | } |
| 343 | if (i >= max) |
| 344 | return false; // An unsafe case was NOT found - don't need graph walk. |
| 345 | |
| 346 | // Unsafe case - check if the Region node is reachable from root. |
| 347 | ResourceMark rm; |
| 348 | |
| 349 | Arena *a = Thread::current()->resource_area(); |
| 350 | Node_List nstack(a); |
| 351 | VectorSet visited(a); |
| 352 | |
| 353 | // Mark all control nodes reachable from root outputs |
| 354 | Node *n = (Node*)phase->C->root(); |
| 355 | nstack.push(n); |
| 356 | visited.set(n->_idx); |
| 357 | while (nstack.size() != 0) { |
| 358 | n = nstack.pop(); |
| 359 | uint max = n->outcnt(); |
| 360 | for (uint i = 0; i < max; i++) { |
| 361 | Node* m = n->raw_out(i); |
| 362 | if (m != NULL && m->is_CFG()) { |
| 363 | if (phase->eqv(m, this)) { |
| 364 | return false; // We reached the Region node - it is not dead. |
| 365 | } |
| 366 | if (!visited.test_set(m->_idx)) |
| 367 | nstack.push(m); |
| 368 | } |
| 369 | } |
| 370 | } |
| 371 | |
| 372 | return true; // The Region node is unreachable - it is dead. |
| 373 | } |
| 374 | |
| 375 | bool RegionNode::try_clean_mem_phi(PhaseGVN *phase) { |
| 376 | // Incremental inlining + PhaseStringOpts sometimes produce: |
| 377 | // |
| 378 | // cmpP with 1 top input |
| 379 | // | |
| 380 | // If |
| 381 | // / \ |
| 382 | // IfFalse IfTrue /- Some Node |
| 383 | // \ / / / |
| 384 | // Region / /-MergeMem |
| 385 | // \---Phi |
| 386 | // |
| 387 | // |
| 388 | // It's expected by PhaseStringOpts that the Region goes away and is |
| 389 | // replaced by If's control input but because there's still a Phi, |
| 390 | // the Region stays in the graph. The top input from the cmpP is |
| 391 | // propagated forward and a subgraph that is useful goes away. The |
| 392 | // code below replaces the Phi with the MergeMem so that the Region |
| 393 | // is simplified. |
| 394 | |
| 395 | PhiNode* phi = has_unique_phi(); |
| 396 | if (phi && phi->type() == Type::MEMORY && req() == 3 && phi->is_diamond_phi(true)) { |
| 397 | MergeMemNode* m = NULL; |
| 398 | assert(phi->req() == 3, "same as region"); |
| 399 | for (uint i = 1; i < 3; ++i) { |
| 400 | Node *mem = phi->in(i); |
| 401 | if (mem && mem->is_MergeMem() && in(i)->outcnt() == 1) { |
| 402 | // Nothing is control-dependent on path #i except the region itself. |
| 403 | m = mem->as_MergeMem(); |
| 404 | uint j = 3 - i; |
| 405 | Node* other = phi->in(j); |
| 406 | if (other && other == m->base_memory()) { |
| 407 | // m is a successor memory to other, and is not pinned inside the diamond, so push it out. |
| 408 | // This will allow the diamond to collapse completely. |
| 409 | phase->is_IterGVN()->replace_node(phi, m); |
| 410 | return true; |
| 411 | } |
| 412 | } |
| 413 | } |
| 414 | } |
| 415 | return false; |
| 416 | } |
| 417 | |
| 418 | //------------------------------Ideal------------------------------------------ |
| 419 | // Return a node which is more "ideal" than the current node. Must preserve |
| 420 | // the CFG, but we can still strip out dead paths. |
| 421 | Node *RegionNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
| 422 | if( !can_reshape && !in(0) ) return NULL; // Already degraded to a Copy |
| 423 | assert(!in(0) || !in(0)->is_Root(), "not a specially hidden merge"); |
| 424 | |
| 425 | // Check for RegionNode with no Phi users and both inputs come from either |
| 426 | // arm of the same IF. If found, then the control-flow split is useless. |
| 427 | bool has_phis = false; |
| 428 | if (can_reshape) { // Need DU info to check for Phi users |
| 429 | has_phis = (has_phi() != NULL); // Cache result |
| 430 | if (has_phis && try_clean_mem_phi(phase)) { |
| 431 | has_phis = false; |
| 432 | } |
| 433 | |
| 434 | if (!has_phis) { // No Phi users? Nothing merging? |
| 435 | for (uint i = 1; i < req()-1; i++) { |
| 436 | Node *if1 = in(i); |
| 437 | if( !if1 ) continue; |
| 438 | Node *iff = if1->in(0); |
| 439 | if( !iff || !iff->is_If() ) continue; |
| 440 | for( uint j=i+1; j<req(); j++ ) { |
| 441 | if( in(j) && in(j)->in(0) == iff && |
| 442 | if1->Opcode() != in(j)->Opcode() ) { |
| 443 | // Add the IF Projections to the worklist. They (and the IF itself) |
| 444 | // will be eliminated if dead. |
| 445 | phase->is_IterGVN()->add_users_to_worklist(iff); |
| 446 | set_req(i, iff->in(0));// Skip around the useless IF diamond |
| 447 | set_req(j, NULL); |
| 448 | return this; // Record progress |
| 449 | } |
| 450 | } |
| 451 | } |
| 452 | } |
| 453 | } |
| 454 | |
| 455 | // Remove TOP or NULL input paths. If only 1 input path remains, this Region |
| 456 | // degrades to a copy. |
| 457 | bool add_to_worklist = false; |
| 458 | bool modified = false; |
| 459 | int cnt = 0; // Count of values merging |
| 460 | DEBUG_ONLY( int cnt_orig = req(); ) // Save original inputs count |
| 461 | int del_it = 0; // The last input path we delete |
| 462 | // For all inputs... |
| 463 | for( uint i=1; i<req(); ++i ){// For all paths in |
| 464 | Node *n = in(i); // Get the input |
| 465 | if( n != NULL ) { |
| 466 | // Remove useless control copy inputs |
| 467 | if( n->is_Region() && n->as_Region()->is_copy() ) { |
| 468 | set_req(i, n->nonnull_req()); |
| 469 | modified = true; |
| 470 | i--; |
| 471 | continue; |
| 472 | } |
| 473 | if( n->is_Proj() ) { // Remove useless rethrows |
| 474 | Node *call = n->in(0); |
| 475 | if (call->is_Call() && call->as_Call()->entry_point() == OptoRuntime::rethrow_stub()) { |
| 476 | set_req(i, call->in(0)); |
| 477 | modified = true; |
| 478 | i--; |
| 479 | continue; |
| 480 | } |
| 481 | } |
| 482 | if( phase->type(n) == Type::TOP ) { |
| 483 | set_req(i, NULL); // Ignore TOP inputs |
| 484 | modified = true; |
| 485 | i--; |
| 486 | continue; |
| 487 | } |
| 488 | cnt++; // One more value merging |
| 489 | |
| 490 | } else if (can_reshape) { // Else found dead path with DU info |
| 491 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 492 | del_req(i); // Yank path from self |
| 493 | del_it = i; |
| 494 | uint max = outcnt(); |
| 495 | DUIterator j; |
| 496 | bool progress = true; |
| 497 | while(progress) { // Need to establish property over all users |
| 498 | progress = false; |
| 499 | for (j = outs(); has_out(j); j++) { |
| 500 | Node *n = out(j); |
| 501 | if( n->req() != req() && n->is_Phi() ) { |
| 502 | assert( n->in(0) == this, ""); |
| 503 | igvn->hash_delete(n); // Yank from hash before hacking edges |
| 504 | n->set_req_X(i,NULL,igvn);// Correct DU info |
| 505 | n->del_req(i); // Yank path from Phis |
| 506 | if( max != outcnt() ) { |
| 507 | progress = true; |
| 508 | j = refresh_out_pos(j); |
| 509 | max = outcnt(); |
| 510 | } |
| 511 | } |
| 512 | } |
| 513 | } |
| 514 | add_to_worklist = true; |
| 515 | i--; |
| 516 | } |
| 517 | } |
| 518 | |
| 519 | if (can_reshape && cnt == 1) { |
| 520 | // Is it dead loop? |
| 521 | // If it is LoopNopde it had 2 (+1 itself) inputs and |
| 522 | // one of them was cut. The loop is dead if it was EntryContol. |
| 523 | // Loop node may have only one input because entry path |
| 524 | // is removed in PhaseIdealLoop::Dominators(). |
| 525 | assert(!this->is_Loop() || cnt_orig <= 3, "Loop node should have 3 or less inputs"); |
| 526 | if ((this->is_Loop() && (del_it == LoopNode::EntryControl || |
| 527 | (del_it == 0 && is_unreachable_region(phase)))) || |
| 528 | (!this->is_Loop() && has_phis && is_unreachable_region(phase))) { |
| 529 | // Yes, the region will be removed during the next step below. |
| 530 | // Cut the backedge input and remove phis since no data paths left. |
| 531 | // We don't cut outputs to other nodes here since we need to put them |
| 532 | // on the worklist. |
| 533 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 534 | if (in(1)->outcnt() == 1) { |
| 535 | igvn->_worklist.push(in(1)); |
| 536 | } |
| 537 | del_req(1); |
| 538 | cnt = 0; |
| 539 | assert( req() == 1, "no more inputs expected"); |
| 540 | uint max = outcnt(); |
| 541 | bool progress = true; |
| 542 | Node *top = phase->C->top(); |
| 543 | DUIterator j; |
| 544 | while(progress) { |
| 545 | progress = false; |
| 546 | for (j = outs(); has_out(j); j++) { |
| 547 | Node *n = out(j); |
| 548 | if( n->is_Phi() ) { |
| 549 | assert( igvn->eqv(n->in(0), this), ""); |
| 550 | assert( n->req() == 2 && n->in(1) != NULL, "Only one data input expected"); |
| 551 | // Break dead loop data path. |
| 552 | // Eagerly replace phis with top to avoid phis copies generation. |
| 553 | igvn->replace_node(n, top); |
| 554 | if( max != outcnt() ) { |
| 555 | progress = true; |
| 556 | j = refresh_out_pos(j); |
| 557 | max = outcnt(); |
| 558 | } |
| 559 | } |
| 560 | } |
| 561 | } |
| 562 | add_to_worklist = true; |
| 563 | } |
| 564 | } |
| 565 | if (add_to_worklist) { |
| 566 | phase->is_IterGVN()->add_users_to_worklist(this); // Revisit collapsed Phis |
| 567 | } |
| 568 | |
| 569 | if( cnt <= 1 ) { // Only 1 path in? |
| 570 | set_req(0, NULL); // Null control input for region copy |
| 571 | if( cnt == 0 && !can_reshape) { // Parse phase - leave the node as it is. |
| 572 | // No inputs or all inputs are NULL. |
| 573 | return NULL; |
| 574 | } else if (can_reshape) { // Optimization phase - remove the node |
| 575 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 576 | // Strip mined (inner) loop is going away, remove outer loop. |
| 577 | if (is_CountedLoop() && |
| 578 | as_Loop()->is_strip_mined()) { |
| 579 | Node* outer_sfpt = as_CountedLoop()->outer_safepoint(); |
| 580 | Node* outer_out = as_CountedLoop()->outer_loop_exit(); |
| 581 | if (outer_sfpt != NULL && outer_out != NULL) { |
| 582 | Node* in = outer_sfpt->in(0); |
| 583 | igvn->replace_node(outer_out, in); |
| 584 | LoopNode* outer = as_CountedLoop()->outer_loop(); |
| 585 | igvn->replace_input_of(outer, LoopNode::LoopBackControl, igvn->C->top()); |
| 586 | } |
| 587 | } |
| 588 | Node *parent_ctrl; |
| 589 | if( cnt == 0 ) { |
| 590 | assert( req() == 1, "no inputs expected"); |
| 591 | // During IGVN phase such region will be subsumed by TOP node |
| 592 | // so region's phis will have TOP as control node. |
| 593 | // Kill phis here to avoid it. PhiNode::is_copy() will be always false. |
| 594 | // Also set other user's input to top. |
| 595 | parent_ctrl = phase->C->top(); |
| 596 | } else { |
| 597 | // The fallthrough case since we already checked dead loops above. |
| 598 | parent_ctrl = in(1); |
| 599 | assert(parent_ctrl != NULL, "Region is a copy of some non-null control"); |
| 600 | assert(!igvn->eqv(parent_ctrl, this), "Close dead loop"); |
| 601 | } |
| 602 | if (!add_to_worklist) |
| 603 | igvn->add_users_to_worklist(this); // Check for further allowed opts |
| 604 | for (DUIterator_Last imin, i = last_outs(imin); i >= imin; --i) { |
| 605 | Node* n = last_out(i); |
| 606 | igvn->hash_delete(n); // Remove from worklist before modifying edges |
| 607 | if( n->is_Phi() ) { // Collapse all Phis |
| 608 | // Eagerly replace phis to avoid copies generation. |
| 609 | Node* in; |
| 610 | if( cnt == 0 ) { |
| 611 | assert( n->req() == 1, "No data inputs expected"); |
| 612 | in = parent_ctrl; // replaced by top |
| 613 | } else { |
| 614 | assert( n->req() == 2 && n->in(1) != NULL, "Only one data input expected"); |
| 615 | in = n->in(1); // replaced by unique input |
| 616 | if( n->as_Phi()->is_unsafe_data_reference(in) ) |
| 617 | in = phase->C->top(); // replaced by top |
| 618 | } |
| 619 | igvn->replace_node(n, in); |
| 620 | } |
| 621 | else if( n->is_Region() ) { // Update all incoming edges |
| 622 | assert( !igvn->eqv(n, this), "Must be removed from DefUse edges"); |
| 623 | uint uses_found = 0; |
| 624 | for( uint k=1; k < n->req(); k++ ) { |
| 625 | if( n->in(k) == this ) { |
| 626 | n->set_req(k, parent_ctrl); |
| 627 | uses_found++; |
| 628 | } |
| 629 | } |
| 630 | if( uses_found > 1 ) { // (--i) done at the end of the loop. |
| 631 | i -= (uses_found - 1); |
| 632 | } |
| 633 | } |
| 634 | else { |
| 635 | assert( igvn->eqv(n->in(0), this), "Expect RegionNode to be control parent"); |
| 636 | n->set_req(0, parent_ctrl); |
| 637 | } |
| 638 | #ifdef ASSERT |
| 639 | for( uint k=0; k < n->req(); k++ ) { |
| 640 | assert( !igvn->eqv(n->in(k), this), "All uses of RegionNode should be gone"); |
| 641 | } |
| 642 | #endif |
| 643 | } |
| 644 | // Remove the RegionNode itself from DefUse info |
| 645 | igvn->remove_dead_node(this); |
| 646 | return NULL; |
| 647 | } |
| 648 | return this; // Record progress |
| 649 | } |
| 650 | |
| 651 | |
| 652 | // If a Region flows into a Region, merge into one big happy merge. |
| 653 | if (can_reshape) { |
| 654 | Node *m = merge_region(this, phase); |
| 655 | if (m != NULL) return m; |
| 656 | } |
| 657 | |
| 658 | // Check if this region is the root of a clipping idiom on floats |
| 659 | if( ConvertFloat2IntClipping && can_reshape && req() == 4 ) { |
| 660 | // Check that only one use is a Phi and that it simplifies to two constants + |
| 661 | PhiNode* phi = has_unique_phi(); |
| 662 | if (phi != NULL) { // One Phi user |
| 663 | // Check inputs to the Phi |
| 664 | ConNode *min; |
| 665 | ConNode *max; |
| 666 | Node *val; |
| 667 | uint min_idx; |
| 668 | uint max_idx; |
| 669 | uint val_idx; |
| 670 | if( check_phi_clipping( phi, min, min_idx, max, max_idx, val, val_idx ) ) { |
| 671 | IfNode *top_if; |
| 672 | IfNode *bot_if; |
| 673 | if( check_if_clipping( this, bot_if, top_if ) ) { |
| 674 | // Control pattern checks, now verify compares |
| 675 | Node *top_in = NULL; // value being compared against |
| 676 | Node *bot_in = NULL; |
| 677 | if( check_compare_clipping( true, bot_if, min, bot_in ) && |
| 678 | check_compare_clipping( false, top_if, max, top_in ) ) { |
| 679 | if( bot_in == top_in ) { |
| 680 | PhaseIterGVN *gvn = phase->is_IterGVN(); |
| 681 | assert( gvn != NULL, "Only had DefUse info in IterGVN"); |
| 682 | // Only remaining check is that bot_in == top_in == (Phi's val + mods) |
| 683 | |
| 684 | // Check for the ConvF2INode |
| 685 | ConvF2INode *convf2i; |
| 686 | if( check_convf2i_clipping( phi, val_idx, convf2i, min, max ) && |
| 687 | convf2i->in(1) == bot_in ) { |
| 688 | // Matched pattern, including LShiftI; RShiftI, replace with integer compares |
| 689 | // max test |
| 690 | Node *cmp = gvn->register_new_node_with_optimizer(new CmpINode( convf2i, min )); |
| 691 | Node *boo = gvn->register_new_node_with_optimizer(new BoolNode( cmp, BoolTest::lt )); |
| 692 | IfNode *iff = (IfNode*)gvn->register_new_node_with_optimizer(new IfNode( top_if->in(0), boo, PROB_UNLIKELY_MAG(5), top_if->_fcnt )); |
| 693 | Node *if_min= gvn->register_new_node_with_optimizer(new IfTrueNode (iff)); |
| 694 | Node *ifF = gvn->register_new_node_with_optimizer(new IfFalseNode(iff)); |
| 695 | // min test |
| 696 | cmp = gvn->register_new_node_with_optimizer(new CmpINode( convf2i, max )); |
| 697 | boo = gvn->register_new_node_with_optimizer(new BoolNode( cmp, BoolTest::gt )); |
| 698 | iff = (IfNode*)gvn->register_new_node_with_optimizer(new IfNode( ifF, boo, PROB_UNLIKELY_MAG(5), bot_if->_fcnt )); |
| 699 | Node *if_max= gvn->register_new_node_with_optimizer(new IfTrueNode (iff)); |
| 700 | ifF = gvn->register_new_node_with_optimizer(new IfFalseNode(iff)); |
| 701 | // update input edges to region node |
| 702 | set_req_X( min_idx, if_min, gvn ); |
| 703 | set_req_X( max_idx, if_max, gvn ); |
| 704 | set_req_X( val_idx, ifF, gvn ); |
| 705 | // remove unnecessary 'LShiftI; RShiftI' idiom |
| 706 | gvn->hash_delete(phi); |
| 707 | phi->set_req_X( val_idx, convf2i, gvn ); |
| 708 | gvn->hash_find_insert(phi); |
| 709 | // Return transformed region node |
| 710 | return this; |
| 711 | } |
| 712 | } |
| 713 | } |
| 714 | } |
| 715 | } |
| 716 | } |
| 717 | } |
| 718 | |
| 719 | if (can_reshape) { |
| 720 | modified |= optimize_trichotomy(phase->is_IterGVN()); |
| 721 | } |
| 722 | |
| 723 | return modified ? this : NULL; |
| 724 | } |
| 725 | |
| 726 | //------------------------------optimize_trichotomy-------------------------- |
| 727 | // Optimize nested comparisons of the following kind: |
| 728 | // |
| 729 | // int compare(int a, int b) { |
| 730 | // return (a < b) ? -1 : (a == b) ? 0 : 1; |
| 731 | // } |
| 732 | // |
| 733 | // Shape 1: |
| 734 | // if (compare(a, b) == 1) { ... } -> if (a > b) { ... } |
| 735 | // |
| 736 | // Shape 2: |
| 737 | // if (compare(a, b) == 0) { ... } -> if (a == b) { ... } |
| 738 | // |
| 739 | // Above code leads to the following IR shapes where both Ifs compare the |
| 740 | // same value and two out of three region inputs idx1 and idx2 map to |
| 741 | // the same value and control flow. |
| 742 | // |
| 743 | // (1) If (2) If |
| 744 | // / \ / \ |
| 745 | // Proj Proj Proj Proj |
| 746 | // | \ | \ |
| 747 | // | If | If If |
| 748 | // | / \ | / \ / \ |
| 749 | // | Proj Proj | Proj Proj ==> Proj Proj |
| 750 | // | / / \ | / | / |
| 751 | // Region / \ | / | / |
| 752 | // \ / \ | / | / |
| 753 | // Region Region Region |
| 754 | // |
| 755 | // The method returns true if 'this' is modified and false otherwise. |
| 756 | bool RegionNode::optimize_trichotomy(PhaseIterGVN* igvn) { |
| 757 | int idx1 = 1, idx2 = 2; |
| 758 | Node* region = NULL; |
| 759 | if (req() == 3 && in(1) != NULL && in(2) != NULL) { |
| 760 | // Shape 1: Check if one of the inputs is a region that merges two control |
| 761 | // inputs and has no other users (especially no Phi users). |
| 762 | region = in(1)->isa_Region() ? in(1) : in(2)->isa_Region(); |
| 763 | if (region == NULL || region->outcnt() != 2 || region->req() != 3) { |
| 764 | return false; // No suitable region input found |
| 765 | } |
| 766 | } else if (req() == 4) { |
| 767 | // Shape 2: Check if two control inputs map to the same value of the unique phi |
| 768 | // user and treat these as if they would come from another region (shape (1)). |
| 769 | PhiNode* phi = has_unique_phi(); |
| 770 | if (phi == NULL) { |
| 771 | return false; // No unique phi user |
| 772 | } |
| 773 | if (phi->in(idx1) != phi->in(idx2)) { |
| 774 | idx2 = 3; |
| 775 | if (phi->in(idx1) != phi->in(idx2)) { |
| 776 | idx1 = 2; |
| 777 | if (phi->in(idx1) != phi->in(idx2)) { |
| 778 | return false; // No equal phi inputs found |
| 779 | } |
| 780 | } |
| 781 | } |
| 782 | assert(phi->in(idx1) == phi->in(idx2), "must be"); // Region is merging same value |
| 783 | region = this; |
| 784 | } |
| 785 | if (region == NULL || region->in(idx1) == NULL || region->in(idx2) == NULL) { |
| 786 | return false; // Region does not merge two control inputs |
| 787 | } |
| 788 | // At this point we know that region->in(idx1) and region->(idx2) map to the same |
| 789 | // value and control flow. Now search for ifs that feed into these region inputs. |
| 790 | ProjNode* proj1 = region->in(idx1)->isa_Proj(); |
| 791 | ProjNode* proj2 = region->in(idx2)->isa_Proj(); |
| 792 | if (proj1 == NULL || proj1->outcnt() != 1 || |
| 793 | proj2 == NULL || proj2->outcnt() != 1) { |
| 794 | return false; // No projection inputs with region as unique user found |
| 795 | } |
| 796 | assert(proj1 != proj2, "should be different projections"); |
| 797 | IfNode* iff1 = proj1->in(0)->isa_If(); |
| 798 | IfNode* iff2 = proj2->in(0)->isa_If(); |
| 799 | if (iff1 == NULL || iff1->outcnt() != 2 || |
| 800 | iff2 == NULL || iff2->outcnt() != 2) { |
| 801 | return false; // No ifs found |
| 802 | } |
| 803 | if (iff1 == iff2) { |
| 804 | igvn->add_users_to_worklist(iff1); // Make sure dead if is eliminated |
| 805 | igvn->replace_input_of(region, idx1, iff1->in(0)); |
| 806 | igvn->replace_input_of(region, idx2, igvn->C->top()); |
| 807 | return (region == this); // Remove useless if (both projections map to the same control/value) |
| 808 | } |
| 809 | BoolNode* bol1 = iff1->in(1)->isa_Bool(); |
| 810 | BoolNode* bol2 = iff2->in(1)->isa_Bool(); |
| 811 | if (bol1 == NULL || bol2 == NULL) { |
| 812 | return false; // No bool inputs found |
| 813 | } |
| 814 | Node* cmp1 = bol1->in(1); |
| 815 | Node* cmp2 = bol2->in(1); |
| 816 | bool commute = false; |
| 817 | if (!cmp1->is_Cmp() || !cmp2->is_Cmp()) { |
| 818 | return false; // No comparison |
| 819 | } else if (cmp1->Opcode() == Op_CmpF || cmp1->Opcode() == Op_CmpD || |
| 820 | cmp2->Opcode() == Op_CmpF || cmp2->Opcode() == Op_CmpD || |
| 821 | cmp1->Opcode() == Op_CmpP || cmp1->Opcode() == Op_CmpN || |
| 822 | cmp2->Opcode() == Op_CmpP || cmp2->Opcode() == Op_CmpN) { |
| 823 | // Floats and pointers don't exactly obey trichotomy. To be on the safe side, don't transform their tests. |
| 824 | return false; |
| 825 | } else if (cmp1 != cmp2) { |
| 826 | if (cmp1->in(1) == cmp2->in(2) && |
| 827 | cmp1->in(2) == cmp2->in(1)) { |
| 828 | commute = true; // Same but swapped inputs, commute the test |
| 829 | } else { |
| 830 | return false; // Ifs are not comparing the same values |
| 831 | } |
| 832 | } |
| 833 | proj1 = proj1->other_if_proj(); |
| 834 | proj2 = proj2->other_if_proj(); |
| 835 | if (!((proj1->unique_ctrl_out() == iff2 && |
| 836 | proj2->unique_ctrl_out() == this) || |
| 837 | (proj2->unique_ctrl_out() == iff1 && |
| 838 | proj1->unique_ctrl_out() == this))) { |
| 839 | return false; // Ifs are not connected through other projs |
| 840 | } |
| 841 | // Found 'iff -> proj -> iff -> proj -> this' shape where all other projs are merged |
| 842 | // through 'region' and map to the same value. Merge the boolean tests and replace |
| 843 | // the ifs by a single comparison. |
| 844 | BoolTest test1 = (proj1->_con == 1) ? bol1->_test : bol1->_test.negate(); |
| 845 | BoolTest test2 = (proj2->_con == 1) ? bol2->_test : bol2->_test.negate(); |
| 846 | test1 = commute ? test1.commute() : test1; |
| 847 | // After possibly commuting test1, if we can merge test1 & test2, then proj2/iff2/bol2 are the nodes to refine. |
| 848 | BoolTest::mask res = test1.merge(test2); |
| 849 | if (res == BoolTest::illegal) { |
| 850 | return false; // Unable to merge tests |
| 851 | } |
| 852 | // Adjust iff1 to always pass (only iff2 will remain) |
| 853 | igvn->replace_input_of(iff1, 1, igvn->intcon(proj1->_con)); |
| 854 | if (res == BoolTest::never) { |
| 855 | // Merged test is always false, adjust iff2 to always fail |
| 856 | igvn->replace_input_of(iff2, 1, igvn->intcon(1 - proj2->_con)); |
| 857 | } else { |
| 858 | // Replace bool input of iff2 with merged test |
| 859 | BoolNode* new_bol = new BoolNode(bol2->in(1), res); |
| 860 | igvn->replace_input_of(iff2, 1, igvn->transform((proj2->_con == 1) ? new_bol : new_bol->negate(igvn))); |
| 861 | } |
| 862 | return false; |
| 863 | } |
| 864 | |
| 865 | const RegMask &RegionNode::out_RegMask() const { |
| 866 | return RegMask::Empty; |
| 867 | } |
| 868 | |
| 869 | // Find the one non-null required input. RegionNode only |
| 870 | Node *Node::nonnull_req() const { |
| 871 | assert( is_Region(), ""); |
| 872 | for( uint i = 1; i < _cnt; i++ ) |
| 873 | if( in(i) ) |
| 874 | return in(i); |
| 875 | ShouldNotReachHere(); |
| 876 | return NULL; |
| 877 | } |
| 878 | |
| 879 | |
| 880 | //============================================================================= |
| 881 | // note that these functions assume that the _adr_type field is flattened |
| 882 | uint PhiNode::hash() const { |
| 883 | const Type* at = _adr_type; |
| 884 | return TypeNode::hash() + (at ? at->hash() : 0); |
| 885 | } |
| 886 | bool PhiNode::cmp( const Node &n ) const { |
| 887 | return TypeNode::cmp(n) && _adr_type == ((PhiNode&)n)._adr_type; |
| 888 | } |
| 889 | static inline |
| 890 | const TypePtr* flatten_phi_adr_type(const TypePtr* at) { |
| 891 | if (at == NULL || at == TypePtr::BOTTOM) return at; |
| 892 | return Compile::current()->alias_type(at)->adr_type(); |
| 893 | } |
| 894 | |
| 895 | //----------------------------make--------------------------------------------- |
| 896 | // create a new phi with edges matching r and set (initially) to x |
| 897 | PhiNode* PhiNode::make(Node* r, Node* x, const Type *t, const TypePtr* at) { |
| 898 | uint preds = r->req(); // Number of predecessor paths |
| 899 | assert(t != Type::MEMORY || at == flatten_phi_adr_type(at), "flatten at"); |
| 900 | PhiNode* p = new PhiNode(r, t, at); |
| 901 | for (uint j = 1; j < preds; j++) { |
| 902 | // Fill in all inputs, except those which the region does not yet have |
| 903 | if (r->in(j) != NULL) |
| 904 | p->init_req(j, x); |
| 905 | } |
| 906 | return p; |
| 907 | } |
| 908 | PhiNode* PhiNode::make(Node* r, Node* x) { |
| 909 | const Type* t = x->bottom_type(); |
| 910 | const TypePtr* at = NULL; |
| 911 | if (t == Type::MEMORY) at = flatten_phi_adr_type(x->adr_type()); |
| 912 | return make(r, x, t, at); |
| 913 | } |
| 914 | PhiNode* PhiNode::make_blank(Node* r, Node* x) { |
| 915 | const Type* t = x->bottom_type(); |
| 916 | const TypePtr* at = NULL; |
| 917 | if (t == Type::MEMORY) at = flatten_phi_adr_type(x->adr_type()); |
| 918 | return new PhiNode(r, t, at); |
| 919 | } |
| 920 | |
| 921 | |
| 922 | //------------------------slice_memory----------------------------------------- |
| 923 | // create a new phi with narrowed memory type |
| 924 | PhiNode* PhiNode::slice_memory(const TypePtr* adr_type) const { |
| 925 | PhiNode* mem = (PhiNode*) clone(); |
| 926 | *(const TypePtr**)&mem->_adr_type = adr_type; |
| 927 | // convert self-loops, or else we get a bad graph |
| 928 | for (uint i = 1; i < req(); i++) { |
| 929 | if ((const Node*)in(i) == this) mem->set_req(i, mem); |
| 930 | } |
| 931 | mem->verify_adr_type(); |
| 932 | return mem; |
| 933 | } |
| 934 | |
| 935 | //------------------------split_out_instance----------------------------------- |
| 936 | // Split out an instance type from a bottom phi. |
| 937 | PhiNode* PhiNode::split_out_instance(const TypePtr* at, PhaseIterGVN *igvn) const { |
| 938 | const TypeOopPtr *t_oop = at->isa_oopptr(); |
| 939 | assert(t_oop != NULL && t_oop->is_known_instance(), "expecting instance oopptr"); |
| 940 | const TypePtr *t = adr_type(); |
| 941 | assert(type() == Type::MEMORY && |
| 942 | (t == TypePtr::BOTTOM || t == TypeRawPtr::BOTTOM || |
| 943 | t->isa_oopptr() && !t->is_oopptr()->is_known_instance() && |
| 944 | t->is_oopptr()->cast_to_exactness(true) |
| 945 | ->is_oopptr()->cast_to_ptr_type(t_oop->ptr()) |
| 946 | ->is_oopptr()->cast_to_instance_id(t_oop->instance_id()) == t_oop), |
| 947 | "bottom or raw memory required"); |
| 948 | |
| 949 | // Check if an appropriate node already exists. |
| 950 | Node *region = in(0); |
| 951 | for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) { |
| 952 | Node* use = region->fast_out(k); |
| 953 | if( use->is_Phi()) { |
| 954 | PhiNode *phi2 = use->as_Phi(); |
| 955 | if (phi2->type() == Type::MEMORY && phi2->adr_type() == at) { |
| 956 | return phi2; |
| 957 | } |
| 958 | } |
| 959 | } |
| 960 | Compile *C = igvn->C; |
| 961 | Arena *a = Thread::current()->resource_area(); |
| 962 | Node_Array node_map = new Node_Array(a); |
| 963 | Node_Stack stack(a, C->live_nodes() >> 4); |
| 964 | PhiNode *nphi = slice_memory(at); |
| 965 | igvn->register_new_node_with_optimizer( nphi ); |
| 966 | node_map.map(_idx, nphi); |
| 967 | stack.push((Node *)this, 1); |
| 968 | while(!stack.is_empty()) { |
| 969 | PhiNode *ophi = stack.node()->as_Phi(); |
| 970 | uint i = stack.index(); |
| 971 | assert(i >= 1, "not control edge"); |
| 972 | stack.pop(); |
| 973 | nphi = node_map[ophi->_idx]->as_Phi(); |
| 974 | for (; i < ophi->req(); i++) { |
| 975 | Node *in = ophi->in(i); |
| 976 | if (in == NULL || igvn->type(in) == Type::TOP) |
| 977 | continue; |
| 978 | Node *opt = MemNode::optimize_simple_memory_chain(in, t_oop, NULL, igvn); |
| 979 | PhiNode *optphi = opt->is_Phi() ? opt->as_Phi() : NULL; |
| 980 | if (optphi != NULL && optphi->adr_type() == TypePtr::BOTTOM) { |
| 981 | opt = node_map[optphi->_idx]; |
| 982 | if (opt == NULL) { |
| 983 | stack.push(ophi, i); |
| 984 | nphi = optphi->slice_memory(at); |
| 985 | igvn->register_new_node_with_optimizer( nphi ); |
| 986 | node_map.map(optphi->_idx, nphi); |
| 987 | ophi = optphi; |
| 988 | i = 0; // will get incremented at top of loop |
| 989 | continue; |
| 990 | } |
| 991 | } |
| 992 | nphi->set_req(i, opt); |
| 993 | } |
| 994 | } |
| 995 | return nphi; |
| 996 | } |
| 997 | |
| 998 | //------------------------verify_adr_type-------------------------------------- |
| 999 | #ifdef ASSERT |
| 1000 | void PhiNode::verify_adr_type(VectorSet& visited, const TypePtr* at) const { |
| 1001 | if (visited.test_set(_idx)) return; //already visited |
| 1002 | |
| 1003 | // recheck constructor invariants: |
| 1004 | verify_adr_type(false); |
| 1005 | |
| 1006 | // recheck local phi/phi consistency: |
| 1007 | assert(_adr_type == at || _adr_type == TypePtr::BOTTOM, |
| 1008 | "adr_type must be consistent across phi nest"); |
| 1009 | |
| 1010 | // walk around |
| 1011 | for (uint i = 1; i < req(); i++) { |
| 1012 | Node* n = in(i); |
| 1013 | if (n == NULL) continue; |
| 1014 | const Node* np = in(i); |
| 1015 | if (np->is_Phi()) { |
| 1016 | np->as_Phi()->verify_adr_type(visited, at); |
| 1017 | } else if (n->bottom_type() == Type::TOP |
| 1018 | || (n->is_Mem() && n->in(MemNode::Address)->bottom_type() == Type::TOP)) { |
| 1019 | // ignore top inputs |
| 1020 | } else { |
| 1021 | const TypePtr* nat = flatten_phi_adr_type(n->adr_type()); |
| 1022 | // recheck phi/non-phi consistency at leaves: |
| 1023 | assert((nat != NULL) == (at != NULL), ""); |
| 1024 | assert(nat == at || nat == TypePtr::BOTTOM, |
| 1025 | "adr_type must be consistent at leaves of phi nest"); |
| 1026 | } |
| 1027 | } |
| 1028 | } |
| 1029 | |
| 1030 | // Verify a whole nest of phis rooted at this one. |
| 1031 | void PhiNode::verify_adr_type(bool recursive) const { |
| 1032 | if (VMError::is_error_reported()) return; // muzzle asserts when debugging an error |
| 1033 | if (Node::in_dump()) return; // muzzle asserts when printing |
| 1034 | |
| 1035 | assert((_type == Type::MEMORY) == (_adr_type != NULL), "adr_type for memory phis only"); |
| 1036 | |
| 1037 | if (!VerifyAliases) return; // verify thoroughly only if requested |
| 1038 | |
| 1039 | assert(_adr_type == flatten_phi_adr_type(_adr_type), |
| 1040 | "Phi::adr_type must be pre-normalized"); |
| 1041 | |
| 1042 | if (recursive) { |
| 1043 | VectorSet visited(Thread::current()->resource_area()); |
| 1044 | verify_adr_type(visited, _adr_type); |
| 1045 | } |
| 1046 | } |
| 1047 | #endif |
| 1048 | |
| 1049 | |
| 1050 | //------------------------------Value------------------------------------------ |
| 1051 | // Compute the type of the PhiNode |
| 1052 | const Type* PhiNode::Value(PhaseGVN* phase) const { |
| 1053 | Node *r = in(0); // RegionNode |
| 1054 | if( !r ) // Copy or dead |
| 1055 | return in(1) ? phase->type(in(1)) : Type::TOP; |
| 1056 | |
| 1057 | // Note: During parsing, phis are often transformed before their regions. |
| 1058 | // This means we have to use type_or_null to defend against untyped regions. |
| 1059 | if( phase->type_or_null(r) == Type::TOP ) // Dead code? |
| 1060 | return Type::TOP; |
| 1061 | |
| 1062 | // Check for trip-counted loop. If so, be smarter. |
| 1063 | CountedLoopNode* l = r->is_CountedLoop() ? r->as_CountedLoop() : NULL; |
| 1064 | if (l && ((const Node*)l->phi() == this)) { // Trip counted loop! |
| 1065 | // protect against init_trip() or limit() returning NULL |
| 1066 | if (l->can_be_counted_loop(phase)) { |
| 1067 | const Node *init = l->init_trip(); |
| 1068 | const Node *limit = l->limit(); |
| 1069 | const Node* stride = l->stride(); |
| 1070 | if (init != NULL && limit != NULL && stride != NULL) { |
| 1071 | const TypeInt* lo = phase->type(init)->isa_int(); |
| 1072 | const TypeInt* hi = phase->type(limit)->isa_int(); |
| 1073 | const TypeInt* stride_t = phase->type(stride)->isa_int(); |
| 1074 | if (lo != NULL && hi != NULL && stride_t != NULL) { // Dying loops might have TOP here |
| 1075 | assert(stride_t->_hi >= stride_t->_lo, "bad stride type"); |
| 1076 | BoolTest::mask bt = l->loopexit()->test_trip(); |
| 1077 | // If the loop exit condition is "not equal", the condition |
| 1078 | // would not trigger if init > limit (if stride > 0) or if |
| 1079 | // init < limit if (stride > 0) so we can't deduce bounds |
| 1080 | // for the iv from the exit condition. |
| 1081 | if (bt != BoolTest::ne) { |
| 1082 | if (stride_t->_hi < 0) { // Down-counter loop |
| 1083 | swap(lo, hi); |
| 1084 | return TypeInt::make(MIN2(lo->_lo, hi->_lo) , hi->_hi, 3); |
| 1085 | } else if (stride_t->_lo >= 0) { |
| 1086 | return TypeInt::make(lo->_lo, MAX2(lo->_hi, hi->_hi), 3); |
| 1087 | } |
| 1088 | } |
| 1089 | } |
| 1090 | } |
| 1091 | } else if (l->in(LoopNode::LoopBackControl) != NULL && |
| 1092 | in(LoopNode::EntryControl) != NULL && |
| 1093 | phase->type(l->in(LoopNode::LoopBackControl)) == Type::TOP) { |
| 1094 | // During CCP, if we saturate the type of a counted loop's Phi |
| 1095 | // before the special code for counted loop above has a chance |
| 1096 | // to run (that is as long as the type of the backedge's control |
| 1097 | // is top), we might end up with non monotonic types |
| 1098 | return phase->type(in(LoopNode::EntryControl))->filter_speculative(_type); |
| 1099 | } |
| 1100 | } |
| 1101 | |
| 1102 | // Until we have harmony between classes and interfaces in the type |
| 1103 | // lattice, we must tread carefully around phis which implicitly |
| 1104 | // convert the one to the other. |
| 1105 | const TypePtr* ttp = _type->make_ptr(); |
| 1106 | const TypeInstPtr* ttip = (ttp != NULL) ? ttp->isa_instptr() : NULL; |
| 1107 | const TypeKlassPtr* ttkp = (ttp != NULL) ? ttp->isa_klassptr() : NULL; |
| 1108 | bool is_intf = false; |
| 1109 | if (ttip != NULL) { |
| 1110 | ciKlass* k = ttip->klass(); |
| 1111 | if (k->is_loaded() && k->is_interface()) |
| 1112 | is_intf = true; |
| 1113 | } |
| 1114 | if (ttkp != NULL) { |
| 1115 | ciKlass* k = ttkp->klass(); |
| 1116 | if (k->is_loaded() && k->is_interface()) |
| 1117 | is_intf = true; |
| 1118 | } |
| 1119 | |
| 1120 | // Default case: merge all inputs |
| 1121 | const Type *t = Type::TOP; // Merged type starting value |
| 1122 | for (uint i = 1; i < req(); ++i) {// For all paths in |
| 1123 | // Reachable control path? |
| 1124 | if (r->in(i) && phase->type(r->in(i)) == Type::CONTROL) { |
| 1125 | const Type* ti = phase->type(in(i)); |
| 1126 | // We assume that each input of an interface-valued Phi is a true |
| 1127 | // subtype of that interface. This might not be true of the meet |
| 1128 | // of all the input types. The lattice is not distributive in |
| 1129 | // such cases. Ward off asserts in type.cpp by refusing to do |
| 1130 | // meets between interfaces and proper classes. |
| 1131 | const TypePtr* tip = ti->make_ptr(); |
| 1132 | const TypeInstPtr* tiip = (tip != NULL) ? tip->isa_instptr() : NULL; |
| 1133 | if (tiip) { |
| 1134 | bool ti_is_intf = false; |
| 1135 | ciKlass* k = tiip->klass(); |
| 1136 | if (k->is_loaded() && k->is_interface()) |
| 1137 | ti_is_intf = true; |
| 1138 | if (is_intf != ti_is_intf) |
| 1139 | { t = _type; break; } |
| 1140 | } |
| 1141 | t = t->meet_speculative(ti); |
| 1142 | } |
| 1143 | } |
| 1144 | |
| 1145 | // The worst-case type (from ciTypeFlow) should be consistent with "t". |
| 1146 | // That is, we expect that "t->higher_equal(_type)" holds true. |
| 1147 | // There are various exceptions: |
| 1148 | // - Inputs which are phis might in fact be widened unnecessarily. |
| 1149 | // For example, an input might be a widened int while the phi is a short. |
| 1150 | // - Inputs might be BotPtrs but this phi is dependent on a null check, |
| 1151 | // and postCCP has removed the cast which encodes the result of the check. |
| 1152 | // - The type of this phi is an interface, and the inputs are classes. |
| 1153 | // - Value calls on inputs might produce fuzzy results. |
| 1154 | // (Occurrences of this case suggest improvements to Value methods.) |
| 1155 | // |
| 1156 | // It is not possible to see Type::BOTTOM values as phi inputs, |
| 1157 | // because the ciTypeFlow pre-pass produces verifier-quality types. |
| 1158 | const Type* ft = t->filter_speculative(_type); // Worst case type |
| 1159 | |
| 1160 | #ifdef ASSERT |
| 1161 | // The following logic has been moved into TypeOopPtr::filter. |
| 1162 | const Type* jt = t->join_speculative(_type); |
| 1163 | if (jt->empty()) { // Emptied out??? |
| 1164 | |
| 1165 | // Check for evil case of 't' being a class and '_type' expecting an |
| 1166 | // interface. This can happen because the bytecodes do not contain |
| 1167 | // enough type info to distinguish a Java-level interface variable |
| 1168 | // from a Java-level object variable. If we meet 2 classes which |
| 1169 | // both implement interface I, but their meet is at 'j/l/O' which |
| 1170 | // doesn't implement I, we have no way to tell if the result should |
| 1171 | // be 'I' or 'j/l/O'. Thus we'll pick 'j/l/O'. If this then flows |
| 1172 | // into a Phi which "knows" it's an Interface type we'll have to |
| 1173 | // uplift the type. |
| 1174 | if (!t->empty() && ttip && ttip->is_loaded() && ttip->klass()->is_interface()) { |
| 1175 | assert(ft == _type, ""); // Uplift to interface |
| 1176 | } else if (!t->empty() && ttkp && ttkp->is_loaded() && ttkp->klass()->is_interface()) { |
| 1177 | assert(ft == _type, ""); // Uplift to interface |
| 1178 | } else { |
| 1179 | // We also have to handle 'evil cases' of interface- vs. class-arrays |
| 1180 | Type::get_arrays_base_elements(jt, _type, NULL, &ttip); |
| 1181 | if (!t->empty() && ttip != NULL && ttip->is_loaded() && ttip->klass()->is_interface()) { |
| 1182 | assert(ft == _type, ""); // Uplift to array of interface |
| 1183 | } else { |
| 1184 | // Otherwise it's something stupid like non-overlapping int ranges |
| 1185 | // found on dying counted loops. |
| 1186 | assert(ft == Type::TOP, ""); // Canonical empty value |
| 1187 | } |
| 1188 | } |
| 1189 | } |
| 1190 | |
| 1191 | else { |
| 1192 | |
| 1193 | // If we have an interface-typed Phi and we narrow to a class type, the join |
| 1194 | // should report back the class. However, if we have a J/L/Object |
| 1195 | // class-typed Phi and an interface flows in, it's possible that the meet & |
| 1196 | // join report an interface back out. This isn't possible but happens |
| 1197 | // because the type system doesn't interact well with interfaces. |
| 1198 | const TypePtr *jtp = jt->make_ptr(); |
| 1199 | const TypeInstPtr *jtip = (jtp != NULL) ? jtp->isa_instptr() : NULL; |
| 1200 | const TypeKlassPtr *jtkp = (jtp != NULL) ? jtp->isa_klassptr() : NULL; |
| 1201 | if( jtip && ttip ) { |
| 1202 | if( jtip->is_loaded() && jtip->klass()->is_interface() && |
| 1203 | ttip->is_loaded() && !ttip->klass()->is_interface() ) { |
| 1204 | assert(ft == ttip->cast_to_ptr_type(jtip->ptr()) || |
| 1205 | ft->isa_narrowoop() && ft->make_ptr() == ttip->cast_to_ptr_type(jtip->ptr()), ""); |
| 1206 | jt = ft; |
| 1207 | } |
| 1208 | } |
| 1209 | if( jtkp && ttkp ) { |
| 1210 | if( jtkp->is_loaded() && jtkp->klass()->is_interface() && |
| 1211 | !jtkp->klass_is_exact() && // Keep exact interface klass (6894807) |
| 1212 | ttkp->is_loaded() && !ttkp->klass()->is_interface() ) { |
| 1213 | assert(ft == ttkp->cast_to_ptr_type(jtkp->ptr()) || |
| 1214 | ft->isa_narrowklass() && ft->make_ptr() == ttkp->cast_to_ptr_type(jtkp->ptr()), ""); |
| 1215 | jt = ft; |
| 1216 | } |
| 1217 | } |
| 1218 | if (jt != ft && jt->base() == ft->base()) { |
| 1219 | if (jt->isa_int() && |
| 1220 | jt->is_int()->_lo == ft->is_int()->_lo && |
| 1221 | jt->is_int()->_hi == ft->is_int()->_hi) |
| 1222 | jt = ft; |
| 1223 | if (jt->isa_long() && |
| 1224 | jt->is_long()->_lo == ft->is_long()->_lo && |
| 1225 | jt->is_long()->_hi == ft->is_long()->_hi) |
| 1226 | jt = ft; |
| 1227 | } |
| 1228 | if (jt != ft) { |
| 1229 | tty->print("merge type: "); t->dump(); tty->cr(); |
| 1230 | tty->print("kill type: "); _type->dump(); tty->cr(); |
| 1231 | tty->print("join type: "); jt->dump(); tty->cr(); |
| 1232 | tty->print("filter type: "); ft->dump(); tty->cr(); |
| 1233 | } |
| 1234 | assert(jt == ft, ""); |
| 1235 | } |
| 1236 | #endif //ASSERT |
| 1237 | |
| 1238 | // Deal with conversion problems found in data loops. |
| 1239 | ft = phase->saturate(ft, phase->type_or_null(this), _type); |
| 1240 | |
| 1241 | return ft; |
| 1242 | } |
| 1243 | |
| 1244 | |
| 1245 | //------------------------------is_diamond_phi--------------------------------- |
| 1246 | // Does this Phi represent a simple well-shaped diamond merge? Return the |
| 1247 | // index of the true path or 0 otherwise. |
| 1248 | // If check_control_only is true, do not inspect the If node at the |
| 1249 | // top, and return -1 (not an edge number) on success. |
| 1250 | int PhiNode::is_diamond_phi(bool check_control_only) const { |
| 1251 | // Check for a 2-path merge |
| 1252 | Node *region = in(0); |
| 1253 | if( !region ) return 0; |
| 1254 | if( region->req() != 3 ) return 0; |
| 1255 | if( req() != 3 ) return 0; |
| 1256 | // Check that both paths come from the same If |
| 1257 | Node *ifp1 = region->in(1); |
| 1258 | Node *ifp2 = region->in(2); |
| 1259 | if( !ifp1 || !ifp2 ) return 0; |
| 1260 | Node *iff = ifp1->in(0); |
| 1261 | if( !iff || !iff->is_If() ) return 0; |
| 1262 | if( iff != ifp2->in(0) ) return 0; |
| 1263 | if (check_control_only) return -1; |
| 1264 | // Check for a proper bool/cmp |
| 1265 | const Node *b = iff->in(1); |
| 1266 | if( !b->is_Bool() ) return 0; |
| 1267 | const Node *cmp = b->in(1); |
| 1268 | if( !cmp->is_Cmp() ) return 0; |
| 1269 | |
| 1270 | // Check for branching opposite expected |
| 1271 | if( ifp2->Opcode() == Op_IfTrue ) { |
| 1272 | assert( ifp1->Opcode() == Op_IfFalse, ""); |
| 1273 | return 2; |
| 1274 | } else { |
| 1275 | assert( ifp1->Opcode() == Op_IfTrue, ""); |
| 1276 | return 1; |
| 1277 | } |
| 1278 | } |
| 1279 | |
| 1280 | //----------------------------check_cmove_id----------------------------------- |
| 1281 | // Check for CMove'ing a constant after comparing against the constant. |
| 1282 | // Happens all the time now, since if we compare equality vs a constant in |
| 1283 | // the parser, we "know" the variable is constant on one path and we force |
| 1284 | // it. Thus code like "if( x==0 ) {/*EMPTY*/}" ends up inserting a |
| 1285 | // conditional move: "x = (x==0)?0:x;". Yucko. This fix is slightly more |
| 1286 | // general in that we don't need constants. Since CMove's are only inserted |
| 1287 | // in very special circumstances, we do it here on generic Phi's. |
| 1288 | Node* PhiNode::is_cmove_id(PhaseTransform* phase, int true_path) { |
| 1289 | assert(true_path !=0, "only diamond shape graph expected"); |
| 1290 | |
| 1291 | // is_diamond_phi() has guaranteed the correctness of the nodes sequence: |
| 1292 | // phi->region->if_proj->ifnode->bool->cmp |
| 1293 | Node* region = in(0); |
| 1294 | Node* iff = region->in(1)->in(0); |
| 1295 | BoolNode* b = iff->in(1)->as_Bool(); |
| 1296 | Node* cmp = b->in(1); |
| 1297 | Node* tval = in(true_path); |
| 1298 | Node* fval = in(3-true_path); |
| 1299 | Node* id = CMoveNode::is_cmove_id(phase, cmp, tval, fval, b); |
| 1300 | if (id == NULL) |
| 1301 | return NULL; |
| 1302 | |
| 1303 | // Either value might be a cast that depends on a branch of 'iff'. |
| 1304 | // Since the 'id' value will float free of the diamond, either |
| 1305 | // decast or return failure. |
| 1306 | Node* ctl = id->in(0); |
| 1307 | if (ctl != NULL && ctl->in(0) == iff) { |
| 1308 | if (id->is_ConstraintCast()) { |
| 1309 | return id->in(1); |
| 1310 | } else { |
| 1311 | // Don't know how to disentangle this value. |
| 1312 | return NULL; |
| 1313 | } |
| 1314 | } |
| 1315 | |
| 1316 | return id; |
| 1317 | } |
| 1318 | |
| 1319 | //------------------------------Identity--------------------------------------- |
| 1320 | // Check for Region being Identity. |
| 1321 | Node* PhiNode::Identity(PhaseGVN* phase) { |
| 1322 | // Check for no merging going on |
| 1323 | // (There used to be special-case code here when this->region->is_Loop. |
| 1324 | // It would check for a tributary phi on the backedge that the main phi |
| 1325 | // trivially, perhaps with a single cast. The unique_input method |
| 1326 | // does all this and more, by reducing such tributaries to 'this'.) |
| 1327 | Node* uin = unique_input(phase, false); |
| 1328 | if (uin != NULL) { |
| 1329 | return uin; |
| 1330 | } |
| 1331 | |
| 1332 | int true_path = is_diamond_phi(); |
| 1333 | if (true_path != 0) { |
| 1334 | Node* id = is_cmove_id(phase, true_path); |
| 1335 | if (id != NULL) return id; |
| 1336 | } |
| 1337 | |
| 1338 | return this; // No identity |
| 1339 | } |
| 1340 | |
| 1341 | //-----------------------------unique_input------------------------------------ |
| 1342 | // Find the unique value, discounting top, self-loops, and casts. |
| 1343 | // Return top if there are no inputs, and self if there are multiple. |
| 1344 | Node* PhiNode::unique_input(PhaseTransform* phase, bool uncast) { |
| 1345 | // 1) One unique direct input, |
| 1346 | // or if uncast is true: |
| 1347 | // 2) some of the inputs have an intervening ConstraintCast |
| 1348 | // 3) an input is a self loop |
| 1349 | // |
| 1350 | // 1) input or 2) input or 3) input __ |
| 1351 | // / \ / \ \ / \ |
| 1352 | // \ / | cast phi cast |
| 1353 | // phi \ / / \ / |
| 1354 | // phi / -- |
| 1355 | |
| 1356 | Node* r = in(0); // RegionNode |
| 1357 | if (r == NULL) return in(1); // Already degraded to a Copy |
| 1358 | Node* input = NULL; // The unique direct input (maybe uncasted = ConstraintCasts removed) |
| 1359 | |
| 1360 | for (uint i = 1, cnt = req(); i < cnt; ++i) { |
| 1361 | Node* rc = r->in(i); |
| 1362 | if (rc == NULL || phase->type(rc) == Type::TOP) |
| 1363 | continue; // ignore unreachable control path |
| 1364 | Node* n = in(i); |
| 1365 | if (n == NULL) |
| 1366 | continue; |
| 1367 | Node* un = n; |
| 1368 | if (uncast) { |
| 1369 | #ifdef ASSERT |
| 1370 | Node* m = un->uncast(); |
| 1371 | #endif |
| 1372 | while (un != NULL && un->req() == 2 && un->is_ConstraintCast()) { |
| 1373 | Node* next = un->in(1); |
| 1374 | if (phase->type(next)->isa_rawptr() && phase->type(un)->isa_oopptr()) { |
| 1375 | // risk exposing raw ptr at safepoint |
| 1376 | break; |
| 1377 | } |
| 1378 | un = next; |
| 1379 | } |
| 1380 | assert(m == un || un->in(1) == m, "Only expected at CheckCastPP from allocation"); |
| 1381 | } |
| 1382 | if (un == NULL || un == this || phase->type(un) == Type::TOP) { |
| 1383 | continue; // ignore if top, or in(i) and "this" are in a data cycle |
| 1384 | } |
| 1385 | // Check for a unique input (maybe uncasted) |
| 1386 | if (input == NULL) { |
| 1387 | input = un; |
| 1388 | } else if (input != un) { |
| 1389 | input = NodeSentinel; // no unique input |
| 1390 | } |
| 1391 | } |
| 1392 | if (input == NULL) { |
| 1393 | return phase->C->top(); // no inputs |
| 1394 | } |
| 1395 | |
| 1396 | if (input != NodeSentinel) { |
| 1397 | return input; // one unique direct input |
| 1398 | } |
| 1399 | |
| 1400 | // Nothing. |
| 1401 | return NULL; |
| 1402 | } |
| 1403 | |
| 1404 | //------------------------------is_x2logic------------------------------------- |
| 1405 | // Check for simple convert-to-boolean pattern |
| 1406 | // If:(C Bool) Region:(IfF IfT) Phi:(Region 0 1) |
| 1407 | // Convert Phi to an ConvIB. |
| 1408 | static Node *is_x2logic( PhaseGVN *phase, PhiNode *phi, int true_path ) { |
| 1409 | assert(true_path !=0, "only diamond shape graph expected"); |
| 1410 | // Convert the true/false index into an expected 0/1 return. |
| 1411 | // Map 2->0 and 1->1. |
| 1412 | int flipped = 2-true_path; |
| 1413 | |
| 1414 | // is_diamond_phi() has guaranteed the correctness of the nodes sequence: |
| 1415 | // phi->region->if_proj->ifnode->bool->cmp |
| 1416 | Node *region = phi->in(0); |
| 1417 | Node *iff = region->in(1)->in(0); |
| 1418 | BoolNode *b = (BoolNode*)iff->in(1); |
| 1419 | const CmpNode *cmp = (CmpNode*)b->in(1); |
| 1420 | |
| 1421 | Node *zero = phi->in(1); |
| 1422 | Node *one = phi->in(2); |
| 1423 | const Type *tzero = phase->type( zero ); |
| 1424 | const Type *tone = phase->type( one ); |
| 1425 | |
| 1426 | // Check for compare vs 0 |
| 1427 | const Type *tcmp = phase->type(cmp->in(2)); |
| 1428 | if( tcmp != TypeInt::ZERO && tcmp != TypePtr::NULL_PTR ) { |
| 1429 | // Allow cmp-vs-1 if the other input is bounded by 0-1 |
| 1430 | if( !(tcmp == TypeInt::ONE && phase->type(cmp->in(1)) == TypeInt::BOOL) ) |
| 1431 | return NULL; |
| 1432 | flipped = 1-flipped; // Test is vs 1 instead of 0! |
| 1433 | } |
| 1434 | |
| 1435 | // Check for setting zero/one opposite expected |
| 1436 | if( tzero == TypeInt::ZERO ) { |
| 1437 | if( tone == TypeInt::ONE ) { |
| 1438 | } else return NULL; |
| 1439 | } else if( tzero == TypeInt::ONE ) { |
| 1440 | if( tone == TypeInt::ZERO ) { |
| 1441 | flipped = 1-flipped; |
| 1442 | } else return NULL; |
| 1443 | } else return NULL; |
| 1444 | |
| 1445 | // Check for boolean test backwards |
| 1446 | if( b->_test._test == BoolTest::ne ) { |
| 1447 | } else if( b->_test._test == BoolTest::eq ) { |
| 1448 | flipped = 1-flipped; |
| 1449 | } else return NULL; |
| 1450 | |
| 1451 | // Build int->bool conversion |
| 1452 | Node *in1 = cmp->in(1); |
| 1453 | BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); |
| 1454 | in1 = bs->step_over_gc_barrier(in1); |
| 1455 | Node *n = new Conv2BNode(in1); |
| 1456 | if( flipped ) |
| 1457 | n = new XorINode( phase->transform(n), phase->intcon(1) ); |
| 1458 | |
| 1459 | return n; |
| 1460 | } |
| 1461 | |
| 1462 | //------------------------------is_cond_add------------------------------------ |
| 1463 | // Check for simple conditional add pattern: "(P < Q) ? X+Y : X;" |
| 1464 | // To be profitable the control flow has to disappear; there can be no other |
| 1465 | // values merging here. We replace the test-and-branch with: |
| 1466 | // "(sgn(P-Q))&Y) + X". Basically, convert "(P < Q)" into 0 or -1 by |
| 1467 | // moving the carry bit from (P-Q) into a register with 'sbb EAX,EAX'. |
| 1468 | // Then convert Y to 0-or-Y and finally add. |
| 1469 | // This is a key transform for SpecJava _201_compress. |
| 1470 | static Node* is_cond_add(PhaseGVN *phase, PhiNode *phi, int true_path) { |
| 1471 | assert(true_path !=0, "only diamond shape graph expected"); |
| 1472 | |
| 1473 | // is_diamond_phi() has guaranteed the correctness of the nodes sequence: |
| 1474 | // phi->region->if_proj->ifnode->bool->cmp |
| 1475 | RegionNode *region = (RegionNode*)phi->in(0); |
| 1476 | Node *iff = region->in(1)->in(0); |
| 1477 | BoolNode* b = iff->in(1)->as_Bool(); |
| 1478 | const CmpNode *cmp = (CmpNode*)b->in(1); |
| 1479 | |
| 1480 | // Make sure only merging this one phi here |
| 1481 | if (region->has_unique_phi() != phi) return NULL; |
| 1482 | |
| 1483 | // Make sure each arm of the diamond has exactly one output, which we assume |
| 1484 | // is the region. Otherwise, the control flow won't disappear. |
| 1485 | if (region->in(1)->outcnt() != 1) return NULL; |
| 1486 | if (region->in(2)->outcnt() != 1) return NULL; |
| 1487 | |
| 1488 | // Check for "(P < Q)" of type signed int |
| 1489 | if (b->_test._test != BoolTest::lt) return NULL; |
| 1490 | if (cmp->Opcode() != Op_CmpI) return NULL; |
| 1491 | |
| 1492 | Node *p = cmp->in(1); |
| 1493 | Node *q = cmp->in(2); |
| 1494 | Node *n1 = phi->in( true_path); |
| 1495 | Node *n2 = phi->in(3-true_path); |
| 1496 | |
| 1497 | int op = n1->Opcode(); |
| 1498 | if( op != Op_AddI // Need zero as additive identity |
| 1499 | /*&&op != Op_SubI && |
| 1500 | op != Op_AddP && |
| 1501 | op != Op_XorI && |
| 1502 | op != Op_OrI*/ ) |
| 1503 | return NULL; |
| 1504 | |
| 1505 | Node *x = n2; |
| 1506 | Node *y = NULL; |
| 1507 | if( x == n1->in(1) ) { |
| 1508 | y = n1->in(2); |
| 1509 | } else if( x == n1->in(2) ) { |
| 1510 | y = n1->in(1); |
| 1511 | } else return NULL; |
| 1512 | |
| 1513 | // Not so profitable if compare and add are constants |
| 1514 | if( q->is_Con() && phase->type(q) != TypeInt::ZERO && y->is_Con() ) |
| 1515 | return NULL; |
| 1516 | |
| 1517 | Node *cmplt = phase->transform( new CmpLTMaskNode(p,q) ); |
| 1518 | Node *j_and = phase->transform( new AndINode(cmplt,y) ); |
| 1519 | return new AddINode(j_and,x); |
| 1520 | } |
| 1521 | |
| 1522 | //------------------------------is_absolute------------------------------------ |
| 1523 | // Check for absolute value. |
| 1524 | static Node* is_absolute( PhaseGVN *phase, PhiNode *phi_root, int true_path) { |
| 1525 | assert(true_path !=0, "only diamond shape graph expected"); |
| 1526 | |
| 1527 | int cmp_zero_idx = 0; // Index of compare input where to look for zero |
| 1528 | int phi_x_idx = 0; // Index of phi input where to find naked x |
| 1529 | |
| 1530 | // ABS ends with the merge of 2 control flow paths. |
| 1531 | // Find the false path from the true path. With only 2 inputs, 3 - x works nicely. |
| 1532 | int false_path = 3 - true_path; |
| 1533 | |
| 1534 | // is_diamond_phi() has guaranteed the correctness of the nodes sequence: |
| 1535 | // phi->region->if_proj->ifnode->bool->cmp |
| 1536 | BoolNode *bol = phi_root->in(0)->in(1)->in(0)->in(1)->as_Bool(); |
| 1537 | |
| 1538 | // Check bool sense |
| 1539 | switch( bol->_test._test ) { |
| 1540 | case BoolTest::lt: cmp_zero_idx = 1; phi_x_idx = true_path; break; |
| 1541 | case BoolTest::le: cmp_zero_idx = 2; phi_x_idx = false_path; break; |
| 1542 | case BoolTest::gt: cmp_zero_idx = 2; phi_x_idx = true_path; break; |
| 1543 | case BoolTest::ge: cmp_zero_idx = 1; phi_x_idx = false_path; break; |
| 1544 | default: return NULL; break; |
| 1545 | } |
| 1546 | |
| 1547 | // Test is next |
| 1548 | Node *cmp = bol->in(1); |
| 1549 | const Type *tzero = NULL; |
| 1550 | switch( cmp->Opcode() ) { |
| 1551 | case Op_CmpF: tzero = TypeF::ZERO; break; // Float ABS |
| 1552 | case Op_CmpD: tzero = TypeD::ZERO; break; // Double ABS |
| 1553 | default: return NULL; |
| 1554 | } |
| 1555 | |
| 1556 | // Find zero input of compare; the other input is being abs'd |
| 1557 | Node *x = NULL; |
| 1558 | bool flip = false; |
| 1559 | if( phase->type(cmp->in(cmp_zero_idx)) == tzero ) { |
| 1560 | x = cmp->in(3 - cmp_zero_idx); |
| 1561 | } else if( phase->type(cmp->in(3 - cmp_zero_idx)) == tzero ) { |
| 1562 | // The test is inverted, we should invert the result... |
| 1563 | x = cmp->in(cmp_zero_idx); |
| 1564 | flip = true; |
| 1565 | } else { |
| 1566 | return NULL; |
| 1567 | } |
| 1568 | |
| 1569 | // Next get the 2 pieces being selected, one is the original value |
| 1570 | // and the other is the negated value. |
| 1571 | if( phi_root->in(phi_x_idx) != x ) return NULL; |
| 1572 | |
| 1573 | // Check other phi input for subtract node |
| 1574 | Node *sub = phi_root->in(3 - phi_x_idx); |
| 1575 | |
| 1576 | // Allow only Sub(0,X) and fail out for all others; Neg is not OK |
| 1577 | if( tzero == TypeF::ZERO ) { |
| 1578 | if( sub->Opcode() != Op_SubF || |
| 1579 | sub->in(2) != x || |
| 1580 | phase->type(sub->in(1)) != tzero ) return NULL; |
| 1581 | x = new AbsFNode(x); |
| 1582 | if (flip) { |
| 1583 | x = new SubFNode(sub->in(1), phase->transform(x)); |
| 1584 | } |
| 1585 | } else { |
| 1586 | if( sub->Opcode() != Op_SubD || |
| 1587 | sub->in(2) != x || |
| 1588 | phase->type(sub->in(1)) != tzero ) return NULL; |
| 1589 | x = new AbsDNode(x); |
| 1590 | if (flip) { |
| 1591 | x = new SubDNode(sub->in(1), phase->transform(x)); |
| 1592 | } |
| 1593 | } |
| 1594 | |
| 1595 | return x; |
| 1596 | } |
| 1597 | |
| 1598 | //------------------------------split_once------------------------------------- |
| 1599 | // Helper for split_flow_path |
| 1600 | static void split_once(PhaseIterGVN *igvn, Node *phi, Node *val, Node *n, Node *newn) { |
| 1601 | igvn->hash_delete(n); // Remove from hash before hacking edges |
| 1602 | |
| 1603 | uint j = 1; |
| 1604 | for (uint i = phi->req()-1; i > 0; i--) { |
| 1605 | if (phi->in(i) == val) { // Found a path with val? |
| 1606 | // Add to NEW Region/Phi, no DU info |
| 1607 | newn->set_req( j++, n->in(i) ); |
| 1608 | // Remove from OLD Region/Phi |
| 1609 | n->del_req(i); |
| 1610 | } |
| 1611 | } |
| 1612 | |
| 1613 | // Register the new node but do not transform it. Cannot transform until the |
| 1614 | // entire Region/Phi conglomerate has been hacked as a single huge transform. |
| 1615 | igvn->register_new_node_with_optimizer( newn ); |
| 1616 | |
| 1617 | // Now I can point to the new node. |
| 1618 | n->add_req(newn); |
| 1619 | igvn->_worklist.push(n); |
| 1620 | } |
| 1621 | |
| 1622 | //------------------------------split_flow_path-------------------------------- |
| 1623 | // Check for merging identical values and split flow paths |
| 1624 | static Node* split_flow_path(PhaseGVN *phase, PhiNode *phi) { |
| 1625 | BasicType bt = phi->type()->basic_type(); |
| 1626 | if( bt == T_ILLEGAL || type2size[bt] <= 0 ) |
| 1627 | return NULL; // Bail out on funny non-value stuff |
| 1628 | if( phi->req() <= 3 ) // Need at least 2 matched inputs and a |
| 1629 | return NULL; // third unequal input to be worth doing |
| 1630 | |
| 1631 | // Scan for a constant |
| 1632 | uint i; |
| 1633 | for( i = 1; i < phi->req()-1; i++ ) { |
| 1634 | Node *n = phi->in(i); |
| 1635 | if( !n ) return NULL; |
| 1636 | if( phase->type(n) == Type::TOP ) return NULL; |
| 1637 | if( n->Opcode() == Op_ConP || n->Opcode() == Op_ConN || n->Opcode() == Op_ConNKlass ) |
| 1638 | break; |
| 1639 | } |
| 1640 | if( i >= phi->req() ) // Only split for constants |
| 1641 | return NULL; |
| 1642 | |
| 1643 | Node *val = phi->in(i); // Constant to split for |
| 1644 | uint hit = 0; // Number of times it occurs |
| 1645 | Node *r = phi->region(); |
| 1646 | |
| 1647 | for( ; i < phi->req(); i++ ){ // Count occurrences of constant |
| 1648 | Node *n = phi->in(i); |
| 1649 | if( !n ) return NULL; |
| 1650 | if( phase->type(n) == Type::TOP ) return NULL; |
| 1651 | if( phi->in(i) == val ) { |
| 1652 | hit++; |
| 1653 | if (PhaseIdealLoop::find_predicate(r->in(i)) != NULL) { |
| 1654 | return NULL; // don't split loop entry path |
| 1655 | } |
| 1656 | } |
| 1657 | } |
| 1658 | |
| 1659 | if( hit <= 1 || // Make sure we find 2 or more |
| 1660 | hit == phi->req()-1 ) // and not ALL the same value |
| 1661 | return NULL; |
| 1662 | |
| 1663 | // Now start splitting out the flow paths that merge the same value. |
| 1664 | // Split first the RegionNode. |
| 1665 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 1666 | RegionNode *newr = new RegionNode(hit+1); |
| 1667 | split_once(igvn, phi, val, r, newr); |
| 1668 | |
| 1669 | // Now split all other Phis than this one |
| 1670 | for (DUIterator_Fast kmax, k = r->fast_outs(kmax); k < kmax; k++) { |
| 1671 | Node* phi2 = r->fast_out(k); |
| 1672 | if( phi2->is_Phi() && phi2->as_Phi() != phi ) { |
| 1673 | PhiNode *newphi = PhiNode::make_blank(newr, phi2); |
| 1674 | split_once(igvn, phi, val, phi2, newphi); |
| 1675 | } |
| 1676 | } |
| 1677 | |
| 1678 | // Clean up this guy |
| 1679 | igvn->hash_delete(phi); |
| 1680 | for( i = phi->req()-1; i > 0; i-- ) { |
| 1681 | if( phi->in(i) == val ) { |
| 1682 | phi->del_req(i); |
| 1683 | } |
| 1684 | } |
| 1685 | phi->add_req(val); |
| 1686 | |
| 1687 | return phi; |
| 1688 | } |
| 1689 | |
| 1690 | //============================================================================= |
| 1691 | //------------------------------simple_data_loop_check------------------------- |
| 1692 | // Try to determining if the phi node in a simple safe/unsafe data loop. |
| 1693 | // Returns: |
| 1694 | // enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop }; |
| 1695 | // Safe - safe case when the phi and it's inputs reference only safe data |
| 1696 | // nodes; |
| 1697 | // Unsafe - the phi and it's inputs reference unsafe data nodes but there |
| 1698 | // is no reference back to the phi - need a graph walk |
| 1699 | // to determine if it is in a loop; |
| 1700 | // UnsafeLoop - unsafe case when the phi references itself directly or through |
| 1701 | // unsafe data node. |
| 1702 | // Note: a safe data node is a node which could/never reference itself during |
| 1703 | // GVN transformations. For now it is Con, Proj, Phi, CastPP, CheckCastPP. |
| 1704 | // I mark Phi nodes as safe node not only because they can reference itself |
| 1705 | // but also to prevent mistaking the fallthrough case inside an outer loop |
| 1706 | // as dead loop when the phi references itselfs through an other phi. |
| 1707 | PhiNode::LoopSafety PhiNode::simple_data_loop_check(Node *in) const { |
| 1708 | // It is unsafe loop if the phi node references itself directly. |
| 1709 | if (in == (Node*)this) |
| 1710 | return UnsafeLoop; // Unsafe loop |
| 1711 | // Unsafe loop if the phi node references itself through an unsafe data node. |
| 1712 | // Exclude cases with null inputs or data nodes which could reference |
| 1713 | // itself (safe for dead loops). |
| 1714 | if (in != NULL && !in->is_dead_loop_safe()) { |
| 1715 | // Check inputs of phi's inputs also. |
| 1716 | // It is much less expensive then full graph walk. |
| 1717 | uint cnt = in->req(); |
| 1718 | uint i = (in->is_Proj() && !in->is_CFG()) ? 0 : 1; |
| 1719 | for (; i < cnt; ++i) { |
| 1720 | Node* m = in->in(i); |
| 1721 | if (m == (Node*)this) |
| 1722 | return UnsafeLoop; // Unsafe loop |
| 1723 | if (m != NULL && !m->is_dead_loop_safe()) { |
| 1724 | // Check the most common case (about 30% of all cases): |
| 1725 | // phi->Load/Store->AddP->(ConP ConP Con)/(Parm Parm Con). |
| 1726 | Node *m1 = (m->is_AddP() && m->req() > 3) ? m->in(1) : NULL; |
| 1727 | if (m1 == (Node*)this) |
| 1728 | return UnsafeLoop; // Unsafe loop |
| 1729 | if (m1 != NULL && m1 == m->in(2) && |
| 1730 | m1->is_dead_loop_safe() && m->in(3)->is_Con()) { |
| 1731 | continue; // Safe case |
| 1732 | } |
| 1733 | // The phi references an unsafe node - need full analysis. |
| 1734 | return Unsafe; |
| 1735 | } |
| 1736 | } |
| 1737 | } |
| 1738 | return Safe; // Safe case - we can optimize the phi node. |
| 1739 | } |
| 1740 | |
| 1741 | //------------------------------is_unsafe_data_reference----------------------- |
| 1742 | // If phi can be reached through the data input - it is data loop. |
| 1743 | bool PhiNode::is_unsafe_data_reference(Node *in) const { |
| 1744 | assert(req() > 1, ""); |
| 1745 | // First, check simple cases when phi references itself directly or |
| 1746 | // through an other node. |
| 1747 | LoopSafety safety = simple_data_loop_check(in); |
| 1748 | if (safety == UnsafeLoop) |
| 1749 | return true; // phi references itself - unsafe loop |
| 1750 | else if (safety == Safe) |
| 1751 | return false; // Safe case - phi could be replaced with the unique input. |
| 1752 | |
| 1753 | // Unsafe case when we should go through data graph to determine |
| 1754 | // if the phi references itself. |
| 1755 | |
| 1756 | ResourceMark rm; |
| 1757 | |
| 1758 | Arena *a = Thread::current()->resource_area(); |
| 1759 | Node_List nstack(a); |
| 1760 | VectorSet visited(a); |
| 1761 | |
| 1762 | nstack.push(in); // Start with unique input. |
| 1763 | visited.set(in->_idx); |
| 1764 | while (nstack.size() != 0) { |
| 1765 | Node* n = nstack.pop(); |
| 1766 | uint cnt = n->req(); |
| 1767 | uint i = (n->is_Proj() && !n->is_CFG()) ? 0 : 1; |
| 1768 | for (; i < cnt; i++) { |
| 1769 | Node* m = n->in(i); |
| 1770 | if (m == (Node*)this) { |
| 1771 | return true; // Data loop |
| 1772 | } |
| 1773 | if (m != NULL && !m->is_dead_loop_safe()) { // Only look for unsafe cases. |
| 1774 | if (!visited.test_set(m->_idx)) |
| 1775 | nstack.push(m); |
| 1776 | } |
| 1777 | } |
| 1778 | } |
| 1779 | return false; // The phi is not reachable from its inputs |
| 1780 | } |
| 1781 | |
| 1782 | |
| 1783 | //------------------------------Ideal------------------------------------------ |
| 1784 | // Return a node which is more "ideal" than the current node. Must preserve |
| 1785 | // the CFG, but we can still strip out dead paths. |
| 1786 | Node *PhiNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
| 1787 | // The next should never happen after 6297035 fix. |
| 1788 | if( is_copy() ) // Already degraded to a Copy ? |
| 1789 | return NULL; // No change |
| 1790 | |
| 1791 | Node *r = in(0); // RegionNode |
| 1792 | assert(r->in(0) == NULL || !r->in(0)->is_Root(), "not a specially hidden merge"); |
| 1793 | |
| 1794 | // Note: During parsing, phis are often transformed before their regions. |
| 1795 | // This means we have to use type_or_null to defend against untyped regions. |
| 1796 | if( phase->type_or_null(r) == Type::TOP ) // Dead code? |
| 1797 | return NULL; // No change |
| 1798 | |
| 1799 | Node *top = phase->C->top(); |
| 1800 | bool new_phi = (outcnt() == 0); // transforming new Phi |
| 1801 | // No change for igvn if new phi is not hooked |
| 1802 | if (new_phi && can_reshape) |
| 1803 | return NULL; |
| 1804 | |
| 1805 | // The are 2 situations when only one valid phi's input is left |
| 1806 | // (in addition to Region input). |
| 1807 | // One: region is not loop - replace phi with this input. |
| 1808 | // Two: region is loop - replace phi with top since this data path is dead |
| 1809 | // and we need to break the dead data loop. |
| 1810 | Node* progress = NULL; // Record if any progress made |
| 1811 | for( uint j = 1; j < req(); ++j ){ // For all paths in |
| 1812 | // Check unreachable control paths |
| 1813 | Node* rc = r->in(j); |
| 1814 | Node* n = in(j); // Get the input |
| 1815 | if (rc == NULL || phase->type(rc) == Type::TOP) { |
| 1816 | if (n != top) { // Not already top? |
| 1817 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 1818 | if (can_reshape && igvn != NULL) { |
| 1819 | igvn->_worklist.push(r); |
| 1820 | } |
| 1821 | // Nuke it down |
| 1822 | if (can_reshape) { |
| 1823 | set_req_X(j, top, igvn); |
| 1824 | } else { |
| 1825 | set_req(j, top); |
| 1826 | } |
| 1827 | progress = this; // Record progress |
| 1828 | } |
| 1829 | } |
| 1830 | } |
| 1831 | |
| 1832 | if (can_reshape && outcnt() == 0) { |
| 1833 | // set_req() above may kill outputs if Phi is referenced |
| 1834 | // only by itself on the dead (top) control path. |
| 1835 | return top; |
| 1836 | } |
| 1837 | |
| 1838 | bool uncasted = false; |
| 1839 | Node* uin = unique_input(phase, false); |
| 1840 | if (uin == NULL && can_reshape) { |
| 1841 | uncasted = true; |
| 1842 | uin = unique_input(phase, true); |
| 1843 | } |
| 1844 | if (uin == top) { // Simplest case: no alive inputs. |
| 1845 | if (can_reshape) // IGVN transformation |
| 1846 | return top; |
| 1847 | else |
| 1848 | return NULL; // Identity will return TOP |
| 1849 | } else if (uin != NULL) { |
| 1850 | // Only one not-NULL unique input path is left. |
| 1851 | // Determine if this input is backedge of a loop. |
| 1852 | // (Skip new phis which have no uses and dead regions). |
| 1853 | if (outcnt() > 0 && r->in(0) != NULL) { |
| 1854 | // First, take the short cut when we know it is a loop and |
| 1855 | // the EntryControl data path is dead. |
| 1856 | // Loop node may have only one input because entry path |
| 1857 | // is removed in PhaseIdealLoop::Dominators(). |
| 1858 | assert(!r->is_Loop() || r->req() <= 3, "Loop node should have 3 or less inputs"); |
| 1859 | bool is_loop = (r->is_Loop() && r->req() == 3); |
| 1860 | // Then, check if there is a data loop when phi references itself directly |
| 1861 | // or through other data nodes. |
| 1862 | if ((is_loop && !uin->eqv_uncast(in(LoopNode::EntryControl))) || |
| 1863 | (!is_loop && is_unsafe_data_reference(uin))) { |
| 1864 | // Break this data loop to avoid creation of a dead loop. |
| 1865 | if (can_reshape) { |
| 1866 | return top; |
| 1867 | } else { |
| 1868 | // We can't return top if we are in Parse phase - cut inputs only |
| 1869 | // let Identity to handle the case. |
| 1870 | replace_edge(uin, top); |
| 1871 | return NULL; |
| 1872 | } |
| 1873 | } |
| 1874 | } |
| 1875 | |
| 1876 | if (uncasted) { |
| 1877 | // Add cast nodes between the phi to be removed and its unique input. |
| 1878 | // Wait until after parsing for the type information to propagate from the casts. |
| 1879 | assert(can_reshape, "Invalid during parsing"); |
| 1880 | const Type* phi_type = bottom_type(); |
| 1881 | assert(phi_type->isa_int() || phi_type->isa_ptr(), "bad phi type"); |
| 1882 | // Add casts to carry the control dependency of the Phi that is |
| 1883 | // going away |
| 1884 | Node* cast = NULL; |
| 1885 | if (phi_type->isa_int()) { |
| 1886 | cast = ConstraintCastNode::make_cast(Op_CastII, r, uin, phi_type, true); |
| 1887 | } else { |
| 1888 | const Type* uin_type = phase->type(uin); |
| 1889 | if (!phi_type->isa_oopptr() && !uin_type->isa_oopptr()) { |
| 1890 | cast = ConstraintCastNode::make_cast(Op_CastPP, r, uin, phi_type, true); |
| 1891 | } else { |
| 1892 | // Use a CastPP for a cast to not null and a CheckCastPP for |
| 1893 | // a cast to a new klass (and both if both null-ness and |
| 1894 | // klass change). |
| 1895 | |
| 1896 | // If the type of phi is not null but the type of uin may be |
| 1897 | // null, uin's type must be casted to not null |
| 1898 | if (phi_type->join(TypePtr::NOTNULL) == phi_type->remove_speculative() && |
| 1899 | uin_type->join(TypePtr::NOTNULL) != uin_type->remove_speculative()) { |
| 1900 | cast = ConstraintCastNode::make_cast(Op_CastPP, r, uin, TypePtr::NOTNULL, true); |
| 1901 | } |
| 1902 | |
| 1903 | // If the type of phi and uin, both casted to not null, |
| 1904 | // differ the klass of uin must be (check)cast'ed to match |
| 1905 | // that of phi |
| 1906 | if (phi_type->join_speculative(TypePtr::NOTNULL) != uin_type->join_speculative(TypePtr::NOTNULL)) { |
| 1907 | Node* n = uin; |
| 1908 | if (cast != NULL) { |
| 1909 | cast = phase->transform(cast); |
| 1910 | n = cast; |
| 1911 | } |
| 1912 | cast = ConstraintCastNode::make_cast(Op_CheckCastPP, r, n, phi_type, true); |
| 1913 | } |
| 1914 | if (cast == NULL) { |
| 1915 | cast = ConstraintCastNode::make_cast(Op_CastPP, r, uin, phi_type, true); |
| 1916 | } |
| 1917 | } |
| 1918 | } |
| 1919 | assert(cast != NULL, "cast should be set"); |
| 1920 | cast = phase->transform(cast); |
| 1921 | // set all inputs to the new cast(s) so the Phi is removed by Identity |
| 1922 | PhaseIterGVN* igvn = phase->is_IterGVN(); |
| 1923 | for (uint i = 1; i < req(); i++) { |
| 1924 | set_req_X(i, cast, igvn); |
| 1925 | } |
| 1926 | uin = cast; |
| 1927 | } |
| 1928 | |
| 1929 | // One unique input. |
| 1930 | debug_only(Node* ident = Identity(phase)); |
| 1931 | // The unique input must eventually be detected by the Identity call. |
| 1932 | #ifdef ASSERT |
| 1933 | if (ident != uin && !ident->is_top()) { |
| 1934 | // print this output before failing assert |
| 1935 | r->dump(3); |
| 1936 | this->dump(3); |
| 1937 | ident->dump(); |
| 1938 | uin->dump(); |
| 1939 | } |
| 1940 | #endif |
| 1941 | assert(ident == uin || ident->is_top(), "Identity must clean this up"); |
| 1942 | return NULL; |
| 1943 | } |
| 1944 | |
| 1945 | Node* opt = NULL; |
| 1946 | int true_path = is_diamond_phi(); |
| 1947 | if( true_path != 0 ) { |
| 1948 | // Check for CMove'ing identity. If it would be unsafe, |
| 1949 | // handle it here. In the safe case, let Identity handle it. |
| 1950 | Node* unsafe_id = is_cmove_id(phase, true_path); |
| 1951 | if( unsafe_id != NULL && is_unsafe_data_reference(unsafe_id) ) |
| 1952 | opt = unsafe_id; |
| 1953 | |
| 1954 | // Check for simple convert-to-boolean pattern |
| 1955 | if( opt == NULL ) |
| 1956 | opt = is_x2logic(phase, this, true_path); |
| 1957 | |
| 1958 | // Check for absolute value |
| 1959 | if( opt == NULL ) |
| 1960 | opt = is_absolute(phase, this, true_path); |
| 1961 | |
| 1962 | // Check for conditional add |
| 1963 | if( opt == NULL && can_reshape ) |
| 1964 | opt = is_cond_add(phase, this, true_path); |
| 1965 | |
| 1966 | // These 4 optimizations could subsume the phi: |
| 1967 | // have to check for a dead data loop creation. |
| 1968 | if( opt != NULL ) { |
| 1969 | if( opt == unsafe_id || is_unsafe_data_reference(opt) ) { |
| 1970 | // Found dead loop. |
| 1971 | if( can_reshape ) |
| 1972 | return top; |
| 1973 | // We can't return top if we are in Parse phase - cut inputs only |
| 1974 | // to stop further optimizations for this phi. Identity will return TOP. |
| 1975 | assert(req() == 3, "only diamond merge phi here"); |
| 1976 | set_req(1, top); |
| 1977 | set_req(2, top); |
| 1978 | return NULL; |
| 1979 | } else { |
| 1980 | return opt; |
| 1981 | } |
| 1982 | } |
| 1983 | } |
| 1984 | |
| 1985 | // Check for merging identical values and split flow paths |
| 1986 | if (can_reshape) { |
| 1987 | opt = split_flow_path(phase, this); |
| 1988 | // This optimization only modifies phi - don't need to check for dead loop. |
| 1989 | assert(opt == NULL || phase->eqv(opt, this), "do not elide phi"); |
| 1990 | if (opt != NULL) return opt; |
| 1991 | } |
| 1992 | |
| 1993 | if (in(1) != NULL && in(1)->Opcode() == Op_AddP && can_reshape) { |
| 1994 | // Try to undo Phi of AddP: |
| 1995 | // (Phi (AddP base base y) (AddP base2 base2 y)) |
| 1996 | // becomes: |
| 1997 | // newbase := (Phi base base2) |
| 1998 | // (AddP newbase newbase y) |
| 1999 | // |
| 2000 | // This occurs as a result of unsuccessful split_thru_phi and |
| 2001 | // interferes with taking advantage of addressing modes. See the |
| 2002 | // clone_shift_expressions code in matcher.cpp |
| 2003 | Node* addp = in(1); |
| 2004 | const Type* type = addp->in(AddPNode::Base)->bottom_type(); |
| 2005 | Node* y = addp->in(AddPNode::Offset); |
| 2006 | if (y != NULL && addp->in(AddPNode::Base) == addp->in(AddPNode::Address)) { |
| 2007 | // make sure that all the inputs are similar to the first one, |
| 2008 | // i.e. AddP with base == address and same offset as first AddP |
| 2009 | bool doit = true; |
| 2010 | for (uint i = 2; i < req(); i++) { |
| 2011 | if (in(i) == NULL || |
| 2012 | in(i)->Opcode() != Op_AddP || |
| 2013 | in(i)->in(AddPNode::Base) != in(i)->in(AddPNode::Address) || |
| 2014 | in(i)->in(AddPNode::Offset) != y) { |
| 2015 | doit = false; |
| 2016 | break; |
| 2017 | } |
| 2018 | // Accumulate type for resulting Phi |
| 2019 | type = type->meet_speculative(in(i)->in(AddPNode::Base)->bottom_type()); |
| 2020 | } |
| 2021 | Node* base = NULL; |
| 2022 | if (doit) { |
| 2023 | // Check for neighboring AddP nodes in a tree. |
| 2024 | // If they have a base, use that it. |
| 2025 | for (DUIterator_Fast kmax, k = this->fast_outs(kmax); k < kmax; k++) { |
| 2026 | Node* u = this->fast_out(k); |
| 2027 | if (u->is_AddP()) { |
| 2028 | Node* base2 = u->in(AddPNode::Base); |
| 2029 | if (base2 != NULL && !base2->is_top()) { |
| 2030 | if (base == NULL) |
| 2031 | base = base2; |
| 2032 | else if (base != base2) |
| 2033 | { doit = false; break; } |
| 2034 | } |
| 2035 | } |
| 2036 | } |
| 2037 | } |
| 2038 | if (doit) { |
| 2039 | if (base == NULL) { |
| 2040 | base = new PhiNode(in(0), type, NULL); |
| 2041 | for (uint i = 1; i < req(); i++) { |
| 2042 | base->init_req(i, in(i)->in(AddPNode::Base)); |
| 2043 | } |
| 2044 | phase->is_IterGVN()->register_new_node_with_optimizer(base); |
| 2045 | } |
| 2046 | return new AddPNode(base, base, y); |
| 2047 | } |
| 2048 | } |
| 2049 | } |
| 2050 | |
| 2051 | // Split phis through memory merges, so that the memory merges will go away. |
| 2052 | // Piggy-back this transformation on the search for a unique input.... |
| 2053 | // It will be as if the merged memory is the unique value of the phi. |
| 2054 | // (Do not attempt this optimization unless parsing is complete. |
| 2055 | // It would make the parser's memory-merge logic sick.) |
| 2056 | // (MergeMemNode is not dead_loop_safe - need to check for dead loop.) |
| 2057 | if (progress == NULL && can_reshape && type() == Type::MEMORY) { |
| 2058 | // see if this phi should be sliced |
| 2059 | uint merge_width = 0; |
| 2060 | bool saw_self = false; |
| 2061 | for( uint i=1; i<req(); ++i ) {// For all paths in |
| 2062 | Node *ii = in(i); |
| 2063 | // TOP inputs should not be counted as safe inputs because if the |
| 2064 | // Phi references itself through all other inputs then splitting the |
| 2065 | // Phi through memory merges would create dead loop at later stage. |
| 2066 | if (ii == top) { |
| 2067 | return NULL; // Delay optimization until graph is cleaned. |
| 2068 | } |
| 2069 | if (ii->is_MergeMem()) { |
| 2070 | MergeMemNode* n = ii->as_MergeMem(); |
| 2071 | merge_width = MAX2(merge_width, n->req()); |
| 2072 | saw_self = saw_self || phase->eqv(n->base_memory(), this); |
| 2073 | } |
| 2074 | } |
| 2075 | |
| 2076 | // This restriction is temporarily necessary to ensure termination: |
| 2077 | if (!saw_self && adr_type() == TypePtr::BOTTOM) merge_width = 0; |
| 2078 | |
| 2079 | if (merge_width > Compile::AliasIdxRaw) { |
| 2080 | // found at least one non-empty MergeMem |
| 2081 | const TypePtr* at = adr_type(); |
| 2082 | if (at != TypePtr::BOTTOM) { |
| 2083 | // Patch the existing phi to select an input from the merge: |
| 2084 | // Phi:AT1(...MergeMem(m0, m1, m2)...) into |
| 2085 | // Phi:AT1(...m1...) |
| 2086 | int alias_idx = phase->C->get_alias_index(at); |
| 2087 | for (uint i=1; i<req(); ++i) { |
| 2088 | Node *ii = in(i); |
| 2089 | if (ii->is_MergeMem()) { |
| 2090 | MergeMemNode* n = ii->as_MergeMem(); |
| 2091 | // compress paths and change unreachable cycles to TOP |
| 2092 | // If not, we can update the input infinitely along a MergeMem cycle |
| 2093 | // Equivalent code is in MemNode::Ideal_common |
| 2094 | Node *m = phase->transform(n); |
| 2095 | if (outcnt() == 0) { // Above transform() may kill us! |
| 2096 | return top; |
| 2097 | } |
| 2098 | // If transformed to a MergeMem, get the desired slice |
| 2099 | // Otherwise the returned node represents memory for every slice |
| 2100 | Node *new_mem = (m->is_MergeMem()) ? |
| 2101 | m->as_MergeMem()->memory_at(alias_idx) : m; |
| 2102 | // Update input if it is progress over what we have now |
| 2103 | if (new_mem != ii) { |
| 2104 | set_req(i, new_mem); |
| 2105 | progress = this; |
| 2106 | } |
| 2107 | } |
| 2108 | } |
| 2109 | } else { |
| 2110 | // We know that at least one MergeMem->base_memory() == this |
| 2111 | // (saw_self == true). If all other inputs also references this phi |
| 2112 | // (directly or through data nodes) - it is dead loop. |
| 2113 | bool saw_safe_input = false; |
| 2114 | for (uint j = 1; j < req(); ++j) { |
| 2115 | Node *n = in(j); |
| 2116 | if (n->is_MergeMem() && n->as_MergeMem()->base_memory() == this) |
| 2117 | continue; // skip known cases |
| 2118 | if (!is_unsafe_data_reference(n)) { |
| 2119 | saw_safe_input = true; // found safe input |
| 2120 | break; |
| 2121 | } |
| 2122 | } |
| 2123 | if (!saw_safe_input) |
| 2124 | return top; // all inputs reference back to this phi - dead loop |
| 2125 | |
| 2126 | // Phi(...MergeMem(m0, m1:AT1, m2:AT2)...) into |
| 2127 | // MergeMem(Phi(...m0...), Phi:AT1(...m1...), Phi:AT2(...m2...)) |
| 2128 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 2129 | Node* hook = new Node(1); |
| 2130 | PhiNode* new_base = (PhiNode*) clone(); |
| 2131 | // Must eagerly register phis, since they participate in loops. |
| 2132 | if (igvn) { |
| 2133 | igvn->register_new_node_with_optimizer(new_base); |
| 2134 | hook->add_req(new_base); |
| 2135 | } |
| 2136 | MergeMemNode* result = MergeMemNode::make(new_base); |
| 2137 | for (uint i = 1; i < req(); ++i) { |
| 2138 | Node *ii = in(i); |
| 2139 | if (ii->is_MergeMem()) { |
| 2140 | MergeMemNode* n = ii->as_MergeMem(); |
| 2141 | for (MergeMemStream mms(result, n); mms.next_non_empty2(); ) { |
| 2142 | // If we have not seen this slice yet, make a phi for it. |
| 2143 | bool made_new_phi = false; |
| 2144 | if (mms.is_empty()) { |
| 2145 | Node* new_phi = new_base->slice_memory(mms.adr_type(phase->C)); |
| 2146 | made_new_phi = true; |
| 2147 | if (igvn) { |
| 2148 | igvn->register_new_node_with_optimizer(new_phi); |
| 2149 | hook->add_req(new_phi); |
| 2150 | } |
| 2151 | mms.set_memory(new_phi); |
| 2152 | } |
| 2153 | Node* phi = mms.memory(); |
| 2154 | assert(made_new_phi || phi->in(i) == n, "replace the i-th merge by a slice"); |
| 2155 | phi->set_req(i, mms.memory2()); |
| 2156 | } |
| 2157 | } |
| 2158 | } |
| 2159 | // Distribute all self-loops. |
| 2160 | { // (Extra braces to hide mms.) |
| 2161 | for (MergeMemStream mms(result); mms.next_non_empty(); ) { |
| 2162 | Node* phi = mms.memory(); |
| 2163 | for (uint i = 1; i < req(); ++i) { |
| 2164 | if (phi->in(i) == this) phi->set_req(i, phi); |
| 2165 | } |
| 2166 | } |
| 2167 | } |
| 2168 | // now transform the new nodes, and return the mergemem |
| 2169 | for (MergeMemStream mms(result); mms.next_non_empty(); ) { |
| 2170 | Node* phi = mms.memory(); |
| 2171 | mms.set_memory(phase->transform(phi)); |
| 2172 | } |
| 2173 | if (igvn) { // Unhook. |
| 2174 | igvn->hash_delete(hook); |
| 2175 | for (uint i = 1; i < hook->req(); i++) { |
| 2176 | hook->set_req(i, NULL); |
| 2177 | } |
| 2178 | } |
| 2179 | // Replace self with the result. |
| 2180 | return result; |
| 2181 | } |
| 2182 | } |
| 2183 | // |
| 2184 | // Other optimizations on the memory chain |
| 2185 | // |
| 2186 | const TypePtr* at = adr_type(); |
| 2187 | for( uint i=1; i<req(); ++i ) {// For all paths in |
| 2188 | Node *ii = in(i); |
| 2189 | Node *new_in = MemNode::optimize_memory_chain(ii, at, NULL, phase); |
| 2190 | if (ii != new_in ) { |
| 2191 | set_req(i, new_in); |
| 2192 | progress = this; |
| 2193 | } |
| 2194 | } |
| 2195 | } |
| 2196 | |
| 2197 | #ifdef _LP64 |
| 2198 | // Push DecodeN/DecodeNKlass down through phi. |
| 2199 | // The rest of phi graph will transform by split EncodeP node though phis up. |
| 2200 | if ((UseCompressedOops || UseCompressedClassPointers) && can_reshape && progress == NULL) { |
| 2201 | bool may_push = true; |
| 2202 | bool has_decodeN = false; |
| 2203 | bool is_decodeN = false; |
| 2204 | for (uint i=1; i<req(); ++i) {// For all paths in |
| 2205 | Node *ii = in(i); |
| 2206 | if (ii->is_DecodeNarrowPtr() && ii->bottom_type() == bottom_type()) { |
| 2207 | // Do optimization if a non dead path exist. |
| 2208 | if (ii->in(1)->bottom_type() != Type::TOP) { |
| 2209 | has_decodeN = true; |
| 2210 | is_decodeN = ii->is_DecodeN(); |
| 2211 | } |
| 2212 | } else if (!ii->is_Phi()) { |
| 2213 | may_push = false; |
| 2214 | } |
| 2215 | } |
| 2216 | |
| 2217 | if (has_decodeN && may_push) { |
| 2218 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 2219 | // Make narrow type for new phi. |
| 2220 | const Type* narrow_t; |
| 2221 | if (is_decodeN) { |
| 2222 | narrow_t = TypeNarrowOop::make(this->bottom_type()->is_ptr()); |
| 2223 | } else { |
| 2224 | narrow_t = TypeNarrowKlass::make(this->bottom_type()->is_ptr()); |
| 2225 | } |
| 2226 | PhiNode* new_phi = new PhiNode(r, narrow_t); |
| 2227 | uint orig_cnt = req(); |
| 2228 | for (uint i=1; i<req(); ++i) {// For all paths in |
| 2229 | Node *ii = in(i); |
| 2230 | Node* new_ii = NULL; |
| 2231 | if (ii->is_DecodeNarrowPtr()) { |
| 2232 | assert(ii->bottom_type() == bottom_type(), "sanity"); |
| 2233 | new_ii = ii->in(1); |
| 2234 | } else { |
| 2235 | assert(ii->is_Phi(), "sanity"); |
| 2236 | if (ii->as_Phi() == this) { |
| 2237 | new_ii = new_phi; |
| 2238 | } else { |
| 2239 | if (is_decodeN) { |
| 2240 | new_ii = new EncodePNode(ii, narrow_t); |
| 2241 | } else { |
| 2242 | new_ii = new EncodePKlassNode(ii, narrow_t); |
| 2243 | } |
| 2244 | igvn->register_new_node_with_optimizer(new_ii); |
| 2245 | } |
| 2246 | } |
| 2247 | new_phi->set_req(i, new_ii); |
| 2248 | } |
| 2249 | igvn->register_new_node_with_optimizer(new_phi, this); |
| 2250 | if (is_decodeN) { |
| 2251 | progress = new DecodeNNode(new_phi, bottom_type()); |
| 2252 | } else { |
| 2253 | progress = new DecodeNKlassNode(new_phi, bottom_type()); |
| 2254 | } |
| 2255 | } |
| 2256 | } |
| 2257 | #endif |
| 2258 | |
| 2259 | return progress; // Return any progress |
| 2260 | } |
| 2261 | |
| 2262 | //------------------------------is_tripcount----------------------------------- |
| 2263 | bool PhiNode::is_tripcount() const { |
| 2264 | return (in(0) != NULL && in(0)->is_CountedLoop() && |
| 2265 | in(0)->as_CountedLoop()->phi() == this); |
| 2266 | } |
| 2267 | |
| 2268 | //------------------------------out_RegMask------------------------------------ |
| 2269 | const RegMask &PhiNode::in_RegMask(uint i) const { |
| 2270 | return i ? out_RegMask() : RegMask::Empty; |
| 2271 | } |
| 2272 | |
| 2273 | const RegMask &PhiNode::out_RegMask() const { |
| 2274 | uint ideal_reg = _type->ideal_reg(); |
| 2275 | assert( ideal_reg != Node::NotAMachineReg, "invalid type at Phi"); |
| 2276 | if( ideal_reg == 0 ) return RegMask::Empty; |
| 2277 | assert(ideal_reg != Op_RegFlags, "flags register is not spillable"); |
| 2278 | return *(Compile::current()->matcher()->idealreg2spillmask[ideal_reg]); |
| 2279 | } |
| 2280 | |
| 2281 | #ifndef PRODUCT |
| 2282 | void PhiNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const { |
| 2283 | // For a PhiNode, the set of related nodes includes all inputs till level 2, |
| 2284 | // and all outputs till level 1. In compact mode, inputs till level 1 are |
| 2285 | // collected. |
| 2286 | this->collect_nodes(in_rel, compact ? 1 : 2, false, false); |
| 2287 | this->collect_nodes(out_rel, -1, false, false); |
| 2288 | } |
| 2289 | |
| 2290 | void PhiNode::dump_spec(outputStream *st) const { |
| 2291 | TypeNode::dump_spec(st); |
| 2292 | if (is_tripcount()) { |
| 2293 | st->print(" #tripcount"); |
| 2294 | } |
| 2295 | } |
| 2296 | #endif |
| 2297 | |
| 2298 | |
| 2299 | //============================================================================= |
| 2300 | const Type* GotoNode::Value(PhaseGVN* phase) const { |
| 2301 | // If the input is reachable, then we are executed. |
| 2302 | // If the input is not reachable, then we are not executed. |
| 2303 | return phase->type(in(0)); |
| 2304 | } |
| 2305 | |
| 2306 | Node* GotoNode::Identity(PhaseGVN* phase) { |
| 2307 | return in(0); // Simple copy of incoming control |
| 2308 | } |
| 2309 | |
| 2310 | const RegMask &GotoNode::out_RegMask() const { |
| 2311 | return RegMask::Empty; |
| 2312 | } |
| 2313 | |
| 2314 | #ifndef PRODUCT |
| 2315 | //-----------------------------related----------------------------------------- |
| 2316 | // The related nodes of a GotoNode are all inputs at level 1, as well as the |
| 2317 | // outputs at level 1. This is regardless of compact mode. |
| 2318 | void GotoNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const { |
| 2319 | this->collect_nodes(in_rel, 1, false, false); |
| 2320 | this->collect_nodes(out_rel, -1, false, false); |
| 2321 | } |
| 2322 | #endif |
| 2323 | |
| 2324 | |
| 2325 | //============================================================================= |
| 2326 | const RegMask &JumpNode::out_RegMask() const { |
| 2327 | return RegMask::Empty; |
| 2328 | } |
| 2329 | |
| 2330 | #ifndef PRODUCT |
| 2331 | //-----------------------------related----------------------------------------- |
| 2332 | // The related nodes of a JumpNode are all inputs at level 1, as well as the |
| 2333 | // outputs at level 2 (to include actual jump targets beyond projection nodes). |
| 2334 | // This is regardless of compact mode. |
| 2335 | void JumpNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const { |
| 2336 | this->collect_nodes(in_rel, 1, false, false); |
| 2337 | this->collect_nodes(out_rel, -2, false, false); |
| 2338 | } |
| 2339 | #endif |
| 2340 | |
| 2341 | //============================================================================= |
| 2342 | const RegMask &JProjNode::out_RegMask() const { |
| 2343 | return RegMask::Empty; |
| 2344 | } |
| 2345 | |
| 2346 | //============================================================================= |
| 2347 | const RegMask &CProjNode::out_RegMask() const { |
| 2348 | return RegMask::Empty; |
| 2349 | } |
| 2350 | |
| 2351 | |
| 2352 | |
| 2353 | //============================================================================= |
| 2354 | |
| 2355 | uint PCTableNode::hash() const { return Node::hash() + _size; } |
| 2356 | bool PCTableNode::cmp( const Node &n ) const |
| 2357 | { return _size == ((PCTableNode&)n)._size; } |
| 2358 | |
| 2359 | const Type *PCTableNode::bottom_type() const { |
| 2360 | const Type** f = TypeTuple::fields(_size); |
| 2361 | for( uint i = 0; i < _size; i++ ) f[i] = Type::CONTROL; |
| 2362 | return TypeTuple::make(_size, f); |
| 2363 | } |
| 2364 | |
| 2365 | //------------------------------Value------------------------------------------ |
| 2366 | // Compute the type of the PCTableNode. If reachable it is a tuple of |
| 2367 | // Control, otherwise the table targets are not reachable |
| 2368 | const Type* PCTableNode::Value(PhaseGVN* phase) const { |
| 2369 | if( phase->type(in(0)) == Type::CONTROL ) |
| 2370 | return bottom_type(); |
| 2371 | return Type::TOP; // All paths dead? Then so are we |
| 2372 | } |
| 2373 | |
| 2374 | //------------------------------Ideal------------------------------------------ |
| 2375 | // Return a node which is more "ideal" than the current node. Strip out |
| 2376 | // control copies |
| 2377 | Node *PCTableNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
| 2378 | return remove_dead_region(phase, can_reshape) ? this : NULL; |
| 2379 | } |
| 2380 | |
| 2381 | //============================================================================= |
| 2382 | uint JumpProjNode::hash() const { |
| 2383 | return Node::hash() + _dest_bci; |
| 2384 | } |
| 2385 | |
| 2386 | bool JumpProjNode::cmp( const Node &n ) const { |
| 2387 | return ProjNode::cmp(n) && |
| 2388 | _dest_bci == ((JumpProjNode&)n)._dest_bci; |
| 2389 | } |
| 2390 | |
| 2391 | #ifndef PRODUCT |
| 2392 | void JumpProjNode::dump_spec(outputStream *st) const { |
| 2393 | ProjNode::dump_spec(st); |
| 2394 | st->print("@bci %d ",_dest_bci); |
| 2395 | } |
| 2396 | |
| 2397 | void JumpProjNode::dump_compact_spec(outputStream *st) const { |
| 2398 | ProjNode::dump_compact_spec(st); |
| 2399 | st->print("(%d)%d@%d", _switch_val, _proj_no, _dest_bci); |
| 2400 | } |
| 2401 | |
| 2402 | void JumpProjNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const { |
| 2403 | // The related nodes of a JumpProjNode are its inputs and outputs at level 1. |
| 2404 | this->collect_nodes(in_rel, 1, false, false); |
| 2405 | this->collect_nodes(out_rel, -1, false, false); |
| 2406 | } |
| 2407 | #endif |
| 2408 | |
| 2409 | //============================================================================= |
| 2410 | //------------------------------Value------------------------------------------ |
| 2411 | // Check for being unreachable, or for coming from a Rethrow. Rethrow's cannot |
| 2412 | // have the default "fall_through_index" path. |
| 2413 | const Type* CatchNode::Value(PhaseGVN* phase) const { |
| 2414 | // Unreachable? Then so are all paths from here. |
| 2415 | if( phase->type(in(0)) == Type::TOP ) return Type::TOP; |
| 2416 | // First assume all paths are reachable |
| 2417 | const Type** f = TypeTuple::fields(_size); |
| 2418 | for( uint i = 0; i < _size; i++ ) f[i] = Type::CONTROL; |
| 2419 | // Identify cases that will always throw an exception |
| 2420 | // () rethrow call |
| 2421 | // () virtual or interface call with NULL receiver |
| 2422 | // () call is a check cast with incompatible arguments |
| 2423 | if( in(1)->is_Proj() ) { |
| 2424 | Node *i10 = in(1)->in(0); |
| 2425 | if( i10->is_Call() ) { |
| 2426 | CallNode *call = i10->as_Call(); |
| 2427 | // Rethrows always throw exceptions, never return |
| 2428 | if (call->entry_point() == OptoRuntime::rethrow_stub()) { |
| 2429 | f[CatchProjNode::fall_through_index] = Type::TOP; |
| 2430 | } else if( call->req() > TypeFunc::Parms ) { |
| 2431 | const Type *arg0 = phase->type( call->in(TypeFunc::Parms) ); |
| 2432 | // Check for null receiver to virtual or interface calls |
| 2433 | if( call->is_CallDynamicJava() && |
| 2434 | arg0->higher_equal(TypePtr::NULL_PTR) ) { |
| 2435 | f[CatchProjNode::fall_through_index] = Type::TOP; |
| 2436 | } |
| 2437 | } // End of if not a runtime stub |
| 2438 | } // End of if have call above me |
| 2439 | } // End of slot 1 is not a projection |
| 2440 | return TypeTuple::make(_size, f); |
| 2441 | } |
| 2442 | |
| 2443 | //============================================================================= |
| 2444 | uint CatchProjNode::hash() const { |
| 2445 | return Node::hash() + _handler_bci; |
| 2446 | } |
| 2447 | |
| 2448 | |
| 2449 | bool CatchProjNode::cmp( const Node &n ) const { |
| 2450 | return ProjNode::cmp(n) && |
| 2451 | _handler_bci == ((CatchProjNode&)n)._handler_bci; |
| 2452 | } |
| 2453 | |
| 2454 | |
| 2455 | //------------------------------Identity--------------------------------------- |
| 2456 | // If only 1 target is possible, choose it if it is the main control |
| 2457 | Node* CatchProjNode::Identity(PhaseGVN* phase) { |
| 2458 | // If my value is control and no other value is, then treat as ID |
| 2459 | const TypeTuple *t = phase->type(in(0))->is_tuple(); |
| 2460 | if (t->field_at(_con) != Type::CONTROL) return this; |
| 2461 | // If we remove the last CatchProj and elide the Catch/CatchProj, then we |
| 2462 | // also remove any exception table entry. Thus we must know the call |
| 2463 | // feeding the Catch will not really throw an exception. This is ok for |
| 2464 | // the main fall-thru control (happens when we know a call can never throw |
| 2465 | // an exception) or for "rethrow", because a further optimization will |
| 2466 | // yank the rethrow (happens when we inline a function that can throw an |
| 2467 | // exception and the caller has no handler). Not legal, e.g., for passing |
| 2468 | // a NULL receiver to a v-call, or passing bad types to a slow-check-cast. |
| 2469 | // These cases MUST throw an exception via the runtime system, so the VM |
| 2470 | // will be looking for a table entry. |
| 2471 | Node *proj = in(0)->in(1); // Expect a proj feeding CatchNode |
| 2472 | CallNode *call; |
| 2473 | if (_con != TypeFunc::Control && // Bail out if not the main control. |
| 2474 | !(proj->is_Proj() && // AND NOT a rethrow |
| 2475 | proj->in(0)->is_Call() && |
| 2476 | (call = proj->in(0)->as_Call()) && |
| 2477 | call->entry_point() == OptoRuntime::rethrow_stub())) |
| 2478 | return this; |
| 2479 | |
| 2480 | // Search for any other path being control |
| 2481 | for (uint i = 0; i < t->cnt(); i++) { |
| 2482 | if (i != _con && t->field_at(i) == Type::CONTROL) |
| 2483 | return this; |
| 2484 | } |
| 2485 | // Only my path is possible; I am identity on control to the jump |
| 2486 | return in(0)->in(0); |
| 2487 | } |
| 2488 | |
| 2489 | |
| 2490 | #ifndef PRODUCT |
| 2491 | void CatchProjNode::dump_spec(outputStream *st) const { |
| 2492 | ProjNode::dump_spec(st); |
| 2493 | st->print("@bci %d ",_handler_bci); |
| 2494 | } |
| 2495 | #endif |
| 2496 | |
| 2497 | //============================================================================= |
| 2498 | //------------------------------Identity--------------------------------------- |
| 2499 | // Check for CreateEx being Identity. |
| 2500 | Node* CreateExNode::Identity(PhaseGVN* phase) { |
| 2501 | if( phase->type(in(1)) == Type::TOP ) return in(1); |
| 2502 | if( phase->type(in(0)) == Type::TOP ) return in(0); |
| 2503 | // We only come from CatchProj, unless the CatchProj goes away. |
| 2504 | // If the CatchProj is optimized away, then we just carry the |
| 2505 | // exception oop through. |
| 2506 | CallNode *call = in(1)->in(0)->as_Call(); |
| 2507 | |
| 2508 | return ( in(0)->is_CatchProj() && in(0)->in(0)->in(1) == in(1) ) |
| 2509 | ? this |
| 2510 | : call->in(TypeFunc::Parms); |
| 2511 | } |
| 2512 | |
| 2513 | //============================================================================= |
| 2514 | //------------------------------Value------------------------------------------ |
| 2515 | // Check for being unreachable. |
| 2516 | const Type* NeverBranchNode::Value(PhaseGVN* phase) const { |
| 2517 | if (!in(0) || in(0)->is_top()) return Type::TOP; |
| 2518 | return bottom_type(); |
| 2519 | } |
| 2520 | |
| 2521 | //------------------------------Ideal------------------------------------------ |
| 2522 | // Check for no longer being part of a loop |
| 2523 | Node *NeverBranchNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
| 2524 | if (can_reshape && !in(0)->is_Loop()) { |
| 2525 | // Dead code elimination can sometimes delete this projection so |
| 2526 | // if it's not there, there's nothing to do. |
| 2527 | Node* fallthru = proj_out_or_null(0); |
| 2528 | if (fallthru != NULL) { |
| 2529 | phase->is_IterGVN()->replace_node(fallthru, in(0)); |
| 2530 | } |
| 2531 | return phase->C->top(); |
| 2532 | } |
| 2533 | return NULL; |
| 2534 | } |
| 2535 | |
| 2536 | #ifndef PRODUCT |
| 2537 | void NeverBranchNode::format( PhaseRegAlloc *ra_, outputStream *st) const { |
| 2538 | st->print("%s", Name()); |
| 2539 | } |
| 2540 | #endif |
| 2541 |
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