Mercurial > hg > graal-compiler
annotate src/share/vm/opto/loopopts.cpp @ 1201:24128c2ffa87
6921339: backout 6917766
Reviewed-by: mr
author | twisti |
---|---|
date | Fri, 29 Jan 2010 08:33:24 -0800 |
parents | 18f526145aea |
children | 4ee1c645110e |
rev | line source |
---|---|
0 | 1 /* |
844 | 2 * Copyright 1999-2009 Sun Microsystems, Inc. All Rights Reserved. |
0 | 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 #include "incls/_precompiled.incl" | |
26 #include "incls/_loopopts.cpp.incl" | |
27 | |
28 //============================================================================= | |
29 //------------------------------split_thru_phi--------------------------------- | |
30 // Split Node 'n' through merge point if there is enough win. | |
31 Node *PhaseIdealLoop::split_thru_phi( Node *n, Node *region, int policy ) { | |
69 | 32 if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) { |
33 // ConvI2L may have type information on it which is unsafe to push up | |
34 // so disable this for now | |
35 return NULL; | |
36 } | |
0 | 37 int wins = 0; |
38 assert( !n->is_CFG(), "" ); | |
39 assert( region->is_Region(), "" ); | |
64
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
40 |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
41 const Type* type = n->bottom_type(); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
42 const TypeOopPtr *t_oop = _igvn.type(n)->isa_oopptr(); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
43 Node *phi; |
223 | 44 if( t_oop != NULL && t_oop->is_known_instance_field() ) { |
64
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
45 int iid = t_oop->instance_id(); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
46 int index = C->get_alias_index(t_oop); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
47 int offset = t_oop->offset(); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
48 phi = new (C,region->req()) PhiNode(region, type, NULL, iid, index, offset); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
49 } else { |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
50 phi = new (C,region->req()) PhiNode(region, type); |
b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
kvn
parents:
35
diff
changeset
|
51 } |
0 | 52 uint old_unique = C->unique(); |
53 for( uint i = 1; i < region->req(); i++ ) { | |
54 Node *x; | |
55 Node* the_clone = NULL; | |
56 if( region->in(i) == C->top() ) { | |
57 x = C->top(); // Dead path? Use a dead data op | |
58 } else { | |
59 x = n->clone(); // Else clone up the data op | |
60 the_clone = x; // Remember for possible deletion. | |
61 // Alter data node to use pre-phi inputs | |
62 if( n->in(0) == region ) | |
63 x->set_req( 0, region->in(i) ); | |
64 for( uint j = 1; j < n->req(); j++ ) { | |
65 Node *in = n->in(j); | |
66 if( in->is_Phi() && in->in(0) == region ) | |
67 x->set_req( j, in->in(i) ); // Use pre-Phi input for the clone | |
68 } | |
69 } | |
70 // Check for a 'win' on some paths | |
71 const Type *t = x->Value(&_igvn); | |
72 | |
73 bool singleton = t->singleton(); | |
74 | |
75 // A TOP singleton indicates that there are no possible values incoming | |
76 // along a particular edge. In most cases, this is OK, and the Phi will | |
77 // be eliminated later in an Ideal call. However, we can't allow this to | |
78 // happen if the singleton occurs on loop entry, as the elimination of | |
79 // the PhiNode may cause the resulting node to migrate back to a previous | |
80 // loop iteration. | |
81 if( singleton && t == Type::TOP ) { | |
82 // Is_Loop() == false does not confirm the absence of a loop (e.g., an | |
83 // irreducible loop may not be indicated by an affirmative is_Loop()); | |
84 // therefore, the only top we can split thru a phi is on a backedge of | |
85 // a loop. | |
86 singleton &= region->is_Loop() && (i != LoopNode::EntryControl); | |
87 } | |
88 | |
89 if( singleton ) { | |
90 wins++; | |
91 x = ((PhaseGVN&)_igvn).makecon(t); | |
92 } else { | |
93 // We now call Identity to try to simplify the cloned node. | |
94 // Note that some Identity methods call phase->type(this). | |
95 // Make sure that the type array is big enough for | |
96 // our new node, even though we may throw the node away. | |
97 // (Note: This tweaking with igvn only works because x is a new node.) | |
98 _igvn.set_type(x, t); | |
293
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
99 // If x is a TypeNode, capture any more-precise type permanently into Node |
605 | 100 // otherwise it will be not updated during igvn->transform since |
293
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
101 // igvn->type(x) is set to x->Value() already. |
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
102 x->raise_bottom_type(t); |
0 | 103 Node *y = x->Identity(&_igvn); |
104 if( y != x ) { | |
105 wins++; | |
106 x = y; | |
107 } else { | |
108 y = _igvn.hash_find(x); | |
109 if( y ) { | |
110 wins++; | |
111 x = y; | |
112 } else { | |
113 // Else x is a new node we are keeping | |
114 // We do not need register_new_node_with_optimizer | |
115 // because set_type has already been called. | |
116 _igvn._worklist.push(x); | |
117 } | |
118 } | |
119 } | |
120 if (x != the_clone && the_clone != NULL) | |
121 _igvn.remove_dead_node(the_clone); | |
122 phi->set_req( i, x ); | |
123 } | |
124 // Too few wins? | |
125 if( wins <= policy ) { | |
126 _igvn.remove_dead_node(phi); | |
127 return NULL; | |
128 } | |
129 | |
130 // Record Phi | |
131 register_new_node( phi, region ); | |
132 | |
133 for( uint i2 = 1; i2 < phi->req(); i2++ ) { | |
134 Node *x = phi->in(i2); | |
135 // If we commoned up the cloned 'x' with another existing Node, | |
136 // the existing Node picks up a new use. We need to make the | |
137 // existing Node occur higher up so it dominates its uses. | |
138 Node *old_ctrl; | |
139 IdealLoopTree *old_loop; | |
140 | |
141 // The occasional new node | |
142 if( x->_idx >= old_unique ) { // Found a new, unplaced node? | |
143 old_ctrl = x->is_Con() ? C->root() : NULL; | |
144 old_loop = NULL; // Not in any prior loop | |
145 } else { | |
146 old_ctrl = x->is_Con() ? C->root() : get_ctrl(x); | |
147 old_loop = get_loop(old_ctrl); // Get prior loop | |
148 } | |
149 // New late point must dominate new use | |
150 Node *new_ctrl = dom_lca( old_ctrl, region->in(i2) ); | |
151 // Set new location | |
152 set_ctrl(x, new_ctrl); | |
153 IdealLoopTree *new_loop = get_loop( new_ctrl ); | |
154 // If changing loop bodies, see if we need to collect into new body | |
155 if( old_loop != new_loop ) { | |
156 if( old_loop && !old_loop->_child ) | |
157 old_loop->_body.yank(x); | |
158 if( !new_loop->_child ) | |
159 new_loop->_body.push(x); // Collect body info | |
160 } | |
161 } | |
162 | |
163 return phi; | |
164 } | |
165 | |
166 //------------------------------dominated_by------------------------------------ | |
167 // Replace the dominated test with an obvious true or false. Place it on the | |
168 // IGVN worklist for later cleanup. Move control-dependent data Nodes on the | |
169 // live path up to the dominating control. | |
170 void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff ) { | |
171 #ifndef PRODUCT | |
172 if( VerifyLoopOptimizations && PrintOpto ) tty->print_cr("dominating test"); | |
173 #endif | |
174 | |
175 | |
176 // prevdom is the dominating projection of the dominating test. | |
177 assert( iff->is_If(), "" ); | |
178 assert( iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd, "Check this code when new subtype is added"); | |
179 int pop = prevdom->Opcode(); | |
180 assert( pop == Op_IfFalse || pop == Op_IfTrue, "" ); | |
181 // 'con' is set to true or false to kill the dominated test. | |
182 Node *con = _igvn.makecon(pop == Op_IfTrue ? TypeInt::ONE : TypeInt::ZERO); | |
183 set_ctrl(con, C->root()); // Constant gets a new use | |
184 // Hack the dominated test | |
185 _igvn.hash_delete(iff); | |
186 iff->set_req(1, con); | |
187 _igvn._worklist.push(iff); | |
188 | |
189 // If I dont have a reachable TRUE and FALSE path following the IfNode then | |
190 // I can assume this path reaches an infinite loop. In this case it's not | |
191 // important to optimize the data Nodes - either the whole compilation will | |
192 // be tossed or this path (and all data Nodes) will go dead. | |
193 if( iff->outcnt() != 2 ) return; | |
194 | |
195 // Make control-dependent data Nodes on the live path (path that will remain | |
196 // once the dominated IF is removed) become control-dependent on the | |
197 // dominating projection. | |
198 Node* dp = ((IfNode*)iff)->proj_out(pop == Op_IfTrue); | |
199 IdealLoopTree *old_loop = get_loop(dp); | |
200 | |
201 for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) { | |
202 Node* cd = dp->fast_out(i); // Control-dependent node | |
203 if( cd->depends_only_on_test() ) { | |
204 assert( cd->in(0) == dp, "" ); | |
205 _igvn.hash_delete( cd ); | |
206 cd->set_req(0, prevdom); | |
207 set_early_ctrl( cd ); | |
208 _igvn._worklist.push(cd); | |
209 IdealLoopTree *new_loop = get_loop(get_ctrl(cd)); | |
210 if( old_loop != new_loop ) { | |
211 if( !old_loop->_child ) old_loop->_body.yank(cd); | |
212 if( !new_loop->_child ) new_loop->_body.push(cd); | |
213 } | |
214 --i; | |
215 --imax; | |
216 } | |
217 } | |
218 } | |
219 | |
220 //------------------------------has_local_phi_input---------------------------- | |
221 // Return TRUE if 'n' has Phi inputs from its local block and no other | |
222 // block-local inputs (all non-local-phi inputs come from earlier blocks) | |
223 Node *PhaseIdealLoop::has_local_phi_input( Node *n ) { | |
224 Node *n_ctrl = get_ctrl(n); | |
225 // See if some inputs come from a Phi in this block, or from before | |
226 // this block. | |
227 uint i; | |
228 for( i = 1; i < n->req(); i++ ) { | |
229 Node *phi = n->in(i); | |
230 if( phi->is_Phi() && phi->in(0) == n_ctrl ) | |
231 break; | |
232 } | |
233 if( i >= n->req() ) | |
234 return NULL; // No Phi inputs; nowhere to clone thru | |
235 | |
236 // Check for inputs created between 'n' and the Phi input. These | |
237 // must split as well; they have already been given the chance | |
238 // (courtesy of a post-order visit) and since they did not we must | |
239 // recover the 'cost' of splitting them by being very profitable | |
240 // when splitting 'n'. Since this is unlikely we simply give up. | |
241 for( i = 1; i < n->req(); i++ ) { | |
242 Node *m = n->in(i); | |
243 if( get_ctrl(m) == n_ctrl && !m->is_Phi() ) { | |
244 // We allow the special case of AddP's with no local inputs. | |
245 // This allows us to split-up address expressions. | |
246 if (m->is_AddP() && | |
247 get_ctrl(m->in(2)) != n_ctrl && | |
248 get_ctrl(m->in(3)) != n_ctrl) { | |
249 // Move the AddP up to dominating point | |
250 set_ctrl_and_loop(m, find_non_split_ctrl(idom(n_ctrl))); | |
251 continue; | |
252 } | |
253 return NULL; | |
254 } | |
255 } | |
256 | |
257 return n_ctrl; | |
258 } | |
259 | |
260 //------------------------------remix_address_expressions---------------------- | |
261 // Rework addressing expressions to get the most loop-invariant stuff | |
262 // moved out. We'd like to do all associative operators, but it's especially | |
263 // important (common) to do address expressions. | |
264 Node *PhaseIdealLoop::remix_address_expressions( Node *n ) { | |
265 if (!has_ctrl(n)) return NULL; | |
266 Node *n_ctrl = get_ctrl(n); | |
267 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
268 | |
269 // See if 'n' mixes loop-varying and loop-invariant inputs and | |
270 // itself is loop-varying. | |
271 | |
272 // Only interested in binary ops (and AddP) | |
273 if( n->req() < 3 || n->req() > 4 ) return NULL; | |
274 | |
275 Node *n1_ctrl = get_ctrl(n->in( 1)); | |
276 Node *n2_ctrl = get_ctrl(n->in( 2)); | |
277 Node *n3_ctrl = get_ctrl(n->in(n->req() == 3 ? 2 : 3)); | |
278 IdealLoopTree *n1_loop = get_loop( n1_ctrl ); | |
279 IdealLoopTree *n2_loop = get_loop( n2_ctrl ); | |
280 IdealLoopTree *n3_loop = get_loop( n3_ctrl ); | |
281 | |
282 // Does one of my inputs spin in a tighter loop than self? | |
283 if( (n_loop->is_member( n1_loop ) && n_loop != n1_loop) || | |
284 (n_loop->is_member( n2_loop ) && n_loop != n2_loop) || | |
285 (n_loop->is_member( n3_loop ) && n_loop != n3_loop) ) | |
286 return NULL; // Leave well enough alone | |
287 | |
288 // Is at least one of my inputs loop-invariant? | |
289 if( n1_loop == n_loop && | |
290 n2_loop == n_loop && | |
291 n3_loop == n_loop ) | |
292 return NULL; // No loop-invariant inputs | |
293 | |
294 | |
295 int n_op = n->Opcode(); | |
296 | |
297 // Replace expressions like ((V+I) << 2) with (V<<2 + I<<2). | |
298 if( n_op == Op_LShiftI ) { | |
299 // Scale is loop invariant | |
300 Node *scale = n->in(2); | |
301 Node *scale_ctrl = get_ctrl(scale); | |
302 IdealLoopTree *scale_loop = get_loop(scale_ctrl ); | |
303 if( n_loop == scale_loop || !scale_loop->is_member( n_loop ) ) | |
304 return NULL; | |
305 const TypeInt *scale_t = scale->bottom_type()->isa_int(); | |
306 if( scale_t && scale_t->is_con() && scale_t->get_con() >= 16 ) | |
307 return NULL; // Dont bother with byte/short masking | |
308 // Add must vary with loop (else shift would be loop-invariant) | |
309 Node *add = n->in(1); | |
310 Node *add_ctrl = get_ctrl(add); | |
311 IdealLoopTree *add_loop = get_loop(add_ctrl); | |
312 //assert( n_loop == add_loop, "" ); | |
313 if( n_loop != add_loop ) return NULL; // happens w/ evil ZKM loops | |
314 | |
315 // Convert I-V into I+ (0-V); same for V-I | |
316 if( add->Opcode() == Op_SubI && | |
317 _igvn.type( add->in(1) ) != TypeInt::ZERO ) { | |
318 Node *zero = _igvn.intcon(0); | |
319 set_ctrl(zero, C->root()); | |
320 Node *neg = new (C, 3) SubINode( _igvn.intcon(0), add->in(2) ); | |
321 register_new_node( neg, get_ctrl(add->in(2) ) ); | |
322 add = new (C, 3) AddINode( add->in(1), neg ); | |
323 register_new_node( add, add_ctrl ); | |
324 } | |
325 if( add->Opcode() != Op_AddI ) return NULL; | |
326 // See if one add input is loop invariant | |
327 Node *add_var = add->in(1); | |
328 Node *add_var_ctrl = get_ctrl(add_var); | |
329 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl ); | |
330 Node *add_invar = add->in(2); | |
331 Node *add_invar_ctrl = get_ctrl(add_invar); | |
332 IdealLoopTree *add_invar_loop = get_loop(add_invar_ctrl ); | |
333 if( add_var_loop == n_loop ) { | |
334 } else if( add_invar_loop == n_loop ) { | |
335 // Swap to find the invariant part | |
336 add_invar = add_var; | |
337 add_invar_ctrl = add_var_ctrl; | |
338 add_invar_loop = add_var_loop; | |
339 add_var = add->in(2); | |
340 Node *add_var_ctrl = get_ctrl(add_var); | |
341 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl ); | |
342 } else // Else neither input is loop invariant | |
343 return NULL; | |
344 if( n_loop == add_invar_loop || !add_invar_loop->is_member( n_loop ) ) | |
345 return NULL; // No invariant part of the add? | |
346 | |
347 // Yes! Reshape address expression! | |
348 Node *inv_scale = new (C, 3) LShiftINode( add_invar, scale ); | |
850
fd50a67f97d1
6860469: remix_address_expressions sets incorrect control causing crash in split_if_with_block_post
never
parents:
834
diff
changeset
|
349 Node *inv_scale_ctrl = |
fd50a67f97d1
6860469: remix_address_expressions sets incorrect control causing crash in split_if_with_block_post
never
parents:
834
diff
changeset
|
350 dom_depth(add_invar_ctrl) > dom_depth(scale_ctrl) ? |
fd50a67f97d1
6860469: remix_address_expressions sets incorrect control causing crash in split_if_with_block_post
never
parents:
834
diff
changeset
|
351 add_invar_ctrl : scale_ctrl; |
fd50a67f97d1
6860469: remix_address_expressions sets incorrect control causing crash in split_if_with_block_post
never
parents:
834
diff
changeset
|
352 register_new_node( inv_scale, inv_scale_ctrl ); |
0 | 353 Node *var_scale = new (C, 3) LShiftINode( add_var, scale ); |
354 register_new_node( var_scale, n_ctrl ); | |
355 Node *var_add = new (C, 3) AddINode( var_scale, inv_scale ); | |
356 register_new_node( var_add, n_ctrl ); | |
357 _igvn.hash_delete( n ); | |
358 _igvn.subsume_node( n, var_add ); | |
359 return var_add; | |
360 } | |
361 | |
362 // Replace (I+V) with (V+I) | |
363 if( n_op == Op_AddI || | |
364 n_op == Op_AddL || | |
365 n_op == Op_AddF || | |
366 n_op == Op_AddD || | |
367 n_op == Op_MulI || | |
368 n_op == Op_MulL || | |
369 n_op == Op_MulF || | |
370 n_op == Op_MulD ) { | |
371 if( n2_loop == n_loop ) { | |
372 assert( n1_loop != n_loop, "" ); | |
373 n->swap_edges(1, 2); | |
374 } | |
375 } | |
376 | |
377 // Replace ((I1 +p V) +p I2) with ((I1 +p I2) +p V), | |
378 // but not if I2 is a constant. | |
379 if( n_op == Op_AddP ) { | |
380 if( n2_loop == n_loop && n3_loop != n_loop ) { | |
381 if( n->in(2)->Opcode() == Op_AddP && !n->in(3)->is_Con() ) { | |
382 Node *n22_ctrl = get_ctrl(n->in(2)->in(2)); | |
383 Node *n23_ctrl = get_ctrl(n->in(2)->in(3)); | |
384 IdealLoopTree *n22loop = get_loop( n22_ctrl ); | |
385 IdealLoopTree *n23_loop = get_loop( n23_ctrl ); | |
386 if( n22loop != n_loop && n22loop->is_member(n_loop) && | |
387 n23_loop == n_loop ) { | |
388 Node *add1 = new (C, 4) AddPNode( n->in(1), n->in(2)->in(2), n->in(3) ); | |
389 // Stuff new AddP in the loop preheader | |
390 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) ); | |
391 Node *add2 = new (C, 4) AddPNode( n->in(1), add1, n->in(2)->in(3) ); | |
392 register_new_node( add2, n_ctrl ); | |
393 _igvn.hash_delete( n ); | |
394 _igvn.subsume_node( n, add2 ); | |
395 return add2; | |
396 } | |
397 } | |
398 } | |
399 | |
400 // Replace (I1 +p (I2 + V)) with ((I1 +p I2) +p V) | |
401 if( n2_loop != n_loop && n3_loop == n_loop ) { | |
402 if( n->in(3)->Opcode() == Op_AddI ) { | |
403 Node *V = n->in(3)->in(1); | |
404 Node *I = n->in(3)->in(2); | |
405 if( is_member(n_loop,get_ctrl(V)) ) { | |
406 } else { | |
407 Node *tmp = V; V = I; I = tmp; | |
408 } | |
409 if( !is_member(n_loop,get_ctrl(I)) ) { | |
410 Node *add1 = new (C, 4) AddPNode( n->in(1), n->in(2), I ); | |
411 // Stuff new AddP in the loop preheader | |
412 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) ); | |
413 Node *add2 = new (C, 4) AddPNode( n->in(1), add1, V ); | |
414 register_new_node( add2, n_ctrl ); | |
415 _igvn.hash_delete( n ); | |
416 _igvn.subsume_node( n, add2 ); | |
417 return add2; | |
418 } | |
419 } | |
420 } | |
421 } | |
422 | |
423 return NULL; | |
424 } | |
425 | |
426 //------------------------------conditional_move------------------------------- | |
427 // Attempt to replace a Phi with a conditional move. We have some pretty | |
428 // strict profitability requirements. All Phis at the merge point must | |
429 // be converted, so we can remove the control flow. We need to limit the | |
430 // number of c-moves to a small handful. All code that was in the side-arms | |
431 // of the CFG diamond is now speculatively executed. This code has to be | |
432 // "cheap enough". We are pretty much limited to CFG diamonds that merge | |
433 // 1 or 2 items with a total of 1 or 2 ops executed speculatively. | |
434 Node *PhaseIdealLoop::conditional_move( Node *region ) { | |
435 | |
436 assert( region->is_Region(), "sanity check" ); | |
437 if( region->req() != 3 ) return NULL; | |
438 | |
439 // Check for CFG diamond | |
440 Node *lp = region->in(1); | |
441 Node *rp = region->in(2); | |
442 if( !lp || !rp ) return NULL; | |
443 Node *lp_c = lp->in(0); | |
444 if( lp_c == NULL || lp_c != rp->in(0) || !lp_c->is_If() ) return NULL; | |
445 IfNode *iff = lp_c->as_If(); | |
446 | |
447 // Check for highly predictable branch. No point in CMOV'ing if | |
448 // we are going to predict accurately all the time. | |
449 // %%% This hides patterns produced by utility methods like Math.min. | |
450 if( iff->_prob < PROB_UNLIKELY_MAG(3) || | |
451 iff->_prob > PROB_LIKELY_MAG(3) ) | |
452 return NULL; | |
453 | |
454 // Check for ops pinned in an arm of the diamond. | |
455 // Can't remove the control flow in this case | |
456 if( lp->outcnt() > 1 ) return NULL; | |
457 if( rp->outcnt() > 1 ) return NULL; | |
458 | |
459 // Check profitability | |
460 int cost = 0; | |
35
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
461 int phis = 0; |
0 | 462 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
463 Node *out = region->fast_out(i); | |
464 if( !out->is_Phi() ) continue; // Ignore other control edges, etc | |
35
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
465 phis++; |
0 | 466 PhiNode* phi = out->as_Phi(); |
467 switch (phi->type()->basic_type()) { | |
468 case T_LONG: | |
469 cost++; // Probably encodes as 2 CMOV's | |
470 case T_INT: // These all CMOV fine | |
471 case T_FLOAT: | |
472 case T_DOUBLE: | |
473 case T_ADDRESS: // (RawPtr) | |
474 cost++; | |
475 break; | |
293
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
476 case T_NARROWOOP: // Fall through |
0 | 477 case T_OBJECT: { // Base oops are OK, but not derived oops |
293
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
478 const TypeOopPtr *tp = phi->type()->make_ptr()->isa_oopptr(); |
0 | 479 // Derived pointers are Bad (tm): what's the Base (for GC purposes) of a |
480 // CMOVE'd derived pointer? It's a CMOVE'd derived base. Thus | |
481 // CMOVE'ing a derived pointer requires we also CMOVE the base. If we | |
482 // have a Phi for the base here that we convert to a CMOVE all is well | |
483 // and good. But if the base is dead, we'll not make a CMOVE. Later | |
484 // the allocator will have to produce a base by creating a CMOVE of the | |
485 // relevant bases. This puts the allocator in the business of | |
486 // manufacturing expensive instructions, generally a bad plan. | |
487 // Just Say No to Conditionally-Moved Derived Pointers. | |
488 if( tp && tp->offset() != 0 ) | |
489 return NULL; | |
490 cost++; | |
491 break; | |
492 } | |
493 default: | |
494 return NULL; // In particular, can't do memory or I/O | |
495 } | |
496 // Add in cost any speculative ops | |
497 for( uint j = 1; j < region->req(); j++ ) { | |
498 Node *proj = region->in(j); | |
499 Node *inp = phi->in(j); | |
500 if (get_ctrl(inp) == proj) { // Found local op | |
501 cost++; | |
502 // Check for a chain of dependent ops; these will all become | |
503 // speculative in a CMOV. | |
504 for( uint k = 1; k < inp->req(); k++ ) | |
505 if (get_ctrl(inp->in(k)) == proj) | |
506 return NULL; // Too much speculative goo | |
507 } | |
508 } | |
293
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
509 // See if the Phi is used by a Cmp or Narrow oop Decode/Encode. |
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
510 // This will likely Split-If, a higher-payoff operation. |
0 | 511 for (DUIterator_Fast kmax, k = phi->fast_outs(kmax); k < kmax; k++) { |
512 Node* use = phi->fast_out(k); | |
293
c3e045194476
6731641: assert(m->adr_type() == mach->adr_type(),"matcher should not change adr type")
kvn
parents:
253
diff
changeset
|
513 if( use->is_Cmp() || use->is_DecodeN() || use->is_EncodeP() ) |
0 | 514 return NULL; |
515 } | |
516 } | |
517 if( cost >= ConditionalMoveLimit ) return NULL; // Too much goo | |
35
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
518 Node* bol = iff->in(1); |
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
519 assert( bol->Opcode() == Op_Bool, "" ); |
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
520 int cmp_op = bol->in(1)->Opcode(); |
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
521 // It is expensive to generate flags from a float compare. |
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
522 // Avoid duplicated float compare. |
e2ae28d2ce91
6667588: Don't generate duplicated CMP for float/double values
kvn
parents:
0
diff
changeset
|
523 if( phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL; |
0 | 524 |
525 // -------------- | |
526 // Now replace all Phis with CMOV's | |
527 Node *cmov_ctrl = iff->in(0); | |
528 uint flip = (lp->Opcode() == Op_IfTrue); | |
529 while( 1 ) { | |
530 PhiNode* phi = NULL; | |
531 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { | |
532 Node *out = region->fast_out(i); | |
533 if (out->is_Phi()) { | |
534 phi = out->as_Phi(); | |
535 break; | |
536 } | |
537 } | |
538 if (phi == NULL) break; | |
539 #ifndef PRODUCT | |
540 if( PrintOpto && VerifyLoopOptimizations ) tty->print_cr("CMOV"); | |
541 #endif | |
542 // Move speculative ops | |
543 for( uint j = 1; j < region->req(); j++ ) { | |
544 Node *proj = region->in(j); | |
545 Node *inp = phi->in(j); | |
546 if (get_ctrl(inp) == proj) { // Found local op | |
547 #ifndef PRODUCT | |
548 if( PrintOpto && VerifyLoopOptimizations ) { | |
549 tty->print(" speculate: "); | |
550 inp->dump(); | |
551 } | |
552 #endif | |
553 set_ctrl(inp, cmov_ctrl); | |
554 } | |
555 } | |
556 Node *cmov = CMoveNode::make( C, cmov_ctrl, iff->in(1), phi->in(1+flip), phi->in(2-flip), _igvn.type(phi) ); | |
557 register_new_node( cmov, cmov_ctrl ); | |
558 _igvn.hash_delete(phi); | |
559 _igvn.subsume_node( phi, cmov ); | |
560 #ifndef PRODUCT | |
561 if( VerifyLoopOptimizations ) verify(); | |
562 #endif | |
563 } | |
564 | |
565 // The useless CFG diamond will fold up later; see the optimization in | |
566 // RegionNode::Ideal. | |
567 _igvn._worklist.push(region); | |
568 | |
569 return iff->in(1); | |
570 } | |
571 | |
572 //------------------------------split_if_with_blocks_pre----------------------- | |
573 // Do the real work in a non-recursive function. Data nodes want to be | |
574 // cloned in the pre-order so they can feed each other nicely. | |
575 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) { | |
576 // Cloning these guys is unlikely to win | |
577 int n_op = n->Opcode(); | |
578 if( n_op == Op_MergeMem ) return n; | |
579 if( n->is_Proj() ) return n; | |
580 // Do not clone-up CmpFXXX variations, as these are always | |
581 // followed by a CmpI | |
582 if( n->is_Cmp() ) return n; | |
583 // Attempt to use a conditional move instead of a phi/branch | |
584 if( ConditionalMoveLimit > 0 && n_op == Op_Region ) { | |
585 Node *cmov = conditional_move( n ); | |
586 if( cmov ) return cmov; | |
587 } | |
253
b0fe4deeb9fb
6726999: nsk/stress/jck12a/jck12a010 assert(n != null,"Bad immediate dominator info.")
kvn
parents:
251
diff
changeset
|
588 if( n->is_CFG() || n->is_LoadStore() ) |
b0fe4deeb9fb
6726999: nsk/stress/jck12a/jck12a010 assert(n != null,"Bad immediate dominator info.")
kvn
parents:
251
diff
changeset
|
589 return n; |
0 | 590 if( n_op == Op_Opaque1 || // Opaque nodes cannot be mod'd |
591 n_op == Op_Opaque2 ) { | |
592 if( !C->major_progress() ) // If chance of no more loop opts... | |
593 _igvn._worklist.push(n); // maybe we'll remove them | |
594 return n; | |
595 } | |
596 | |
597 if( n->is_Con() ) return n; // No cloning for Con nodes | |
598 | |
599 Node *n_ctrl = get_ctrl(n); | |
600 if( !n_ctrl ) return n; // Dead node | |
601 | |
602 // Attempt to remix address expressions for loop invariants | |
603 Node *m = remix_address_expressions( n ); | |
604 if( m ) return m; | |
605 | |
606 // Determine if the Node has inputs from some local Phi. | |
607 // Returns the block to clone thru. | |
608 Node *n_blk = has_local_phi_input( n ); | |
609 if( !n_blk ) return n; | |
610 // Do not clone the trip counter through on a CountedLoop | |
611 // (messes up the canonical shape). | |
612 if( n_blk->is_CountedLoop() && n->Opcode() == Op_AddI ) return n; | |
613 | |
614 // Check for having no control input; not pinned. Allow | |
615 // dominating control. | |
616 if( n->in(0) ) { | |
617 Node *dom = idom(n_blk); | |
618 if( dom_lca( n->in(0), dom ) != n->in(0) ) | |
619 return n; | |
620 } | |
621 // Policy: when is it profitable. You must get more wins than | |
622 // policy before it is considered profitable. Policy is usually 0, | |
623 // so 1 win is considered profitable. Big merges will require big | |
624 // cloning, so get a larger policy. | |
625 int policy = n_blk->req() >> 2; | |
626 | |
627 // If the loop is a candidate for range check elimination, | |
628 // delay splitting through it's phi until a later loop optimization | |
629 if (n_blk->is_CountedLoop()) { | |
630 IdealLoopTree *lp = get_loop(n_blk); | |
631 if (lp && lp->_rce_candidate) { | |
632 return n; | |
633 } | |
634 } | |
635 | |
636 // Use same limit as split_if_with_blocks_post | |
637 if( C->unique() > 35000 ) return n; // Method too big | |
638 | |
639 // Split 'n' through the merge point if it is profitable | |
640 Node *phi = split_thru_phi( n, n_blk, policy ); | |
641 if( !phi ) return n; | |
642 | |
643 // Found a Phi to split thru! | |
644 // Replace 'n' with the new phi | |
645 _igvn.hash_delete(n); | |
646 _igvn.subsume_node( n, phi ); | |
647 // Moved a load around the loop, 'en-registering' something. | |
648 if( n_blk->Opcode() == Op_Loop && n->is_Load() && | |
649 !phi->in(LoopNode::LoopBackControl)->is_Load() ) | |
650 C->set_major_progress(); | |
651 | |
652 return phi; | |
653 } | |
654 | |
655 static bool merge_point_too_heavy(Compile* C, Node* region) { | |
656 // Bail out if the region and its phis have too many users. | |
657 int weight = 0; | |
658 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { | |
659 weight += region->fast_out(i)->outcnt(); | |
660 } | |
661 int nodes_left = MaxNodeLimit - C->unique(); | |
662 if (weight * 8 > nodes_left) { | |
663 #ifndef PRODUCT | |
664 if (PrintOpto) | |
665 tty->print_cr("*** Split-if bails out: %d nodes, region weight %d", C->unique(), weight); | |
666 #endif | |
667 return true; | |
668 } else { | |
669 return false; | |
670 } | |
671 } | |
672 | |
673 static bool merge_point_safe(Node* region) { | |
674 // 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode | |
675 // having a PhiNode input. This sidesteps the dangerous case where the split | |
676 // ConvI2LNode may become TOP if the input Value() does not | |
677 // overlap the ConvI2L range, leaving a node which may not dominate its | |
678 // uses. | |
679 // A better fix for this problem can be found in the BugTraq entry, but | |
680 // expediency for Mantis demands this hack. | |
834
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
681 // 6855164: If the merge point has a FastLockNode with a PhiNode input, we stop |
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
682 // split_if_with_blocks from splitting a block because we could not move around |
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
683 // the FastLockNode. |
0 | 684 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
685 Node* n = region->fast_out(i); | |
686 if (n->is_Phi()) { | |
687 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
688 Node* m = n->fast_out(j); | |
834
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
689 if (m->is_FastLock()) |
0 | 690 return false; |
834
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
691 #ifdef _LP64 |
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
692 if (m->Opcode() == Op_ConvI2L) |
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
693 return false; |
0f2d888530e7
6855164: SIGSEGV during compilation of method involving loop over CharSequence.
cfang
parents:
605
diff
changeset
|
694 #endif |
0 | 695 } |
696 } | |
697 } | |
698 return true; | |
699 } | |
700 | |
701 | |
702 //------------------------------place_near_use--------------------------------- | |
703 // Place some computation next to use but not inside inner loops. | |
704 // For inner loop uses move it to the preheader area. | |
705 Node *PhaseIdealLoop::place_near_use( Node *useblock ) const { | |
706 IdealLoopTree *u_loop = get_loop( useblock ); | |
707 return (u_loop->_irreducible || u_loop->_child) | |
708 ? useblock | |
709 : u_loop->_head->in(LoopNode::EntryControl); | |
710 } | |
711 | |
712 | |
713 //------------------------------split_if_with_blocks_post---------------------- | |
714 // Do the real work in a non-recursive function. CFG hackery wants to be | |
715 // in the post-order, so it can dirty the I-DOM info and not use the dirtied | |
716 // info. | |
717 void PhaseIdealLoop::split_if_with_blocks_post( Node *n ) { | |
718 | |
719 // Cloning Cmp through Phi's involves the split-if transform. | |
720 // FastLock is not used by an If | |
721 if( n->is_Cmp() && !n->is_FastLock() ) { | |
722 if( C->unique() > 35000 ) return; // Method too big | |
723 | |
724 // Do not do 'split-if' if irreducible loops are present. | |
725 if( _has_irreducible_loops ) | |
726 return; | |
727 | |
728 Node *n_ctrl = get_ctrl(n); | |
729 // Determine if the Node has inputs from some local Phi. | |
730 // Returns the block to clone thru. | |
731 Node *n_blk = has_local_phi_input( n ); | |
732 if( n_blk != n_ctrl ) return; | |
733 | |
734 if( merge_point_too_heavy(C, n_ctrl) ) | |
735 return; | |
736 | |
737 if( n->outcnt() != 1 ) return; // Multiple bool's from 1 compare? | |
738 Node *bol = n->unique_out(); | |
739 assert( bol->is_Bool(), "expect a bool here" ); | |
740 if( bol->outcnt() != 1 ) return;// Multiple branches from 1 compare? | |
741 Node *iff = bol->unique_out(); | |
742 | |
743 // Check some safety conditions | |
744 if( iff->is_If() ) { // Classic split-if? | |
745 if( iff->in(0) != n_ctrl ) return; // Compare must be in same blk as if | |
746 } else if (iff->is_CMove()) { // Trying to split-up a CMOVE | |
747 if( get_ctrl(iff->in(2)) == n_ctrl || | |
748 get_ctrl(iff->in(3)) == n_ctrl ) | |
749 return; // Inputs not yet split-up | |
750 if ( get_loop(n_ctrl) != get_loop(get_ctrl(iff)) ) { | |
751 return; // Loop-invar test gates loop-varying CMOVE | |
752 } | |
753 } else { | |
754 return; // some other kind of node, such as an Allocate | |
755 } | |
756 | |
757 // Do not do 'split-if' if some paths are dead. First do dead code | |
758 // elimination and then see if its still profitable. | |
759 for( uint i = 1; i < n_ctrl->req(); i++ ) | |
760 if( n_ctrl->in(i) == C->top() ) | |
761 return; | |
762 | |
763 // When is split-if profitable? Every 'win' on means some control flow | |
764 // goes dead, so it's almost always a win. | |
765 int policy = 0; | |
766 // If trying to do a 'Split-If' at the loop head, it is only | |
767 // profitable if the cmp folds up on BOTH paths. Otherwise we | |
768 // risk peeling a loop forever. | |
769 | |
770 // CNC - Disabled for now. Requires careful handling of loop | |
771 // body selection for the cloned code. Also, make sure we check | |
772 // for any input path not being in the same loop as n_ctrl. For | |
773 // irreducible loops we cannot check for 'n_ctrl->is_Loop()' | |
774 // because the alternative loop entry points won't be converted | |
775 // into LoopNodes. | |
776 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
777 for( uint j = 1; j < n_ctrl->req(); j++ ) | |
778 if( get_loop(n_ctrl->in(j)) != n_loop ) | |
779 return; | |
780 | |
781 // Check for safety of the merge point. | |
782 if( !merge_point_safe(n_ctrl) ) { | |
783 return; | |
784 } | |
785 | |
786 // Split compare 'n' through the merge point if it is profitable | |
787 Node *phi = split_thru_phi( n, n_ctrl, policy ); | |
788 if( !phi ) return; | |
789 | |
790 // Found a Phi to split thru! | |
791 // Replace 'n' with the new phi | |
792 _igvn.hash_delete(n); | |
793 _igvn.subsume_node( n, phi ); | |
794 | |
795 // Now split the bool up thru the phi | |
796 Node *bolphi = split_thru_phi( bol, n_ctrl, -1 ); | |
797 _igvn.hash_delete(bol); | |
798 _igvn.subsume_node( bol, bolphi ); | |
799 assert( iff->in(1) == bolphi, "" ); | |
800 if( bolphi->Value(&_igvn)->singleton() ) | |
801 return; | |
802 | |
803 // Conditional-move? Must split up now | |
804 if( !iff->is_If() ) { | |
805 Node *cmovphi = split_thru_phi( iff, n_ctrl, -1 ); | |
806 _igvn.hash_delete(iff); | |
807 _igvn.subsume_node( iff, cmovphi ); | |
808 return; | |
809 } | |
810 | |
811 // Now split the IF | |
812 do_split_if( iff ); | |
813 return; | |
814 } | |
815 | |
816 // Check for an IF ready to split; one that has its | |
817 // condition codes input coming from a Phi at the block start. | |
818 int n_op = n->Opcode(); | |
819 | |
820 // Check for an IF being dominated by another IF same test | |
821 if( n_op == Op_If ) { | |
822 Node *bol = n->in(1); | |
823 uint max = bol->outcnt(); | |
824 // Check for same test used more than once? | |
825 if( n_op == Op_If && max > 1 && bol->is_Bool() ) { | |
826 // Search up IDOMs to see if this IF is dominated. | |
827 Node *cutoff = get_ctrl(bol); | |
828 | |
829 // Now search up IDOMs till cutoff, looking for a dominating test | |
830 Node *prevdom = n; | |
831 Node *dom = idom(prevdom); | |
832 while( dom != cutoff ) { | |
833 if( dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom ) { | |
834 // Replace the dominated test with an obvious true or false. | |
835 // Place it on the IGVN worklist for later cleanup. | |
836 C->set_major_progress(); | |
837 dominated_by( prevdom, n ); | |
838 #ifndef PRODUCT | |
839 if( VerifyLoopOptimizations ) verify(); | |
840 #endif | |
841 return; | |
842 } | |
843 prevdom = dom; | |
844 dom = idom(prevdom); | |
845 } | |
846 } | |
847 } | |
848 | |
849 // See if a shared loop-varying computation has no loop-varying uses. | |
850 // Happens if something is only used for JVM state in uncommon trap exits, | |
851 // like various versions of induction variable+offset. Clone the | |
852 // computation per usage to allow it to sink out of the loop. | |
853 if (has_ctrl(n) && !n->in(0)) {// n not dead and has no control edge (can float about) | |
854 Node *n_ctrl = get_ctrl(n); | |
855 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
856 if( n_loop != _ltree_root ) { | |
857 DUIterator_Fast imax, i = n->fast_outs(imax); | |
858 for (; i < imax; i++) { | |
859 Node* u = n->fast_out(i); | |
860 if( !has_ctrl(u) ) break; // Found control user | |
861 IdealLoopTree *u_loop = get_loop(get_ctrl(u)); | |
862 if( u_loop == n_loop ) break; // Found loop-varying use | |
863 if( n_loop->is_member( u_loop ) ) break; // Found use in inner loop | |
864 if( u->Opcode() == Op_Opaque1 ) break; // Found loop limit, bugfix for 4677003 | |
865 } | |
866 bool did_break = (i < imax); // Did we break out of the previous loop? | |
867 if (!did_break && n->outcnt() > 1) { // All uses in outer loops! | |
868 Node *late_load_ctrl; | |
869 if (n->is_Load()) { | |
870 // If n is a load, get and save the result from get_late_ctrl(), | |
871 // to be later used in calculating the control for n's clones. | |
872 clear_dom_lca_tags(); | |
873 late_load_ctrl = get_late_ctrl(n, n_ctrl); | |
874 } | |
875 // If n is a load, and the late control is the same as the current | |
876 // control, then the cloning of n is a pointless exercise, because | |
877 // GVN will ensure that we end up where we started. | |
878 if (!n->is_Load() || late_load_ctrl != n_ctrl) { | |
879 for (DUIterator_Last jmin, j = n->last_outs(jmin); j >= jmin; ) { | |
880 Node *u = n->last_out(j); // Clone private computation per use | |
881 _igvn.hash_delete(u); | |
882 _igvn._worklist.push(u); | |
883 Node *x = n->clone(); // Clone computation | |
884 Node *x_ctrl = NULL; | |
885 if( u->is_Phi() ) { | |
886 // Replace all uses of normal nodes. Replace Phi uses | |
605 | 887 // individually, so the separate Nodes can sink down |
0 | 888 // different paths. |
889 uint k = 1; | |
890 while( u->in(k) != n ) k++; | |
891 u->set_req( k, x ); | |
892 // x goes next to Phi input path | |
893 x_ctrl = u->in(0)->in(k); | |
894 --j; | |
895 } else { // Normal use | |
896 // Replace all uses | |
897 for( uint k = 0; k < u->req(); k++ ) { | |
898 if( u->in(k) == n ) { | |
899 u->set_req( k, x ); | |
900 --j; | |
901 } | |
902 } | |
903 x_ctrl = get_ctrl(u); | |
904 } | |
905 | |
906 // Find control for 'x' next to use but not inside inner loops. | |
907 // For inner loop uses get the preheader area. | |
908 x_ctrl = place_near_use(x_ctrl); | |
909 | |
910 if (n->is_Load()) { | |
911 // For loads, add a control edge to a CFG node outside of the loop | |
912 // to force them to not combine and return back inside the loop | |
913 // during GVN optimization (4641526). | |
914 // | |
915 // Because we are setting the actual control input, factor in | |
916 // the result from get_late_ctrl() so we respect any | |
917 // anti-dependences. (6233005). | |
918 x_ctrl = dom_lca(late_load_ctrl, x_ctrl); | |
919 | |
920 // Don't allow the control input to be a CFG splitting node. | |
921 // Such nodes should only have ProjNodes as outs, e.g. IfNode | |
922 // should only have IfTrueNode and IfFalseNode (4985384). | |
923 x_ctrl = find_non_split_ctrl(x_ctrl); | |
924 assert(dom_depth(n_ctrl) <= dom_depth(x_ctrl), "n is later than its clone"); | |
925 | |
926 x->set_req(0, x_ctrl); | |
927 } | |
928 register_new_node(x, x_ctrl); | |
929 | |
930 // Some institutional knowledge is needed here: 'x' is | |
931 // yanked because if the optimizer runs GVN on it all the | |
932 // cloned x's will common up and undo this optimization and | |
933 // be forced back in the loop. This is annoying because it | |
934 // makes +VerifyOpto report false-positives on progress. I | |
935 // tried setting control edges on the x's to force them to | |
936 // not combine, but the matching gets worried when it tries | |
937 // to fold a StoreP and an AddP together (as part of an | |
938 // address expression) and the AddP and StoreP have | |
939 // different controls. | |
318
60bc5071073f
6738933: assert with base pointers must match with compressed oops enabled
never
parents:
293
diff
changeset
|
940 if( !x->is_Load() && !x->is_DecodeN() ) _igvn._worklist.yank(x); |
0 | 941 } |
942 _igvn.remove_dead_node(n); | |
943 } | |
944 } | |
945 } | |
946 } | |
947 | |
948 // Check for Opaque2's who's loop has disappeared - who's input is in the | |
949 // same loop nest as their output. Remove 'em, they are no longer useful. | |
950 if( n_op == Op_Opaque2 && | |
951 n->in(1) != NULL && | |
952 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) { | |
953 _igvn.add_users_to_worklist(n); | |
954 _igvn.hash_delete(n); | |
955 _igvn.subsume_node( n, n->in(1) ); | |
956 } | |
957 } | |
958 | |
959 //------------------------------split_if_with_blocks--------------------------- | |
960 // Check for aggressive application of 'split-if' optimization, | |
961 // using basic block level info. | |
962 void PhaseIdealLoop::split_if_with_blocks( VectorSet &visited, Node_Stack &nstack ) { | |
963 Node *n = C->root(); | |
964 visited.set(n->_idx); // first, mark node as visited | |
965 // Do pre-visit work for root | |
966 n = split_if_with_blocks_pre( n ); | |
967 uint cnt = n->outcnt(); | |
968 uint i = 0; | |
969 while (true) { | |
970 // Visit all children | |
971 if (i < cnt) { | |
972 Node* use = n->raw_out(i); | |
973 ++i; | |
974 if (use->outcnt() != 0 && !visited.test_set(use->_idx)) { | |
975 // Now do pre-visit work for this use | |
976 use = split_if_with_blocks_pre( use ); | |
977 nstack.push(n, i); // Save parent and next use's index. | |
978 n = use; // Process all children of current use. | |
979 cnt = use->outcnt(); | |
980 i = 0; | |
981 } | |
982 } | |
983 else { | |
984 // All of n's children have been processed, complete post-processing. | |
985 if (cnt != 0 && !n->is_Con()) { | |
986 assert(has_node(n), "no dead nodes"); | |
987 split_if_with_blocks_post( n ); | |
988 } | |
989 if (nstack.is_empty()) { | |
990 // Finished all nodes on stack. | |
991 break; | |
992 } | |
993 // Get saved parent node and next use's index. Visit the rest of uses. | |
994 n = nstack.node(); | |
995 cnt = n->outcnt(); | |
996 i = nstack.index(); | |
997 nstack.pop(); | |
998 } | |
999 } | |
1000 } | |
1001 | |
1002 | |
1003 //============================================================================= | |
1004 // | |
1005 // C L O N E A L O O P B O D Y | |
1006 // | |
1007 | |
1008 //------------------------------clone_iff-------------------------------------- | |
1009 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
1010 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
1011 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
1012 // through the Phi recursively, and return a Bool. | |
1013 BoolNode *PhaseIdealLoop::clone_iff( PhiNode *phi, IdealLoopTree *loop ) { | |
1014 | |
1015 // Convert this Phi into a Phi merging Bools | |
1016 uint i; | |
1017 for( i = 1; i < phi->req(); i++ ) { | |
1018 Node *b = phi->in(i); | |
1019 if( b->is_Phi() ) { | |
1020 _igvn.hash_delete(phi); | |
1021 _igvn._worklist.push(phi); | |
1022 phi->set_req(i, clone_iff( b->as_Phi(), loop )); | |
1023 } else { | |
1024 assert( b->is_Bool(), "" ); | |
1025 } | |
1026 } | |
1027 | |
1028 Node *sample_bool = phi->in(1); | |
1029 Node *sample_cmp = sample_bool->in(1); | |
1030 | |
1031 // Make Phis to merge the Cmp's inputs. | |
1032 int size = phi->in(0)->req(); | |
1033 PhiNode *phi1 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1034 PhiNode *phi2 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1035 for( i = 1; i < phi->req(); i++ ) { | |
1036 Node *n1 = phi->in(i)->in(1)->in(1); | |
1037 Node *n2 = phi->in(i)->in(1)->in(2); | |
1038 phi1->set_req( i, n1 ); | |
1039 phi2->set_req( i, n2 ); | |
1040 phi1->set_type( phi1->type()->meet(n1->bottom_type()) ); | |
1041 phi2->set_type( phi2->type()->meet(n2->bottom_type()) ); | |
1042 } | |
1043 // See if these Phis have been made before. | |
1044 // Register with optimizer | |
1045 Node *hit1 = _igvn.hash_find_insert(phi1); | |
1046 if( hit1 ) { // Hit, toss just made Phi | |
1047 _igvn.remove_dead_node(phi1); // Remove new phi | |
1048 assert( hit1->is_Phi(), "" ); | |
1049 phi1 = (PhiNode*)hit1; // Use existing phi | |
1050 } else { // Miss | |
1051 _igvn.register_new_node_with_optimizer(phi1); | |
1052 } | |
1053 Node *hit2 = _igvn.hash_find_insert(phi2); | |
1054 if( hit2 ) { // Hit, toss just made Phi | |
1055 _igvn.remove_dead_node(phi2); // Remove new phi | |
1056 assert( hit2->is_Phi(), "" ); | |
1057 phi2 = (PhiNode*)hit2; // Use existing phi | |
1058 } else { // Miss | |
1059 _igvn.register_new_node_with_optimizer(phi2); | |
1060 } | |
1061 // Register Phis with loop/block info | |
1062 set_ctrl(phi1, phi->in(0)); | |
1063 set_ctrl(phi2, phi->in(0)); | |
1064 // Make a new Cmp | |
1065 Node *cmp = sample_cmp->clone(); | |
1066 cmp->set_req( 1, phi1 ); | |
1067 cmp->set_req( 2, phi2 ); | |
1068 _igvn.register_new_node_with_optimizer(cmp); | |
1069 set_ctrl(cmp, phi->in(0)); | |
1070 | |
1071 // Make a new Bool | |
1072 Node *b = sample_bool->clone(); | |
1073 b->set_req(1,cmp); | |
1074 _igvn.register_new_node_with_optimizer(b); | |
1075 set_ctrl(b, phi->in(0)); | |
1076 | |
1077 assert( b->is_Bool(), "" ); | |
1078 return (BoolNode*)b; | |
1079 } | |
1080 | |
1081 //------------------------------clone_bool------------------------------------- | |
1082 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
1083 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
1084 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
1085 // through the Phi recursively, and return a Bool. | |
1086 CmpNode *PhaseIdealLoop::clone_bool( PhiNode *phi, IdealLoopTree *loop ) { | |
1087 uint i; | |
1088 // Convert this Phi into a Phi merging Bools | |
1089 for( i = 1; i < phi->req(); i++ ) { | |
1090 Node *b = phi->in(i); | |
1091 if( b->is_Phi() ) { | |
1092 _igvn.hash_delete(phi); | |
1093 _igvn._worklist.push(phi); | |
1094 phi->set_req(i, clone_bool( b->as_Phi(), loop )); | |
1095 } else { | |
1096 assert( b->is_Cmp() || b->is_top(), "inputs are all Cmp or TOP" ); | |
1097 } | |
1098 } | |
1099 | |
1100 Node *sample_cmp = phi->in(1); | |
1101 | |
1102 // Make Phis to merge the Cmp's inputs. | |
1103 int size = phi->in(0)->req(); | |
1104 PhiNode *phi1 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1105 PhiNode *phi2 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1106 for( uint j = 1; j < phi->req(); j++ ) { | |
1107 Node *cmp_top = phi->in(j); // Inputs are all Cmp or TOP | |
1108 Node *n1, *n2; | |
1109 if( cmp_top->is_Cmp() ) { | |
1110 n1 = cmp_top->in(1); | |
1111 n2 = cmp_top->in(2); | |
1112 } else { | |
1113 n1 = n2 = cmp_top; | |
1114 } | |
1115 phi1->set_req( j, n1 ); | |
1116 phi2->set_req( j, n2 ); | |
1117 phi1->set_type( phi1->type()->meet(n1->bottom_type()) ); | |
1118 phi2->set_type( phi2->type()->meet(n2->bottom_type()) ); | |
1119 } | |
1120 | |
1121 // See if these Phis have been made before. | |
1122 // Register with optimizer | |
1123 Node *hit1 = _igvn.hash_find_insert(phi1); | |
1124 if( hit1 ) { // Hit, toss just made Phi | |
1125 _igvn.remove_dead_node(phi1); // Remove new phi | |
1126 assert( hit1->is_Phi(), "" ); | |
1127 phi1 = (PhiNode*)hit1; // Use existing phi | |
1128 } else { // Miss | |
1129 _igvn.register_new_node_with_optimizer(phi1); | |
1130 } | |
1131 Node *hit2 = _igvn.hash_find_insert(phi2); | |
1132 if( hit2 ) { // Hit, toss just made Phi | |
1133 _igvn.remove_dead_node(phi2); // Remove new phi | |
1134 assert( hit2->is_Phi(), "" ); | |
1135 phi2 = (PhiNode*)hit2; // Use existing phi | |
1136 } else { // Miss | |
1137 _igvn.register_new_node_with_optimizer(phi2); | |
1138 } | |
1139 // Register Phis with loop/block info | |
1140 set_ctrl(phi1, phi->in(0)); | |
1141 set_ctrl(phi2, phi->in(0)); | |
1142 // Make a new Cmp | |
1143 Node *cmp = sample_cmp->clone(); | |
1144 cmp->set_req( 1, phi1 ); | |
1145 cmp->set_req( 2, phi2 ); | |
1146 _igvn.register_new_node_with_optimizer(cmp); | |
1147 set_ctrl(cmp, phi->in(0)); | |
1148 | |
1149 assert( cmp->is_Cmp(), "" ); | |
1150 return (CmpNode*)cmp; | |
1151 } | |
1152 | |
1153 //------------------------------sink_use--------------------------------------- | |
1154 // If 'use' was in the loop-exit block, it now needs to be sunk | |
1155 // below the post-loop merge point. | |
1156 void PhaseIdealLoop::sink_use( Node *use, Node *post_loop ) { | |
1157 if (!use->is_CFG() && get_ctrl(use) == post_loop->in(2)) { | |
1158 set_ctrl(use, post_loop); | |
1159 for (DUIterator j = use->outs(); use->has_out(j); j++) | |
1160 sink_use(use->out(j), post_loop); | |
1161 } | |
1162 } | |
1163 | |
1164 //------------------------------clone_loop------------------------------------- | |
1165 // | |
1166 // C L O N E A L O O P B O D Y | |
1167 // | |
1168 // This is the basic building block of the loop optimizations. It clones an | |
1169 // entire loop body. It makes an old_new loop body mapping; with this mapping | |
1170 // you can find the new-loop equivalent to an old-loop node. All new-loop | |
1171 // nodes are exactly equal to their old-loop counterparts, all edges are the | |
1172 // same. All exits from the old-loop now have a RegionNode that merges the | |
1173 // equivalent new-loop path. This is true even for the normal "loop-exit" | |
1174 // condition. All uses of loop-invariant old-loop values now come from (one | |
1175 // or more) Phis that merge their new-loop equivalents. | |
1176 // | |
1177 // This operation leaves the graph in an illegal state: there are two valid | |
1178 // control edges coming from the loop pre-header to both loop bodies. I'll | |
1179 // definitely have to hack the graph after running this transform. | |
1180 // | |
1181 // From this building block I will further edit edges to perform loop peeling | |
1182 // or loop unrolling or iteration splitting (Range-Check-Elimination), etc. | |
1183 // | |
1184 // Parameter side_by_size_idom: | |
1185 // When side_by_size_idom is NULL, the dominator tree is constructed for | |
1186 // the clone loop to dominate the original. Used in construction of | |
1187 // pre-main-post loop sequence. | |
1188 // When nonnull, the clone and original are side-by-side, both are | |
1189 // dominated by the side_by_side_idom node. Used in construction of | |
1190 // unswitched loops. | |
1191 void PhaseIdealLoop::clone_loop( IdealLoopTree *loop, Node_List &old_new, int dd, | |
1192 Node* side_by_side_idom) { | |
1193 | |
1194 // Step 1: Clone the loop body. Make the old->new mapping. | |
1195 uint i; | |
1196 for( i = 0; i < loop->_body.size(); i++ ) { | |
1197 Node *old = loop->_body.at(i); | |
1198 Node *nnn = old->clone(); | |
1199 old_new.map( old->_idx, nnn ); | |
1200 _igvn.register_new_node_with_optimizer(nnn); | |
1201 } | |
1202 | |
1203 | |
1204 // Step 2: Fix the edges in the new body. If the old input is outside the | |
1205 // loop use it. If the old input is INside the loop, use the corresponding | |
1206 // new node instead. | |
1207 for( i = 0; i < loop->_body.size(); i++ ) { | |
1208 Node *old = loop->_body.at(i); | |
1209 Node *nnn = old_new[old->_idx]; | |
1210 // Fix CFG/Loop controlling the new node | |
1211 if (has_ctrl(old)) { | |
1212 set_ctrl(nnn, old_new[get_ctrl(old)->_idx]); | |
1213 } else { | |
1214 set_loop(nnn, loop->_parent); | |
1215 if (old->outcnt() > 0) { | |
1216 set_idom( nnn, old_new[idom(old)->_idx], dd ); | |
1217 } | |
1218 } | |
1219 // Correct edges to the new node | |
1220 for( uint j = 0; j < nnn->req(); j++ ) { | |
1221 Node *n = nnn->in(j); | |
1222 if( n ) { | |
1223 IdealLoopTree *old_in_loop = get_loop( has_ctrl(n) ? get_ctrl(n) : n ); | |
1224 if( loop->is_member( old_in_loop ) ) | |
1225 nnn->set_req(j, old_new[n->_idx]); | |
1226 } | |
1227 } | |
1228 _igvn.hash_find_insert(nnn); | |
1229 } | |
1230 Node *newhead = old_new[loop->_head->_idx]; | |
1231 set_idom(newhead, newhead->in(LoopNode::EntryControl), dd); | |
1232 | |
1233 | |
1234 // Step 3: Now fix control uses. Loop varying control uses have already | |
1235 // been fixed up (as part of all input edges in Step 2). Loop invariant | |
1236 // control uses must be either an IfFalse or an IfTrue. Make a merge | |
1237 // point to merge the old and new IfFalse/IfTrue nodes; make the use | |
1238 // refer to this. | |
1239 ResourceArea *area = Thread::current()->resource_area(); | |
1240 Node_List worklist(area); | |
1241 uint new_counter = C->unique(); | |
1242 for( i = 0; i < loop->_body.size(); i++ ) { | |
1243 Node* old = loop->_body.at(i); | |
1244 if( !old->is_CFG() ) continue; | |
1245 Node* nnn = old_new[old->_idx]; | |
1246 | |
1247 // Copy uses to a worklist, so I can munge the def-use info | |
1248 // with impunity. | |
1249 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++) | |
1250 worklist.push(old->fast_out(j)); | |
1251 | |
1252 while( worklist.size() ) { // Visit all uses | |
1253 Node *use = worklist.pop(); | |
1254 if (!has_node(use)) continue; // Ignore dead nodes | |
1255 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use ); | |
1256 if( !loop->is_member( use_loop ) && use->is_CFG() ) { | |
1257 // Both OLD and USE are CFG nodes here. | |
1258 assert( use->is_Proj(), "" ); | |
1259 | |
1260 // Clone the loop exit control projection | |
1261 Node *newuse = use->clone(); | |
1262 newuse->set_req(0,nnn); | |
1263 _igvn.register_new_node_with_optimizer(newuse); | |
1264 set_loop(newuse, use_loop); | |
1265 set_idom(newuse, nnn, dom_depth(nnn) + 1 ); | |
1266 | |
1267 // We need a Region to merge the exit from the peeled body and the | |
1268 // exit from the old loop body. | |
1269 RegionNode *r = new (C, 3) RegionNode(3); | |
1270 // Map the old use to the new merge point | |
1271 old_new.map( use->_idx, r ); | |
1272 uint dd_r = MIN2(dom_depth(newuse),dom_depth(use)); | |
1273 assert( dd_r >= dom_depth(dom_lca(newuse,use)), "" ); | |
1274 | |
1275 // The original user of 'use' uses 'r' instead. | |
1276 for (DUIterator_Last lmin, l = use->last_outs(lmin); l >= lmin;) { | |
1277 Node* useuse = use->last_out(l); | |
1278 _igvn.hash_delete(useuse); | |
1279 _igvn._worklist.push(useuse); | |
1280 uint uses_found = 0; | |
1281 if( useuse->in(0) == use ) { | |
1282 useuse->set_req(0, r); | |
1283 uses_found++; | |
1284 if( useuse->is_CFG() ) { | |
1285 assert( dom_depth(useuse) > dd_r, "" ); | |
1286 set_idom(useuse, r, dom_depth(useuse)); | |
1287 } | |
1288 } | |
1289 for( uint k = 1; k < useuse->req(); k++ ) { | |
1290 if( useuse->in(k) == use ) { | |
1291 useuse->set_req(k, r); | |
1292 uses_found++; | |
1293 } | |
1294 } | |
1295 l -= uses_found; // we deleted 1 or more copies of this edge | |
1296 } | |
1297 | |
1298 // Now finish up 'r' | |
1299 r->set_req( 1, newuse ); | |
1300 r->set_req( 2, use ); | |
1301 _igvn.register_new_node_with_optimizer(r); | |
1302 set_loop(r, use_loop); | |
1303 set_idom(r, !side_by_side_idom ? newuse->in(0) : side_by_side_idom, dd_r); | |
1304 } // End of if a loop-exit test | |
1305 } | |
1306 } | |
1307 | |
1308 // Step 4: If loop-invariant use is not control, it must be dominated by a | |
1309 // loop exit IfFalse/IfTrue. Find "proper" loop exit. Make a Region | |
1310 // there if needed. Make a Phi there merging old and new used values. | |
1311 Node_List *split_if_set = NULL; | |
1312 Node_List *split_bool_set = NULL; | |
1313 Node_List *split_cex_set = NULL; | |
1314 for( i = 0; i < loop->_body.size(); i++ ) { | |
1315 Node* old = loop->_body.at(i); | |
1316 Node* nnn = old_new[old->_idx]; | |
1317 // Copy uses to a worklist, so I can munge the def-use info | |
1318 // with impunity. | |
1319 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++) | |
1320 worklist.push(old->fast_out(j)); | |
1321 | |
1322 while( worklist.size() ) { | |
1323 Node *use = worklist.pop(); | |
1324 if (!has_node(use)) continue; // Ignore dead nodes | |
1325 if (use->in(0) == C->top()) continue; | |
1326 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use ); | |
1327 // Check for data-use outside of loop - at least one of OLD or USE | |
1328 // must not be a CFG node. | |
1329 if( !loop->is_member( use_loop ) && (!old->is_CFG() || !use->is_CFG())) { | |
1330 | |
1331 // If the Data use is an IF, that means we have an IF outside of the | |
1332 // loop that is switching on a condition that is set inside of the | |
1333 // loop. Happens if people set a loop-exit flag; then test the flag | |
1334 // in the loop to break the loop, then test is again outside of the | |
1335 // loop to determine which way the loop exited. | |
1336 if( use->is_If() || use->is_CMove() ) { | |
1337 // Since this code is highly unlikely, we lazily build the worklist | |
1338 // of such Nodes to go split. | |
1339 if( !split_if_set ) | |
1340 split_if_set = new Node_List(area); | |
1341 split_if_set->push(use); | |
1342 } | |
1343 if( use->is_Bool() ) { | |
1344 if( !split_bool_set ) | |
1345 split_bool_set = new Node_List(area); | |
1346 split_bool_set->push(use); | |
1347 } | |
1348 if( use->Opcode() == Op_CreateEx ) { | |
1349 if( !split_cex_set ) | |
1350 split_cex_set = new Node_List(area); | |
1351 split_cex_set->push(use); | |
1352 } | |
1353 | |
1354 | |
1355 // Get "block" use is in | |
1356 uint idx = 0; | |
1357 while( use->in(idx) != old ) idx++; | |
1358 Node *prev = use->is_CFG() ? use : get_ctrl(use); | |
1359 assert( !loop->is_member( get_loop( prev ) ), "" ); | |
1360 Node *cfg = prev->_idx >= new_counter | |
1361 ? prev->in(2) | |
1362 : idom(prev); | |
1363 if( use->is_Phi() ) // Phi use is in prior block | |
1364 cfg = prev->in(idx); // NOT in block of Phi itself | |
1365 if (cfg->is_top()) { // Use is dead? | |
1366 _igvn.hash_delete(use); | |
1367 _igvn._worklist.push(use); | |
1368 use->set_req(idx, C->top()); | |
1369 continue; | |
1370 } | |
1371 | |
1372 while( !loop->is_member( get_loop( cfg ) ) ) { | |
1373 prev = cfg; | |
1374 cfg = cfg->_idx >= new_counter ? cfg->in(2) : idom(cfg); | |
1375 } | |
1376 // If the use occurs after merging several exits from the loop, then | |
1377 // old value must have dominated all those exits. Since the same old | |
1378 // value was used on all those exits we did not need a Phi at this | |
1379 // merge point. NOW we do need a Phi here. Each loop exit value | |
1380 // is now merged with the peeled body exit; each exit gets its own | |
1381 // private Phi and those Phis need to be merged here. | |
1382 Node *phi; | |
1383 if( prev->is_Region() ) { | |
1384 if( idx == 0 ) { // Updating control edge? | |
1385 phi = prev; // Just use existing control | |
1386 } else { // Else need a new Phi | |
1387 phi = PhiNode::make( prev, old ); | |
1388 // Now recursively fix up the new uses of old! | |
1389 for( uint i = 1; i < prev->req(); i++ ) { | |
1390 worklist.push(phi); // Onto worklist once for each 'old' input | |
1391 } | |
1392 } | |
1393 } else { | |
1394 // Get new RegionNode merging old and new loop exits | |
1395 prev = old_new[prev->_idx]; | |
1396 assert( prev, "just made this in step 7" ); | |
1397 if( idx == 0 ) { // Updating control edge? | |
1398 phi = prev; // Just use existing control | |
1399 } else { // Else need a new Phi | |
1400 // Make a new Phi merging data values properly | |
1401 phi = PhiNode::make( prev, old ); | |
1402 phi->set_req( 1, nnn ); | |
1403 } | |
1404 } | |
1405 // If inserting a new Phi, check for prior hits | |
1406 if( idx != 0 ) { | |
1407 Node *hit = _igvn.hash_find_insert(phi); | |
1408 if( hit == NULL ) { | |
1409 _igvn.register_new_node_with_optimizer(phi); // Register new phi | |
1410 } else { // or | |
1411 // Remove the new phi from the graph and use the hit | |
1412 _igvn.remove_dead_node(phi); | |
1413 phi = hit; // Use existing phi | |
1414 } | |
1415 set_ctrl(phi, prev); | |
1416 } | |
1417 // Make 'use' use the Phi instead of the old loop body exit value | |
1418 _igvn.hash_delete(use); | |
1419 _igvn._worklist.push(use); | |
1420 use->set_req(idx, phi); | |
1421 if( use->_idx >= new_counter ) { // If updating new phis | |
1422 // Not needed for correctness, but prevents a weak assert | |
1423 // in AddPNode from tripping (when we end up with different | |
1424 // base & derived Phis that will become the same after | |
1425 // IGVN does CSE). | |
1426 Node *hit = _igvn.hash_find_insert(use); | |
1427 if( hit ) // Go ahead and re-hash for hits. | |
1428 _igvn.subsume_node( use, hit ); | |
1429 } | |
1430 | |
1431 // If 'use' was in the loop-exit block, it now needs to be sunk | |
1432 // below the post-loop merge point. | |
1433 sink_use( use, prev ); | |
1434 } | |
1435 } | |
1436 } | |
1437 | |
1438 // Check for IFs that need splitting/cloning. Happens if an IF outside of | |
1439 // the loop uses a condition set in the loop. The original IF probably | |
1440 // takes control from one or more OLD Regions (which in turn get from NEW | |
1441 // Regions). In any case, there will be a set of Phis for each merge point | |
1442 // from the IF up to where the original BOOL def exists the loop. | |
1443 if( split_if_set ) { | |
1444 while( split_if_set->size() ) { | |
1445 Node *iff = split_if_set->pop(); | |
1446 if( iff->in(1)->is_Phi() ) { | |
1447 BoolNode *b = clone_iff( iff->in(1)->as_Phi(), loop ); | |
1448 _igvn.hash_delete(iff); | |
1449 _igvn._worklist.push(iff); | |
1450 iff->set_req(1, b); | |
1451 } | |
1452 } | |
1453 } | |
1454 if( split_bool_set ) { | |
1455 while( split_bool_set->size() ) { | |
1456 Node *b = split_bool_set->pop(); | |
1457 Node *phi = b->in(1); | |
1458 assert( phi->is_Phi(), "" ); | |
1459 CmpNode *cmp = clone_bool( (PhiNode*)phi, loop ); | |
1460 _igvn.hash_delete(b); | |
1461 _igvn._worklist.push(b); | |
1462 b->set_req(1, cmp); | |
1463 } | |
1464 } | |
1465 if( split_cex_set ) { | |
1466 while( split_cex_set->size() ) { | |
1467 Node *b = split_cex_set->pop(); | |
1468 assert( b->in(0)->is_Region(), "" ); | |
1469 assert( b->in(1)->is_Phi(), "" ); | |
1470 assert( b->in(0)->in(0) == b->in(1)->in(0), "" ); | |
1471 split_up( b, b->in(0), NULL ); | |
1472 } | |
1473 } | |
1474 | |
1475 } | |
1476 | |
1477 | |
1478 //---------------------- stride_of_possible_iv ------------------------------------- | |
1479 // Looks for an iff/bool/comp with one operand of the compare | |
1480 // being a cycle involving an add and a phi, | |
1481 // with an optional truncation (left-shift followed by a right-shift) | |
1482 // of the add. Returns zero if not an iv. | |
1483 int PhaseIdealLoop::stride_of_possible_iv(Node* iff) { | |
1484 Node* trunc1 = NULL; | |
1485 Node* trunc2 = NULL; | |
1486 const TypeInt* ttype = NULL; | |
1487 if (!iff->is_If() || iff->in(1) == NULL || !iff->in(1)->is_Bool()) { | |
1488 return 0; | |
1489 } | |
1490 BoolNode* bl = iff->in(1)->as_Bool(); | |
1491 Node* cmp = bl->in(1); | |
1492 if (!cmp || cmp->Opcode() != Op_CmpI && cmp->Opcode() != Op_CmpU) { | |
1493 return 0; | |
1494 } | |
1495 // Must have an invariant operand | |
1496 if (is_member(get_loop(iff), get_ctrl(cmp->in(2)))) { | |
1497 return 0; | |
1498 } | |
1499 Node* add2 = NULL; | |
1500 Node* cmp1 = cmp->in(1); | |
1501 if (cmp1->is_Phi()) { | |
1502 // (If (Bool (CmpX phi:(Phi ...(Optional-trunc(AddI phi add2))) ))) | |
1503 Node* phi = cmp1; | |
1504 for (uint i = 1; i < phi->req(); i++) { | |
1505 Node* in = phi->in(i); | |
1506 Node* add = CountedLoopNode::match_incr_with_optional_truncation(in, | |
1507 &trunc1, &trunc2, &ttype); | |
1508 if (add && add->in(1) == phi) { | |
1509 add2 = add->in(2); | |
1510 break; | |
1511 } | |
1512 } | |
1513 } else { | |
1514 // (If (Bool (CmpX addtrunc:(Optional-trunc((AddI (Phi ...addtrunc...) add2)) ))) | |
1515 Node* addtrunc = cmp1; | |
1516 Node* add = CountedLoopNode::match_incr_with_optional_truncation(addtrunc, | |
1517 &trunc1, &trunc2, &ttype); | |
1518 if (add && add->in(1)->is_Phi()) { | |
1519 Node* phi = add->in(1); | |
1520 for (uint i = 1; i < phi->req(); i++) { | |
1521 if (phi->in(i) == addtrunc) { | |
1522 add2 = add->in(2); | |
1523 break; | |
1524 } | |
1525 } | |
1526 } | |
1527 } | |
1528 if (add2 != NULL) { | |
1529 const TypeInt* add2t = _igvn.type(add2)->is_int(); | |
1530 if (add2t->is_con()) { | |
1531 return add2t->get_con(); | |
1532 } | |
1533 } | |
1534 return 0; | |
1535 } | |
1536 | |
1537 | |
1538 //---------------------- stay_in_loop ------------------------------------- | |
1539 // Return the (unique) control output node that's in the loop (if it exists.) | |
1540 Node* PhaseIdealLoop::stay_in_loop( Node* n, IdealLoopTree *loop) { | |
1541 Node* unique = NULL; | |
1542 if (!n) return NULL; | |
1543 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { | |
1544 Node* use = n->fast_out(i); | |
1545 if (!has_ctrl(use) && loop->is_member(get_loop(use))) { | |
1546 if (unique != NULL) { | |
1547 return NULL; | |
1548 } | |
1549 unique = use; | |
1550 } | |
1551 } | |
1552 return unique; | |
1553 } | |
1554 | |
1555 //------------------------------ register_node ------------------------------------- | |
1556 // Utility to register node "n" with PhaseIdealLoop | |
1557 void PhaseIdealLoop::register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth) { | |
1558 _igvn.register_new_node_with_optimizer(n); | |
1559 loop->_body.push(n); | |
1560 if (n->is_CFG()) { | |
1561 set_loop(n, loop); | |
1562 set_idom(n, pred, ddepth); | |
1563 } else { | |
1564 set_ctrl(n, pred); | |
1565 } | |
1566 } | |
1567 | |
1568 //------------------------------ proj_clone ------------------------------------- | |
1569 // Utility to create an if-projection | |
1570 ProjNode* PhaseIdealLoop::proj_clone(ProjNode* p, IfNode* iff) { | |
1571 ProjNode* c = p->clone()->as_Proj(); | |
1572 c->set_req(0, iff); | |
1573 return c; | |
1574 } | |
1575 | |
1576 //------------------------------ short_circuit_if ------------------------------------- | |
1577 // Force the iff control output to be the live_proj | |
1578 Node* PhaseIdealLoop::short_circuit_if(IfNode* iff, ProjNode* live_proj) { | |
1579 int proj_con = live_proj->_con; | |
1580 assert(proj_con == 0 || proj_con == 1, "false or true projection"); | |
1581 Node *con = _igvn.intcon(proj_con); | |
1582 set_ctrl(con, C->root()); | |
1583 if (iff) { | |
1584 iff->set_req(1, con); | |
1585 } | |
1586 return con; | |
1587 } | |
1588 | |
1589 //------------------------------ insert_if_before_proj ------------------------------------- | |
1590 // Insert a new if before an if projection (* - new node) | |
1591 // | |
1592 // before | |
1593 // if(test) | |
1594 // / \ | |
1595 // v v | |
1596 // other-proj proj (arg) | |
1597 // | |
1598 // after | |
1599 // if(test) | |
1600 // / \ | |
1601 // / v | |
1602 // | * proj-clone | |
1603 // v | | |
1604 // other-proj v | |
1605 // * new_if(relop(cmp[IU](left,right))) | |
1606 // / \ | |
1607 // v v | |
1608 // * new-proj proj | |
1609 // (returned) | |
1610 // | |
1611 ProjNode* PhaseIdealLoop::insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj) { | |
1612 IfNode* iff = proj->in(0)->as_If(); | |
1613 IdealLoopTree *loop = get_loop(proj); | |
1614 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj(); | |
1615 int ddepth = dom_depth(proj); | |
1616 | |
1617 _igvn.hash_delete(iff); | |
1618 _igvn._worklist.push(iff); | |
1619 _igvn.hash_delete(proj); | |
1620 _igvn._worklist.push(proj); | |
1621 | |
1622 proj->set_req(0, NULL); // temporary disconnect | |
1623 ProjNode* proj2 = proj_clone(proj, iff); | |
1624 register_node(proj2, loop, iff, ddepth); | |
1625 | |
1626 Node* cmp = Signed ? (Node*) new (C,3)CmpINode(left, right) : (Node*) new (C,3)CmpUNode(left, right); | |
1627 register_node(cmp, loop, proj2, ddepth); | |
1628 | |
1629 BoolNode* bol = new (C,2)BoolNode(cmp, relop); | |
1630 register_node(bol, loop, proj2, ddepth); | |
1631 | |
1632 IfNode* new_if = new (C,2)IfNode(proj2, bol, iff->_prob, iff->_fcnt); | |
1633 register_node(new_if, loop, proj2, ddepth); | |
1634 | |
1635 proj->set_req(0, new_if); // reattach | |
1636 set_idom(proj, new_if, ddepth); | |
1637 | |
1638 ProjNode* new_exit = proj_clone(other_proj, new_if)->as_Proj(); | |
1639 register_node(new_exit, get_loop(other_proj), new_if, ddepth); | |
1640 | |
1641 return new_exit; | |
1642 } | |
1643 | |
1644 //------------------------------ insert_region_before_proj ------------------------------------- | |
1645 // Insert a region before an if projection (* - new node) | |
1646 // | |
1647 // before | |
1648 // if(test) | |
1649 // / | | |
1650 // v | | |
1651 // proj v | |
1652 // other-proj | |
1653 // | |
1654 // after | |
1655 // if(test) | |
1656 // / | | |
1657 // v | | |
1658 // * proj-clone v | |
1659 // | other-proj | |
1660 // v | |
1661 // * new-region | |
1662 // | | |
1663 // v | |
1664 // * dum_if | |
1665 // / \ | |
1666 // v \ | |
1667 // * dum-proj v | |
1668 // proj | |
1669 // | |
1670 RegionNode* PhaseIdealLoop::insert_region_before_proj(ProjNode* proj) { | |
1671 IfNode* iff = proj->in(0)->as_If(); | |
1672 IdealLoopTree *loop = get_loop(proj); | |
1673 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj(); | |
1674 int ddepth = dom_depth(proj); | |
1675 | |
1676 _igvn.hash_delete(iff); | |
1677 _igvn._worklist.push(iff); | |
1678 _igvn.hash_delete(proj); | |
1679 _igvn._worklist.push(proj); | |
1680 | |
1681 proj->set_req(0, NULL); // temporary disconnect | |
1682 ProjNode* proj2 = proj_clone(proj, iff); | |
1683 register_node(proj2, loop, iff, ddepth); | |
1684 | |
1685 RegionNode* reg = new (C,2)RegionNode(2); | |
1686 reg->set_req(1, proj2); | |
1687 register_node(reg, loop, iff, ddepth); | |
1688 | |
1689 IfNode* dum_if = new (C,2)IfNode(reg, short_circuit_if(NULL, proj), iff->_prob, iff->_fcnt); | |
1690 register_node(dum_if, loop, reg, ddepth); | |
1691 | |
1692 proj->set_req(0, dum_if); // reattach | |
1693 set_idom(proj, dum_if, ddepth); | |
1694 | |
1695 ProjNode* dum_proj = proj_clone(other_proj, dum_if); | |
1696 register_node(dum_proj, loop, dum_if, ddepth); | |
1697 | |
1698 return reg; | |
1699 } | |
1700 | |
1701 //------------------------------ insert_cmpi_loop_exit ------------------------------------- | |
1702 // Clone a signed compare loop exit from an unsigned compare and | |
1703 // insert it before the unsigned cmp on the stay-in-loop path. | |
1704 // All new nodes inserted in the dominator tree between the original | |
1705 // if and it's projections. The original if test is replaced with | |
1706 // a constant to force the stay-in-loop path. | |
1707 // | |
1708 // This is done to make sure that the original if and it's projections | |
1709 // still dominate the same set of control nodes, that the ctrl() relation | |
1710 // from data nodes to them is preserved, and that their loop nesting is | |
1711 // preserved. | |
1712 // | |
1713 // before | |
1714 // if(i <u limit) unsigned compare loop exit | |
1715 // / | | |
1716 // v v | |
1717 // exit-proj stay-in-loop-proj | |
1718 // | |
1719 // after | |
1720 // if(stay-in-loop-const) original if | |
1721 // / | | |
1722 // / v | |
1723 // / if(i < limit) new signed test | |
1724 // / / | | |
1725 // / / v | |
1726 // / / if(i <u limit) new cloned unsigned test | |
1727 // / / / | | |
1728 // v v v | | |
1729 // region | | |
1730 // | | | |
1731 // dum-if | | |
1732 // / | | | |
1733 // ether | | | |
1734 // v v | |
1735 // exit-proj stay-in-loop-proj | |
1736 // | |
1737 IfNode* PhaseIdealLoop::insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop) { | |
1738 const bool Signed = true; | |
1739 const bool Unsigned = false; | |
1740 | |
1741 BoolNode* bol = if_cmpu->in(1)->as_Bool(); | |
1742 if (bol->_test._test != BoolTest::lt) return NULL; | |
1743 CmpNode* cmpu = bol->in(1)->as_Cmp(); | |
1744 if (cmpu->Opcode() != Op_CmpU) return NULL; | |
1745 int stride = stride_of_possible_iv(if_cmpu); | |
1746 if (stride == 0) return NULL; | |
1747 | |
1748 ProjNode* lp_continue = stay_in_loop(if_cmpu, loop)->as_Proj(); | |
1749 ProjNode* lp_exit = if_cmpu->proj_out(!lp_continue->is_IfTrue())->as_Proj(); | |
1750 | |
1751 Node* limit = NULL; | |
1752 if (stride > 0) { | |
1753 limit = cmpu->in(2); | |
1754 } else { | |
1755 limit = _igvn.makecon(TypeInt::ZERO); | |
1756 set_ctrl(limit, C->root()); | |
1757 } | |
1758 // Create a new region on the exit path | |
1759 RegionNode* reg = insert_region_before_proj(lp_exit); | |
1760 | |
1761 // Clone the if-cmpu-true-false using a signed compare | |
1762 BoolTest::mask rel_i = stride > 0 ? bol->_test._test : BoolTest::ge; | |
1763 ProjNode* cmpi_exit = insert_if_before_proj(cmpu->in(1), Signed, rel_i, limit, lp_continue); | |
1764 reg->add_req(cmpi_exit); | |
1765 | |
1766 // Clone the if-cmpu-true-false | |
1767 BoolTest::mask rel_u = bol->_test._test; | |
1768 ProjNode* cmpu_exit = insert_if_before_proj(cmpu->in(1), Unsigned, rel_u, cmpu->in(2), lp_continue); | |
1769 reg->add_req(cmpu_exit); | |
1770 | |
1771 // Force original if to stay in loop. | |
1772 short_circuit_if(if_cmpu, lp_continue); | |
1773 | |
1774 return cmpi_exit->in(0)->as_If(); | |
1775 } | |
1776 | |
1777 //------------------------------ remove_cmpi_loop_exit ------------------------------------- | |
1778 // Remove a previously inserted signed compare loop exit. | |
1779 void PhaseIdealLoop::remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop) { | |
1780 Node* lp_proj = stay_in_loop(if_cmp, loop); | |
1781 assert(if_cmp->in(1)->in(1)->Opcode() == Op_CmpI && | |
1782 stay_in_loop(lp_proj, loop)->is_If() && | |
1783 stay_in_loop(lp_proj, loop)->in(1)->in(1)->Opcode() == Op_CmpU, "inserted cmpi before cmpu"); | |
1784 Node *con = _igvn.makecon(lp_proj->is_IfTrue() ? TypeInt::ONE : TypeInt::ZERO); | |
1785 set_ctrl(con, C->root()); | |
1786 if_cmp->set_req(1, con); | |
1787 } | |
1788 | |
1789 //------------------------------ scheduled_nodelist ------------------------------------- | |
1790 // Create a post order schedule of nodes that are in the | |
1791 // "member" set. The list is returned in "sched". | |
1792 // The first node in "sched" is the loop head, followed by | |
1793 // nodes which have no inputs in the "member" set, and then | |
1794 // followed by the nodes that have an immediate input dependence | |
1795 // on a node in "sched". | |
1796 void PhaseIdealLoop::scheduled_nodelist( IdealLoopTree *loop, VectorSet& member, Node_List &sched ) { | |
1797 | |
1798 assert(member.test(loop->_head->_idx), "loop head must be in member set"); | |
1799 Arena *a = Thread::current()->resource_area(); | |
1800 VectorSet visited(a); | |
1801 Node_Stack nstack(a, loop->_body.size()); | |
1802 | |
1803 Node* n = loop->_head; // top of stack is cached in "n" | |
1804 uint idx = 0; | |
1805 visited.set(n->_idx); | |
1806 | |
1807 // Initially push all with no inputs from within member set | |
1808 for(uint i = 0; i < loop->_body.size(); i++ ) { | |
1809 Node *elt = loop->_body.at(i); | |
1810 if (member.test(elt->_idx)) { | |
1811 bool found = false; | |
1812 for (uint j = 0; j < elt->req(); j++) { | |
1813 Node* def = elt->in(j); | |
1814 if (def && member.test(def->_idx) && def != elt) { | |
1815 found = true; | |
1816 break; | |
1817 } | |
1818 } | |
1819 if (!found && elt != loop->_head) { | |
1820 nstack.push(n, idx); | |
1821 n = elt; | |
1822 assert(!visited.test(n->_idx), "not seen yet"); | |
1823 visited.set(n->_idx); | |
1824 } | |
1825 } | |
1826 } | |
1827 | |
1828 // traverse out's that are in the member set | |
1829 while (true) { | |
1830 if (idx < n->outcnt()) { | |
1831 Node* use = n->raw_out(idx); | |
1832 idx++; | |
1833 if (!visited.test_set(use->_idx)) { | |
1834 if (member.test(use->_idx)) { | |
1835 nstack.push(n, idx); | |
1836 n = use; | |
1837 idx = 0; | |
1838 } | |
1839 } | |
1840 } else { | |
1841 // All outputs processed | |
1842 sched.push(n); | |
1843 if (nstack.is_empty()) break; | |
1844 n = nstack.node(); | |
1845 idx = nstack.index(); | |
1846 nstack.pop(); | |
1847 } | |
1848 } | |
1849 } | |
1850 | |
1851 | |
1852 //------------------------------ has_use_in_set ------------------------------------- | |
1853 // Has a use in the vector set | |
1854 bool PhaseIdealLoop::has_use_in_set( Node* n, VectorSet& vset ) { | |
1855 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1856 Node* use = n->fast_out(j); | |
1857 if (vset.test(use->_idx)) { | |
1858 return true; | |
1859 } | |
1860 } | |
1861 return false; | |
1862 } | |
1863 | |
1864 | |
1865 //------------------------------ has_use_internal_to_set ------------------------------------- | |
1866 // Has use internal to the vector set (ie. not in a phi at the loop head) | |
1867 bool PhaseIdealLoop::has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop ) { | |
1868 Node* head = loop->_head; | |
1869 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1870 Node* use = n->fast_out(j); | |
1871 if (vset.test(use->_idx) && !(use->is_Phi() && use->in(0) == head)) { | |
1872 return true; | |
1873 } | |
1874 } | |
1875 return false; | |
1876 } | |
1877 | |
1878 | |
1879 //------------------------------ clone_for_use_outside_loop ------------------------------------- | |
1880 // clone "n" for uses that are outside of loop | |
1881 void PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) { | |
1882 | |
1883 assert(worklist.size() == 0, "should be empty"); | |
1884 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1885 Node* use = n->fast_out(j); | |
1886 if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) { | |
1887 worklist.push(use); | |
1888 } | |
1889 } | |
1890 while( worklist.size() ) { | |
1891 Node *use = worklist.pop(); | |
1892 if (!has_node(use) || use->in(0) == C->top()) continue; | |
1893 uint j; | |
1894 for (j = 0; j < use->req(); j++) { | |
1895 if (use->in(j) == n) break; | |
1896 } | |
1897 assert(j < use->req(), "must be there"); | |
1898 | |
1899 // clone "n" and insert it between the inputs of "n" and the use outside the loop | |
1900 Node* n_clone = n->clone(); | |
1901 _igvn.hash_delete(use); | |
1902 use->set_req(j, n_clone); | |
1903 _igvn._worklist.push(use); | |
251 | 1904 Node* use_c; |
0 | 1905 if (!use->is_Phi()) { |
251 | 1906 use_c = has_ctrl(use) ? get_ctrl(use) : use->in(0); |
0 | 1907 } else { |
1908 // Use in a phi is considered a use in the associated predecessor block | |
251 | 1909 use_c = use->in(0)->in(j); |
0 | 1910 } |
251 | 1911 set_ctrl(n_clone, use_c); |
1912 assert(!loop->is_member(get_loop(use_c)), "should be outside loop"); | |
1913 get_loop(use_c)->_body.push(n_clone); | |
0 | 1914 _igvn.register_new_node_with_optimizer(n_clone); |
1915 #if !defined(PRODUCT) | |
1916 if (TracePartialPeeling) { | |
1917 tty->print_cr("loop exit cloning old: %d new: %d newbb: %d", n->_idx, n_clone->_idx, get_ctrl(n_clone)->_idx); | |
1918 } | |
1919 #endif | |
1920 } | |
1921 } | |
1922 | |
1923 | |
1924 //------------------------------ clone_for_special_use_inside_loop ------------------------------------- | |
1925 // clone "n" for special uses that are in the not_peeled region. | |
1926 // If these def-uses occur in separate blocks, the code generator | |
1927 // marks the method as not compilable. For example, if a "BoolNode" | |
1928 // is in a different basic block than the "IfNode" that uses it, then | |
1929 // the compilation is aborted in the code generator. | |
1930 void PhaseIdealLoop::clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n, | |
1931 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist ) { | |
1932 if (n->is_Phi() || n->is_Load()) { | |
1933 return; | |
1934 } | |
1935 assert(worklist.size() == 0, "should be empty"); | |
1936 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1937 Node* use = n->fast_out(j); | |
1938 if ( not_peel.test(use->_idx) && | |
1939 (use->is_If() || use->is_CMove() || use->is_Bool()) && | |
1940 use->in(1) == n) { | |
1941 worklist.push(use); | |
1942 } | |
1943 } | |
1944 if (worklist.size() > 0) { | |
1945 // clone "n" and insert it between inputs of "n" and the use | |
1946 Node* n_clone = n->clone(); | |
1947 loop->_body.push(n_clone); | |
1948 _igvn.register_new_node_with_optimizer(n_clone); | |
1949 set_ctrl(n_clone, get_ctrl(n)); | |
1950 sink_list.push(n_clone); | |
1951 not_peel <<= n_clone->_idx; // add n_clone to not_peel set. | |
1952 #if !defined(PRODUCT) | |
1953 if (TracePartialPeeling) { | |
1954 tty->print_cr("special not_peeled cloning old: %d new: %d", n->_idx, n_clone->_idx); | |
1955 } | |
1956 #endif | |
1957 while( worklist.size() ) { | |
1958 Node *use = worklist.pop(); | |
1959 _igvn.hash_delete(use); | |
1960 _igvn._worklist.push(use); | |
1961 for (uint j = 1; j < use->req(); j++) { | |
1962 if (use->in(j) == n) { | |
1963 use->set_req(j, n_clone); | |
1964 } | |
1965 } | |
1966 } | |
1967 } | |
1968 } | |
1969 | |
1970 | |
1971 //------------------------------ insert_phi_for_loop ------------------------------------- | |
1972 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist | |
1973 void PhaseIdealLoop::insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp ) { | |
1974 Node *phi = PhiNode::make(lp, back_edge_val); | |
1975 phi->set_req(LoopNode::EntryControl, lp_entry_val); | |
1976 // Use existing phi if it already exists | |
1977 Node *hit = _igvn.hash_find_insert(phi); | |
1978 if( hit == NULL ) { | |
1979 _igvn.register_new_node_with_optimizer(phi); | |
1980 set_ctrl(phi, lp); | |
1981 } else { | |
1982 // Remove the new phi from the graph and use the hit | |
1983 _igvn.remove_dead_node(phi); | |
1984 phi = hit; | |
1985 } | |
1986 _igvn.hash_delete(use); | |
1987 _igvn._worklist.push(use); | |
1988 use->set_req(idx, phi); | |
1989 } | |
1990 | |
1991 #ifdef ASSERT | |
1992 //------------------------------ is_valid_loop_partition ------------------------------------- | |
1993 // Validate the loop partition sets: peel and not_peel | |
1994 bool PhaseIdealLoop::is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list, | |
1995 VectorSet& not_peel ) { | |
1996 uint i; | |
1997 // Check that peel_list entries are in the peel set | |
1998 for (i = 0; i < peel_list.size(); i++) { | |
1999 if (!peel.test(peel_list.at(i)->_idx)) { | |
2000 return false; | |
2001 } | |
2002 } | |
2003 // Check at loop members are in one of peel set or not_peel set | |
2004 for (i = 0; i < loop->_body.size(); i++ ) { | |
2005 Node *def = loop->_body.at(i); | |
2006 uint di = def->_idx; | |
2007 // Check that peel set elements are in peel_list | |
2008 if (peel.test(di)) { | |
2009 if (not_peel.test(di)) { | |
2010 return false; | |
2011 } | |
2012 // Must be in peel_list also | |
2013 bool found = false; | |
2014 for (uint j = 0; j < peel_list.size(); j++) { | |
2015 if (peel_list.at(j)->_idx == di) { | |
2016 found = true; | |
2017 break; | |
2018 } | |
2019 } | |
2020 if (!found) { | |
2021 return false; | |
2022 } | |
2023 } else if (not_peel.test(di)) { | |
2024 if (peel.test(di)) { | |
2025 return false; | |
2026 } | |
2027 } else { | |
2028 return false; | |
2029 } | |
2030 } | |
2031 return true; | |
2032 } | |
2033 | |
2034 //------------------------------ is_valid_clone_loop_exit_use ------------------------------------- | |
2035 // Ensure a use outside of loop is of the right form | |
2036 bool PhaseIdealLoop::is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx) { | |
2037 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
2038 return (use->is_Phi() && | |
2039 use_c->is_Region() && use_c->req() == 3 && | |
2040 (use_c->in(exit_idx)->Opcode() == Op_IfTrue || | |
2041 use_c->in(exit_idx)->Opcode() == Op_IfFalse || | |
2042 use_c->in(exit_idx)->Opcode() == Op_JumpProj) && | |
2043 loop->is_member( get_loop( use_c->in(exit_idx)->in(0) ) ) ); | |
2044 } | |
2045 | |
2046 //------------------------------ is_valid_clone_loop_form ------------------------------------- | |
2047 // Ensure that all uses outside of loop are of the right form | |
2048 bool PhaseIdealLoop::is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list, | |
2049 uint orig_exit_idx, uint clone_exit_idx) { | |
2050 uint len = peel_list.size(); | |
2051 for (uint i = 0; i < len; i++) { | |
2052 Node *def = peel_list.at(i); | |
2053 | |
2054 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) { | |
2055 Node *use = def->fast_out(j); | |
2056 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
2057 if (!loop->is_member(get_loop(use_c))) { | |
2058 // use is not in the loop, check for correct structure | |
2059 if (use->in(0) == def) { | |
2060 // Okay | |
2061 } else if (!is_valid_clone_loop_exit_use(loop, use, orig_exit_idx)) { | |
2062 return false; | |
2063 } | |
2064 } | |
2065 } | |
2066 } | |
2067 return true; | |
2068 } | |
2069 #endif | |
2070 | |
2071 //------------------------------ partial_peel ------------------------------------- | |
2072 // Partially peel (aka loop rotation) the top portion of a loop (called | |
2073 // the peel section below) by cloning it and placing one copy just before | |
2074 // the new loop head and the other copy at the bottom of the new loop. | |
2075 // | |
2076 // before after where it came from | |
2077 // | |
2078 // stmt1 stmt1 | |
2079 // loop: stmt2 clone | |
2080 // stmt2 if condA goto exitA clone | |
2081 // if condA goto exitA new_loop: new | |
2082 // stmt3 stmt3 clone | |
2083 // if !condB goto loop if condB goto exitB clone | |
2084 // exitB: stmt2 orig | |
2085 // stmt4 if !condA goto new_loop orig | |
2086 // exitA: goto exitA | |
2087 // exitB: | |
2088 // stmt4 | |
2089 // exitA: | |
2090 // | |
2091 // Step 1: find the cut point: an exit test on probable | |
2092 // induction variable. | |
2093 // Step 2: schedule (with cloning) operations in the peel | |
2094 // section that can be executed after the cut into | |
2095 // the section that is not peeled. This may need | |
2096 // to clone operations into exit blocks. For | |
2097 // instance, a reference to A[i] in the not-peel | |
2098 // section and a reference to B[i] in an exit block | |
2099 // may cause a left-shift of i by 2 to be placed | |
2100 // in the peel block. This step will clone the left | |
2101 // shift into the exit block and sink the left shift | |
2102 // from the peel to the not-peel section. | |
2103 // Step 3: clone the loop, retarget the control, and insert | |
2104 // phis for values that are live across the new loop | |
2105 // head. This is very dependent on the graph structure | |
2106 // from clone_loop. It creates region nodes for | |
2107 // exit control and associated phi nodes for values | |
2108 // flow out of the loop through that exit. The region | |
2109 // node is dominated by the clone's control projection. | |
2110 // So the clone's peel section is placed before the | |
2111 // new loop head, and the clone's not-peel section is | |
2112 // forms the top part of the new loop. The original | |
2113 // peel section forms the tail of the new loop. | |
2114 // Step 4: update the dominator tree and recompute the | |
2115 // dominator depth. | |
2116 // | |
2117 // orig | |
2118 // | |
2119 // stmt1 | |
2120 // | | |
2121 // v | |
2122 // loop<----+ | |
2123 // | | | |
2124 // stmt2 | | |
2125 // | | | |
2126 // v | | |
2127 // ifA | | |
2128 // / | | | |
2129 // v v | | |
2130 // false true ^ <-- last_peel | |
2131 // / | | | |
2132 // / ===|==cut | | |
2133 // / stmt3 | <-- first_not_peel | |
2134 // / | | | |
2135 // | v | | |
2136 // v ifB | | |
2137 // exitA: / \ | | |
2138 // / \ | | |
2139 // v v | | |
2140 // false true | | |
2141 // / \ | | |
2142 // / ----+ | |
2143 // | | |
2144 // v | |
2145 // exitB: | |
2146 // stmt4 | |
2147 // | |
2148 // | |
2149 // after clone loop | |
2150 // | |
2151 // stmt1 | |
2152 // / \ | |
2153 // clone / \ orig | |
2154 // / \ | |
2155 // / \ | |
2156 // v v | |
2157 // +---->loop loop<----+ | |
2158 // | | | | | |
2159 // | stmt2 stmt2 | | |
2160 // | | | | | |
2161 // | v v | | |
2162 // | ifA ifA | | |
2163 // | | \ / | | | |
2164 // | v v v v | | |
2165 // ^ true false false true ^ <-- last_peel | |
2166 // | | ^ \ / | | | |
2167 // | cut==|== \ \ / ===|==cut | | |
2168 // | stmt3 \ \ / stmt3 | <-- first_not_peel | |
2169 // | | dom | | | | | |
2170 // | v \ 1v v2 v | | |
2171 // | ifB regionA ifB | | |
2172 // | / \ | / \ | | |
2173 // | / \ v / \ | | |
2174 // | v v exitA: v v | | |
2175 // | true false false true | | |
2176 // | / ^ \ / \ | | |
2177 // +---- \ \ / ----+ | |
2178 // dom \ / | |
2179 // \ 1v v2 | |
2180 // regionB | |
2181 // | | |
2182 // v | |
2183 // exitB: | |
2184 // stmt4 | |
2185 // | |
2186 // | |
2187 // after partial peel | |
2188 // | |
2189 // stmt1 | |
2190 // / | |
2191 // clone / orig | |
2192 // / TOP | |
2193 // / \ | |
2194 // v v | |
2195 // TOP->region region----+ | |
2196 // | | | | |
2197 // stmt2 stmt2 | | |
2198 // | | | | |
2199 // v v | | |
2200 // ifA ifA | | |
2201 // | \ / | | | |
2202 // v v v v | | |
2203 // true false false true | <-- last_peel | |
2204 // | ^ \ / +------|---+ | |
2205 // +->newloop \ \ / === ==cut | | | |
2206 // | stmt3 \ \ / TOP | | | |
2207 // | | dom | | stmt3 | | <-- first_not_peel | |
2208 // | v \ 1v v2 v | | | |
2209 // | ifB regionA ifB ^ v | |
2210 // | / \ | / \ | | | |
2211 // | / \ v / \ | | | |
2212 // | v v exitA: v v | | | |
2213 // | true false false true | | | |
2214 // | / ^ \ / \ | | | |
2215 // | | \ \ / v | | | |
2216 // | | dom \ / TOP | | | |
2217 // | | \ 1v v2 | | | |
2218 // ^ v regionB | | | |
2219 // | | | | | | |
2220 // | | v ^ v | |
2221 // | | exitB: | | | |
2222 // | | stmt4 | | | |
2223 // | +------------>-----------------+ | | |
2224 // | | | |
2225 // +-----------------<---------------------+ | |
2226 // | |
2227 // | |
2228 // final graph | |
2229 // | |
2230 // stmt1 | |
2231 // | | |
2232 // v | |
2233 // ........> ifA clone | |
2234 // : / | | |
2235 // dom / | | |
2236 // : v v | |
2237 // : false true | |
2238 // : | | | |
2239 // : | stmt2 clone | |
2240 // : | | | |
2241 // : | v | |
2242 // : | newloop<-----+ | |
2243 // : | | | | |
2244 // : | stmt3 clone | | |
2245 // : | | | | |
2246 // : | v | | |
2247 // : | ifB | | |
2248 // : | / \ | | |
2249 // : | v v | | |
2250 // : | false true | | |
2251 // : | | | | | |
2252 // : | v stmt2 | | |
2253 // : | exitB: | | | |
2254 // : | stmt4 v | | |
2255 // : | ifA orig | | |
2256 // : | / \ | | |
2257 // : | / \ | | |
2258 // : | v v | | |
2259 // : | false true | | |
2260 // : | / \ | | |
2261 // : v v -----+ | |
2262 // RegionA | |
2263 // | | |
2264 // v | |
2265 // exitA | |
2266 // | |
2267 bool PhaseIdealLoop::partial_peel( IdealLoopTree *loop, Node_List &old_new ) { | |
2268 | |
108 | 2269 if (!loop->_head->is_Loop()) { |
2270 return false; } | |
2271 | |
0 | 2272 LoopNode *head = loop->_head->as_Loop(); |
2273 | |
2274 if (head->is_partial_peel_loop() || head->partial_peel_has_failed()) { | |
2275 return false; | |
2276 } | |
2277 | |
2278 // Check for complex exit control | |
2279 for(uint ii = 0; ii < loop->_body.size(); ii++ ) { | |
2280 Node *n = loop->_body.at(ii); | |
2281 int opc = n->Opcode(); | |
2282 if (n->is_Call() || | |
2283 opc == Op_Catch || | |
2284 opc == Op_CatchProj || | |
2285 opc == Op_Jump || | |
2286 opc == Op_JumpProj) { | |
2287 #if !defined(PRODUCT) | |
2288 if (TracePartialPeeling) { | |
2289 tty->print_cr("\nExit control too complex: lp: %d", head->_idx); | |
2290 } | |
2291 #endif | |
2292 return false; | |
2293 } | |
2294 } | |
2295 | |
2296 int dd = dom_depth(head); | |
2297 | |
2298 // Step 1: find cut point | |
2299 | |
2300 // Walk up dominators to loop head looking for first loop exit | |
2301 // which is executed on every path thru loop. | |
2302 IfNode *peel_if = NULL; | |
2303 IfNode *peel_if_cmpu = NULL; | |
2304 | |
2305 Node *iff = loop->tail(); | |
2306 while( iff != head ) { | |
2307 if( iff->is_If() ) { | |
2308 Node *ctrl = get_ctrl(iff->in(1)); | |
2309 if (ctrl->is_top()) return false; // Dead test on live IF. | |
2310 // If loop-varying exit-test, check for induction variable | |
2311 if( loop->is_member(get_loop(ctrl)) && | |
2312 loop->is_loop_exit(iff) && | |
2313 is_possible_iv_test(iff)) { | |
2314 Node* cmp = iff->in(1)->in(1); | |
2315 if (cmp->Opcode() == Op_CmpI) { | |
2316 peel_if = iff->as_If(); | |
2317 } else { | |
2318 assert(cmp->Opcode() == Op_CmpU, "must be CmpI or CmpU"); | |
2319 peel_if_cmpu = iff->as_If(); | |
2320 } | |
2321 } | |
2322 } | |
2323 iff = idom(iff); | |
2324 } | |
2325 // Prefer signed compare over unsigned compare. | |
2326 IfNode* new_peel_if = NULL; | |
2327 if (peel_if == NULL) { | |
2328 if (!PartialPeelAtUnsignedTests || peel_if_cmpu == NULL) { | |
2329 return false; // No peel point found | |
2330 } | |
2331 new_peel_if = insert_cmpi_loop_exit(peel_if_cmpu, loop); | |
2332 if (new_peel_if == NULL) { | |
2333 return false; // No peel point found | |
2334 } | |
2335 peel_if = new_peel_if; | |
2336 } | |
2337 Node* last_peel = stay_in_loop(peel_if, loop); | |
2338 Node* first_not_peeled = stay_in_loop(last_peel, loop); | |
2339 if (first_not_peeled == NULL || first_not_peeled == head) { | |
2340 return false; | |
2341 } | |
2342 | |
2343 #if !defined(PRODUCT) | |
2344 if (TracePartialPeeling) { | |
2345 tty->print_cr("before partial peel one iteration"); | |
2346 Node_List wl; | |
2347 Node* t = head->in(2); | |
2348 while (true) { | |
2349 wl.push(t); | |
2350 if (t == head) break; | |
2351 t = idom(t); | |
2352 } | |
2353 while (wl.size() > 0) { | |
2354 Node* tt = wl.pop(); | |
2355 tt->dump(); | |
2356 if (tt == last_peel) tty->print_cr("-- cut --"); | |
2357 } | |
2358 } | |
2359 #endif | |
2360 ResourceArea *area = Thread::current()->resource_area(); | |
2361 VectorSet peel(area); | |
2362 VectorSet not_peel(area); | |
2363 Node_List peel_list(area); | |
2364 Node_List worklist(area); | |
2365 Node_List sink_list(area); | |
2366 | |
2367 // Set of cfg nodes to peel are those that are executable from | |
2368 // the head through last_peel. | |
2369 assert(worklist.size() == 0, "should be empty"); | |
2370 worklist.push(head); | |
2371 peel.set(head->_idx); | |
2372 while (worklist.size() > 0) { | |
2373 Node *n = worklist.pop(); | |
2374 if (n != last_peel) { | |
2375 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
2376 Node* use = n->fast_out(j); | |
2377 if (use->is_CFG() && | |
2378 loop->is_member(get_loop(use)) && | |
2379 !peel.test_set(use->_idx)) { | |
2380 worklist.push(use); | |
2381 } | |
2382 } | |
2383 } | |
2384 } | |
2385 | |
2386 // Set of non-cfg nodes to peel are those that are control | |
2387 // dependent on the cfg nodes. | |
2388 uint i; | |
2389 for(i = 0; i < loop->_body.size(); i++ ) { | |
2390 Node *n = loop->_body.at(i); | |
2391 Node *n_c = has_ctrl(n) ? get_ctrl(n) : n; | |
2392 if (peel.test(n_c->_idx)) { | |
2393 peel.set(n->_idx); | |
2394 } else { | |
2395 not_peel.set(n->_idx); | |
2396 } | |
2397 } | |
2398 | |
2399 // Step 2: move operations from the peeled section down into the | |
2400 // not-peeled section | |
2401 | |
2402 // Get a post order schedule of nodes in the peel region | |
2403 // Result in right-most operand. | |
2404 scheduled_nodelist(loop, peel, peel_list ); | |
2405 | |
2406 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition"); | |
2407 | |
2408 // For future check for too many new phis | |
2409 uint old_phi_cnt = 0; | |
2410 for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) { | |
2411 Node* use = head->fast_out(j); | |
2412 if (use->is_Phi()) old_phi_cnt++; | |
2413 } | |
2414 | |
2415 #if !defined(PRODUCT) | |
2416 if (TracePartialPeeling) { | |
2417 tty->print_cr("\npeeled list"); | |
2418 } | |
2419 #endif | |
2420 | |
2421 // Evacuate nodes in peel region into the not_peeled region if possible | |
2422 uint new_phi_cnt = 0; | |
2423 for (i = 0; i < peel_list.size();) { | |
2424 Node* n = peel_list.at(i); | |
2425 #if !defined(PRODUCT) | |
2426 if (TracePartialPeeling) n->dump(); | |
2427 #endif | |
2428 bool incr = true; | |
2429 if ( !n->is_CFG() ) { | |
2430 | |
2431 if ( has_use_in_set(n, not_peel) ) { | |
2432 | |
2433 // If not used internal to the peeled region, | |
2434 // move "n" from peeled to not_peeled region. | |
2435 | |
2436 if ( !has_use_internal_to_set(n, peel, loop) ) { | |
2437 | |
2438 // if not pinned and not a load (which maybe anti-dependent on a store) | |
2439 // and not a CMove (Matcher expects only bool->cmove). | |
2440 if ( n->in(0) == NULL && !n->is_Load() && !n->is_CMove() ) { | |
2441 clone_for_use_outside_loop( loop, n, worklist ); | |
2442 | |
2443 sink_list.push(n); | |
2444 peel >>= n->_idx; // delete n from peel set. | |
2445 not_peel <<= n->_idx; // add n to not_peel set. | |
2446 peel_list.remove(i); | |
2447 incr = false; | |
2448 #if !defined(PRODUCT) | |
2449 if (TracePartialPeeling) { | |
2450 tty->print_cr("sink to not_peeled region: %d newbb: %d", | |
2451 n->_idx, get_ctrl(n)->_idx); | |
2452 } | |
2453 #endif | |
2454 } | |
2455 } else { | |
2456 // Otherwise check for special def-use cases that span | |
2457 // the peel/not_peel boundary such as bool->if | |
2458 clone_for_special_use_inside_loop( loop, n, not_peel, sink_list, worklist ); | |
2459 new_phi_cnt++; | |
2460 } | |
2461 } | |
2462 } | |
2463 if (incr) i++; | |
2464 } | |
2465 | |
2466 if (new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta) { | |
2467 #if !defined(PRODUCT) | |
2468 if (TracePartialPeeling) { | |
2469 tty->print_cr("\nToo many new phis: %d old %d new cmpi: %c", | |
2470 new_phi_cnt, old_phi_cnt, new_peel_if != NULL?'T':'F'); | |
2471 } | |
2472 #endif | |
2473 if (new_peel_if != NULL) { | |
2474 remove_cmpi_loop_exit(new_peel_if, loop); | |
2475 } | |
2476 // Inhibit more partial peeling on this loop | |
2477 assert(!head->is_partial_peel_loop(), "not partial peeled"); | |
2478 head->mark_partial_peel_failed(); | |
2479 return false; | |
2480 } | |
2481 | |
2482 // Step 3: clone loop, retarget control, and insert new phis | |
2483 | |
2484 // Create new loop head for new phis and to hang | |
2485 // the nodes being moved (sinked) from the peel region. | |
2486 LoopNode* new_head = new (C, 3) LoopNode(last_peel, last_peel); | |
2487 _igvn.register_new_node_with_optimizer(new_head); | |
2488 assert(first_not_peeled->in(0) == last_peel, "last_peel <- first_not_peeled"); | |
2489 first_not_peeled->set_req(0, new_head); | |
2490 set_loop(new_head, loop); | |
2491 loop->_body.push(new_head); | |
2492 not_peel.set(new_head->_idx); | |
2493 set_idom(new_head, last_peel, dom_depth(first_not_peeled)); | |
2494 set_idom(first_not_peeled, new_head, dom_depth(first_not_peeled)); | |
2495 | |
2496 while (sink_list.size() > 0) { | |
2497 Node* n = sink_list.pop(); | |
2498 set_ctrl(n, new_head); | |
2499 } | |
2500 | |
2501 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition"); | |
2502 | |
2503 clone_loop( loop, old_new, dd ); | |
2504 | |
2505 const uint clone_exit_idx = 1; | |
2506 const uint orig_exit_idx = 2; | |
2507 assert(is_valid_clone_loop_form( loop, peel_list, orig_exit_idx, clone_exit_idx ), "bad clone loop"); | |
2508 | |
2509 Node* head_clone = old_new[head->_idx]; | |
2510 LoopNode* new_head_clone = old_new[new_head->_idx]->as_Loop(); | |
2511 Node* orig_tail_clone = head_clone->in(2); | |
2512 | |
2513 // Add phi if "def" node is in peel set and "use" is not | |
2514 | |
2515 for(i = 0; i < peel_list.size(); i++ ) { | |
2516 Node *def = peel_list.at(i); | |
2517 if (!def->is_CFG()) { | |
2518 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) { | |
2519 Node *use = def->fast_out(j); | |
2520 if (has_node(use) && use->in(0) != C->top() && | |
2521 (!peel.test(use->_idx) || | |
2522 (use->is_Phi() && use->in(0) == head)) ) { | |
2523 worklist.push(use); | |
2524 } | |
2525 } | |
2526 while( worklist.size() ) { | |
2527 Node *use = worklist.pop(); | |
2528 for (uint j = 1; j < use->req(); j++) { | |
2529 Node* n = use->in(j); | |
2530 if (n == def) { | |
2531 | |
2532 // "def" is in peel set, "use" is not in peel set | |
2533 // or "use" is in the entry boundary (a phi) of the peel set | |
2534 | |
2535 Node* use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
2536 | |
2537 if ( loop->is_member(get_loop( use_c )) ) { | |
2538 // use is in loop | |
2539 if (old_new[use->_idx] != NULL) { // null for dead code | |
2540 Node* use_clone = old_new[use->_idx]; | |
2541 _igvn.hash_delete(use); | |
2542 use->set_req(j, C->top()); | |
2543 _igvn._worklist.push(use); | |
2544 insert_phi_for_loop( use_clone, j, old_new[def->_idx], def, new_head_clone ); | |
2545 } | |
2546 } else { | |
2547 assert(is_valid_clone_loop_exit_use(loop, use, orig_exit_idx), "clone loop format"); | |
2548 // use is not in the loop, check if the live range includes the cut | |
2549 Node* lp_if = use_c->in(orig_exit_idx)->in(0); | |
2550 if (not_peel.test(lp_if->_idx)) { | |
2551 assert(j == orig_exit_idx, "use from original loop"); | |
2552 insert_phi_for_loop( use, clone_exit_idx, old_new[def->_idx], def, new_head_clone ); | |
2553 } | |
2554 } | |
2555 } | |
2556 } | |
2557 } | |
2558 } | |
2559 } | |
2560 | |
2561 // Step 3b: retarget control | |
2562 | |
2563 // Redirect control to the new loop head if a cloned node in | |
2564 // the not_peeled region has control that points into the peeled region. | |
2565 // This necessary because the cloned peeled region will be outside | |
2566 // the loop. | |
2567 // from to | |
2568 // cloned-peeled <---+ | |
2569 // new_head_clone: | <--+ | |
2570 // cloned-not_peeled in(0) in(0) | |
2571 // orig-peeled | |
2572 | |
2573 for(i = 0; i < loop->_body.size(); i++ ) { | |
2574 Node *n = loop->_body.at(i); | |
2575 if (!n->is_CFG() && n->in(0) != NULL && | |
2576 not_peel.test(n->_idx) && peel.test(n->in(0)->_idx)) { | |
2577 Node* n_clone = old_new[n->_idx]; | |
2578 _igvn.hash_delete(n_clone); | |
2579 n_clone->set_req(0, new_head_clone); | |
2580 _igvn._worklist.push(n_clone); | |
2581 } | |
2582 } | |
2583 | |
2584 // Backedge of the surviving new_head (the clone) is original last_peel | |
2585 _igvn.hash_delete(new_head_clone); | |
2586 new_head_clone->set_req(LoopNode::LoopBackControl, last_peel); | |
2587 _igvn._worklist.push(new_head_clone); | |
2588 | |
2589 // Cut first node in original not_peel set | |
2590 _igvn.hash_delete(new_head); | |
2591 new_head->set_req(LoopNode::EntryControl, C->top()); | |
2592 new_head->set_req(LoopNode::LoopBackControl, C->top()); | |
2593 _igvn._worklist.push(new_head); | |
2594 | |
2595 // Copy head_clone back-branch info to original head | |
2596 // and remove original head's loop entry and | |
2597 // clone head's back-branch | |
2598 _igvn.hash_delete(head); | |
2599 _igvn.hash_delete(head_clone); | |
2600 head->set_req(LoopNode::EntryControl, head_clone->in(LoopNode::LoopBackControl)); | |
2601 head->set_req(LoopNode::LoopBackControl, C->top()); | |
2602 head_clone->set_req(LoopNode::LoopBackControl, C->top()); | |
2603 _igvn._worklist.push(head); | |
2604 _igvn._worklist.push(head_clone); | |
2605 | |
2606 // Similarly modify the phis | |
2607 for (DUIterator_Fast kmax, k = head->fast_outs(kmax); k < kmax; k++) { | |
2608 Node* use = head->fast_out(k); | |
2609 if (use->is_Phi() && use->outcnt() > 0) { | |
2610 Node* use_clone = old_new[use->_idx]; | |
2611 _igvn.hash_delete(use); | |
2612 _igvn.hash_delete(use_clone); | |
2613 use->set_req(LoopNode::EntryControl, use_clone->in(LoopNode::LoopBackControl)); | |
2614 use->set_req(LoopNode::LoopBackControl, C->top()); | |
2615 use_clone->set_req(LoopNode::LoopBackControl, C->top()); | |
2616 _igvn._worklist.push(use); | |
2617 _igvn._worklist.push(use_clone); | |
2618 } | |
2619 } | |
2620 | |
2621 // Step 4: update dominator tree and dominator depth | |
2622 | |
2623 set_idom(head, orig_tail_clone, dd); | |
2624 recompute_dom_depth(); | |
2625 | |
2626 // Inhibit more partial peeling on this loop | |
2627 new_head_clone->set_partial_peel_loop(); | |
2628 C->set_major_progress(); | |
2629 | |
2630 #if !defined(PRODUCT) | |
2631 if (TracePartialPeeling) { | |
2632 tty->print_cr("\nafter partial peel one iteration"); | |
2633 Node_List wl(area); | |
2634 Node* t = last_peel; | |
2635 while (true) { | |
2636 wl.push(t); | |
2637 if (t == head_clone) break; | |
2638 t = idom(t); | |
2639 } | |
2640 while (wl.size() > 0) { | |
2641 Node* tt = wl.pop(); | |
2642 if (tt == head) tty->print_cr("orig head"); | |
2643 else if (tt == new_head_clone) tty->print_cr("new head"); | |
2644 else if (tt == head_clone) tty->print_cr("clone head"); | |
2645 tt->dump(); | |
2646 } | |
2647 } | |
2648 #endif | |
2649 return true; | |
2650 } | |
2651 | |
2652 //------------------------------reorg_offsets---------------------------------- | |
2653 // Reorganize offset computations to lower register pressure. Mostly | |
2654 // prevent loop-fallout uses of the pre-incremented trip counter (which are | |
2655 // then alive with the post-incremented trip counter forcing an extra | |
2656 // register move) | |
2657 void PhaseIdealLoop::reorg_offsets( IdealLoopTree *loop ) { | |
2658 | |
2659 CountedLoopNode *cl = loop->_head->as_CountedLoop(); | |
2660 CountedLoopEndNode *cle = cl->loopexit(); | |
2661 if( !cle ) return; // The occasional dead loop | |
2662 // Find loop exit control | |
2663 Node *exit = cle->proj_out(false); | |
2664 assert( exit->Opcode() == Op_IfFalse, "" ); | |
2665 | |
2666 // Check for the special case of folks using the pre-incremented | |
2667 // trip-counter on the fall-out path (forces the pre-incremented | |
2668 // and post-incremented trip counter to be live at the same time). | |
2669 // Fix this by adjusting to use the post-increment trip counter. | |
2670 Node *phi = cl->phi(); | |
2671 if( !phi ) return; // Dead infinite loop | |
367
194b8e3a2fc4
6384206: Phis which are later unneeded are impairing our ability to inline based on static types
never
parents:
318
diff
changeset
|
2672 |
194b8e3a2fc4
6384206: Phis which are later unneeded are impairing our ability to inline based on static types
never
parents:
318
diff
changeset
|
2673 // Shape messed up, probably by iteration_split_impl |
194b8e3a2fc4
6384206: Phis which are later unneeded are impairing our ability to inline based on static types
never
parents:
318
diff
changeset
|
2674 if (phi->in(LoopNode::LoopBackControl) != cl->incr()) return; |
194b8e3a2fc4
6384206: Phis which are later unneeded are impairing our ability to inline based on static types
never
parents:
318
diff
changeset
|
2675 |
0 | 2676 bool progress = true; |
2677 while (progress) { | |
2678 progress = false; | |
2679 for (DUIterator_Fast imax, i = phi->fast_outs(imax); i < imax; i++) { | |
2680 Node* use = phi->fast_out(i); // User of trip-counter | |
2681 if (!has_ctrl(use)) continue; | |
2682 Node *u_ctrl = get_ctrl(use); | |
2683 if( use->is_Phi() ) { | |
2684 u_ctrl = NULL; | |
2685 for( uint j = 1; j < use->req(); j++ ) | |
2686 if( use->in(j) == phi ) | |
2687 u_ctrl = dom_lca( u_ctrl, use->in(0)->in(j) ); | |
2688 } | |
2689 IdealLoopTree *u_loop = get_loop(u_ctrl); | |
2690 // Look for loop-invariant use | |
2691 if( u_loop == loop ) continue; | |
2692 if( loop->is_member( u_loop ) ) continue; | |
2693 // Check that use is live out the bottom. Assuming the trip-counter | |
2694 // update is right at the bottom, uses of of the loop middle are ok. | |
2695 if( dom_lca( exit, u_ctrl ) != exit ) continue; | |
2696 // protect against stride not being a constant | |
2697 if( !cle->stride_is_con() ) continue; | |
2698 // Hit! Refactor use to use the post-incremented tripcounter. | |
2699 // Compute a post-increment tripcounter. | |
216
8d191a7697e2
6715633: when matching a memory node the adr_type should not change
kvn
parents:
164
diff
changeset
|
2700 Node *opaq = new (C, 2) Opaque2Node( C, cle->incr() ); |
0 | 2701 register_new_node( opaq, u_ctrl ); |
2702 Node *neg_stride = _igvn.intcon(-cle->stride_con()); | |
2703 set_ctrl(neg_stride, C->root()); | |
2704 Node *post = new (C, 3) AddINode( opaq, neg_stride); | |
2705 register_new_node( post, u_ctrl ); | |
2706 _igvn.hash_delete(use); | |
2707 _igvn._worklist.push(use); | |
2708 for( uint j = 1; j < use->req(); j++ ) | |
2709 if( use->in(j) == phi ) | |
2710 use->set_req(j, post); | |
2711 // Since DU info changed, rerun loop | |
2712 progress = true; | |
2713 break; | |
2714 } | |
2715 } | |
2716 | |
2717 } |