0
|
1 /*
|
|
2 * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
20 * CA 95054 USA or visit www.sun.com if you need additional information or
|
|
21 * have any questions.
|
|
22 *
|
|
23 */
|
|
24
|
|
25 // Portions of code courtesy of Clifford Click
|
|
26
|
|
27 // Optimization - Graph Style
|
|
28
|
|
29 #include "incls/_precompiled.incl"
|
|
30 #include "incls/_cfgnode.cpp.incl"
|
|
31
|
|
32 //=============================================================================
|
|
33 //------------------------------Value------------------------------------------
|
|
34 // Compute the type of the RegionNode.
|
|
35 const Type *RegionNode::Value( PhaseTransform *phase ) const {
|
|
36 for( uint i=1; i<req(); ++i ) { // For all paths in
|
|
37 Node *n = in(i); // Get Control source
|
|
38 if( !n ) continue; // Missing inputs are TOP
|
|
39 if( phase->type(n) == Type::CONTROL )
|
|
40 return Type::CONTROL;
|
|
41 }
|
|
42 return Type::TOP; // All paths dead? Then so are we
|
|
43 }
|
|
44
|
|
45 //------------------------------Identity---------------------------------------
|
|
46 // Check for Region being Identity.
|
|
47 Node *RegionNode::Identity( PhaseTransform *phase ) {
|
|
48 // Cannot have Region be an identity, even if it has only 1 input.
|
|
49 // Phi users cannot have their Region input folded away for them,
|
|
50 // since they need to select the proper data input
|
|
51 return this;
|
|
52 }
|
|
53
|
|
54 //------------------------------merge_region-----------------------------------
|
|
55 // If a Region flows into a Region, merge into one big happy merge. This is
|
|
56 // hard to do if there is stuff that has to happen
|
|
57 static Node *merge_region(RegionNode *region, PhaseGVN *phase) {
|
|
58 if( region->Opcode() != Op_Region ) // Do not do to LoopNodes
|
|
59 return NULL;
|
|
60 Node *progress = NULL; // Progress flag
|
|
61 PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
62
|
|
63 uint rreq = region->req();
|
|
64 for( uint i = 1; i < rreq; i++ ) {
|
|
65 Node *r = region->in(i);
|
|
66 if( r && r->Opcode() == Op_Region && // Found a region?
|
|
67 r->in(0) == r && // Not already collapsed?
|
|
68 r != region && // Avoid stupid situations
|
|
69 r->outcnt() == 2 ) { // Self user and 'region' user only?
|
|
70 assert(!r->as_Region()->has_phi(), "no phi users");
|
|
71 if( !progress ) { // No progress
|
|
72 if (region->has_phi()) {
|
|
73 return NULL; // Only flatten if no Phi users
|
|
74 // igvn->hash_delete( phi );
|
|
75 }
|
|
76 igvn->hash_delete( region );
|
|
77 progress = region; // Making progress
|
|
78 }
|
|
79 igvn->hash_delete( r );
|
|
80
|
|
81 // Append inputs to 'r' onto 'region'
|
|
82 for( uint j = 1; j < r->req(); j++ ) {
|
|
83 // Move an input from 'r' to 'region'
|
|
84 region->add_req(r->in(j));
|
|
85 r->set_req(j, phase->C->top());
|
|
86 // Update phis of 'region'
|
|
87 //for( uint k = 0; k < max; k++ ) {
|
|
88 // Node *phi = region->out(k);
|
|
89 // if( phi->is_Phi() ) {
|
|
90 // phi->add_req(phi->in(i));
|
|
91 // }
|
|
92 //}
|
|
93
|
|
94 rreq++; // One more input to Region
|
|
95 } // Found a region to merge into Region
|
|
96 // Clobber pointer to the now dead 'r'
|
|
97 region->set_req(i, phase->C->top());
|
|
98 }
|
|
99 }
|
|
100
|
|
101 return progress;
|
|
102 }
|
|
103
|
|
104
|
|
105
|
|
106 //--------------------------------has_phi--------------------------------------
|
|
107 // Helper function: Return any PhiNode that uses this region or NULL
|
|
108 PhiNode* RegionNode::has_phi() const {
|
|
109 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
|
|
110 Node* phi = fast_out(i);
|
|
111 if (phi->is_Phi()) { // Check for Phi users
|
|
112 assert(phi->in(0) == (Node*)this, "phi uses region only via in(0)");
|
|
113 return phi->as_Phi(); // this one is good enough
|
|
114 }
|
|
115 }
|
|
116
|
|
117 return NULL;
|
|
118 }
|
|
119
|
|
120
|
|
121 //-----------------------------has_unique_phi----------------------------------
|
|
122 // Helper function: Return the only PhiNode that uses this region or NULL
|
|
123 PhiNode* RegionNode::has_unique_phi() const {
|
|
124 // Check that only one use is a Phi
|
|
125 PhiNode* only_phi = NULL;
|
|
126 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
|
|
127 Node* phi = fast_out(i);
|
|
128 if (phi->is_Phi()) { // Check for Phi users
|
|
129 assert(phi->in(0) == (Node*)this, "phi uses region only via in(0)");
|
|
130 if (only_phi == NULL) {
|
|
131 only_phi = phi->as_Phi();
|
|
132 } else {
|
|
133 return NULL; // multiple phis
|
|
134 }
|
|
135 }
|
|
136 }
|
|
137
|
|
138 return only_phi;
|
|
139 }
|
|
140
|
|
141
|
|
142 //------------------------------check_phi_clipping-----------------------------
|
|
143 // Helper function for RegionNode's identification of FP clipping
|
|
144 // Check inputs to the Phi
|
|
145 static bool check_phi_clipping( PhiNode *phi, ConNode * &min, uint &min_idx, ConNode * &max, uint &max_idx, Node * &val, uint &val_idx ) {
|
|
146 min = NULL;
|
|
147 max = NULL;
|
|
148 val = NULL;
|
|
149 min_idx = 0;
|
|
150 max_idx = 0;
|
|
151 val_idx = 0;
|
|
152 uint phi_max = phi->req();
|
|
153 if( phi_max == 4 ) {
|
|
154 for( uint j = 1; j < phi_max; ++j ) {
|
|
155 Node *n = phi->in(j);
|
|
156 int opcode = n->Opcode();
|
|
157 switch( opcode ) {
|
|
158 case Op_ConI:
|
|
159 {
|
|
160 if( min == NULL ) {
|
|
161 min = n->Opcode() == Op_ConI ? (ConNode*)n : NULL;
|
|
162 min_idx = j;
|
|
163 } else {
|
|
164 max = n->Opcode() == Op_ConI ? (ConNode*)n : NULL;
|
|
165 max_idx = j;
|
|
166 if( min->get_int() > max->get_int() ) {
|
|
167 // Swap min and max
|
|
168 ConNode *temp;
|
|
169 uint temp_idx;
|
|
170 temp = min; min = max; max = temp;
|
|
171 temp_idx = min_idx; min_idx = max_idx; max_idx = temp_idx;
|
|
172 }
|
|
173 }
|
|
174 }
|
|
175 break;
|
|
176 default:
|
|
177 {
|
|
178 val = n;
|
|
179 val_idx = j;
|
|
180 }
|
|
181 break;
|
|
182 }
|
|
183 }
|
|
184 }
|
|
185 return ( min && max && val && (min->get_int() <= 0) && (max->get_int() >=0) );
|
|
186 }
|
|
187
|
|
188
|
|
189 //------------------------------check_if_clipping------------------------------
|
|
190 // Helper function for RegionNode's identification of FP clipping
|
|
191 // Check that inputs to Region come from two IfNodes,
|
|
192 //
|
|
193 // If
|
|
194 // False True
|
|
195 // If |
|
|
196 // False True |
|
|
197 // | | |
|
|
198 // RegionNode_inputs
|
|
199 //
|
|
200 static bool check_if_clipping( const RegionNode *region, IfNode * &bot_if, IfNode * &top_if ) {
|
|
201 top_if = NULL;
|
|
202 bot_if = NULL;
|
|
203
|
|
204 // Check control structure above RegionNode for (if ( if ) )
|
|
205 Node *in1 = region->in(1);
|
|
206 Node *in2 = region->in(2);
|
|
207 Node *in3 = region->in(3);
|
|
208 // Check that all inputs are projections
|
|
209 if( in1->is_Proj() && in2->is_Proj() && in3->is_Proj() ) {
|
|
210 Node *in10 = in1->in(0);
|
|
211 Node *in20 = in2->in(0);
|
|
212 Node *in30 = in3->in(0);
|
|
213 // Check that #1 and #2 are ifTrue and ifFalse from same If
|
|
214 if( in10 != NULL && in10->is_If() &&
|
|
215 in20 != NULL && in20->is_If() &&
|
|
216 in30 != NULL && in30->is_If() && in10 == in20 &&
|
|
217 (in1->Opcode() != in2->Opcode()) ) {
|
|
218 Node *in100 = in10->in(0);
|
|
219 Node *in1000 = (in100 != NULL && in100->is_Proj()) ? in100->in(0) : NULL;
|
|
220 // Check that control for in10 comes from other branch of IF from in3
|
|
221 if( in1000 != NULL && in1000->is_If() &&
|
|
222 in30 == in1000 && (in3->Opcode() != in100->Opcode()) ) {
|
|
223 // Control pattern checks
|
|
224 top_if = (IfNode*)in1000;
|
|
225 bot_if = (IfNode*)in10;
|
|
226 }
|
|
227 }
|
|
228 }
|
|
229
|
|
230 return (top_if != NULL);
|
|
231 }
|
|
232
|
|
233
|
|
234 //------------------------------check_convf2i_clipping-------------------------
|
|
235 // Helper function for RegionNode's identification of FP clipping
|
|
236 // Verify that the value input to the phi comes from "ConvF2I; LShift; RShift"
|
|
237 static bool check_convf2i_clipping( PhiNode *phi, uint idx, ConvF2INode * &convf2i, Node *min, Node *max) {
|
|
238 convf2i = NULL;
|
|
239
|
|
240 // Check for the RShiftNode
|
|
241 Node *rshift = phi->in(idx);
|
|
242 assert( rshift, "Previous checks ensure phi input is present");
|
|
243 if( rshift->Opcode() != Op_RShiftI ) { return false; }
|
|
244
|
|
245 // Check for the LShiftNode
|
|
246 Node *lshift = rshift->in(1);
|
|
247 assert( lshift, "Previous checks ensure phi input is present");
|
|
248 if( lshift->Opcode() != Op_LShiftI ) { return false; }
|
|
249
|
|
250 // Check for the ConvF2INode
|
|
251 Node *conv = lshift->in(1);
|
|
252 if( conv->Opcode() != Op_ConvF2I ) { return false; }
|
|
253
|
|
254 // Check that shift amounts are only to get sign bits set after F2I
|
|
255 jint max_cutoff = max->get_int();
|
|
256 jint min_cutoff = min->get_int();
|
|
257 jint left_shift = lshift->in(2)->get_int();
|
|
258 jint right_shift = rshift->in(2)->get_int();
|
|
259 jint max_post_shift = nth_bit(BitsPerJavaInteger - left_shift - 1);
|
|
260 if( left_shift != right_shift ||
|
|
261 0 > left_shift || left_shift >= BitsPerJavaInteger ||
|
|
262 max_post_shift < max_cutoff ||
|
|
263 max_post_shift < -min_cutoff ) {
|
|
264 // Shifts are necessary but current transformation eliminates them
|
|
265 return false;
|
|
266 }
|
|
267
|
|
268 // OK to return the result of ConvF2I without shifting
|
|
269 convf2i = (ConvF2INode*)conv;
|
|
270 return true;
|
|
271 }
|
|
272
|
|
273
|
|
274 //------------------------------check_compare_clipping-------------------------
|
|
275 // Helper function for RegionNode's identification of FP clipping
|
|
276 static bool check_compare_clipping( bool less_than, IfNode *iff, ConNode *limit, Node * & input ) {
|
|
277 Node *i1 = iff->in(1);
|
|
278 if ( !i1->is_Bool() ) { return false; }
|
|
279 BoolNode *bool1 = i1->as_Bool();
|
|
280 if( less_than && bool1->_test._test != BoolTest::le ) { return false; }
|
|
281 else if( !less_than && bool1->_test._test != BoolTest::lt ) { return false; }
|
|
282 const Node *cmpF = bool1->in(1);
|
|
283 if( cmpF->Opcode() != Op_CmpF ) { return false; }
|
|
284 // Test that the float value being compared against
|
|
285 // is equivalent to the int value used as a limit
|
|
286 Node *nodef = cmpF->in(2);
|
|
287 if( nodef->Opcode() != Op_ConF ) { return false; }
|
|
288 jfloat conf = nodef->getf();
|
|
289 jint coni = limit->get_int();
|
|
290 if( ((int)conf) != coni ) { return false; }
|
|
291 input = cmpF->in(1);
|
|
292 return true;
|
|
293 }
|
|
294
|
|
295 //------------------------------is_unreachable_region--------------------------
|
|
296 // Find if the Region node is reachable from the root.
|
|
297 bool RegionNode::is_unreachable_region(PhaseGVN *phase) const {
|
|
298 assert(req() == 2, "");
|
|
299
|
|
300 // First, cut the simple case of fallthrough region when NONE of
|
|
301 // region's phis references itself directly or through a data node.
|
|
302 uint max = outcnt();
|
|
303 uint i;
|
|
304 for (i = 0; i < max; i++) {
|
|
305 Node* phi = raw_out(i);
|
|
306 if (phi != NULL && phi->is_Phi()) {
|
|
307 assert(phase->eqv(phi->in(0), this) && phi->req() == 2, "");
|
|
308 if (phi->outcnt() == 0)
|
|
309 continue; // Safe case - no loops
|
|
310 if (phi->outcnt() == 1) {
|
|
311 Node* u = phi->raw_out(0);
|
|
312 // Skip if only one use is an other Phi or Call or Uncommon trap.
|
|
313 // It is safe to consider this case as fallthrough.
|
|
314 if (u != NULL && (u->is_Phi() || u->is_CFG()))
|
|
315 continue;
|
|
316 }
|
|
317 // Check when phi references itself directly or through an other node.
|
|
318 if (phi->as_Phi()->simple_data_loop_check(phi->in(1)) >= PhiNode::Unsafe)
|
|
319 break; // Found possible unsafe data loop.
|
|
320 }
|
|
321 }
|
|
322 if (i >= max)
|
|
323 return false; // An unsafe case was NOT found - don't need graph walk.
|
|
324
|
|
325 // Unsafe case - check if the Region node is reachable from root.
|
|
326 ResourceMark rm;
|
|
327
|
|
328 Arena *a = Thread::current()->resource_area();
|
|
329 Node_List nstack(a);
|
|
330 VectorSet visited(a);
|
|
331
|
|
332 // Mark all control nodes reachable from root outputs
|
|
333 Node *n = (Node*)phase->C->root();
|
|
334 nstack.push(n);
|
|
335 visited.set(n->_idx);
|
|
336 while (nstack.size() != 0) {
|
|
337 n = nstack.pop();
|
|
338 uint max = n->outcnt();
|
|
339 for (uint i = 0; i < max; i++) {
|
|
340 Node* m = n->raw_out(i);
|
|
341 if (m != NULL && m->is_CFG()) {
|
|
342 if (phase->eqv(m, this)) {
|
|
343 return false; // We reached the Region node - it is not dead.
|
|
344 }
|
|
345 if (!visited.test_set(m->_idx))
|
|
346 nstack.push(m);
|
|
347 }
|
|
348 }
|
|
349 }
|
|
350
|
|
351 return true; // The Region node is unreachable - it is dead.
|
|
352 }
|
|
353
|
|
354 //------------------------------Ideal------------------------------------------
|
|
355 // Return a node which is more "ideal" than the current node. Must preserve
|
|
356 // the CFG, but we can still strip out dead paths.
|
|
357 Node *RegionNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
358 if( !can_reshape && !in(0) ) return NULL; // Already degraded to a Copy
|
|
359 assert(!in(0) || !in(0)->is_Root(), "not a specially hidden merge");
|
|
360
|
|
361 // Check for RegionNode with no Phi users and both inputs come from either
|
|
362 // arm of the same IF. If found, then the control-flow split is useless.
|
|
363 bool has_phis = false;
|
|
364 if (can_reshape) { // Need DU info to check for Phi users
|
|
365 has_phis = (has_phi() != NULL); // Cache result
|
|
366 if (!has_phis) { // No Phi users? Nothing merging?
|
|
367 for (uint i = 1; i < req()-1; i++) {
|
|
368 Node *if1 = in(i);
|
|
369 if( !if1 ) continue;
|
|
370 Node *iff = if1->in(0);
|
|
371 if( !iff || !iff->is_If() ) continue;
|
|
372 for( uint j=i+1; j<req(); j++ ) {
|
|
373 if( in(j) && in(j)->in(0) == iff &&
|
|
374 if1->Opcode() != in(j)->Opcode() ) {
|
|
375 // Add the IF Projections to the worklist. They (and the IF itself)
|
|
376 // will be eliminated if dead.
|
|
377 phase->is_IterGVN()->add_users_to_worklist(iff);
|
|
378 set_req(i, iff->in(0));// Skip around the useless IF diamond
|
|
379 set_req(j, NULL);
|
|
380 return this; // Record progress
|
|
381 }
|
|
382 }
|
|
383 }
|
|
384 }
|
|
385 }
|
|
386
|
|
387 // Remove TOP or NULL input paths. If only 1 input path remains, this Region
|
|
388 // degrades to a copy.
|
|
389 bool add_to_worklist = false;
|
|
390 int cnt = 0; // Count of values merging
|
|
391 DEBUG_ONLY( int cnt_orig = req(); ) // Save original inputs count
|
|
392 int del_it = 0; // The last input path we delete
|
|
393 // For all inputs...
|
|
394 for( uint i=1; i<req(); ++i ){// For all paths in
|
|
395 Node *n = in(i); // Get the input
|
|
396 if( n != NULL ) {
|
|
397 // Remove useless control copy inputs
|
|
398 if( n->is_Region() && n->as_Region()->is_copy() ) {
|
|
399 set_req(i, n->nonnull_req());
|
|
400 i--;
|
|
401 continue;
|
|
402 }
|
|
403 if( n->is_Proj() ) { // Remove useless rethrows
|
|
404 Node *call = n->in(0);
|
|
405 if (call->is_Call() && call->as_Call()->entry_point() == OptoRuntime::rethrow_stub()) {
|
|
406 set_req(i, call->in(0));
|
|
407 i--;
|
|
408 continue;
|
|
409 }
|
|
410 }
|
|
411 if( phase->type(n) == Type::TOP ) {
|
|
412 set_req(i, NULL); // Ignore TOP inputs
|
|
413 i--;
|
|
414 continue;
|
|
415 }
|
|
416 cnt++; // One more value merging
|
|
417
|
|
418 } else if (can_reshape) { // Else found dead path with DU info
|
|
419 PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
420 del_req(i); // Yank path from self
|
|
421 del_it = i;
|
|
422 uint max = outcnt();
|
|
423 DUIterator j;
|
|
424 bool progress = true;
|
|
425 while(progress) { // Need to establish property over all users
|
|
426 progress = false;
|
|
427 for (j = outs(); has_out(j); j++) {
|
|
428 Node *n = out(j);
|
|
429 if( n->req() != req() && n->is_Phi() ) {
|
|
430 assert( n->in(0) == this, "" );
|
|
431 igvn->hash_delete(n); // Yank from hash before hacking edges
|
|
432 n->set_req_X(i,NULL,igvn);// Correct DU info
|
|
433 n->del_req(i); // Yank path from Phis
|
|
434 if( max != outcnt() ) {
|
|
435 progress = true;
|
|
436 j = refresh_out_pos(j);
|
|
437 max = outcnt();
|
|
438 }
|
|
439 }
|
|
440 }
|
|
441 }
|
|
442 add_to_worklist = true;
|
|
443 i--;
|
|
444 }
|
|
445 }
|
|
446
|
|
447 if (can_reshape && cnt == 1) {
|
|
448 // Is it dead loop?
|
|
449 // If it is LoopNopde it had 2 (+1 itself) inputs and
|
|
450 // one of them was cut. The loop is dead if it was EntryContol.
|
|
451 assert(!this->is_Loop() || cnt_orig == 3, "Loop node should have 3 inputs");
|
|
452 if (this->is_Loop() && del_it == LoopNode::EntryControl ||
|
|
453 !this->is_Loop() && has_phis && is_unreachable_region(phase)) {
|
|
454 // Yes, the region will be removed during the next step below.
|
|
455 // Cut the backedge input and remove phis since no data paths left.
|
|
456 // We don't cut outputs to other nodes here since we need to put them
|
|
457 // on the worklist.
|
|
458 del_req(1);
|
|
459 cnt = 0;
|
|
460 assert( req() == 1, "no more inputs expected" );
|
|
461 uint max = outcnt();
|
|
462 bool progress = true;
|
|
463 Node *top = phase->C->top();
|
|
464 PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
465 DUIterator j;
|
|
466 while(progress) {
|
|
467 progress = false;
|
|
468 for (j = outs(); has_out(j); j++) {
|
|
469 Node *n = out(j);
|
|
470 if( n->is_Phi() ) {
|
|
471 assert( igvn->eqv(n->in(0), this), "" );
|
|
472 assert( n->req() == 2 && n->in(1) != NULL, "Only one data input expected" );
|
|
473 // Break dead loop data path.
|
|
474 // Eagerly replace phis with top to avoid phis copies generation.
|
|
475 igvn->add_users_to_worklist(n);
|
|
476 igvn->hash_delete(n); // Yank from hash before hacking edges
|
|
477 igvn->subsume_node(n, top);
|
|
478 if( max != outcnt() ) {
|
|
479 progress = true;
|
|
480 j = refresh_out_pos(j);
|
|
481 max = outcnt();
|
|
482 }
|
|
483 }
|
|
484 }
|
|
485 }
|
|
486 add_to_worklist = true;
|
|
487 }
|
|
488 }
|
|
489 if (add_to_worklist) {
|
|
490 phase->is_IterGVN()->add_users_to_worklist(this); // Revisit collapsed Phis
|
|
491 }
|
|
492
|
|
493 if( cnt <= 1 ) { // Only 1 path in?
|
|
494 set_req(0, NULL); // Null control input for region copy
|
|
495 if( cnt == 0 && !can_reshape) { // Parse phase - leave the node as it is.
|
|
496 // No inputs or all inputs are NULL.
|
|
497 return NULL;
|
|
498 } else if (can_reshape) { // Optimization phase - remove the node
|
|
499 PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
500 Node *parent_ctrl;
|
|
501 if( cnt == 0 ) {
|
|
502 assert( req() == 1, "no inputs expected" );
|
|
503 // During IGVN phase such region will be subsumed by TOP node
|
|
504 // so region's phis will have TOP as control node.
|
|
505 // Kill phis here to avoid it. PhiNode::is_copy() will be always false.
|
|
506 // Also set other user's input to top.
|
|
507 parent_ctrl = phase->C->top();
|
|
508 } else {
|
|
509 // The fallthrough case since we already checked dead loops above.
|
|
510 parent_ctrl = in(1);
|
|
511 assert(parent_ctrl != NULL, "Region is a copy of some non-null control");
|
|
512 assert(!igvn->eqv(parent_ctrl, this), "Close dead loop");
|
|
513 }
|
|
514 if (!add_to_worklist)
|
|
515 igvn->add_users_to_worklist(this); // Check for further allowed opts
|
|
516 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; --i) {
|
|
517 Node* n = last_out(i);
|
|
518 igvn->hash_delete(n); // Remove from worklist before modifying edges
|
|
519 if( n->is_Phi() ) { // Collapse all Phis
|
|
520 // Eagerly replace phis to avoid copies generation.
|
|
521 igvn->add_users_to_worklist(n);
|
|
522 igvn->hash_delete(n); // Yank from hash before hacking edges
|
|
523 if( cnt == 0 ) {
|
|
524 assert( n->req() == 1, "No data inputs expected" );
|
|
525 igvn->subsume_node(n, parent_ctrl); // replaced by top
|
|
526 } else {
|
|
527 assert( n->req() == 2 && n->in(1) != NULL, "Only one data input expected" );
|
|
528 Node* in1 = n->in(1); // replaced by unique input
|
|
529 if( n->as_Phi()->is_unsafe_data_reference(in1) )
|
|
530 in1 = phase->C->top(); // replaced by top
|
|
531 igvn->subsume_node(n, in1);
|
|
532 }
|
|
533 }
|
|
534 else if( n->is_Region() ) { // Update all incoming edges
|
|
535 assert( !igvn->eqv(n, this), "Must be removed from DefUse edges");
|
|
536 uint uses_found = 0;
|
|
537 for( uint k=1; k < n->req(); k++ ) {
|
|
538 if( n->in(k) == this ) {
|
|
539 n->set_req(k, parent_ctrl);
|
|
540 uses_found++;
|
|
541 }
|
|
542 }
|
|
543 if( uses_found > 1 ) { // (--i) done at the end of the loop.
|
|
544 i -= (uses_found - 1);
|
|
545 }
|
|
546 }
|
|
547 else {
|
|
548 assert( igvn->eqv(n->in(0), this), "Expect RegionNode to be control parent");
|
|
549 n->set_req(0, parent_ctrl);
|
|
550 }
|
|
551 #ifdef ASSERT
|
|
552 for( uint k=0; k < n->req(); k++ ) {
|
|
553 assert( !igvn->eqv(n->in(k), this), "All uses of RegionNode should be gone");
|
|
554 }
|
|
555 #endif
|
|
556 }
|
|
557 // Remove the RegionNode itself from DefUse info
|
|
558 igvn->remove_dead_node(this);
|
|
559 return NULL;
|
|
560 }
|
|
561 return this; // Record progress
|
|
562 }
|
|
563
|
|
564
|
|
565 // If a Region flows into a Region, merge into one big happy merge.
|
|
566 if (can_reshape) {
|
|
567 Node *m = merge_region(this, phase);
|
|
568 if (m != NULL) return m;
|
|
569 }
|
|
570
|
|
571 // Check if this region is the root of a clipping idiom on floats
|
|
572 if( ConvertFloat2IntClipping && can_reshape && req() == 4 ) {
|
|
573 // Check that only one use is a Phi and that it simplifies to two constants +
|
|
574 PhiNode* phi = has_unique_phi();
|
|
575 if (phi != NULL) { // One Phi user
|
|
576 // Check inputs to the Phi
|
|
577 ConNode *min;
|
|
578 ConNode *max;
|
|
579 Node *val;
|
|
580 uint min_idx;
|
|
581 uint max_idx;
|
|
582 uint val_idx;
|
|
583 if( check_phi_clipping( phi, min, min_idx, max, max_idx, val, val_idx ) ) {
|
|
584 IfNode *top_if;
|
|
585 IfNode *bot_if;
|
|
586 if( check_if_clipping( this, bot_if, top_if ) ) {
|
|
587 // Control pattern checks, now verify compares
|
|
588 Node *top_in = NULL; // value being compared against
|
|
589 Node *bot_in = NULL;
|
|
590 if( check_compare_clipping( true, bot_if, min, bot_in ) &&
|
|
591 check_compare_clipping( false, top_if, max, top_in ) ) {
|
|
592 if( bot_in == top_in ) {
|
|
593 PhaseIterGVN *gvn = phase->is_IterGVN();
|
|
594 assert( gvn != NULL, "Only had DefUse info in IterGVN");
|
|
595 // Only remaining check is that bot_in == top_in == (Phi's val + mods)
|
|
596
|
|
597 // Check for the ConvF2INode
|
|
598 ConvF2INode *convf2i;
|
|
599 if( check_convf2i_clipping( phi, val_idx, convf2i, min, max ) &&
|
|
600 convf2i->in(1) == bot_in ) {
|
|
601 // Matched pattern, including LShiftI; RShiftI, replace with integer compares
|
|
602 // max test
|
|
603 Node *cmp = gvn->register_new_node_with_optimizer(new (phase->C, 3) CmpINode( convf2i, min ));
|
|
604 Node *boo = gvn->register_new_node_with_optimizer(new (phase->C, 2) BoolNode( cmp, BoolTest::lt ));
|
|
605 IfNode *iff = (IfNode*)gvn->register_new_node_with_optimizer(new (phase->C, 2) IfNode( top_if->in(0), boo, PROB_UNLIKELY_MAG(5), top_if->_fcnt ));
|
|
606 Node *if_min= gvn->register_new_node_with_optimizer(new (phase->C, 1) IfTrueNode (iff));
|
|
607 Node *ifF = gvn->register_new_node_with_optimizer(new (phase->C, 1) IfFalseNode(iff));
|
|
608 // min test
|
|
609 cmp = gvn->register_new_node_with_optimizer(new (phase->C, 3) CmpINode( convf2i, max ));
|
|
610 boo = gvn->register_new_node_with_optimizer(new (phase->C, 2) BoolNode( cmp, BoolTest::gt ));
|
|
611 iff = (IfNode*)gvn->register_new_node_with_optimizer(new (phase->C, 2) IfNode( ifF, boo, PROB_UNLIKELY_MAG(5), bot_if->_fcnt ));
|
|
612 Node *if_max= gvn->register_new_node_with_optimizer(new (phase->C, 1) IfTrueNode (iff));
|
|
613 ifF = gvn->register_new_node_with_optimizer(new (phase->C, 1) IfFalseNode(iff));
|
|
614 // update input edges to region node
|
|
615 set_req_X( min_idx, if_min, gvn );
|
|
616 set_req_X( max_idx, if_max, gvn );
|
|
617 set_req_X( val_idx, ifF, gvn );
|
|
618 // remove unnecessary 'LShiftI; RShiftI' idiom
|
|
619 gvn->hash_delete(phi);
|
|
620 phi->set_req_X( val_idx, convf2i, gvn );
|
|
621 gvn->hash_find_insert(phi);
|
|
622 // Return transformed region node
|
|
623 return this;
|
|
624 }
|
|
625 }
|
|
626 }
|
|
627 }
|
|
628 }
|
|
629 }
|
|
630 }
|
|
631
|
|
632 return NULL;
|
|
633 }
|
|
634
|
|
635
|
|
636
|
|
637 const RegMask &RegionNode::out_RegMask() const {
|
|
638 return RegMask::Empty;
|
|
639 }
|
|
640
|
|
641 // Find the one non-null required input. RegionNode only
|
|
642 Node *Node::nonnull_req() const {
|
|
643 assert( is_Region(), "" );
|
|
644 for( uint i = 1; i < _cnt; i++ )
|
|
645 if( in(i) )
|
|
646 return in(i);
|
|
647 ShouldNotReachHere();
|
|
648 return NULL;
|
|
649 }
|
|
650
|
|
651
|
|
652 //=============================================================================
|
|
653 // note that these functions assume that the _adr_type field is flattened
|
|
654 uint PhiNode::hash() const {
|
|
655 const Type* at = _adr_type;
|
|
656 return TypeNode::hash() + (at ? at->hash() : 0);
|
|
657 }
|
|
658 uint PhiNode::cmp( const Node &n ) const {
|
|
659 return TypeNode::cmp(n) && _adr_type == ((PhiNode&)n)._adr_type;
|
|
660 }
|
|
661 static inline
|
|
662 const TypePtr* flatten_phi_adr_type(const TypePtr* at) {
|
|
663 if (at == NULL || at == TypePtr::BOTTOM) return at;
|
|
664 return Compile::current()->alias_type(at)->adr_type();
|
|
665 }
|
|
666
|
|
667 //----------------------------make---------------------------------------------
|
|
668 // create a new phi with edges matching r and set (initially) to x
|
|
669 PhiNode* PhiNode::make(Node* r, Node* x, const Type *t, const TypePtr* at) {
|
|
670 uint preds = r->req(); // Number of predecessor paths
|
|
671 assert(t != Type::MEMORY || at == flatten_phi_adr_type(at), "flatten at");
|
|
672 PhiNode* p = new (Compile::current(), preds) PhiNode(r, t, at);
|
|
673 for (uint j = 1; j < preds; j++) {
|
|
674 // Fill in all inputs, except those which the region does not yet have
|
|
675 if (r->in(j) != NULL)
|
|
676 p->init_req(j, x);
|
|
677 }
|
|
678 return p;
|
|
679 }
|
|
680 PhiNode* PhiNode::make(Node* r, Node* x) {
|
|
681 const Type* t = x->bottom_type();
|
|
682 const TypePtr* at = NULL;
|
|
683 if (t == Type::MEMORY) at = flatten_phi_adr_type(x->adr_type());
|
|
684 return make(r, x, t, at);
|
|
685 }
|
|
686 PhiNode* PhiNode::make_blank(Node* r, Node* x) {
|
|
687 const Type* t = x->bottom_type();
|
|
688 const TypePtr* at = NULL;
|
|
689 if (t == Type::MEMORY) at = flatten_phi_adr_type(x->adr_type());
|
|
690 return new (Compile::current(), r->req()) PhiNode(r, t, at);
|
|
691 }
|
|
692
|
|
693
|
|
694 //------------------------slice_memory-----------------------------------------
|
|
695 // create a new phi with narrowed memory type
|
|
696 PhiNode* PhiNode::slice_memory(const TypePtr* adr_type) const {
|
|
697 PhiNode* mem = (PhiNode*) clone();
|
|
698 *(const TypePtr**)&mem->_adr_type = adr_type;
|
|
699 // convert self-loops, or else we get a bad graph
|
|
700 for (uint i = 1; i < req(); i++) {
|
|
701 if ((const Node*)in(i) == this) mem->set_req(i, mem);
|
|
702 }
|
|
703 mem->verify_adr_type();
|
|
704 return mem;
|
|
705 }
|
|
706
|
|
707 //------------------------verify_adr_type--------------------------------------
|
|
708 #ifdef ASSERT
|
|
709 void PhiNode::verify_adr_type(VectorSet& visited, const TypePtr* at) const {
|
|
710 if (visited.test_set(_idx)) return; //already visited
|
|
711
|
|
712 // recheck constructor invariants:
|
|
713 verify_adr_type(false);
|
|
714
|
|
715 // recheck local phi/phi consistency:
|
|
716 assert(_adr_type == at || _adr_type == TypePtr::BOTTOM,
|
|
717 "adr_type must be consistent across phi nest");
|
|
718
|
|
719 // walk around
|
|
720 for (uint i = 1; i < req(); i++) {
|
|
721 Node* n = in(i);
|
|
722 if (n == NULL) continue;
|
|
723 const Node* np = in(i);
|
|
724 if (np->is_Phi()) {
|
|
725 np->as_Phi()->verify_adr_type(visited, at);
|
|
726 } else if (n->bottom_type() == Type::TOP
|
|
727 || (n->is_Mem() && n->in(MemNode::Address)->bottom_type() == Type::TOP)) {
|
|
728 // ignore top inputs
|
|
729 } else {
|
|
730 const TypePtr* nat = flatten_phi_adr_type(n->adr_type());
|
|
731 // recheck phi/non-phi consistency at leaves:
|
|
732 assert((nat != NULL) == (at != NULL), "");
|
|
733 assert(nat == at || nat == TypePtr::BOTTOM,
|
|
734 "adr_type must be consistent at leaves of phi nest");
|
|
735 }
|
|
736 }
|
|
737 }
|
|
738
|
|
739 // Verify a whole nest of phis rooted at this one.
|
|
740 void PhiNode::verify_adr_type(bool recursive) const {
|
|
741 if (is_error_reported()) return; // muzzle asserts when debugging an error
|
|
742 if (Node::in_dump()) return; // muzzle asserts when printing
|
|
743
|
|
744 assert((_type == Type::MEMORY) == (_adr_type != NULL), "adr_type for memory phis only");
|
|
745
|
|
746 if (!VerifyAliases) return; // verify thoroughly only if requested
|
|
747
|
|
748 assert(_adr_type == flatten_phi_adr_type(_adr_type),
|
|
749 "Phi::adr_type must be pre-normalized");
|
|
750
|
|
751 if (recursive) {
|
|
752 VectorSet visited(Thread::current()->resource_area());
|
|
753 verify_adr_type(visited, _adr_type);
|
|
754 }
|
|
755 }
|
|
756 #endif
|
|
757
|
|
758
|
|
759 //------------------------------Value------------------------------------------
|
|
760 // Compute the type of the PhiNode
|
|
761 const Type *PhiNode::Value( PhaseTransform *phase ) const {
|
|
762 Node *r = in(0); // RegionNode
|
|
763 if( !r ) // Copy or dead
|
|
764 return in(1) ? phase->type(in(1)) : Type::TOP;
|
|
765
|
|
766 // Note: During parsing, phis are often transformed before their regions.
|
|
767 // This means we have to use type_or_null to defend against untyped regions.
|
|
768 if( phase->type_or_null(r) == Type::TOP ) // Dead code?
|
|
769 return Type::TOP;
|
|
770
|
|
771 // Check for trip-counted loop. If so, be smarter.
|
|
772 CountedLoopNode *l = r->is_CountedLoop() ? r->as_CountedLoop() : NULL;
|
|
773 if( l && l->can_be_counted_loop(phase) &&
|
|
774 ((const Node*)l->phi() == this) ) { // Trip counted loop!
|
|
775 // protect against init_trip() or limit() returning NULL
|
|
776 const Node *init = l->init_trip();
|
|
777 const Node *limit = l->limit();
|
|
778 if( init != NULL && limit != NULL && l->stride_is_con() ) {
|
|
779 const TypeInt *lo = init ->bottom_type()->isa_int();
|
|
780 const TypeInt *hi = limit->bottom_type()->isa_int();
|
|
781 if( lo && hi ) { // Dying loops might have TOP here
|
|
782 int stride = l->stride_con();
|
|
783 if( stride < 0 ) { // Down-counter loop
|
|
784 const TypeInt *tmp = lo; lo = hi; hi = tmp;
|
|
785 stride = -stride;
|
|
786 }
|
|
787 if( lo->_hi < hi->_lo ) // Reversed endpoints are well defined :-(
|
|
788 return TypeInt::make(lo->_lo,hi->_hi,3);
|
|
789 }
|
|
790 }
|
|
791 }
|
|
792
|
|
793 // Until we have harmony between classes and interfaces in the type
|
|
794 // lattice, we must tread carefully around phis which implicitly
|
|
795 // convert the one to the other.
|
|
796 const TypeInstPtr* ttip = _type->isa_instptr();
|
|
797 bool is_intf = false;
|
|
798 if (ttip != NULL) {
|
|
799 ciKlass* k = ttip->klass();
|
|
800 if (k->is_loaded() && k->is_interface())
|
|
801 is_intf = true;
|
|
802 }
|
|
803
|
|
804 // Default case: merge all inputs
|
|
805 const Type *t = Type::TOP; // Merged type starting value
|
|
806 for (uint i = 1; i < req(); ++i) {// For all paths in
|
|
807 // Reachable control path?
|
|
808 if (r->in(i) && phase->type(r->in(i)) == Type::CONTROL) {
|
|
809 const Type* ti = phase->type(in(i));
|
|
810 // We assume that each input of an interface-valued Phi is a true
|
|
811 // subtype of that interface. This might not be true of the meet
|
|
812 // of all the input types. The lattice is not distributive in
|
|
813 // such cases. Ward off asserts in type.cpp by refusing to do
|
|
814 // meets between interfaces and proper classes.
|
|
815 const TypeInstPtr* tiip = ti->isa_instptr();
|
|
816 if (tiip) {
|
|
817 bool ti_is_intf = false;
|
|
818 ciKlass* k = tiip->klass();
|
|
819 if (k->is_loaded() && k->is_interface())
|
|
820 ti_is_intf = true;
|
|
821 if (is_intf != ti_is_intf)
|
|
822 { t = _type; break; }
|
|
823 }
|
|
824 t = t->meet(ti);
|
|
825 }
|
|
826 }
|
|
827
|
|
828 // The worst-case type (from ciTypeFlow) should be consistent with "t".
|
|
829 // That is, we expect that "t->higher_equal(_type)" holds true.
|
|
830 // There are various exceptions:
|
|
831 // - Inputs which are phis might in fact be widened unnecessarily.
|
|
832 // For example, an input might be a widened int while the phi is a short.
|
|
833 // - Inputs might be BotPtrs but this phi is dependent on a null check,
|
|
834 // and postCCP has removed the cast which encodes the result of the check.
|
|
835 // - The type of this phi is an interface, and the inputs are classes.
|
|
836 // - Value calls on inputs might produce fuzzy results.
|
|
837 // (Occurrences of this case suggest improvements to Value methods.)
|
|
838 //
|
|
839 // It is not possible to see Type::BOTTOM values as phi inputs,
|
|
840 // because the ciTypeFlow pre-pass produces verifier-quality types.
|
|
841 const Type* ft = t->filter(_type); // Worst case type
|
|
842
|
|
843 #ifdef ASSERT
|
|
844 // The following logic has been moved into TypeOopPtr::filter.
|
|
845 const Type* jt = t->join(_type);
|
|
846 if( jt->empty() ) { // Emptied out???
|
|
847
|
|
848 // Check for evil case of 't' being a class and '_type' expecting an
|
|
849 // interface. This can happen because the bytecodes do not contain
|
|
850 // enough type info to distinguish a Java-level interface variable
|
|
851 // from a Java-level object variable. If we meet 2 classes which
|
|
852 // both implement interface I, but their meet is at 'j/l/O' which
|
|
853 // doesn't implement I, we have no way to tell if the result should
|
|
854 // be 'I' or 'j/l/O'. Thus we'll pick 'j/l/O'. If this then flows
|
|
855 // into a Phi which "knows" it's an Interface type we'll have to
|
|
856 // uplift the type.
|
|
857 if( !t->empty() && ttip && ttip->is_loaded() && ttip->klass()->is_interface() )
|
|
858 { assert(ft == _type, ""); } // Uplift to interface
|
|
859 // Otherwise it's something stupid like non-overlapping int ranges
|
|
860 // found on dying counted loops.
|
|
861 else
|
|
862 { assert(ft == Type::TOP, ""); } // Canonical empty value
|
|
863 }
|
|
864
|
|
865 else {
|
|
866
|
|
867 // If we have an interface-typed Phi and we narrow to a class type, the join
|
|
868 // should report back the class. However, if we have a J/L/Object
|
|
869 // class-typed Phi and an interface flows in, it's possible that the meet &
|
|
870 // join report an interface back out. This isn't possible but happens
|
|
871 // because the type system doesn't interact well with interfaces.
|
|
872 const TypeInstPtr *jtip = jt->isa_instptr();
|
|
873 if( jtip && ttip ) {
|
|
874 if( jtip->is_loaded() && jtip->klass()->is_interface() &&
|
|
875 ttip->is_loaded() && !ttip->klass()->is_interface() )
|
|
876 // Happens in a CTW of rt.jar, 320-341, no extra flags
|
|
877 { assert(ft == ttip->cast_to_ptr_type(jtip->ptr()), ""); jt = ft; }
|
|
878 }
|
|
879 if (jt != ft && jt->base() == ft->base()) {
|
|
880 if (jt->isa_int() &&
|
|
881 jt->is_int()->_lo == ft->is_int()->_lo &&
|
|
882 jt->is_int()->_hi == ft->is_int()->_hi)
|
|
883 jt = ft;
|
|
884 if (jt->isa_long() &&
|
|
885 jt->is_long()->_lo == ft->is_long()->_lo &&
|
|
886 jt->is_long()->_hi == ft->is_long()->_hi)
|
|
887 jt = ft;
|
|
888 }
|
|
889 if (jt != ft) {
|
|
890 tty->print("merge type: "); t->dump(); tty->cr();
|
|
891 tty->print("kill type: "); _type->dump(); tty->cr();
|
|
892 tty->print("join type: "); jt->dump(); tty->cr();
|
|
893 tty->print("filter type: "); ft->dump(); tty->cr();
|
|
894 }
|
|
895 assert(jt == ft, "");
|
|
896 }
|
|
897 #endif //ASSERT
|
|
898
|
|
899 // Deal with conversion problems found in data loops.
|
|
900 ft = phase->saturate(ft, phase->type_or_null(this), _type);
|
|
901
|
|
902 return ft;
|
|
903 }
|
|
904
|
|
905
|
|
906 //------------------------------is_diamond_phi---------------------------------
|
|
907 // Does this Phi represent a simple well-shaped diamond merge? Return the
|
|
908 // index of the true path or 0 otherwise.
|
|
909 int PhiNode::is_diamond_phi() const {
|
|
910 // Check for a 2-path merge
|
|
911 Node *region = in(0);
|
|
912 if( !region ) return 0;
|
|
913 if( region->req() != 3 ) return 0;
|
|
914 if( req() != 3 ) return 0;
|
|
915 // Check that both paths come from the same If
|
|
916 Node *ifp1 = region->in(1);
|
|
917 Node *ifp2 = region->in(2);
|
|
918 if( !ifp1 || !ifp2 ) return 0;
|
|
919 Node *iff = ifp1->in(0);
|
|
920 if( !iff || !iff->is_If() ) return 0;
|
|
921 if( iff != ifp2->in(0) ) return 0;
|
|
922 // Check for a proper bool/cmp
|
|
923 const Node *b = iff->in(1);
|
|
924 if( !b->is_Bool() ) return 0;
|
|
925 const Node *cmp = b->in(1);
|
|
926 if( !cmp->is_Cmp() ) return 0;
|
|
927
|
|
928 // Check for branching opposite expected
|
|
929 if( ifp2->Opcode() == Op_IfTrue ) {
|
|
930 assert( ifp1->Opcode() == Op_IfFalse, "" );
|
|
931 return 2;
|
|
932 } else {
|
|
933 assert( ifp1->Opcode() == Op_IfTrue, "" );
|
|
934 return 1;
|
|
935 }
|
|
936 }
|
|
937
|
|
938 //----------------------------check_cmove_id-----------------------------------
|
|
939 // Check for CMove'ing a constant after comparing against the constant.
|
|
940 // Happens all the time now, since if we compare equality vs a constant in
|
|
941 // the parser, we "know" the variable is constant on one path and we force
|
|
942 // it. Thus code like "if( x==0 ) {/*EMPTY*/}" ends up inserting a
|
|
943 // conditional move: "x = (x==0)?0:x;". Yucko. This fix is slightly more
|
|
944 // general in that we don't need constants. Since CMove's are only inserted
|
|
945 // in very special circumstances, we do it here on generic Phi's.
|
|
946 Node* PhiNode::is_cmove_id(PhaseTransform* phase, int true_path) {
|
|
947 assert(true_path !=0, "only diamond shape graph expected");
|
|
948
|
|
949 // is_diamond_phi() has guaranteed the correctness of the nodes sequence:
|
|
950 // phi->region->if_proj->ifnode->bool->cmp
|
|
951 Node* region = in(0);
|
|
952 Node* iff = region->in(1)->in(0);
|
|
953 BoolNode* b = iff->in(1)->as_Bool();
|
|
954 Node* cmp = b->in(1);
|
|
955 Node* tval = in(true_path);
|
|
956 Node* fval = in(3-true_path);
|
|
957 Node* id = CMoveNode::is_cmove_id(phase, cmp, tval, fval, b);
|
|
958 if (id == NULL)
|
|
959 return NULL;
|
|
960
|
|
961 // Either value might be a cast that depends on a branch of 'iff'.
|
|
962 // Since the 'id' value will float free of the diamond, either
|
|
963 // decast or return failure.
|
|
964 Node* ctl = id->in(0);
|
|
965 if (ctl != NULL && ctl->in(0) == iff) {
|
|
966 if (id->is_ConstraintCast()) {
|
|
967 return id->in(1);
|
|
968 } else {
|
|
969 // Don't know how to disentangle this value.
|
|
970 return NULL;
|
|
971 }
|
|
972 }
|
|
973
|
|
974 return id;
|
|
975 }
|
|
976
|
|
977 //------------------------------Identity---------------------------------------
|
|
978 // Check for Region being Identity.
|
|
979 Node *PhiNode::Identity( PhaseTransform *phase ) {
|
|
980 // Check for no merging going on
|
|
981 // (There used to be special-case code here when this->region->is_Loop.
|
|
982 // It would check for a tributary phi on the backedge that the main phi
|
|
983 // trivially, perhaps with a single cast. The unique_input method
|
|
984 // does all this and more, by reducing such tributaries to 'this'.)
|
|
985 Node* uin = unique_input(phase);
|
|
986 if (uin != NULL) {
|
|
987 return uin;
|
|
988 }
|
|
989
|
|
990 int true_path = is_diamond_phi();
|
|
991 if (true_path != 0) {
|
|
992 Node* id = is_cmove_id(phase, true_path);
|
|
993 if (id != NULL) return id;
|
|
994 }
|
|
995
|
|
996 return this; // No identity
|
|
997 }
|
|
998
|
|
999 //-----------------------------unique_input------------------------------------
|
|
1000 // Find the unique value, discounting top, self-loops, and casts.
|
|
1001 // Return top if there are no inputs, and self if there are multiple.
|
|
1002 Node* PhiNode::unique_input(PhaseTransform* phase) {
|
|
1003 // 1) One unique direct input, or
|
|
1004 // 2) some of the inputs have an intervening ConstraintCast and
|
|
1005 // the type of input is the same or sharper (more specific)
|
|
1006 // than the phi's type.
|
|
1007 // 3) an input is a self loop
|
|
1008 //
|
|
1009 // 1) input or 2) input or 3) input __
|
|
1010 // / \ / \ \ / \
|
|
1011 // \ / | cast phi cast
|
|
1012 // phi \ / / \ /
|
|
1013 // phi / --
|
|
1014
|
|
1015 Node* r = in(0); // RegionNode
|
|
1016 if (r == NULL) return in(1); // Already degraded to a Copy
|
|
1017 Node* uncasted_input = NULL; // The unique uncasted input (ConstraintCasts removed)
|
|
1018 Node* direct_input = NULL; // The unique direct input
|
|
1019
|
|
1020 for (uint i = 1, cnt = req(); i < cnt; ++i) {
|
|
1021 Node* rc = r->in(i);
|
|
1022 if (rc == NULL || phase->type(rc) == Type::TOP)
|
|
1023 continue; // ignore unreachable control path
|
|
1024 Node* n = in(i);
|
|
1025 Node* un = n->uncast();
|
|
1026 if (un == NULL || un == this || phase->type(un) == Type::TOP) {
|
|
1027 continue; // ignore if top, or in(i) and "this" are in a data cycle
|
|
1028 }
|
|
1029 // Check for a unique uncasted input
|
|
1030 if (uncasted_input == NULL) {
|
|
1031 uncasted_input = un;
|
|
1032 } else if (uncasted_input != un) {
|
|
1033 uncasted_input = NodeSentinel; // no unique uncasted input
|
|
1034 }
|
|
1035 // Check for a unique direct input
|
|
1036 if (direct_input == NULL) {
|
|
1037 direct_input = n;
|
|
1038 } else if (direct_input != n) {
|
|
1039 direct_input = NodeSentinel; // no unique direct input
|
|
1040 }
|
|
1041 }
|
|
1042 if (direct_input == NULL) {
|
|
1043 return phase->C->top(); // no inputs
|
|
1044 }
|
|
1045 assert(uncasted_input != NULL,"");
|
|
1046
|
|
1047 if (direct_input != NodeSentinel) {
|
|
1048 return direct_input; // one unique direct input
|
|
1049 }
|
|
1050 if (uncasted_input != NodeSentinel &&
|
|
1051 phase->type(uncasted_input)->higher_equal(type())) {
|
|
1052 return uncasted_input; // one unique uncasted input
|
|
1053 }
|
|
1054
|
|
1055 // Nothing.
|
|
1056 return NULL;
|
|
1057 }
|
|
1058
|
|
1059 //------------------------------is_x2logic-------------------------------------
|
|
1060 // Check for simple convert-to-boolean pattern
|
|
1061 // If:(C Bool) Region:(IfF IfT) Phi:(Region 0 1)
|
|
1062 // Convert Phi to an ConvIB.
|
|
1063 static Node *is_x2logic( PhaseGVN *phase, PhiNode *phi, int true_path ) {
|
|
1064 assert(true_path !=0, "only diamond shape graph expected");
|
|
1065 // Convert the true/false index into an expected 0/1 return.
|
|
1066 // Map 2->0 and 1->1.
|
|
1067 int flipped = 2-true_path;
|
|
1068
|
|
1069 // is_diamond_phi() has guaranteed the correctness of the nodes sequence:
|
|
1070 // phi->region->if_proj->ifnode->bool->cmp
|
|
1071 Node *region = phi->in(0);
|
|
1072 Node *iff = region->in(1)->in(0);
|
|
1073 BoolNode *b = (BoolNode*)iff->in(1);
|
|
1074 const CmpNode *cmp = (CmpNode*)b->in(1);
|
|
1075
|
|
1076 Node *zero = phi->in(1);
|
|
1077 Node *one = phi->in(2);
|
|
1078 const Type *tzero = phase->type( zero );
|
|
1079 const Type *tone = phase->type( one );
|
|
1080
|
|
1081 // Check for compare vs 0
|
|
1082 const Type *tcmp = phase->type(cmp->in(2));
|
|
1083 if( tcmp != TypeInt::ZERO && tcmp != TypePtr::NULL_PTR ) {
|
|
1084 // Allow cmp-vs-1 if the other input is bounded by 0-1
|
|
1085 if( !(tcmp == TypeInt::ONE && phase->type(cmp->in(1)) == TypeInt::BOOL) )
|
|
1086 return NULL;
|
|
1087 flipped = 1-flipped; // Test is vs 1 instead of 0!
|
|
1088 }
|
|
1089
|
|
1090 // Check for setting zero/one opposite expected
|
|
1091 if( tzero == TypeInt::ZERO ) {
|
|
1092 if( tone == TypeInt::ONE ) {
|
|
1093 } else return NULL;
|
|
1094 } else if( tzero == TypeInt::ONE ) {
|
|
1095 if( tone == TypeInt::ZERO ) {
|
|
1096 flipped = 1-flipped;
|
|
1097 } else return NULL;
|
|
1098 } else return NULL;
|
|
1099
|
|
1100 // Check for boolean test backwards
|
|
1101 if( b->_test._test == BoolTest::ne ) {
|
|
1102 } else if( b->_test._test == BoolTest::eq ) {
|
|
1103 flipped = 1-flipped;
|
|
1104 } else return NULL;
|
|
1105
|
|
1106 // Build int->bool conversion
|
|
1107 Node *n = new (phase->C, 2) Conv2BNode( cmp->in(1) );
|
|
1108 if( flipped )
|
|
1109 n = new (phase->C, 3) XorINode( phase->transform(n), phase->intcon(1) );
|
|
1110
|
|
1111 return n;
|
|
1112 }
|
|
1113
|
|
1114 //------------------------------is_cond_add------------------------------------
|
|
1115 // Check for simple conditional add pattern: "(P < Q) ? X+Y : X;"
|
|
1116 // To be profitable the control flow has to disappear; there can be no other
|
|
1117 // values merging here. We replace the test-and-branch with:
|
|
1118 // "(sgn(P-Q))&Y) + X". Basically, convert "(P < Q)" into 0 or -1 by
|
|
1119 // moving the carry bit from (P-Q) into a register with 'sbb EAX,EAX'.
|
|
1120 // Then convert Y to 0-or-Y and finally add.
|
|
1121 // This is a key transform for SpecJava _201_compress.
|
|
1122 static Node* is_cond_add(PhaseGVN *phase, PhiNode *phi, int true_path) {
|
|
1123 assert(true_path !=0, "only diamond shape graph expected");
|
|
1124
|
|
1125 // is_diamond_phi() has guaranteed the correctness of the nodes sequence:
|
|
1126 // phi->region->if_proj->ifnode->bool->cmp
|
|
1127 RegionNode *region = (RegionNode*)phi->in(0);
|
|
1128 Node *iff = region->in(1)->in(0);
|
|
1129 BoolNode* b = iff->in(1)->as_Bool();
|
|
1130 const CmpNode *cmp = (CmpNode*)b->in(1);
|
|
1131
|
|
1132 // Make sure only merging this one phi here
|
|
1133 if (region->has_unique_phi() != phi) return NULL;
|
|
1134
|
|
1135 // Make sure each arm of the diamond has exactly one output, which we assume
|
|
1136 // is the region. Otherwise, the control flow won't disappear.
|
|
1137 if (region->in(1)->outcnt() != 1) return NULL;
|
|
1138 if (region->in(2)->outcnt() != 1) return NULL;
|
|
1139
|
|
1140 // Check for "(P < Q)" of type signed int
|
|
1141 if (b->_test._test != BoolTest::lt) return NULL;
|
|
1142 if (cmp->Opcode() != Op_CmpI) return NULL;
|
|
1143
|
|
1144 Node *p = cmp->in(1);
|
|
1145 Node *q = cmp->in(2);
|
|
1146 Node *n1 = phi->in( true_path);
|
|
1147 Node *n2 = phi->in(3-true_path);
|
|
1148
|
|
1149 int op = n1->Opcode();
|
|
1150 if( op != Op_AddI // Need zero as additive identity
|
|
1151 /*&&op != Op_SubI &&
|
|
1152 op != Op_AddP &&
|
|
1153 op != Op_XorI &&
|
|
1154 op != Op_OrI*/ )
|
|
1155 return NULL;
|
|
1156
|
|
1157 Node *x = n2;
|
|
1158 Node *y = n1->in(1);
|
|
1159 if( n2 == n1->in(1) ) {
|
|
1160 y = n1->in(2);
|
|
1161 } else if( n2 == n1->in(1) ) {
|
|
1162 } else return NULL;
|
|
1163
|
|
1164 // Not so profitable if compare and add are constants
|
|
1165 if( q->is_Con() && phase->type(q) != TypeInt::ZERO && y->is_Con() )
|
|
1166 return NULL;
|
|
1167
|
|
1168 Node *cmplt = phase->transform( new (phase->C, 3) CmpLTMaskNode(p,q) );
|
|
1169 Node *j_and = phase->transform( new (phase->C, 3) AndINode(cmplt,y) );
|
|
1170 return new (phase->C, 3) AddINode(j_and,x);
|
|
1171 }
|
|
1172
|
|
1173 //------------------------------is_absolute------------------------------------
|
|
1174 // Check for absolute value.
|
|
1175 static Node* is_absolute( PhaseGVN *phase, PhiNode *phi_root, int true_path) {
|
|
1176 assert(true_path !=0, "only diamond shape graph expected");
|
|
1177
|
|
1178 int cmp_zero_idx = 0; // Index of compare input where to look for zero
|
|
1179 int phi_x_idx = 0; // Index of phi input where to find naked x
|
|
1180
|
|
1181 // ABS ends with the merge of 2 control flow paths.
|
|
1182 // Find the false path from the true path. With only 2 inputs, 3 - x works nicely.
|
|
1183 int false_path = 3 - true_path;
|
|
1184
|
|
1185 // is_diamond_phi() has guaranteed the correctness of the nodes sequence:
|
|
1186 // phi->region->if_proj->ifnode->bool->cmp
|
|
1187 BoolNode *bol = phi_root->in(0)->in(1)->in(0)->in(1)->as_Bool();
|
|
1188
|
|
1189 // Check bool sense
|
|
1190 switch( bol->_test._test ) {
|
|
1191 case BoolTest::lt: cmp_zero_idx = 1; phi_x_idx = true_path; break;
|
|
1192 case BoolTest::le: cmp_zero_idx = 2; phi_x_idx = false_path; break;
|
|
1193 case BoolTest::gt: cmp_zero_idx = 2; phi_x_idx = true_path; break;
|
|
1194 case BoolTest::ge: cmp_zero_idx = 1; phi_x_idx = false_path; break;
|
|
1195 default: return NULL; break;
|
|
1196 }
|
|
1197
|
|
1198 // Test is next
|
|
1199 Node *cmp = bol->in(1);
|
|
1200 const Type *tzero = NULL;
|
|
1201 switch( cmp->Opcode() ) {
|
|
1202 case Op_CmpF: tzero = TypeF::ZERO; break; // Float ABS
|
|
1203 case Op_CmpD: tzero = TypeD::ZERO; break; // Double ABS
|
|
1204 default: return NULL;
|
|
1205 }
|
|
1206
|
|
1207 // Find zero input of compare; the other input is being abs'd
|
|
1208 Node *x = NULL;
|
|
1209 bool flip = false;
|
|
1210 if( phase->type(cmp->in(cmp_zero_idx)) == tzero ) {
|
|
1211 x = cmp->in(3 - cmp_zero_idx);
|
|
1212 } else if( phase->type(cmp->in(3 - cmp_zero_idx)) == tzero ) {
|
|
1213 // The test is inverted, we should invert the result...
|
|
1214 x = cmp->in(cmp_zero_idx);
|
|
1215 flip = true;
|
|
1216 } else {
|
|
1217 return NULL;
|
|
1218 }
|
|
1219
|
|
1220 // Next get the 2 pieces being selected, one is the original value
|
|
1221 // and the other is the negated value.
|
|
1222 if( phi_root->in(phi_x_idx) != x ) return NULL;
|
|
1223
|
|
1224 // Check other phi input for subtract node
|
|
1225 Node *sub = phi_root->in(3 - phi_x_idx);
|
|
1226
|
|
1227 // Allow only Sub(0,X) and fail out for all others; Neg is not OK
|
|
1228 if( tzero == TypeF::ZERO ) {
|
|
1229 if( sub->Opcode() != Op_SubF ||
|
|
1230 sub->in(2) != x ||
|
|
1231 phase->type(sub->in(1)) != tzero ) return NULL;
|
|
1232 x = new (phase->C, 2) AbsFNode(x);
|
|
1233 if (flip) {
|
|
1234 x = new (phase->C, 3) SubFNode(sub->in(1), phase->transform(x));
|
|
1235 }
|
|
1236 } else {
|
|
1237 if( sub->Opcode() != Op_SubD ||
|
|
1238 sub->in(2) != x ||
|
|
1239 phase->type(sub->in(1)) != tzero ) return NULL;
|
|
1240 x = new (phase->C, 2) AbsDNode(x);
|
|
1241 if (flip) {
|
|
1242 x = new (phase->C, 3) SubDNode(sub->in(1), phase->transform(x));
|
|
1243 }
|
|
1244 }
|
|
1245
|
|
1246 return x;
|
|
1247 }
|
|
1248
|
|
1249 //------------------------------split_once-------------------------------------
|
|
1250 // Helper for split_flow_path
|
|
1251 static void split_once(PhaseIterGVN *igvn, Node *phi, Node *val, Node *n, Node *newn) {
|
|
1252 igvn->hash_delete(n); // Remove from hash before hacking edges
|
|
1253
|
|
1254 uint j = 1;
|
|
1255 for( uint i = phi->req()-1; i > 0; i-- ) {
|
|
1256 if( phi->in(i) == val ) { // Found a path with val?
|
|
1257 // Add to NEW Region/Phi, no DU info
|
|
1258 newn->set_req( j++, n->in(i) );
|
|
1259 // Remove from OLD Region/Phi
|
|
1260 n->del_req(i);
|
|
1261 }
|
|
1262 }
|
|
1263
|
|
1264 // Register the new node but do not transform it. Cannot transform until the
|
|
1265 // entire Region/Phi conglerate has been hacked as a single huge transform.
|
|
1266 igvn->register_new_node_with_optimizer( newn );
|
|
1267 // Now I can point to the new node.
|
|
1268 n->add_req(newn);
|
|
1269 igvn->_worklist.push(n);
|
|
1270 }
|
|
1271
|
|
1272 //------------------------------split_flow_path--------------------------------
|
|
1273 // Check for merging identical values and split flow paths
|
|
1274 static Node* split_flow_path(PhaseGVN *phase, PhiNode *phi) {
|
|
1275 BasicType bt = phi->type()->basic_type();
|
|
1276 if( bt == T_ILLEGAL || type2size[bt] <= 0 )
|
|
1277 return NULL; // Bail out on funny non-value stuff
|
|
1278 if( phi->req() <= 3 ) // Need at least 2 matched inputs and a
|
|
1279 return NULL; // third unequal input to be worth doing
|
|
1280
|
|
1281 // Scan for a constant
|
|
1282 uint i;
|
|
1283 for( i = 1; i < phi->req()-1; i++ ) {
|
|
1284 Node *n = phi->in(i);
|
|
1285 if( !n ) return NULL;
|
|
1286 if( phase->type(n) == Type::TOP ) return NULL;
|
|
1287 if( n->Opcode() == Op_ConP )
|
|
1288 break;
|
|
1289 }
|
|
1290 if( i >= phi->req() ) // Only split for constants
|
|
1291 return NULL;
|
|
1292
|
|
1293 Node *val = phi->in(i); // Constant to split for
|
|
1294 uint hit = 0; // Number of times it occurs
|
|
1295
|
|
1296 for( ; i < phi->req(); i++ ){ // Count occurances of constant
|
|
1297 Node *n = phi->in(i);
|
|
1298 if( !n ) return NULL;
|
|
1299 if( phase->type(n) == Type::TOP ) return NULL;
|
|
1300 if( phi->in(i) == val )
|
|
1301 hit++;
|
|
1302 }
|
|
1303
|
|
1304 if( hit <= 1 || // Make sure we find 2 or more
|
|
1305 hit == phi->req()-1 ) // and not ALL the same value
|
|
1306 return NULL;
|
|
1307
|
|
1308 // Now start splitting out the flow paths that merge the same value.
|
|
1309 // Split first the RegionNode.
|
|
1310 PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
1311 Node *r = phi->region();
|
|
1312 RegionNode *newr = new (phase->C, hit+1) RegionNode(hit+1);
|
|
1313 split_once(igvn, phi, val, r, newr);
|
|
1314
|
|
1315 // Now split all other Phis than this one
|
|
1316 for (DUIterator_Fast kmax, k = r->fast_outs(kmax); k < kmax; k++) {
|
|
1317 Node* phi2 = r->fast_out(k);
|
|
1318 if( phi2->is_Phi() && phi2->as_Phi() != phi ) {
|
|
1319 PhiNode *newphi = PhiNode::make_blank(newr, phi2);
|
|
1320 split_once(igvn, phi, val, phi2, newphi);
|
|
1321 }
|
|
1322 }
|
|
1323
|
|
1324 // Clean up this guy
|
|
1325 igvn->hash_delete(phi);
|
|
1326 for( i = phi->req()-1; i > 0; i-- ) {
|
|
1327 if( phi->in(i) == val ) {
|
|
1328 phi->del_req(i);
|
|
1329 }
|
|
1330 }
|
|
1331 phi->add_req(val);
|
|
1332
|
|
1333 return phi;
|
|
1334 }
|
|
1335
|
|
1336 //=============================================================================
|
|
1337 //------------------------------simple_data_loop_check-------------------------
|
|
1338 // Try to determing if the phi node in a simple safe/unsafe data loop.
|
|
1339 // Returns:
|
|
1340 // enum LoopSafety { Safe = 0, Unsafe, UnsafeLoop };
|
|
1341 // Safe - safe case when the phi and it's inputs reference only safe data
|
|
1342 // nodes;
|
|
1343 // Unsafe - the phi and it's inputs reference unsafe data nodes but there
|
|
1344 // is no reference back to the phi - need a graph walk
|
|
1345 // to determine if it is in a loop;
|
|
1346 // UnsafeLoop - unsafe case when the phi references itself directly or through
|
|
1347 // unsafe data node.
|
|
1348 // Note: a safe data node is a node which could/never reference itself during
|
|
1349 // GVN transformations. For now it is Con, Proj, Phi, CastPP, CheckCastPP.
|
|
1350 // I mark Phi nodes as safe node not only because they can reference itself
|
|
1351 // but also to prevent mistaking the fallthrough case inside an outer loop
|
|
1352 // as dead loop when the phi references itselfs through an other phi.
|
|
1353 PhiNode::LoopSafety PhiNode::simple_data_loop_check(Node *in) const {
|
|
1354 // It is unsafe loop if the phi node references itself directly.
|
|
1355 if (in == (Node*)this)
|
|
1356 return UnsafeLoop; // Unsafe loop
|
|
1357 // Unsafe loop if the phi node references itself through an unsafe data node.
|
|
1358 // Exclude cases with null inputs or data nodes which could reference
|
|
1359 // itself (safe for dead loops).
|
|
1360 if (in != NULL && !in->is_dead_loop_safe()) {
|
|
1361 // Check inputs of phi's inputs also.
|
|
1362 // It is much less expensive then full graph walk.
|
|
1363 uint cnt = in->req();
|
|
1364 for (uint i = 1; i < cnt; ++i) {
|
|
1365 Node* m = in->in(i);
|
|
1366 if (m == (Node*)this)
|
|
1367 return UnsafeLoop; // Unsafe loop
|
|
1368 if (m != NULL && !m->is_dead_loop_safe()) {
|
|
1369 // Check the most common case (about 30% of all cases):
|
|
1370 // phi->Load/Store->AddP->(ConP ConP Con)/(Parm Parm Con).
|
|
1371 Node *m1 = (m->is_AddP() && m->req() > 3) ? m->in(1) : NULL;
|
|
1372 if (m1 == (Node*)this)
|
|
1373 return UnsafeLoop; // Unsafe loop
|
|
1374 if (m1 != NULL && m1 == m->in(2) &&
|
|
1375 m1->is_dead_loop_safe() && m->in(3)->is_Con()) {
|
|
1376 continue; // Safe case
|
|
1377 }
|
|
1378 // The phi references an unsafe node - need full analysis.
|
|
1379 return Unsafe;
|
|
1380 }
|
|
1381 }
|
|
1382 }
|
|
1383 return Safe; // Safe case - we can optimize the phi node.
|
|
1384 }
|
|
1385
|
|
1386 //------------------------------is_unsafe_data_reference-----------------------
|
|
1387 // If phi can be reached through the data input - it is data loop.
|
|
1388 bool PhiNode::is_unsafe_data_reference(Node *in) const {
|
|
1389 assert(req() > 1, "");
|
|
1390 // First, check simple cases when phi references itself directly or
|
|
1391 // through an other node.
|
|
1392 LoopSafety safety = simple_data_loop_check(in);
|
|
1393 if (safety == UnsafeLoop)
|
|
1394 return true; // phi references itself - unsafe loop
|
|
1395 else if (safety == Safe)
|
|
1396 return false; // Safe case - phi could be replaced with the unique input.
|
|
1397
|
|
1398 // Unsafe case when we should go through data graph to determine
|
|
1399 // if the phi references itself.
|
|
1400
|
|
1401 ResourceMark rm;
|
|
1402
|
|
1403 Arena *a = Thread::current()->resource_area();
|
|
1404 Node_List nstack(a);
|
|
1405 VectorSet visited(a);
|
|
1406
|
|
1407 nstack.push(in); // Start with unique input.
|
|
1408 visited.set(in->_idx);
|
|
1409 while (nstack.size() != 0) {
|
|
1410 Node* n = nstack.pop();
|
|
1411 uint cnt = n->req();
|
|
1412 for (uint i = 1; i < cnt; i++) { // Only data paths
|
|
1413 Node* m = n->in(i);
|
|
1414 if (m == (Node*)this) {
|
|
1415 return true; // Data loop
|
|
1416 }
|
|
1417 if (m != NULL && !m->is_dead_loop_safe()) { // Only look for unsafe cases.
|
|
1418 if (!visited.test_set(m->_idx))
|
|
1419 nstack.push(m);
|
|
1420 }
|
|
1421 }
|
|
1422 }
|
|
1423 return false; // The phi is not reachable from its inputs
|
|
1424 }
|
|
1425
|
|
1426
|
|
1427 //------------------------------Ideal------------------------------------------
|
|
1428 // Return a node which is more "ideal" than the current node. Must preserve
|
|
1429 // the CFG, but we can still strip out dead paths.
|
|
1430 Node *PhiNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
1431 // The next should never happen after 6297035 fix.
|
|
1432 if( is_copy() ) // Already degraded to a Copy ?
|
|
1433 return NULL; // No change
|
|
1434
|
|
1435 Node *r = in(0); // RegionNode
|
|
1436 assert(r->in(0) == NULL || !r->in(0)->is_Root(), "not a specially hidden merge");
|
|
1437
|
|
1438 // Note: During parsing, phis are often transformed before their regions.
|
|
1439 // This means we have to use type_or_null to defend against untyped regions.
|
|
1440 if( phase->type_or_null(r) == Type::TOP ) // Dead code?
|
|
1441 return NULL; // No change
|
|
1442
|
|
1443 Node *top = phase->C->top();
|
|
1444
|
|
1445 // The are 2 situations when only one valid phi's input is left
|
|
1446 // (in addition to Region input).
|
|
1447 // One: region is not loop - replace phi with this input.
|
|
1448 // Two: region is loop - replace phi with top since this data path is dead
|
|
1449 // and we need to break the dead data loop.
|
|
1450 Node* progress = NULL; // Record if any progress made
|
|
1451 for( uint j = 1; j < req(); ++j ){ // For all paths in
|
|
1452 // Check unreachable control paths
|
|
1453 Node* rc = r->in(j);
|
|
1454 Node* n = in(j); // Get the input
|
|
1455 if (rc == NULL || phase->type(rc) == Type::TOP) {
|
|
1456 if (n != top) { // Not already top?
|
|
1457 set_req(j, top); // Nuke it down
|
|
1458 progress = this; // Record progress
|
|
1459 }
|
|
1460 }
|
|
1461 }
|
|
1462
|
|
1463 Node* uin = unique_input(phase);
|
|
1464 if (uin == top) { // Simplest case: no alive inputs.
|
|
1465 if (can_reshape) // IGVN transformation
|
|
1466 return top;
|
|
1467 else
|
|
1468 return NULL; // Identity will return TOP
|
|
1469 } else if (uin != NULL) {
|
|
1470 // Only one not-NULL unique input path is left.
|
|
1471 // Determine if this input is backedge of a loop.
|
|
1472 // (Skip new phis which have no uses and dead regions).
|
|
1473 if( outcnt() > 0 && r->in(0) != NULL ) {
|
|
1474 // First, take the short cut when we know it is a loop and
|
|
1475 // the EntryControl data path is dead.
|
|
1476 assert(!r->is_Loop() || r->req() == 3, "Loop node should have 3 inputs");
|
|
1477 // Then, check if there is a data loop when phi references itself directly
|
|
1478 // or through other data nodes.
|
|
1479 if( r->is_Loop() && !phase->eqv_uncast(uin, in(LoopNode::EntryControl)) ||
|
|
1480 !r->is_Loop() && is_unsafe_data_reference(uin) ) {
|
|
1481 // Break this data loop to avoid creation of a dead loop.
|
|
1482 if (can_reshape) {
|
|
1483 return top;
|
|
1484 } else {
|
|
1485 // We can't return top if we are in Parse phase - cut inputs only
|
|
1486 // let Identity to handle the case.
|
|
1487 replace_edge(uin, top);
|
|
1488 return NULL;
|
|
1489 }
|
|
1490 }
|
|
1491 }
|
|
1492
|
|
1493 // One unique input.
|
|
1494 debug_only(Node* ident = Identity(phase));
|
|
1495 // The unique input must eventually be detected by the Identity call.
|
|
1496 #ifdef ASSERT
|
|
1497 if (ident != uin && !ident->is_top()) {
|
|
1498 // print this output before failing assert
|
|
1499 r->dump(3);
|
|
1500 this->dump(3);
|
|
1501 ident->dump();
|
|
1502 uin->dump();
|
|
1503 }
|
|
1504 #endif
|
|
1505 assert(ident == uin || ident->is_top(), "Identity must clean this up");
|
|
1506 return NULL;
|
|
1507 }
|
|
1508
|
|
1509
|
|
1510 Node* opt = NULL;
|
|
1511 int true_path = is_diamond_phi();
|
|
1512 if( true_path != 0 ) {
|
|
1513 // Check for CMove'ing identity. If it would be unsafe,
|
|
1514 // handle it here. In the safe case, let Identity handle it.
|
|
1515 Node* unsafe_id = is_cmove_id(phase, true_path);
|
|
1516 if( unsafe_id != NULL && is_unsafe_data_reference(unsafe_id) )
|
|
1517 opt = unsafe_id;
|
|
1518
|
|
1519 // Check for simple convert-to-boolean pattern
|
|
1520 if( opt == NULL )
|
|
1521 opt = is_x2logic(phase, this, true_path);
|
|
1522
|
|
1523 // Check for absolute value
|
|
1524 if( opt == NULL )
|
|
1525 opt = is_absolute(phase, this, true_path);
|
|
1526
|
|
1527 // Check for conditional add
|
|
1528 if( opt == NULL && can_reshape )
|
|
1529 opt = is_cond_add(phase, this, true_path);
|
|
1530
|
|
1531 // These 4 optimizations could subsume the phi:
|
|
1532 // have to check for a dead data loop creation.
|
|
1533 if( opt != NULL ) {
|
|
1534 if( opt == unsafe_id || is_unsafe_data_reference(opt) ) {
|
|
1535 // Found dead loop.
|
|
1536 if( can_reshape )
|
|
1537 return top;
|
|
1538 // We can't return top if we are in Parse phase - cut inputs only
|
|
1539 // to stop further optimizations for this phi. Identity will return TOP.
|
|
1540 assert(req() == 3, "only diamond merge phi here");
|
|
1541 set_req(1, top);
|
|
1542 set_req(2, top);
|
|
1543 return NULL;
|
|
1544 } else {
|
|
1545 return opt;
|
|
1546 }
|
|
1547 }
|
|
1548 }
|
|
1549
|
|
1550 // Check for merging identical values and split flow paths
|
|
1551 if (can_reshape) {
|
|
1552 opt = split_flow_path(phase, this);
|
|
1553 // This optimization only modifies phi - don't need to check for dead loop.
|
|
1554 assert(opt == NULL || phase->eqv(opt, this), "do not elide phi");
|
|
1555 if (opt != NULL) return opt;
|
|
1556 }
|
|
1557
|
|
1558 if (in(1) != NULL && in(1)->Opcode() == Op_AddP && can_reshape) {
|
|
1559 // Try to undo Phi of AddP:
|
|
1560 // (Phi (AddP base base y) (AddP base2 base2 y))
|
|
1561 // becomes:
|
|
1562 // newbase := (Phi base base2)
|
|
1563 // (AddP newbase newbase y)
|
|
1564 //
|
|
1565 // This occurs as a result of unsuccessful split_thru_phi and
|
|
1566 // interferes with taking advantage of addressing modes. See the
|
|
1567 // clone_shift_expressions code in matcher.cpp
|
|
1568 Node* addp = in(1);
|
|
1569 const Type* type = addp->in(AddPNode::Base)->bottom_type();
|
|
1570 Node* y = addp->in(AddPNode::Offset);
|
|
1571 if (y != NULL && addp->in(AddPNode::Base) == addp->in(AddPNode::Address)) {
|
|
1572 // make sure that all the inputs are similar to the first one,
|
|
1573 // i.e. AddP with base == address and same offset as first AddP
|
|
1574 bool doit = true;
|
|
1575 for (uint i = 2; i < req(); i++) {
|
|
1576 if (in(i) == NULL ||
|
|
1577 in(i)->Opcode() != Op_AddP ||
|
|
1578 in(i)->in(AddPNode::Base) != in(i)->in(AddPNode::Address) ||
|
|
1579 in(i)->in(AddPNode::Offset) != y) {
|
|
1580 doit = false;
|
|
1581 break;
|
|
1582 }
|
|
1583 // Accumulate type for resulting Phi
|
|
1584 type = type->meet(in(i)->in(AddPNode::Base)->bottom_type());
|
|
1585 }
|
|
1586 Node* base = NULL;
|
|
1587 if (doit) {
|
|
1588 // Check for neighboring AddP nodes in a tree.
|
|
1589 // If they have a base, use that it.
|
|
1590 for (DUIterator_Fast kmax, k = this->fast_outs(kmax); k < kmax; k++) {
|
|
1591 Node* u = this->fast_out(k);
|
|
1592 if (u->is_AddP()) {
|
|
1593 Node* base2 = u->in(AddPNode::Base);
|
|
1594 if (base2 != NULL && !base2->is_top()) {
|
|
1595 if (base == NULL)
|
|
1596 base = base2;
|
|
1597 else if (base != base2)
|
|
1598 { doit = false; break; }
|
|
1599 }
|
|
1600 }
|
|
1601 }
|
|
1602 }
|
|
1603 if (doit) {
|
|
1604 if (base == NULL) {
|
|
1605 base = new (phase->C, in(0)->req()) PhiNode(in(0), type, NULL);
|
|
1606 for (uint i = 1; i < req(); i++) {
|
|
1607 base->init_req(i, in(i)->in(AddPNode::Base));
|
|
1608 }
|
|
1609 phase->is_IterGVN()->register_new_node_with_optimizer(base);
|
|
1610 }
|
|
1611 return new (phase->C, 4) AddPNode(base, base, y);
|
|
1612 }
|
|
1613 }
|
|
1614 }
|
|
1615
|
|
1616 // Split phis through memory merges, so that the memory merges will go away.
|
|
1617 // Piggy-back this transformation on the search for a unique input....
|
|
1618 // It will be as if the merged memory is the unique value of the phi.
|
|
1619 // (Do not attempt this optimization unless parsing is complete.
|
|
1620 // It would make the parser's memory-merge logic sick.)
|
|
1621 // (MergeMemNode is not dead_loop_safe - need to check for dead loop.)
|
|
1622 if (progress == NULL && can_reshape && type() == Type::MEMORY) {
|
|
1623 // see if this phi should be sliced
|
|
1624 uint merge_width = 0;
|
|
1625 bool saw_self = false;
|
|
1626 for( uint i=1; i<req(); ++i ) {// For all paths in
|
|
1627 Node *ii = in(i);
|
|
1628 if (ii->is_MergeMem()) {
|
|
1629 MergeMemNode* n = ii->as_MergeMem();
|
|
1630 merge_width = MAX2(merge_width, n->req());
|
|
1631 saw_self = saw_self || phase->eqv(n->base_memory(), this);
|
|
1632 }
|
|
1633 }
|
|
1634
|
|
1635 // This restriction is temporarily necessary to ensure termination:
|
|
1636 if (!saw_self && adr_type() == TypePtr::BOTTOM) merge_width = 0;
|
|
1637
|
|
1638 if (merge_width > Compile::AliasIdxRaw) {
|
|
1639 // found at least one non-empty MergeMem
|
|
1640 const TypePtr* at = adr_type();
|
|
1641 if (at != TypePtr::BOTTOM) {
|
|
1642 // Patch the existing phi to select an input from the merge:
|
|
1643 // Phi:AT1(...MergeMem(m0, m1, m2)...) into
|
|
1644 // Phi:AT1(...m1...)
|
|
1645 int alias_idx = phase->C->get_alias_index(at);
|
|
1646 for (uint i=1; i<req(); ++i) {
|
|
1647 Node *ii = in(i);
|
|
1648 if (ii->is_MergeMem()) {
|
|
1649 MergeMemNode* n = ii->as_MergeMem();
|
|
1650 // compress paths and change unreachable cycles to TOP
|
|
1651 // If not, we can update the input infinitely along a MergeMem cycle
|
|
1652 // Equivalent code is in MemNode::Ideal_common
|
|
1653 Node *m = phase->transform(n);
|
|
1654 // If tranformed to a MergeMem, get the desired slice
|
|
1655 // Otherwise the returned node represents memory for every slice
|
|
1656 Node *new_mem = (m->is_MergeMem()) ?
|
|
1657 m->as_MergeMem()->memory_at(alias_idx) : m;
|
|
1658 // Update input if it is progress over what we have now
|
|
1659 if (new_mem != ii) {
|
|
1660 set_req(i, new_mem);
|
|
1661 progress = this;
|
|
1662 }
|
|
1663 }
|
|
1664 }
|
|
1665 } else {
|
|
1666 // We know that at least one MergeMem->base_memory() == this
|
|
1667 // (saw_self == true). If all other inputs also references this phi
|
|
1668 // (directly or through data nodes) - it is dead loop.
|
|
1669 bool saw_safe_input = false;
|
|
1670 for (uint j = 1; j < req(); ++j) {
|
|
1671 Node *n = in(j);
|
|
1672 if (n->is_MergeMem() && n->as_MergeMem()->base_memory() == this)
|
|
1673 continue; // skip known cases
|
|
1674 if (!is_unsafe_data_reference(n)) {
|
|
1675 saw_safe_input = true; // found safe input
|
|
1676 break;
|
|
1677 }
|
|
1678 }
|
|
1679 if (!saw_safe_input)
|
|
1680 return top; // all inputs reference back to this phi - dead loop
|
|
1681
|
|
1682 // Phi(...MergeMem(m0, m1:AT1, m2:AT2)...) into
|
|
1683 // MergeMem(Phi(...m0...), Phi:AT1(...m1...), Phi:AT2(...m2...))
|
|
1684 PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
1685 Node* hook = new (phase->C, 1) Node(1);
|
|
1686 PhiNode* new_base = (PhiNode*) clone();
|
|
1687 // Must eagerly register phis, since they participate in loops.
|
|
1688 if (igvn) {
|
|
1689 igvn->register_new_node_with_optimizer(new_base);
|
|
1690 hook->add_req(new_base);
|
|
1691 }
|
|
1692 MergeMemNode* result = MergeMemNode::make(phase->C, new_base);
|
|
1693 for (uint i = 1; i < req(); ++i) {
|
|
1694 Node *ii = in(i);
|
|
1695 if (ii->is_MergeMem()) {
|
|
1696 MergeMemNode* n = ii->as_MergeMem();
|
|
1697 for (MergeMemStream mms(result, n); mms.next_non_empty2(); ) {
|
|
1698 // If we have not seen this slice yet, make a phi for it.
|
|
1699 bool made_new_phi = false;
|
|
1700 if (mms.is_empty()) {
|
|
1701 Node* new_phi = new_base->slice_memory(mms.adr_type(phase->C));
|
|
1702 made_new_phi = true;
|
|
1703 if (igvn) {
|
|
1704 igvn->register_new_node_with_optimizer(new_phi);
|
|
1705 hook->add_req(new_phi);
|
|
1706 }
|
|
1707 mms.set_memory(new_phi);
|
|
1708 }
|
|
1709 Node* phi = mms.memory();
|
|
1710 assert(made_new_phi || phi->in(i) == n, "replace the i-th merge by a slice");
|
|
1711 phi->set_req(i, mms.memory2());
|
|
1712 }
|
|
1713 }
|
|
1714 }
|
|
1715 // Distribute all self-loops.
|
|
1716 { // (Extra braces to hide mms.)
|
|
1717 for (MergeMemStream mms(result); mms.next_non_empty(); ) {
|
|
1718 Node* phi = mms.memory();
|
|
1719 for (uint i = 1; i < req(); ++i) {
|
|
1720 if (phi->in(i) == this) phi->set_req(i, phi);
|
|
1721 }
|
|
1722 }
|
|
1723 }
|
|
1724 // now transform the new nodes, and return the mergemem
|
|
1725 for (MergeMemStream mms(result); mms.next_non_empty(); ) {
|
|
1726 Node* phi = mms.memory();
|
|
1727 mms.set_memory(phase->transform(phi));
|
|
1728 }
|
|
1729 if (igvn) { // Unhook.
|
|
1730 igvn->hash_delete(hook);
|
|
1731 for (uint i = 1; i < hook->req(); i++) {
|
|
1732 hook->set_req(i, NULL);
|
|
1733 }
|
|
1734 }
|
|
1735 // Replace self with the result.
|
|
1736 return result;
|
|
1737 }
|
|
1738 }
|
|
1739 }
|
|
1740
|
|
1741 return progress; // Return any progress
|
|
1742 }
|
|
1743
|
|
1744 //------------------------------out_RegMask------------------------------------
|
|
1745 const RegMask &PhiNode::in_RegMask(uint i) const {
|
|
1746 return i ? out_RegMask() : RegMask::Empty;
|
|
1747 }
|
|
1748
|
|
1749 const RegMask &PhiNode::out_RegMask() const {
|
|
1750 uint ideal_reg = Matcher::base2reg[_type->base()];
|
|
1751 assert( ideal_reg != Node::NotAMachineReg, "invalid type at Phi" );
|
|
1752 if( ideal_reg == 0 ) return RegMask::Empty;
|
|
1753 return *(Compile::current()->matcher()->idealreg2spillmask[ideal_reg]);
|
|
1754 }
|
|
1755
|
|
1756 #ifndef PRODUCT
|
|
1757 void PhiNode::dump_spec(outputStream *st) const {
|
|
1758 TypeNode::dump_spec(st);
|
|
1759 if (in(0) != NULL &&
|
|
1760 in(0)->is_CountedLoop() &&
|
|
1761 in(0)->as_CountedLoop()->phi() == this) {
|
|
1762 st->print(" #tripcount");
|
|
1763 }
|
|
1764 }
|
|
1765 #endif
|
|
1766
|
|
1767
|
|
1768 //=============================================================================
|
|
1769 const Type *GotoNode::Value( PhaseTransform *phase ) const {
|
|
1770 // If the input is reachable, then we are executed.
|
|
1771 // If the input is not reachable, then we are not executed.
|
|
1772 return phase->type(in(0));
|
|
1773 }
|
|
1774
|
|
1775 Node *GotoNode::Identity( PhaseTransform *phase ) {
|
|
1776 return in(0); // Simple copy of incoming control
|
|
1777 }
|
|
1778
|
|
1779 const RegMask &GotoNode::out_RegMask() const {
|
|
1780 return RegMask::Empty;
|
|
1781 }
|
|
1782
|
|
1783 //=============================================================================
|
|
1784 const RegMask &JumpNode::out_RegMask() const {
|
|
1785 return RegMask::Empty;
|
|
1786 }
|
|
1787
|
|
1788 //=============================================================================
|
|
1789 const RegMask &JProjNode::out_RegMask() const {
|
|
1790 return RegMask::Empty;
|
|
1791 }
|
|
1792
|
|
1793 //=============================================================================
|
|
1794 const RegMask &CProjNode::out_RegMask() const {
|
|
1795 return RegMask::Empty;
|
|
1796 }
|
|
1797
|
|
1798
|
|
1799
|
|
1800 //=============================================================================
|
|
1801
|
|
1802 uint PCTableNode::hash() const { return Node::hash() + _size; }
|
|
1803 uint PCTableNode::cmp( const Node &n ) const
|
|
1804 { return _size == ((PCTableNode&)n)._size; }
|
|
1805
|
|
1806 const Type *PCTableNode::bottom_type() const {
|
|
1807 const Type** f = TypeTuple::fields(_size);
|
|
1808 for( uint i = 0; i < _size; i++ ) f[i] = Type::CONTROL;
|
|
1809 return TypeTuple::make(_size, f);
|
|
1810 }
|
|
1811
|
|
1812 //------------------------------Value------------------------------------------
|
|
1813 // Compute the type of the PCTableNode. If reachable it is a tuple of
|
|
1814 // Control, otherwise the table targets are not reachable
|
|
1815 const Type *PCTableNode::Value( PhaseTransform *phase ) const {
|
|
1816 if( phase->type(in(0)) == Type::CONTROL )
|
|
1817 return bottom_type();
|
|
1818 return Type::TOP; // All paths dead? Then so are we
|
|
1819 }
|
|
1820
|
|
1821 //------------------------------Ideal------------------------------------------
|
|
1822 // Return a node which is more "ideal" than the current node. Strip out
|
|
1823 // control copies
|
|
1824 Node *PCTableNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
1825 return remove_dead_region(phase, can_reshape) ? this : NULL;
|
|
1826 }
|
|
1827
|
|
1828 //=============================================================================
|
|
1829 uint JumpProjNode::hash() const {
|
|
1830 return Node::hash() + _dest_bci;
|
|
1831 }
|
|
1832
|
|
1833 uint JumpProjNode::cmp( const Node &n ) const {
|
|
1834 return ProjNode::cmp(n) &&
|
|
1835 _dest_bci == ((JumpProjNode&)n)._dest_bci;
|
|
1836 }
|
|
1837
|
|
1838 #ifndef PRODUCT
|
|
1839 void JumpProjNode::dump_spec(outputStream *st) const {
|
|
1840 ProjNode::dump_spec(st);
|
|
1841 st->print("@bci %d ",_dest_bci);
|
|
1842 }
|
|
1843 #endif
|
|
1844
|
|
1845 //=============================================================================
|
|
1846 //------------------------------Value------------------------------------------
|
|
1847 // Check for being unreachable, or for coming from a Rethrow. Rethrow's cannot
|
|
1848 // have the default "fall_through_index" path.
|
|
1849 const Type *CatchNode::Value( PhaseTransform *phase ) const {
|
|
1850 // Unreachable? Then so are all paths from here.
|
|
1851 if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
|
|
1852 // First assume all paths are reachable
|
|
1853 const Type** f = TypeTuple::fields(_size);
|
|
1854 for( uint i = 0; i < _size; i++ ) f[i] = Type::CONTROL;
|
|
1855 // Identify cases that will always throw an exception
|
|
1856 // () rethrow call
|
|
1857 // () virtual or interface call with NULL receiver
|
|
1858 // () call is a check cast with incompatible arguments
|
|
1859 if( in(1)->is_Proj() ) {
|
|
1860 Node *i10 = in(1)->in(0);
|
|
1861 if( i10->is_Call() ) {
|
|
1862 CallNode *call = i10->as_Call();
|
|
1863 // Rethrows always throw exceptions, never return
|
|
1864 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
|
|
1865 f[CatchProjNode::fall_through_index] = Type::TOP;
|
|
1866 } else if( call->req() > TypeFunc::Parms ) {
|
|
1867 const Type *arg0 = phase->type( call->in(TypeFunc::Parms) );
|
|
1868 // Check for null reciever to virtual or interface calls
|
|
1869 if( call->is_CallDynamicJava() &&
|
|
1870 arg0->higher_equal(TypePtr::NULL_PTR) ) {
|
|
1871 f[CatchProjNode::fall_through_index] = Type::TOP;
|
|
1872 }
|
|
1873 } // End of if not a runtime stub
|
|
1874 } // End of if have call above me
|
|
1875 } // End of slot 1 is not a projection
|
|
1876 return TypeTuple::make(_size, f);
|
|
1877 }
|
|
1878
|
|
1879 //=============================================================================
|
|
1880 uint CatchProjNode::hash() const {
|
|
1881 return Node::hash() + _handler_bci;
|
|
1882 }
|
|
1883
|
|
1884
|
|
1885 uint CatchProjNode::cmp( const Node &n ) const {
|
|
1886 return ProjNode::cmp(n) &&
|
|
1887 _handler_bci == ((CatchProjNode&)n)._handler_bci;
|
|
1888 }
|
|
1889
|
|
1890
|
|
1891 //------------------------------Identity---------------------------------------
|
|
1892 // If only 1 target is possible, choose it if it is the main control
|
|
1893 Node *CatchProjNode::Identity( PhaseTransform *phase ) {
|
|
1894 // If my value is control and no other value is, then treat as ID
|
|
1895 const TypeTuple *t = phase->type(in(0))->is_tuple();
|
|
1896 if (t->field_at(_con) != Type::CONTROL) return this;
|
|
1897 // If we remove the last CatchProj and elide the Catch/CatchProj, then we
|
|
1898 // also remove any exception table entry. Thus we must know the call
|
|
1899 // feeding the Catch will not really throw an exception. This is ok for
|
|
1900 // the main fall-thru control (happens when we know a call can never throw
|
|
1901 // an exception) or for "rethrow", because a further optimnization will
|
|
1902 // yank the rethrow (happens when we inline a function that can throw an
|
|
1903 // exception and the caller has no handler). Not legal, e.g., for passing
|
|
1904 // a NULL receiver to a v-call, or passing bad types to a slow-check-cast.
|
|
1905 // These cases MUST throw an exception via the runtime system, so the VM
|
|
1906 // will be looking for a table entry.
|
|
1907 Node *proj = in(0)->in(1); // Expect a proj feeding CatchNode
|
|
1908 CallNode *call;
|
|
1909 if (_con != TypeFunc::Control && // Bail out if not the main control.
|
|
1910 !(proj->is_Proj() && // AND NOT a rethrow
|
|
1911 proj->in(0)->is_Call() &&
|
|
1912 (call = proj->in(0)->as_Call()) &&
|
|
1913 call->entry_point() == OptoRuntime::rethrow_stub()))
|
|
1914 return this;
|
|
1915
|
|
1916 // Search for any other path being control
|
|
1917 for (uint i = 0; i < t->cnt(); i++) {
|
|
1918 if (i != _con && t->field_at(i) == Type::CONTROL)
|
|
1919 return this;
|
|
1920 }
|
|
1921 // Only my path is possible; I am identity on control to the jump
|
|
1922 return in(0)->in(0);
|
|
1923 }
|
|
1924
|
|
1925
|
|
1926 #ifndef PRODUCT
|
|
1927 void CatchProjNode::dump_spec(outputStream *st) const {
|
|
1928 ProjNode::dump_spec(st);
|
|
1929 st->print("@bci %d ",_handler_bci);
|
|
1930 }
|
|
1931 #endif
|
|
1932
|
|
1933 //=============================================================================
|
|
1934 //------------------------------Identity---------------------------------------
|
|
1935 // Check for CreateEx being Identity.
|
|
1936 Node *CreateExNode::Identity( PhaseTransform *phase ) {
|
|
1937 if( phase->type(in(1)) == Type::TOP ) return in(1);
|
|
1938 if( phase->type(in(0)) == Type::TOP ) return in(0);
|
|
1939 // We only come from CatchProj, unless the CatchProj goes away.
|
|
1940 // If the CatchProj is optimized away, then we just carry the
|
|
1941 // exception oop through.
|
|
1942 CallNode *call = in(1)->in(0)->as_Call();
|
|
1943
|
|
1944 return ( in(0)->is_CatchProj() && in(0)->in(0)->in(1) == in(1) )
|
|
1945 ? this
|
|
1946 : call->in(TypeFunc::Parms);
|
|
1947 }
|
|
1948
|
|
1949 //=============================================================================
|
|
1950 #ifndef PRODUCT
|
|
1951 void NeverBranchNode::format( PhaseRegAlloc *ra_, outputStream *st) const {
|
|
1952 st->print("%s", Name());
|
|
1953 }
|
|
1954 #endif
|