Mercurial > hg > truffle
annotate src/share/vm/opto/loopopts.cpp @ 2831:f072013daba9
Added lookup method.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Tue, 31 May 2011 11:32:48 +0200 |
parents | 6c97c830fb6f |
children | 273b56978029 |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "memory/allocation.inline.hpp" | |
27 #include "opto/addnode.hpp" | |
28 #include "opto/connode.hpp" | |
29 #include "opto/divnode.hpp" | |
30 #include "opto/loopnode.hpp" | |
31 #include "opto/mulnode.hpp" | |
32 #include "opto/rootnode.hpp" | |
33 #include "opto/subnode.hpp" | |
0 | 34 |
35 //============================================================================= | |
36 //------------------------------split_thru_phi--------------------------------- | |
37 // Split Node 'n' through merge point if there is enough win. | |
38 Node *PhaseIdealLoop::split_thru_phi( Node *n, Node *region, int policy ) { | |
69 | 39 if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) { |
40 // ConvI2L may have type information on it which is unsafe to push up | |
41 // so disable this for now | |
42 return NULL; | |
43 } | |
0 | 44 int wins = 0; |
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45 assert(!n->is_CFG(), ""); |
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46 assert(region->is_Region(), ""); |
64
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47 |
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48 const Type* type = n->bottom_type(); |
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49 const TypeOopPtr *t_oop = _igvn.type(n)->isa_oopptr(); |
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50 Node *phi; |
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51 if (t_oop != NULL && t_oop->is_known_instance_field()) { |
64
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52 int iid = t_oop->instance_id(); |
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53 int index = C->get_alias_index(t_oop); |
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54 int offset = t_oop->offset(); |
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55 phi = new (C,region->req()) PhiNode(region, type, NULL, iid, index, offset); |
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56 } else { |
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57 phi = PhiNode::make_blank(region, n); |
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58 } |
0 | 59 uint old_unique = C->unique(); |
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60 for (uint i = 1; i < region->req(); i++) { |
0 | 61 Node *x; |
62 Node* the_clone = NULL; | |
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63 if (region->in(i) == C->top()) { |
0 | 64 x = C->top(); // Dead path? Use a dead data op |
65 } else { | |
66 x = n->clone(); // Else clone up the data op | |
67 the_clone = x; // Remember for possible deletion. | |
68 // Alter data node to use pre-phi inputs | |
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69 if (n->in(0) == region) |
0 | 70 x->set_req( 0, region->in(i) ); |
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71 for (uint j = 1; j < n->req(); j++) { |
0 | 72 Node *in = n->in(j); |
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73 if (in->is_Phi() && in->in(0) == region) |
0 | 74 x->set_req( j, in->in(i) ); // Use pre-Phi input for the clone |
75 } | |
76 } | |
77 // Check for a 'win' on some paths | |
78 const Type *t = x->Value(&_igvn); | |
79 | |
80 bool singleton = t->singleton(); | |
81 | |
82 // A TOP singleton indicates that there are no possible values incoming | |
83 // along a particular edge. In most cases, this is OK, and the Phi will | |
84 // be eliminated later in an Ideal call. However, we can't allow this to | |
85 // happen if the singleton occurs on loop entry, as the elimination of | |
86 // the PhiNode may cause the resulting node to migrate back to a previous | |
87 // loop iteration. | |
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88 if (singleton && t == Type::TOP) { |
0 | 89 // Is_Loop() == false does not confirm the absence of a loop (e.g., an |
90 // irreducible loop may not be indicated by an affirmative is_Loop()); | |
91 // therefore, the only top we can split thru a phi is on a backedge of | |
92 // a loop. | |
93 singleton &= region->is_Loop() && (i != LoopNode::EntryControl); | |
94 } | |
95 | |
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96 if (singleton) { |
0 | 97 wins++; |
98 x = ((PhaseGVN&)_igvn).makecon(t); | |
99 } else { | |
100 // We now call Identity to try to simplify the cloned node. | |
101 // Note that some Identity methods call phase->type(this). | |
102 // Make sure that the type array is big enough for | |
103 // our new node, even though we may throw the node away. | |
104 // (Note: This tweaking with igvn only works because x is a new node.) | |
105 _igvn.set_type(x, t); | |
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106 // If x is a TypeNode, capture any more-precise type permanently into Node |
605 | 107 // otherwise it will be not updated during igvn->transform since |
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108 // igvn->type(x) is set to x->Value() already. |
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109 x->raise_bottom_type(t); |
0 | 110 Node *y = x->Identity(&_igvn); |
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111 if (y != x) { |
0 | 112 wins++; |
113 x = y; | |
114 } else { | |
115 y = _igvn.hash_find(x); | |
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116 if (y) { |
0 | 117 wins++; |
118 x = y; | |
119 } else { | |
120 // Else x is a new node we are keeping | |
121 // We do not need register_new_node_with_optimizer | |
122 // because set_type has already been called. | |
123 _igvn._worklist.push(x); | |
124 } | |
125 } | |
126 } | |
127 if (x != the_clone && the_clone != NULL) | |
128 _igvn.remove_dead_node(the_clone); | |
129 phi->set_req( i, x ); | |
130 } | |
131 // Too few wins? | |
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132 if (wins <= policy) { |
0 | 133 _igvn.remove_dead_node(phi); |
134 return NULL; | |
135 } | |
136 | |
137 // Record Phi | |
138 register_new_node( phi, region ); | |
139 | |
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140 for (uint i2 = 1; i2 < phi->req(); i2++) { |
0 | 141 Node *x = phi->in(i2); |
142 // If we commoned up the cloned 'x' with another existing Node, | |
143 // the existing Node picks up a new use. We need to make the | |
144 // existing Node occur higher up so it dominates its uses. | |
145 Node *old_ctrl; | |
146 IdealLoopTree *old_loop; | |
147 | |
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148 if (x->is_Con()) { |
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149 // Constant's control is always root. |
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150 set_ctrl(x, C->root()); |
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151 continue; |
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152 } |
0 | 153 // The occasional new node |
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154 if (x->_idx >= old_unique) { // Found a new, unplaced node? |
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155 old_ctrl = NULL; |
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156 old_loop = NULL; // Not in any prior loop |
0 | 157 } else { |
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158 old_ctrl = get_ctrl(x); |
0 | 159 old_loop = get_loop(old_ctrl); // Get prior loop |
160 } | |
161 // New late point must dominate new use | |
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162 Node *new_ctrl = dom_lca(old_ctrl, region->in(i2)); |
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163 if (new_ctrl == old_ctrl) // Nothing is changed |
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164 continue; |
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165 |
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166 IdealLoopTree *new_loop = get_loop(new_ctrl); |
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167 |
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168 // Don't move x into a loop if its uses are |
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169 // outside of loop. Otherwise x will be cloned |
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170 // for each use outside of this loop. |
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171 IdealLoopTree *use_loop = get_loop(region); |
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172 if (!new_loop->is_member(use_loop) && |
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173 (old_loop == NULL || !new_loop->is_member(old_loop))) { |
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174 // Take early control, later control will be recalculated |
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175 // during next iteration of loop optimizations. |
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176 new_ctrl = get_early_ctrl(x); |
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177 new_loop = get_loop(new_ctrl); |
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178 } |
0 | 179 // Set new location |
180 set_ctrl(x, new_ctrl); | |
181 // If changing loop bodies, see if we need to collect into new body | |
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182 if (old_loop != new_loop) { |
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183 if (old_loop && !old_loop->_child) |
0 | 184 old_loop->_body.yank(x); |
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185 if (!new_loop->_child) |
0 | 186 new_loop->_body.push(x); // Collect body info |
187 } | |
188 } | |
189 | |
190 return phi; | |
191 } | |
192 | |
193 //------------------------------dominated_by------------------------------------ | |
194 // Replace the dominated test with an obvious true or false. Place it on the | |
195 // IGVN worklist for later cleanup. Move control-dependent data Nodes on the | |
196 // live path up to the dominating control. | |
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197 void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff, bool flip ) { |
0 | 198 #ifndef PRODUCT |
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199 if (VerifyLoopOptimizations && PrintOpto) tty->print_cr("dominating test"); |
0 | 200 #endif |
201 | |
202 | |
203 // prevdom is the dominating projection of the dominating test. | |
204 assert( iff->is_If(), "" ); | |
205 assert( iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd, "Check this code when new subtype is added"); | |
206 int pop = prevdom->Opcode(); | |
207 assert( pop == Op_IfFalse || pop == Op_IfTrue, "" ); | |
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208 if (flip) { |
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209 if (pop == Op_IfTrue) |
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210 pop = Op_IfFalse; |
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211 else |
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212 pop = Op_IfTrue; |
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213 } |
0 | 214 // 'con' is set to true or false to kill the dominated test. |
215 Node *con = _igvn.makecon(pop == Op_IfTrue ? TypeInt::ONE : TypeInt::ZERO); | |
216 set_ctrl(con, C->root()); // Constant gets a new use | |
217 // Hack the dominated test | |
218 _igvn.hash_delete(iff); | |
219 iff->set_req(1, con); | |
220 _igvn._worklist.push(iff); | |
221 | |
222 // If I dont have a reachable TRUE and FALSE path following the IfNode then | |
223 // I can assume this path reaches an infinite loop. In this case it's not | |
224 // important to optimize the data Nodes - either the whole compilation will | |
225 // be tossed or this path (and all data Nodes) will go dead. | |
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226 if (iff->outcnt() != 2) return; |
0 | 227 |
228 // Make control-dependent data Nodes on the live path (path that will remain | |
229 // once the dominated IF is removed) become control-dependent on the | |
230 // dominating projection. | |
231 Node* dp = ((IfNode*)iff)->proj_out(pop == Op_IfTrue); | |
232 IdealLoopTree *old_loop = get_loop(dp); | |
233 | |
234 for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) { | |
235 Node* cd = dp->fast_out(i); // Control-dependent node | |
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236 if (cd->depends_only_on_test()) { |
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237 assert(cd->in(0) == dp, ""); |
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238 _igvn.hash_delete(cd); |
0 | 239 cd->set_req(0, prevdom); |
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240 set_early_ctrl(cd); |
0 | 241 _igvn._worklist.push(cd); |
242 IdealLoopTree *new_loop = get_loop(get_ctrl(cd)); | |
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243 if (old_loop != new_loop) { |
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244 if (!old_loop->_child) old_loop->_body.yank(cd); |
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245 if (!new_loop->_child) new_loop->_body.push(cd); |
0 | 246 } |
247 --i; | |
248 --imax; | |
249 } | |
250 } | |
251 } | |
252 | |
253 //------------------------------has_local_phi_input---------------------------- | |
254 // Return TRUE if 'n' has Phi inputs from its local block and no other | |
255 // block-local inputs (all non-local-phi inputs come from earlier blocks) | |
256 Node *PhaseIdealLoop::has_local_phi_input( Node *n ) { | |
257 Node *n_ctrl = get_ctrl(n); | |
258 // See if some inputs come from a Phi in this block, or from before | |
259 // this block. | |
260 uint i; | |
261 for( i = 1; i < n->req(); i++ ) { | |
262 Node *phi = n->in(i); | |
263 if( phi->is_Phi() && phi->in(0) == n_ctrl ) | |
264 break; | |
265 } | |
266 if( i >= n->req() ) | |
267 return NULL; // No Phi inputs; nowhere to clone thru | |
268 | |
269 // Check for inputs created between 'n' and the Phi input. These | |
270 // must split as well; they have already been given the chance | |
271 // (courtesy of a post-order visit) and since they did not we must | |
272 // recover the 'cost' of splitting them by being very profitable | |
273 // when splitting 'n'. Since this is unlikely we simply give up. | |
274 for( i = 1; i < n->req(); i++ ) { | |
275 Node *m = n->in(i); | |
276 if( get_ctrl(m) == n_ctrl && !m->is_Phi() ) { | |
277 // We allow the special case of AddP's with no local inputs. | |
278 // This allows us to split-up address expressions. | |
279 if (m->is_AddP() && | |
280 get_ctrl(m->in(2)) != n_ctrl && | |
281 get_ctrl(m->in(3)) != n_ctrl) { | |
282 // Move the AddP up to dominating point | |
283 set_ctrl_and_loop(m, find_non_split_ctrl(idom(n_ctrl))); | |
284 continue; | |
285 } | |
286 return NULL; | |
287 } | |
288 } | |
289 | |
290 return n_ctrl; | |
291 } | |
292 | |
293 //------------------------------remix_address_expressions---------------------- | |
294 // Rework addressing expressions to get the most loop-invariant stuff | |
295 // moved out. We'd like to do all associative operators, but it's especially | |
296 // important (common) to do address expressions. | |
297 Node *PhaseIdealLoop::remix_address_expressions( Node *n ) { | |
298 if (!has_ctrl(n)) return NULL; | |
299 Node *n_ctrl = get_ctrl(n); | |
300 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
301 | |
302 // See if 'n' mixes loop-varying and loop-invariant inputs and | |
303 // itself is loop-varying. | |
304 | |
305 // Only interested in binary ops (and AddP) | |
306 if( n->req() < 3 || n->req() > 4 ) return NULL; | |
307 | |
308 Node *n1_ctrl = get_ctrl(n->in( 1)); | |
309 Node *n2_ctrl = get_ctrl(n->in( 2)); | |
310 Node *n3_ctrl = get_ctrl(n->in(n->req() == 3 ? 2 : 3)); | |
311 IdealLoopTree *n1_loop = get_loop( n1_ctrl ); | |
312 IdealLoopTree *n2_loop = get_loop( n2_ctrl ); | |
313 IdealLoopTree *n3_loop = get_loop( n3_ctrl ); | |
314 | |
315 // Does one of my inputs spin in a tighter loop than self? | |
316 if( (n_loop->is_member( n1_loop ) && n_loop != n1_loop) || | |
317 (n_loop->is_member( n2_loop ) && n_loop != n2_loop) || | |
318 (n_loop->is_member( n3_loop ) && n_loop != n3_loop) ) | |
319 return NULL; // Leave well enough alone | |
320 | |
321 // Is at least one of my inputs loop-invariant? | |
322 if( n1_loop == n_loop && | |
323 n2_loop == n_loop && | |
324 n3_loop == n_loop ) | |
325 return NULL; // No loop-invariant inputs | |
326 | |
327 | |
328 int n_op = n->Opcode(); | |
329 | |
330 // Replace expressions like ((V+I) << 2) with (V<<2 + I<<2). | |
331 if( n_op == Op_LShiftI ) { | |
332 // Scale is loop invariant | |
333 Node *scale = n->in(2); | |
334 Node *scale_ctrl = get_ctrl(scale); | |
335 IdealLoopTree *scale_loop = get_loop(scale_ctrl ); | |
336 if( n_loop == scale_loop || !scale_loop->is_member( n_loop ) ) | |
337 return NULL; | |
338 const TypeInt *scale_t = scale->bottom_type()->isa_int(); | |
339 if( scale_t && scale_t->is_con() && scale_t->get_con() >= 16 ) | |
340 return NULL; // Dont bother with byte/short masking | |
341 // Add must vary with loop (else shift would be loop-invariant) | |
342 Node *add = n->in(1); | |
343 Node *add_ctrl = get_ctrl(add); | |
344 IdealLoopTree *add_loop = get_loop(add_ctrl); | |
345 //assert( n_loop == add_loop, "" ); | |
346 if( n_loop != add_loop ) return NULL; // happens w/ evil ZKM loops | |
347 | |
348 // Convert I-V into I+ (0-V); same for V-I | |
349 if( add->Opcode() == Op_SubI && | |
350 _igvn.type( add->in(1) ) != TypeInt::ZERO ) { | |
351 Node *zero = _igvn.intcon(0); | |
352 set_ctrl(zero, C->root()); | |
353 Node *neg = new (C, 3) SubINode( _igvn.intcon(0), add->in(2) ); | |
354 register_new_node( neg, get_ctrl(add->in(2) ) ); | |
355 add = new (C, 3) AddINode( add->in(1), neg ); | |
356 register_new_node( add, add_ctrl ); | |
357 } | |
358 if( add->Opcode() != Op_AddI ) return NULL; | |
359 // See if one add input is loop invariant | |
360 Node *add_var = add->in(1); | |
361 Node *add_var_ctrl = get_ctrl(add_var); | |
362 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl ); | |
363 Node *add_invar = add->in(2); | |
364 Node *add_invar_ctrl = get_ctrl(add_invar); | |
365 IdealLoopTree *add_invar_loop = get_loop(add_invar_ctrl ); | |
366 if( add_var_loop == n_loop ) { | |
367 } else if( add_invar_loop == n_loop ) { | |
368 // Swap to find the invariant part | |
369 add_invar = add_var; | |
370 add_invar_ctrl = add_var_ctrl; | |
371 add_invar_loop = add_var_loop; | |
372 add_var = add->in(2); | |
373 Node *add_var_ctrl = get_ctrl(add_var); | |
374 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl ); | |
375 } else // Else neither input is loop invariant | |
376 return NULL; | |
377 if( n_loop == add_invar_loop || !add_invar_loop->is_member( n_loop ) ) | |
378 return NULL; // No invariant part of the add? | |
379 | |
380 // Yes! Reshape address expression! | |
381 Node *inv_scale = new (C, 3) LShiftINode( add_invar, scale ); | |
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382 Node *inv_scale_ctrl = |
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383 dom_depth(add_invar_ctrl) > dom_depth(scale_ctrl) ? |
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384 add_invar_ctrl : scale_ctrl; |
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385 register_new_node( inv_scale, inv_scale_ctrl ); |
0 | 386 Node *var_scale = new (C, 3) LShiftINode( add_var, scale ); |
387 register_new_node( var_scale, n_ctrl ); | |
388 Node *var_add = new (C, 3) AddINode( var_scale, inv_scale ); | |
389 register_new_node( var_add, n_ctrl ); | |
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390 _igvn.replace_node( n, var_add ); |
0 | 391 return var_add; |
392 } | |
393 | |
394 // Replace (I+V) with (V+I) | |
395 if( n_op == Op_AddI || | |
396 n_op == Op_AddL || | |
397 n_op == Op_AddF || | |
398 n_op == Op_AddD || | |
399 n_op == Op_MulI || | |
400 n_op == Op_MulL || | |
401 n_op == Op_MulF || | |
402 n_op == Op_MulD ) { | |
403 if( n2_loop == n_loop ) { | |
404 assert( n1_loop != n_loop, "" ); | |
405 n->swap_edges(1, 2); | |
406 } | |
407 } | |
408 | |
409 // Replace ((I1 +p V) +p I2) with ((I1 +p I2) +p V), | |
410 // but not if I2 is a constant. | |
411 if( n_op == Op_AddP ) { | |
412 if( n2_loop == n_loop && n3_loop != n_loop ) { | |
413 if( n->in(2)->Opcode() == Op_AddP && !n->in(3)->is_Con() ) { | |
414 Node *n22_ctrl = get_ctrl(n->in(2)->in(2)); | |
415 Node *n23_ctrl = get_ctrl(n->in(2)->in(3)); | |
416 IdealLoopTree *n22loop = get_loop( n22_ctrl ); | |
417 IdealLoopTree *n23_loop = get_loop( n23_ctrl ); | |
418 if( n22loop != n_loop && n22loop->is_member(n_loop) && | |
419 n23_loop == n_loop ) { | |
420 Node *add1 = new (C, 4) AddPNode( n->in(1), n->in(2)->in(2), n->in(3) ); | |
421 // Stuff new AddP in the loop preheader | |
422 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) ); | |
423 Node *add2 = new (C, 4) AddPNode( n->in(1), add1, n->in(2)->in(3) ); | |
424 register_new_node( add2, n_ctrl ); | |
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425 _igvn.replace_node( n, add2 ); |
0 | 426 return add2; |
427 } | |
428 } | |
429 } | |
430 | |
431 // Replace (I1 +p (I2 + V)) with ((I1 +p I2) +p V) | |
432 if( n2_loop != n_loop && n3_loop == n_loop ) { | |
433 if( n->in(3)->Opcode() == Op_AddI ) { | |
434 Node *V = n->in(3)->in(1); | |
435 Node *I = n->in(3)->in(2); | |
436 if( is_member(n_loop,get_ctrl(V)) ) { | |
437 } else { | |
438 Node *tmp = V; V = I; I = tmp; | |
439 } | |
440 if( !is_member(n_loop,get_ctrl(I)) ) { | |
441 Node *add1 = new (C, 4) AddPNode( n->in(1), n->in(2), I ); | |
442 // Stuff new AddP in the loop preheader | |
443 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) ); | |
444 Node *add2 = new (C, 4) AddPNode( n->in(1), add1, V ); | |
445 register_new_node( add2, n_ctrl ); | |
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446 _igvn.replace_node( n, add2 ); |
0 | 447 return add2; |
448 } | |
449 } | |
450 } | |
451 } | |
452 | |
453 return NULL; | |
454 } | |
455 | |
456 //------------------------------conditional_move------------------------------- | |
457 // Attempt to replace a Phi with a conditional move. We have some pretty | |
458 // strict profitability requirements. All Phis at the merge point must | |
459 // be converted, so we can remove the control flow. We need to limit the | |
460 // number of c-moves to a small handful. All code that was in the side-arms | |
461 // of the CFG diamond is now speculatively executed. This code has to be | |
462 // "cheap enough". We are pretty much limited to CFG diamonds that merge | |
463 // 1 or 2 items with a total of 1 or 2 ops executed speculatively. | |
464 Node *PhaseIdealLoop::conditional_move( Node *region ) { | |
465 | |
466 assert( region->is_Region(), "sanity check" ); | |
467 if( region->req() != 3 ) return NULL; | |
468 | |
469 // Check for CFG diamond | |
470 Node *lp = region->in(1); | |
471 Node *rp = region->in(2); | |
472 if( !lp || !rp ) return NULL; | |
473 Node *lp_c = lp->in(0); | |
474 if( lp_c == NULL || lp_c != rp->in(0) || !lp_c->is_If() ) return NULL; | |
475 IfNode *iff = lp_c->as_If(); | |
476 | |
477 // Check for highly predictable branch. No point in CMOV'ing if | |
478 // we are going to predict accurately all the time. | |
479 // %%% This hides patterns produced by utility methods like Math.min. | |
480 if( iff->_prob < PROB_UNLIKELY_MAG(3) || | |
481 iff->_prob > PROB_LIKELY_MAG(3) ) | |
482 return NULL; | |
483 | |
484 // Check for ops pinned in an arm of the diamond. | |
485 // Can't remove the control flow in this case | |
486 if( lp->outcnt() > 1 ) return NULL; | |
487 if( rp->outcnt() > 1 ) return NULL; | |
488 | |
489 // Check profitability | |
490 int cost = 0; | |
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491 int phis = 0; |
0 | 492 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
493 Node *out = region->fast_out(i); | |
494 if( !out->is_Phi() ) continue; // Ignore other control edges, etc | |
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495 phis++; |
0 | 496 PhiNode* phi = out->as_Phi(); |
497 switch (phi->type()->basic_type()) { | |
498 case T_LONG: | |
499 cost++; // Probably encodes as 2 CMOV's | |
500 case T_INT: // These all CMOV fine | |
501 case T_FLOAT: | |
502 case T_DOUBLE: | |
503 case T_ADDRESS: // (RawPtr) | |
504 cost++; | |
505 break; | |
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506 case T_NARROWOOP: // Fall through |
0 | 507 case T_OBJECT: { // Base oops are OK, but not derived oops |
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508 const TypeOopPtr *tp = phi->type()->make_ptr()->isa_oopptr(); |
0 | 509 // Derived pointers are Bad (tm): what's the Base (for GC purposes) of a |
510 // CMOVE'd derived pointer? It's a CMOVE'd derived base. Thus | |
511 // CMOVE'ing a derived pointer requires we also CMOVE the base. If we | |
512 // have a Phi for the base here that we convert to a CMOVE all is well | |
513 // and good. But if the base is dead, we'll not make a CMOVE. Later | |
514 // the allocator will have to produce a base by creating a CMOVE of the | |
515 // relevant bases. This puts the allocator in the business of | |
516 // manufacturing expensive instructions, generally a bad plan. | |
517 // Just Say No to Conditionally-Moved Derived Pointers. | |
518 if( tp && tp->offset() != 0 ) | |
519 return NULL; | |
520 cost++; | |
521 break; | |
522 } | |
523 default: | |
524 return NULL; // In particular, can't do memory or I/O | |
525 } | |
526 // Add in cost any speculative ops | |
527 for( uint j = 1; j < region->req(); j++ ) { | |
528 Node *proj = region->in(j); | |
529 Node *inp = phi->in(j); | |
530 if (get_ctrl(inp) == proj) { // Found local op | |
531 cost++; | |
532 // Check for a chain of dependent ops; these will all become | |
533 // speculative in a CMOV. | |
534 for( uint k = 1; k < inp->req(); k++ ) | |
535 if (get_ctrl(inp->in(k)) == proj) | |
536 return NULL; // Too much speculative goo | |
537 } | |
538 } | |
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539 // See if the Phi is used by a Cmp or Narrow oop Decode/Encode. |
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540 // This will likely Split-If, a higher-payoff operation. |
0 | 541 for (DUIterator_Fast kmax, k = phi->fast_outs(kmax); k < kmax; k++) { |
542 Node* use = phi->fast_out(k); | |
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543 if( use->is_Cmp() || use->is_DecodeN() || use->is_EncodeP() ) |
0 | 544 return NULL; |
545 } | |
546 } | |
547 if( cost >= ConditionalMoveLimit ) return NULL; // Too much goo | |
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548 Node* bol = iff->in(1); |
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549 assert( bol->Opcode() == Op_Bool, "" ); |
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550 int cmp_op = bol->in(1)->Opcode(); |
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551 // It is expensive to generate flags from a float compare. |
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552 // Avoid duplicated float compare. |
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553 if( phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL; |
0 | 554 |
555 // -------------- | |
556 // Now replace all Phis with CMOV's | |
557 Node *cmov_ctrl = iff->in(0); | |
558 uint flip = (lp->Opcode() == Op_IfTrue); | |
559 while( 1 ) { | |
560 PhiNode* phi = NULL; | |
561 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { | |
562 Node *out = region->fast_out(i); | |
563 if (out->is_Phi()) { | |
564 phi = out->as_Phi(); | |
565 break; | |
566 } | |
567 } | |
568 if (phi == NULL) break; | |
569 #ifndef PRODUCT | |
570 if( PrintOpto && VerifyLoopOptimizations ) tty->print_cr("CMOV"); | |
571 #endif | |
572 // Move speculative ops | |
573 for( uint j = 1; j < region->req(); j++ ) { | |
574 Node *proj = region->in(j); | |
575 Node *inp = phi->in(j); | |
576 if (get_ctrl(inp) == proj) { // Found local op | |
577 #ifndef PRODUCT | |
578 if( PrintOpto && VerifyLoopOptimizations ) { | |
579 tty->print(" speculate: "); | |
580 inp->dump(); | |
581 } | |
582 #endif | |
583 set_ctrl(inp, cmov_ctrl); | |
584 } | |
585 } | |
586 Node *cmov = CMoveNode::make( C, cmov_ctrl, iff->in(1), phi->in(1+flip), phi->in(2-flip), _igvn.type(phi) ); | |
587 register_new_node( cmov, cmov_ctrl ); | |
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588 _igvn.replace_node( phi, cmov ); |
0 | 589 #ifndef PRODUCT |
590 if( VerifyLoopOptimizations ) verify(); | |
591 #endif | |
592 } | |
593 | |
594 // The useless CFG diamond will fold up later; see the optimization in | |
595 // RegionNode::Ideal. | |
596 _igvn._worklist.push(region); | |
597 | |
598 return iff->in(1); | |
599 } | |
600 | |
601 //------------------------------split_if_with_blocks_pre----------------------- | |
602 // Do the real work in a non-recursive function. Data nodes want to be | |
603 // cloned in the pre-order so they can feed each other nicely. | |
604 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) { | |
605 // Cloning these guys is unlikely to win | |
606 int n_op = n->Opcode(); | |
607 if( n_op == Op_MergeMem ) return n; | |
608 if( n->is_Proj() ) return n; | |
609 // Do not clone-up CmpFXXX variations, as these are always | |
610 // followed by a CmpI | |
611 if( n->is_Cmp() ) return n; | |
612 // Attempt to use a conditional move instead of a phi/branch | |
613 if( ConditionalMoveLimit > 0 && n_op == Op_Region ) { | |
614 Node *cmov = conditional_move( n ); | |
615 if( cmov ) return cmov; | |
616 } | |
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617 if( n->is_CFG() || n->is_LoadStore() ) |
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618 return n; |
0 | 619 if( n_op == Op_Opaque1 || // Opaque nodes cannot be mod'd |
620 n_op == Op_Opaque2 ) { | |
621 if( !C->major_progress() ) // If chance of no more loop opts... | |
622 _igvn._worklist.push(n); // maybe we'll remove them | |
623 return n; | |
624 } | |
625 | |
626 if( n->is_Con() ) return n; // No cloning for Con nodes | |
627 | |
628 Node *n_ctrl = get_ctrl(n); | |
629 if( !n_ctrl ) return n; // Dead node | |
630 | |
631 // Attempt to remix address expressions for loop invariants | |
632 Node *m = remix_address_expressions( n ); | |
633 if( m ) return m; | |
634 | |
635 // Determine if the Node has inputs from some local Phi. | |
636 // Returns the block to clone thru. | |
637 Node *n_blk = has_local_phi_input( n ); | |
638 if( !n_blk ) return n; | |
639 // Do not clone the trip counter through on a CountedLoop | |
640 // (messes up the canonical shape). | |
641 if( n_blk->is_CountedLoop() && n->Opcode() == Op_AddI ) return n; | |
642 | |
643 // Check for having no control input; not pinned. Allow | |
644 // dominating control. | |
645 if( n->in(0) ) { | |
646 Node *dom = idom(n_blk); | |
647 if( dom_lca( n->in(0), dom ) != n->in(0) ) | |
648 return n; | |
649 } | |
650 // Policy: when is it profitable. You must get more wins than | |
651 // policy before it is considered profitable. Policy is usually 0, | |
652 // so 1 win is considered profitable. Big merges will require big | |
653 // cloning, so get a larger policy. | |
654 int policy = n_blk->req() >> 2; | |
655 | |
656 // If the loop is a candidate for range check elimination, | |
657 // delay splitting through it's phi until a later loop optimization | |
658 if (n_blk->is_CountedLoop()) { | |
659 IdealLoopTree *lp = get_loop(n_blk); | |
660 if (lp && lp->_rce_candidate) { | |
661 return n; | |
662 } | |
663 } | |
664 | |
665 // Use same limit as split_if_with_blocks_post | |
666 if( C->unique() > 35000 ) return n; // Method too big | |
667 | |
668 // Split 'n' through the merge point if it is profitable | |
669 Node *phi = split_thru_phi( n, n_blk, policy ); | |
670 if( !phi ) return n; | |
671 | |
672 // Found a Phi to split thru! | |
673 // Replace 'n' with the new phi | |
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674 _igvn.replace_node( n, phi ); |
0 | 675 // Moved a load around the loop, 'en-registering' something. |
676 if( n_blk->Opcode() == Op_Loop && n->is_Load() && | |
677 !phi->in(LoopNode::LoopBackControl)->is_Load() ) | |
678 C->set_major_progress(); | |
679 | |
680 return phi; | |
681 } | |
682 | |
683 static bool merge_point_too_heavy(Compile* C, Node* region) { | |
684 // Bail out if the region and its phis have too many users. | |
685 int weight = 0; | |
686 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { | |
687 weight += region->fast_out(i)->outcnt(); | |
688 } | |
689 int nodes_left = MaxNodeLimit - C->unique(); | |
690 if (weight * 8 > nodes_left) { | |
691 #ifndef PRODUCT | |
692 if (PrintOpto) | |
693 tty->print_cr("*** Split-if bails out: %d nodes, region weight %d", C->unique(), weight); | |
694 #endif | |
695 return true; | |
696 } else { | |
697 return false; | |
698 } | |
699 } | |
700 | |
701 static bool merge_point_safe(Node* region) { | |
702 // 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode | |
703 // having a PhiNode input. This sidesteps the dangerous case where the split | |
704 // ConvI2LNode may become TOP if the input Value() does not | |
705 // overlap the ConvI2L range, leaving a node which may not dominate its | |
706 // uses. | |
707 // A better fix for this problem can be found in the BugTraq entry, but | |
708 // expediency for Mantis demands this hack. | |
834
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709 // 6855164: If the merge point has a FastLockNode with a PhiNode input, we stop |
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710 // split_if_with_blocks from splitting a block because we could not move around |
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711 // the FastLockNode. |
0 | 712 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
713 Node* n = region->fast_out(i); | |
714 if (n->is_Phi()) { | |
715 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
716 Node* m = n->fast_out(j); | |
834
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717 if (m->is_FastLock()) |
0 | 718 return false; |
834
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719 #ifdef _LP64 |
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720 if (m->Opcode() == Op_ConvI2L) |
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721 return false; |
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722 #endif |
0 | 723 } |
724 } | |
725 } | |
726 return true; | |
727 } | |
728 | |
729 | |
730 //------------------------------place_near_use--------------------------------- | |
731 // Place some computation next to use but not inside inner loops. | |
732 // For inner loop uses move it to the preheader area. | |
733 Node *PhaseIdealLoop::place_near_use( Node *useblock ) const { | |
734 IdealLoopTree *u_loop = get_loop( useblock ); | |
735 return (u_loop->_irreducible || u_loop->_child) | |
736 ? useblock | |
737 : u_loop->_head->in(LoopNode::EntryControl); | |
738 } | |
739 | |
740 | |
741 //------------------------------split_if_with_blocks_post---------------------- | |
742 // Do the real work in a non-recursive function. CFG hackery wants to be | |
743 // in the post-order, so it can dirty the I-DOM info and not use the dirtied | |
744 // info. | |
745 void PhaseIdealLoop::split_if_with_blocks_post( Node *n ) { | |
746 | |
747 // Cloning Cmp through Phi's involves the split-if transform. | |
748 // FastLock is not used by an If | |
749 if( n->is_Cmp() && !n->is_FastLock() ) { | |
750 if( C->unique() > 35000 ) return; // Method too big | |
751 | |
752 // Do not do 'split-if' if irreducible loops are present. | |
753 if( _has_irreducible_loops ) | |
754 return; | |
755 | |
756 Node *n_ctrl = get_ctrl(n); | |
757 // Determine if the Node has inputs from some local Phi. | |
758 // Returns the block to clone thru. | |
759 Node *n_blk = has_local_phi_input( n ); | |
760 if( n_blk != n_ctrl ) return; | |
761 | |
762 if( merge_point_too_heavy(C, n_ctrl) ) | |
763 return; | |
764 | |
765 if( n->outcnt() != 1 ) return; // Multiple bool's from 1 compare? | |
766 Node *bol = n->unique_out(); | |
767 assert( bol->is_Bool(), "expect a bool here" ); | |
768 if( bol->outcnt() != 1 ) return;// Multiple branches from 1 compare? | |
769 Node *iff = bol->unique_out(); | |
770 | |
771 // Check some safety conditions | |
772 if( iff->is_If() ) { // Classic split-if? | |
773 if( iff->in(0) != n_ctrl ) return; // Compare must be in same blk as if | |
774 } else if (iff->is_CMove()) { // Trying to split-up a CMOVE | |
775 if( get_ctrl(iff->in(2)) == n_ctrl || | |
776 get_ctrl(iff->in(3)) == n_ctrl ) | |
777 return; // Inputs not yet split-up | |
778 if ( get_loop(n_ctrl) != get_loop(get_ctrl(iff)) ) { | |
779 return; // Loop-invar test gates loop-varying CMOVE | |
780 } | |
781 } else { | |
782 return; // some other kind of node, such as an Allocate | |
783 } | |
784 | |
785 // Do not do 'split-if' if some paths are dead. First do dead code | |
786 // elimination and then see if its still profitable. | |
787 for( uint i = 1; i < n_ctrl->req(); i++ ) | |
788 if( n_ctrl->in(i) == C->top() ) | |
789 return; | |
790 | |
791 // When is split-if profitable? Every 'win' on means some control flow | |
792 // goes dead, so it's almost always a win. | |
793 int policy = 0; | |
794 // If trying to do a 'Split-If' at the loop head, it is only | |
795 // profitable if the cmp folds up on BOTH paths. Otherwise we | |
796 // risk peeling a loop forever. | |
797 | |
798 // CNC - Disabled for now. Requires careful handling of loop | |
799 // body selection for the cloned code. Also, make sure we check | |
800 // for any input path not being in the same loop as n_ctrl. For | |
801 // irreducible loops we cannot check for 'n_ctrl->is_Loop()' | |
802 // because the alternative loop entry points won't be converted | |
803 // into LoopNodes. | |
804 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
805 for( uint j = 1; j < n_ctrl->req(); j++ ) | |
806 if( get_loop(n_ctrl->in(j)) != n_loop ) | |
807 return; | |
808 | |
809 // Check for safety of the merge point. | |
810 if( !merge_point_safe(n_ctrl) ) { | |
811 return; | |
812 } | |
813 | |
814 // Split compare 'n' through the merge point if it is profitable | |
815 Node *phi = split_thru_phi( n, n_ctrl, policy ); | |
816 if( !phi ) return; | |
817 | |
818 // Found a Phi to split thru! | |
819 // Replace 'n' with the new phi | |
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820 _igvn.replace_node( n, phi ); |
0 | 821 |
822 // Now split the bool up thru the phi | |
823 Node *bolphi = split_thru_phi( bol, n_ctrl, -1 ); | |
1621
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824 _igvn.replace_node( bol, bolphi ); |
0 | 825 assert( iff->in(1) == bolphi, "" ); |
826 if( bolphi->Value(&_igvn)->singleton() ) | |
827 return; | |
828 | |
829 // Conditional-move? Must split up now | |
830 if( !iff->is_If() ) { | |
831 Node *cmovphi = split_thru_phi( iff, n_ctrl, -1 ); | |
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832 _igvn.replace_node( iff, cmovphi ); |
0 | 833 return; |
834 } | |
835 | |
836 // Now split the IF | |
837 do_split_if( iff ); | |
838 return; | |
839 } | |
840 | |
841 // Check for an IF ready to split; one that has its | |
842 // condition codes input coming from a Phi at the block start. | |
843 int n_op = n->Opcode(); | |
844 | |
845 // Check for an IF being dominated by another IF same test | |
846 if( n_op == Op_If ) { | |
847 Node *bol = n->in(1); | |
848 uint max = bol->outcnt(); | |
849 // Check for same test used more than once? | |
850 if( n_op == Op_If && max > 1 && bol->is_Bool() ) { | |
851 // Search up IDOMs to see if this IF is dominated. | |
852 Node *cutoff = get_ctrl(bol); | |
853 | |
854 // Now search up IDOMs till cutoff, looking for a dominating test | |
855 Node *prevdom = n; | |
856 Node *dom = idom(prevdom); | |
857 while( dom != cutoff ) { | |
858 if( dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom ) { | |
859 // Replace the dominated test with an obvious true or false. | |
860 // Place it on the IGVN worklist for later cleanup. | |
861 C->set_major_progress(); | |
862 dominated_by( prevdom, n ); | |
863 #ifndef PRODUCT | |
864 if( VerifyLoopOptimizations ) verify(); | |
865 #endif | |
866 return; | |
867 } | |
868 prevdom = dom; | |
869 dom = idom(prevdom); | |
870 } | |
871 } | |
872 } | |
873 | |
874 // See if a shared loop-varying computation has no loop-varying uses. | |
875 // Happens if something is only used for JVM state in uncommon trap exits, | |
876 // like various versions of induction variable+offset. Clone the | |
877 // computation per usage to allow it to sink out of the loop. | |
878 if (has_ctrl(n) && !n->in(0)) {// n not dead and has no control edge (can float about) | |
879 Node *n_ctrl = get_ctrl(n); | |
880 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
881 if( n_loop != _ltree_root ) { | |
882 DUIterator_Fast imax, i = n->fast_outs(imax); | |
883 for (; i < imax; i++) { | |
884 Node* u = n->fast_out(i); | |
885 if( !has_ctrl(u) ) break; // Found control user | |
886 IdealLoopTree *u_loop = get_loop(get_ctrl(u)); | |
887 if( u_loop == n_loop ) break; // Found loop-varying use | |
888 if( n_loop->is_member( u_loop ) ) break; // Found use in inner loop | |
889 if( u->Opcode() == Op_Opaque1 ) break; // Found loop limit, bugfix for 4677003 | |
890 } | |
891 bool did_break = (i < imax); // Did we break out of the previous loop? | |
892 if (!did_break && n->outcnt() > 1) { // All uses in outer loops! | |
893 Node *late_load_ctrl; | |
894 if (n->is_Load()) { | |
895 // If n is a load, get and save the result from get_late_ctrl(), | |
896 // to be later used in calculating the control for n's clones. | |
897 clear_dom_lca_tags(); | |
898 late_load_ctrl = get_late_ctrl(n, n_ctrl); | |
899 } | |
900 // If n is a load, and the late control is the same as the current | |
901 // control, then the cloning of n is a pointless exercise, because | |
902 // GVN will ensure that we end up where we started. | |
903 if (!n->is_Load() || late_load_ctrl != n_ctrl) { | |
904 for (DUIterator_Last jmin, j = n->last_outs(jmin); j >= jmin; ) { | |
905 Node *u = n->last_out(j); // Clone private computation per use | |
906 _igvn.hash_delete(u); | |
907 _igvn._worklist.push(u); | |
908 Node *x = n->clone(); // Clone computation | |
909 Node *x_ctrl = NULL; | |
910 if( u->is_Phi() ) { | |
911 // Replace all uses of normal nodes. Replace Phi uses | |
605 | 912 // individually, so the separate Nodes can sink down |
0 | 913 // different paths. |
914 uint k = 1; | |
915 while( u->in(k) != n ) k++; | |
916 u->set_req( k, x ); | |
917 // x goes next to Phi input path | |
918 x_ctrl = u->in(0)->in(k); | |
919 --j; | |
920 } else { // Normal use | |
921 // Replace all uses | |
922 for( uint k = 0; k < u->req(); k++ ) { | |
923 if( u->in(k) == n ) { | |
924 u->set_req( k, x ); | |
925 --j; | |
926 } | |
927 } | |
928 x_ctrl = get_ctrl(u); | |
929 } | |
930 | |
931 // Find control for 'x' next to use but not inside inner loops. | |
932 // For inner loop uses get the preheader area. | |
933 x_ctrl = place_near_use(x_ctrl); | |
934 | |
935 if (n->is_Load()) { | |
936 // For loads, add a control edge to a CFG node outside of the loop | |
937 // to force them to not combine and return back inside the loop | |
938 // during GVN optimization (4641526). | |
939 // | |
940 // Because we are setting the actual control input, factor in | |
941 // the result from get_late_ctrl() so we respect any | |
942 // anti-dependences. (6233005). | |
943 x_ctrl = dom_lca(late_load_ctrl, x_ctrl); | |
944 | |
945 // Don't allow the control input to be a CFG splitting node. | |
946 // Such nodes should only have ProjNodes as outs, e.g. IfNode | |
947 // should only have IfTrueNode and IfFalseNode (4985384). | |
948 x_ctrl = find_non_split_ctrl(x_ctrl); | |
949 assert(dom_depth(n_ctrl) <= dom_depth(x_ctrl), "n is later than its clone"); | |
950 | |
951 x->set_req(0, x_ctrl); | |
952 } | |
953 register_new_node(x, x_ctrl); | |
954 | |
955 // Some institutional knowledge is needed here: 'x' is | |
956 // yanked because if the optimizer runs GVN on it all the | |
957 // cloned x's will common up and undo this optimization and | |
958 // be forced back in the loop. This is annoying because it | |
959 // makes +VerifyOpto report false-positives on progress. I | |
960 // tried setting control edges on the x's to force them to | |
961 // not combine, but the matching gets worried when it tries | |
962 // to fold a StoreP and an AddP together (as part of an | |
963 // address expression) and the AddP and StoreP have | |
964 // different controls. | |
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965 if( !x->is_Load() && !x->is_DecodeN() ) _igvn._worklist.yank(x); |
0 | 966 } |
967 _igvn.remove_dead_node(n); | |
968 } | |
969 } | |
970 } | |
971 } | |
972 | |
973 // Check for Opaque2's who's loop has disappeared - who's input is in the | |
974 // same loop nest as their output. Remove 'em, they are no longer useful. | |
975 if( n_op == Op_Opaque2 && | |
976 n->in(1) != NULL && | |
977 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) { | |
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978 _igvn.replace_node( n, n->in(1) ); |
0 | 979 } |
980 } | |
981 | |
982 //------------------------------split_if_with_blocks--------------------------- | |
983 // Check for aggressive application of 'split-if' optimization, | |
984 // using basic block level info. | |
985 void PhaseIdealLoop::split_if_with_blocks( VectorSet &visited, Node_Stack &nstack ) { | |
986 Node *n = C->root(); | |
987 visited.set(n->_idx); // first, mark node as visited | |
988 // Do pre-visit work for root | |
989 n = split_if_with_blocks_pre( n ); | |
990 uint cnt = n->outcnt(); | |
991 uint i = 0; | |
992 while (true) { | |
993 // Visit all children | |
994 if (i < cnt) { | |
995 Node* use = n->raw_out(i); | |
996 ++i; | |
997 if (use->outcnt() != 0 && !visited.test_set(use->_idx)) { | |
998 // Now do pre-visit work for this use | |
999 use = split_if_with_blocks_pre( use ); | |
1000 nstack.push(n, i); // Save parent and next use's index. | |
1001 n = use; // Process all children of current use. | |
1002 cnt = use->outcnt(); | |
1003 i = 0; | |
1004 } | |
1005 } | |
1006 else { | |
1007 // All of n's children have been processed, complete post-processing. | |
1008 if (cnt != 0 && !n->is_Con()) { | |
1009 assert(has_node(n), "no dead nodes"); | |
1010 split_if_with_blocks_post( n ); | |
1011 } | |
1012 if (nstack.is_empty()) { | |
1013 // Finished all nodes on stack. | |
1014 break; | |
1015 } | |
1016 // Get saved parent node and next use's index. Visit the rest of uses. | |
1017 n = nstack.node(); | |
1018 cnt = n->outcnt(); | |
1019 i = nstack.index(); | |
1020 nstack.pop(); | |
1021 } | |
1022 } | |
1023 } | |
1024 | |
1025 | |
1026 //============================================================================= | |
1027 // | |
1028 // C L O N E A L O O P B O D Y | |
1029 // | |
1030 | |
1031 //------------------------------clone_iff-------------------------------------- | |
1032 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
1033 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
1034 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
1035 // through the Phi recursively, and return a Bool. | |
1036 BoolNode *PhaseIdealLoop::clone_iff( PhiNode *phi, IdealLoopTree *loop ) { | |
1037 | |
1038 // Convert this Phi into a Phi merging Bools | |
1039 uint i; | |
1040 for( i = 1; i < phi->req(); i++ ) { | |
1041 Node *b = phi->in(i); | |
1042 if( b->is_Phi() ) { | |
1043 _igvn.hash_delete(phi); | |
1044 _igvn._worklist.push(phi); | |
1045 phi->set_req(i, clone_iff( b->as_Phi(), loop )); | |
1046 } else { | |
1047 assert( b->is_Bool(), "" ); | |
1048 } | |
1049 } | |
1050 | |
1051 Node *sample_bool = phi->in(1); | |
1052 Node *sample_cmp = sample_bool->in(1); | |
1053 | |
1054 // Make Phis to merge the Cmp's inputs. | |
1055 int size = phi->in(0)->req(); | |
1056 PhiNode *phi1 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1057 PhiNode *phi2 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1058 for( i = 1; i < phi->req(); i++ ) { | |
1059 Node *n1 = phi->in(i)->in(1)->in(1); | |
1060 Node *n2 = phi->in(i)->in(1)->in(2); | |
1061 phi1->set_req( i, n1 ); | |
1062 phi2->set_req( i, n2 ); | |
1063 phi1->set_type( phi1->type()->meet(n1->bottom_type()) ); | |
1064 phi2->set_type( phi2->type()->meet(n2->bottom_type()) ); | |
1065 } | |
1066 // See if these Phis have been made before. | |
1067 // Register with optimizer | |
1068 Node *hit1 = _igvn.hash_find_insert(phi1); | |
1069 if( hit1 ) { // Hit, toss just made Phi | |
1070 _igvn.remove_dead_node(phi1); // Remove new phi | |
1071 assert( hit1->is_Phi(), "" ); | |
1072 phi1 = (PhiNode*)hit1; // Use existing phi | |
1073 } else { // Miss | |
1074 _igvn.register_new_node_with_optimizer(phi1); | |
1075 } | |
1076 Node *hit2 = _igvn.hash_find_insert(phi2); | |
1077 if( hit2 ) { // Hit, toss just made Phi | |
1078 _igvn.remove_dead_node(phi2); // Remove new phi | |
1079 assert( hit2->is_Phi(), "" ); | |
1080 phi2 = (PhiNode*)hit2; // Use existing phi | |
1081 } else { // Miss | |
1082 _igvn.register_new_node_with_optimizer(phi2); | |
1083 } | |
1084 // Register Phis with loop/block info | |
1085 set_ctrl(phi1, phi->in(0)); | |
1086 set_ctrl(phi2, phi->in(0)); | |
1087 // Make a new Cmp | |
1088 Node *cmp = sample_cmp->clone(); | |
1089 cmp->set_req( 1, phi1 ); | |
1090 cmp->set_req( 2, phi2 ); | |
1091 _igvn.register_new_node_with_optimizer(cmp); | |
1092 set_ctrl(cmp, phi->in(0)); | |
1093 | |
1094 // Make a new Bool | |
1095 Node *b = sample_bool->clone(); | |
1096 b->set_req(1,cmp); | |
1097 _igvn.register_new_node_with_optimizer(b); | |
1098 set_ctrl(b, phi->in(0)); | |
1099 | |
1100 assert( b->is_Bool(), "" ); | |
1101 return (BoolNode*)b; | |
1102 } | |
1103 | |
1104 //------------------------------clone_bool------------------------------------- | |
1105 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
1106 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
1107 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
1108 // through the Phi recursively, and return a Bool. | |
1109 CmpNode *PhaseIdealLoop::clone_bool( PhiNode *phi, IdealLoopTree *loop ) { | |
1110 uint i; | |
1111 // Convert this Phi into a Phi merging Bools | |
1112 for( i = 1; i < phi->req(); i++ ) { | |
1113 Node *b = phi->in(i); | |
1114 if( b->is_Phi() ) { | |
1115 _igvn.hash_delete(phi); | |
1116 _igvn._worklist.push(phi); | |
1117 phi->set_req(i, clone_bool( b->as_Phi(), loop )); | |
1118 } else { | |
1119 assert( b->is_Cmp() || b->is_top(), "inputs are all Cmp or TOP" ); | |
1120 } | |
1121 } | |
1122 | |
1123 Node *sample_cmp = phi->in(1); | |
1124 | |
1125 // Make Phis to merge the Cmp's inputs. | |
1126 int size = phi->in(0)->req(); | |
1127 PhiNode *phi1 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1128 PhiNode *phi2 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
1129 for( uint j = 1; j < phi->req(); j++ ) { | |
1130 Node *cmp_top = phi->in(j); // Inputs are all Cmp or TOP | |
1131 Node *n1, *n2; | |
1132 if( cmp_top->is_Cmp() ) { | |
1133 n1 = cmp_top->in(1); | |
1134 n2 = cmp_top->in(2); | |
1135 } else { | |
1136 n1 = n2 = cmp_top; | |
1137 } | |
1138 phi1->set_req( j, n1 ); | |
1139 phi2->set_req( j, n2 ); | |
1140 phi1->set_type( phi1->type()->meet(n1->bottom_type()) ); | |
1141 phi2->set_type( phi2->type()->meet(n2->bottom_type()) ); | |
1142 } | |
1143 | |
1144 // See if these Phis have been made before. | |
1145 // Register with optimizer | |
1146 Node *hit1 = _igvn.hash_find_insert(phi1); | |
1147 if( hit1 ) { // Hit, toss just made Phi | |
1148 _igvn.remove_dead_node(phi1); // Remove new phi | |
1149 assert( hit1->is_Phi(), "" ); | |
1150 phi1 = (PhiNode*)hit1; // Use existing phi | |
1151 } else { // Miss | |
1152 _igvn.register_new_node_with_optimizer(phi1); | |
1153 } | |
1154 Node *hit2 = _igvn.hash_find_insert(phi2); | |
1155 if( hit2 ) { // Hit, toss just made Phi | |
1156 _igvn.remove_dead_node(phi2); // Remove new phi | |
1157 assert( hit2->is_Phi(), "" ); | |
1158 phi2 = (PhiNode*)hit2; // Use existing phi | |
1159 } else { // Miss | |
1160 _igvn.register_new_node_with_optimizer(phi2); | |
1161 } | |
1162 // Register Phis with loop/block info | |
1163 set_ctrl(phi1, phi->in(0)); | |
1164 set_ctrl(phi2, phi->in(0)); | |
1165 // Make a new Cmp | |
1166 Node *cmp = sample_cmp->clone(); | |
1167 cmp->set_req( 1, phi1 ); | |
1168 cmp->set_req( 2, phi2 ); | |
1169 _igvn.register_new_node_with_optimizer(cmp); | |
1170 set_ctrl(cmp, phi->in(0)); | |
1171 | |
1172 assert( cmp->is_Cmp(), "" ); | |
1173 return (CmpNode*)cmp; | |
1174 } | |
1175 | |
1176 //------------------------------sink_use--------------------------------------- | |
1177 // If 'use' was in the loop-exit block, it now needs to be sunk | |
1178 // below the post-loop merge point. | |
1179 void PhaseIdealLoop::sink_use( Node *use, Node *post_loop ) { | |
1180 if (!use->is_CFG() && get_ctrl(use) == post_loop->in(2)) { | |
1181 set_ctrl(use, post_loop); | |
1182 for (DUIterator j = use->outs(); use->has_out(j); j++) | |
1183 sink_use(use->out(j), post_loop); | |
1184 } | |
1185 } | |
1186 | |
1187 //------------------------------clone_loop------------------------------------- | |
1188 // | |
1189 // C L O N E A L O O P B O D Y | |
1190 // | |
1191 // This is the basic building block of the loop optimizations. It clones an | |
1192 // entire loop body. It makes an old_new loop body mapping; with this mapping | |
1193 // you can find the new-loop equivalent to an old-loop node. All new-loop | |
1194 // nodes are exactly equal to their old-loop counterparts, all edges are the | |
1195 // same. All exits from the old-loop now have a RegionNode that merges the | |
1196 // equivalent new-loop path. This is true even for the normal "loop-exit" | |
1197 // condition. All uses of loop-invariant old-loop values now come from (one | |
1198 // or more) Phis that merge their new-loop equivalents. | |
1199 // | |
1200 // This operation leaves the graph in an illegal state: there are two valid | |
1201 // control edges coming from the loop pre-header to both loop bodies. I'll | |
1202 // definitely have to hack the graph after running this transform. | |
1203 // | |
1204 // From this building block I will further edit edges to perform loop peeling | |
1205 // or loop unrolling or iteration splitting (Range-Check-Elimination), etc. | |
1206 // | |
1207 // Parameter side_by_size_idom: | |
1208 // When side_by_size_idom is NULL, the dominator tree is constructed for | |
1209 // the clone loop to dominate the original. Used in construction of | |
1210 // pre-main-post loop sequence. | |
1211 // When nonnull, the clone and original are side-by-side, both are | |
1212 // dominated by the side_by_side_idom node. Used in construction of | |
1213 // unswitched loops. | |
1214 void PhaseIdealLoop::clone_loop( IdealLoopTree *loop, Node_List &old_new, int dd, | |
1215 Node* side_by_side_idom) { | |
1216 | |
1217 // Step 1: Clone the loop body. Make the old->new mapping. | |
1218 uint i; | |
1219 for( i = 0; i < loop->_body.size(); i++ ) { | |
1220 Node *old = loop->_body.at(i); | |
1221 Node *nnn = old->clone(); | |
1222 old_new.map( old->_idx, nnn ); | |
1223 _igvn.register_new_node_with_optimizer(nnn); | |
1224 } | |
1225 | |
1226 | |
1227 // Step 2: Fix the edges in the new body. If the old input is outside the | |
1228 // loop use it. If the old input is INside the loop, use the corresponding | |
1229 // new node instead. | |
1230 for( i = 0; i < loop->_body.size(); i++ ) { | |
1231 Node *old = loop->_body.at(i); | |
1232 Node *nnn = old_new[old->_idx]; | |
1233 // Fix CFG/Loop controlling the new node | |
1234 if (has_ctrl(old)) { | |
1235 set_ctrl(nnn, old_new[get_ctrl(old)->_idx]); | |
1236 } else { | |
1237 set_loop(nnn, loop->_parent); | |
1238 if (old->outcnt() > 0) { | |
1239 set_idom( nnn, old_new[idom(old)->_idx], dd ); | |
1240 } | |
1241 } | |
1242 // Correct edges to the new node | |
1243 for( uint j = 0; j < nnn->req(); j++ ) { | |
1244 Node *n = nnn->in(j); | |
1245 if( n ) { | |
1246 IdealLoopTree *old_in_loop = get_loop( has_ctrl(n) ? get_ctrl(n) : n ); | |
1247 if( loop->is_member( old_in_loop ) ) | |
1248 nnn->set_req(j, old_new[n->_idx]); | |
1249 } | |
1250 } | |
1251 _igvn.hash_find_insert(nnn); | |
1252 } | |
1253 Node *newhead = old_new[loop->_head->_idx]; | |
1254 set_idom(newhead, newhead->in(LoopNode::EntryControl), dd); | |
1255 | |
1256 | |
1257 // Step 3: Now fix control uses. Loop varying control uses have already | |
1258 // been fixed up (as part of all input edges in Step 2). Loop invariant | |
1259 // control uses must be either an IfFalse or an IfTrue. Make a merge | |
1260 // point to merge the old and new IfFalse/IfTrue nodes; make the use | |
1261 // refer to this. | |
1262 ResourceArea *area = Thread::current()->resource_area(); | |
1263 Node_List worklist(area); | |
1264 uint new_counter = C->unique(); | |
1265 for( i = 0; i < loop->_body.size(); i++ ) { | |
1266 Node* old = loop->_body.at(i); | |
1267 if( !old->is_CFG() ) continue; | |
1268 Node* nnn = old_new[old->_idx]; | |
1269 | |
1270 // Copy uses to a worklist, so I can munge the def-use info | |
1271 // with impunity. | |
1272 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++) | |
1273 worklist.push(old->fast_out(j)); | |
1274 | |
1275 while( worklist.size() ) { // Visit all uses | |
1276 Node *use = worklist.pop(); | |
1277 if (!has_node(use)) continue; // Ignore dead nodes | |
1278 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use ); | |
1279 if( !loop->is_member( use_loop ) && use->is_CFG() ) { | |
1280 // Both OLD and USE are CFG nodes here. | |
1281 assert( use->is_Proj(), "" ); | |
1282 | |
1283 // Clone the loop exit control projection | |
1284 Node *newuse = use->clone(); | |
1285 newuse->set_req(0,nnn); | |
1286 _igvn.register_new_node_with_optimizer(newuse); | |
1287 set_loop(newuse, use_loop); | |
1288 set_idom(newuse, nnn, dom_depth(nnn) + 1 ); | |
1289 | |
1290 // We need a Region to merge the exit from the peeled body and the | |
1291 // exit from the old loop body. | |
1292 RegionNode *r = new (C, 3) RegionNode(3); | |
1293 // Map the old use to the new merge point | |
1294 old_new.map( use->_idx, r ); | |
1295 uint dd_r = MIN2(dom_depth(newuse),dom_depth(use)); | |
1296 assert( dd_r >= dom_depth(dom_lca(newuse,use)), "" ); | |
1297 | |
1298 // The original user of 'use' uses 'r' instead. | |
1299 for (DUIterator_Last lmin, l = use->last_outs(lmin); l >= lmin;) { | |
1300 Node* useuse = use->last_out(l); | |
1301 _igvn.hash_delete(useuse); | |
1302 _igvn._worklist.push(useuse); | |
1303 uint uses_found = 0; | |
1304 if( useuse->in(0) == use ) { | |
1305 useuse->set_req(0, r); | |
1306 uses_found++; | |
1307 if( useuse->is_CFG() ) { | |
1308 assert( dom_depth(useuse) > dd_r, "" ); | |
1309 set_idom(useuse, r, dom_depth(useuse)); | |
1310 } | |
1311 } | |
1312 for( uint k = 1; k < useuse->req(); k++ ) { | |
1313 if( useuse->in(k) == use ) { | |
1314 useuse->set_req(k, r); | |
1315 uses_found++; | |
1316 } | |
1317 } | |
1318 l -= uses_found; // we deleted 1 or more copies of this edge | |
1319 } | |
1320 | |
1321 // Now finish up 'r' | |
1322 r->set_req( 1, newuse ); | |
1323 r->set_req( 2, use ); | |
1324 _igvn.register_new_node_with_optimizer(r); | |
1325 set_loop(r, use_loop); | |
1326 set_idom(r, !side_by_side_idom ? newuse->in(0) : side_by_side_idom, dd_r); | |
1327 } // End of if a loop-exit test | |
1328 } | |
1329 } | |
1330 | |
1331 // Step 4: If loop-invariant use is not control, it must be dominated by a | |
1332 // loop exit IfFalse/IfTrue. Find "proper" loop exit. Make a Region | |
1333 // there if needed. Make a Phi there merging old and new used values. | |
1334 Node_List *split_if_set = NULL; | |
1335 Node_List *split_bool_set = NULL; | |
1336 Node_List *split_cex_set = NULL; | |
1337 for( i = 0; i < loop->_body.size(); i++ ) { | |
1338 Node* old = loop->_body.at(i); | |
1339 Node* nnn = old_new[old->_idx]; | |
1340 // Copy uses to a worklist, so I can munge the def-use info | |
1341 // with impunity. | |
1342 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++) | |
1343 worklist.push(old->fast_out(j)); | |
1344 | |
1345 while( worklist.size() ) { | |
1346 Node *use = worklist.pop(); | |
1347 if (!has_node(use)) continue; // Ignore dead nodes | |
1348 if (use->in(0) == C->top()) continue; | |
1349 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use ); | |
1350 // Check for data-use outside of loop - at least one of OLD or USE | |
1351 // must not be a CFG node. | |
1352 if( !loop->is_member( use_loop ) && (!old->is_CFG() || !use->is_CFG())) { | |
1353 | |
1354 // If the Data use is an IF, that means we have an IF outside of the | |
1355 // loop that is switching on a condition that is set inside of the | |
1356 // loop. Happens if people set a loop-exit flag; then test the flag | |
1357 // in the loop to break the loop, then test is again outside of the | |
1358 // loop to determine which way the loop exited. | |
1359 if( use->is_If() || use->is_CMove() ) { | |
1360 // Since this code is highly unlikely, we lazily build the worklist | |
1361 // of such Nodes to go split. | |
1362 if( !split_if_set ) | |
1363 split_if_set = new Node_List(area); | |
1364 split_if_set->push(use); | |
1365 } | |
1366 if( use->is_Bool() ) { | |
1367 if( !split_bool_set ) | |
1368 split_bool_set = new Node_List(area); | |
1369 split_bool_set->push(use); | |
1370 } | |
1371 if( use->Opcode() == Op_CreateEx ) { | |
1372 if( !split_cex_set ) | |
1373 split_cex_set = new Node_List(area); | |
1374 split_cex_set->push(use); | |
1375 } | |
1376 | |
1377 | |
1378 // Get "block" use is in | |
1379 uint idx = 0; | |
1380 while( use->in(idx) != old ) idx++; | |
1381 Node *prev = use->is_CFG() ? use : get_ctrl(use); | |
1382 assert( !loop->is_member( get_loop( prev ) ), "" ); | |
1383 Node *cfg = prev->_idx >= new_counter | |
1384 ? prev->in(2) | |
1385 : idom(prev); | |
1386 if( use->is_Phi() ) // Phi use is in prior block | |
1387 cfg = prev->in(idx); // NOT in block of Phi itself | |
1388 if (cfg->is_top()) { // Use is dead? | |
1389 _igvn.hash_delete(use); | |
1390 _igvn._worklist.push(use); | |
1391 use->set_req(idx, C->top()); | |
1392 continue; | |
1393 } | |
1394 | |
1395 while( !loop->is_member( get_loop( cfg ) ) ) { | |
1396 prev = cfg; | |
1397 cfg = cfg->_idx >= new_counter ? cfg->in(2) : idom(cfg); | |
1398 } | |
1399 // If the use occurs after merging several exits from the loop, then | |
1400 // old value must have dominated all those exits. Since the same old | |
1401 // value was used on all those exits we did not need a Phi at this | |
1402 // merge point. NOW we do need a Phi here. Each loop exit value | |
1403 // is now merged with the peeled body exit; each exit gets its own | |
1404 // private Phi and those Phis need to be merged here. | |
1405 Node *phi; | |
1406 if( prev->is_Region() ) { | |
1407 if( idx == 0 ) { // Updating control edge? | |
1408 phi = prev; // Just use existing control | |
1409 } else { // Else need a new Phi | |
1410 phi = PhiNode::make( prev, old ); | |
1411 // Now recursively fix up the new uses of old! | |
1412 for( uint i = 1; i < prev->req(); i++ ) { | |
1413 worklist.push(phi); // Onto worklist once for each 'old' input | |
1414 } | |
1415 } | |
1416 } else { | |
1417 // Get new RegionNode merging old and new loop exits | |
1418 prev = old_new[prev->_idx]; | |
1419 assert( prev, "just made this in step 7" ); | |
1420 if( idx == 0 ) { // Updating control edge? | |
1421 phi = prev; // Just use existing control | |
1422 } else { // Else need a new Phi | |
1423 // Make a new Phi merging data values properly | |
1424 phi = PhiNode::make( prev, old ); | |
1425 phi->set_req( 1, nnn ); | |
1426 } | |
1427 } | |
1428 // If inserting a new Phi, check for prior hits | |
1429 if( idx != 0 ) { | |
1430 Node *hit = _igvn.hash_find_insert(phi); | |
1431 if( hit == NULL ) { | |
1432 _igvn.register_new_node_with_optimizer(phi); // Register new phi | |
1433 } else { // or | |
1434 // Remove the new phi from the graph and use the hit | |
1435 _igvn.remove_dead_node(phi); | |
1436 phi = hit; // Use existing phi | |
1437 } | |
1438 set_ctrl(phi, prev); | |
1439 } | |
1440 // Make 'use' use the Phi instead of the old loop body exit value | |
1441 _igvn.hash_delete(use); | |
1442 _igvn._worklist.push(use); | |
1443 use->set_req(idx, phi); | |
1444 if( use->_idx >= new_counter ) { // If updating new phis | |
1445 // Not needed for correctness, but prevents a weak assert | |
1446 // in AddPNode from tripping (when we end up with different | |
1447 // base & derived Phis that will become the same after | |
1448 // IGVN does CSE). | |
1449 Node *hit = _igvn.hash_find_insert(use); | |
1450 if( hit ) // Go ahead and re-hash for hits. | |
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6677629: PhaseIterGVN::subsume_node() should call hash_delete() and add_users_to_worklist()
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1552
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|
1451 _igvn.replace_node( use, hit ); |
0 | 1452 } |
1453 | |
1454 // If 'use' was in the loop-exit block, it now needs to be sunk | |
1455 // below the post-loop merge point. | |
1456 sink_use( use, prev ); | |
1457 } | |
1458 } | |
1459 } | |
1460 | |
1461 // Check for IFs that need splitting/cloning. Happens if an IF outside of | |
1462 // the loop uses a condition set in the loop. The original IF probably | |
1463 // takes control from one or more OLD Regions (which in turn get from NEW | |
1464 // Regions). In any case, there will be a set of Phis for each merge point | |
1465 // from the IF up to where the original BOOL def exists the loop. | |
1466 if( split_if_set ) { | |
1467 while( split_if_set->size() ) { | |
1468 Node *iff = split_if_set->pop(); | |
1469 if( iff->in(1)->is_Phi() ) { | |
1470 BoolNode *b = clone_iff( iff->in(1)->as_Phi(), loop ); | |
1471 _igvn.hash_delete(iff); | |
1472 _igvn._worklist.push(iff); | |
1473 iff->set_req(1, b); | |
1474 } | |
1475 } | |
1476 } | |
1477 if( split_bool_set ) { | |
1478 while( split_bool_set->size() ) { | |
1479 Node *b = split_bool_set->pop(); | |
1480 Node *phi = b->in(1); | |
1481 assert( phi->is_Phi(), "" ); | |
1482 CmpNode *cmp = clone_bool( (PhiNode*)phi, loop ); | |
1483 _igvn.hash_delete(b); | |
1484 _igvn._worklist.push(b); | |
1485 b->set_req(1, cmp); | |
1486 } | |
1487 } | |
1488 if( split_cex_set ) { | |
1489 while( split_cex_set->size() ) { | |
1490 Node *b = split_cex_set->pop(); | |
1491 assert( b->in(0)->is_Region(), "" ); | |
1492 assert( b->in(1)->is_Phi(), "" ); | |
1493 assert( b->in(0)->in(0) == b->in(1)->in(0), "" ); | |
1494 split_up( b, b->in(0), NULL ); | |
1495 } | |
1496 } | |
1497 | |
1498 } | |
1499 | |
1500 | |
1501 //---------------------- stride_of_possible_iv ------------------------------------- | |
1502 // Looks for an iff/bool/comp with one operand of the compare | |
1503 // being a cycle involving an add and a phi, | |
1504 // with an optional truncation (left-shift followed by a right-shift) | |
1505 // of the add. Returns zero if not an iv. | |
1506 int PhaseIdealLoop::stride_of_possible_iv(Node* iff) { | |
1507 Node* trunc1 = NULL; | |
1508 Node* trunc2 = NULL; | |
1509 const TypeInt* ttype = NULL; | |
1510 if (!iff->is_If() || iff->in(1) == NULL || !iff->in(1)->is_Bool()) { | |
1511 return 0; | |
1512 } | |
1513 BoolNode* bl = iff->in(1)->as_Bool(); | |
1514 Node* cmp = bl->in(1); | |
1515 if (!cmp || cmp->Opcode() != Op_CmpI && cmp->Opcode() != Op_CmpU) { | |
1516 return 0; | |
1517 } | |
1518 // Must have an invariant operand | |
1519 if (is_member(get_loop(iff), get_ctrl(cmp->in(2)))) { | |
1520 return 0; | |
1521 } | |
1522 Node* add2 = NULL; | |
1523 Node* cmp1 = cmp->in(1); | |
1524 if (cmp1->is_Phi()) { | |
1525 // (If (Bool (CmpX phi:(Phi ...(Optional-trunc(AddI phi add2))) ))) | |
1526 Node* phi = cmp1; | |
1527 for (uint i = 1; i < phi->req(); i++) { | |
1528 Node* in = phi->in(i); | |
1529 Node* add = CountedLoopNode::match_incr_with_optional_truncation(in, | |
1530 &trunc1, &trunc2, &ttype); | |
1531 if (add && add->in(1) == phi) { | |
1532 add2 = add->in(2); | |
1533 break; | |
1534 } | |
1535 } | |
1536 } else { | |
1537 // (If (Bool (CmpX addtrunc:(Optional-trunc((AddI (Phi ...addtrunc...) add2)) ))) | |
1538 Node* addtrunc = cmp1; | |
1539 Node* add = CountedLoopNode::match_incr_with_optional_truncation(addtrunc, | |
1540 &trunc1, &trunc2, &ttype); | |
1541 if (add && add->in(1)->is_Phi()) { | |
1542 Node* phi = add->in(1); | |
1543 for (uint i = 1; i < phi->req(); i++) { | |
1544 if (phi->in(i) == addtrunc) { | |
1545 add2 = add->in(2); | |
1546 break; | |
1547 } | |
1548 } | |
1549 } | |
1550 } | |
1551 if (add2 != NULL) { | |
1552 const TypeInt* add2t = _igvn.type(add2)->is_int(); | |
1553 if (add2t->is_con()) { | |
1554 return add2t->get_con(); | |
1555 } | |
1556 } | |
1557 return 0; | |
1558 } | |
1559 | |
1560 | |
1561 //---------------------- stay_in_loop ------------------------------------- | |
1562 // Return the (unique) control output node that's in the loop (if it exists.) | |
1563 Node* PhaseIdealLoop::stay_in_loop( Node* n, IdealLoopTree *loop) { | |
1564 Node* unique = NULL; | |
1565 if (!n) return NULL; | |
1566 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { | |
1567 Node* use = n->fast_out(i); | |
1568 if (!has_ctrl(use) && loop->is_member(get_loop(use))) { | |
1569 if (unique != NULL) { | |
1570 return NULL; | |
1571 } | |
1572 unique = use; | |
1573 } | |
1574 } | |
1575 return unique; | |
1576 } | |
1577 | |
1578 //------------------------------ register_node ------------------------------------- | |
1579 // Utility to register node "n" with PhaseIdealLoop | |
1580 void PhaseIdealLoop::register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth) { | |
1581 _igvn.register_new_node_with_optimizer(n); | |
1582 loop->_body.push(n); | |
1583 if (n->is_CFG()) { | |
1584 set_loop(n, loop); | |
1585 set_idom(n, pred, ddepth); | |
1586 } else { | |
1587 set_ctrl(n, pred); | |
1588 } | |
1589 } | |
1590 | |
1591 //------------------------------ proj_clone ------------------------------------- | |
1592 // Utility to create an if-projection | |
1593 ProjNode* PhaseIdealLoop::proj_clone(ProjNode* p, IfNode* iff) { | |
1594 ProjNode* c = p->clone()->as_Proj(); | |
1595 c->set_req(0, iff); | |
1596 return c; | |
1597 } | |
1598 | |
1599 //------------------------------ short_circuit_if ------------------------------------- | |
1600 // Force the iff control output to be the live_proj | |
1601 Node* PhaseIdealLoop::short_circuit_if(IfNode* iff, ProjNode* live_proj) { | |
1602 int proj_con = live_proj->_con; | |
1603 assert(proj_con == 0 || proj_con == 1, "false or true projection"); | |
1604 Node *con = _igvn.intcon(proj_con); | |
1605 set_ctrl(con, C->root()); | |
1606 if (iff) { | |
1607 iff->set_req(1, con); | |
1608 } | |
1609 return con; | |
1610 } | |
1611 | |
1612 //------------------------------ insert_if_before_proj ------------------------------------- | |
1613 // Insert a new if before an if projection (* - new node) | |
1614 // | |
1615 // before | |
1616 // if(test) | |
1617 // / \ | |
1618 // v v | |
1619 // other-proj proj (arg) | |
1620 // | |
1621 // after | |
1622 // if(test) | |
1623 // / \ | |
1624 // / v | |
1625 // | * proj-clone | |
1626 // v | | |
1627 // other-proj v | |
1628 // * new_if(relop(cmp[IU](left,right))) | |
1629 // / \ | |
1630 // v v | |
1631 // * new-proj proj | |
1632 // (returned) | |
1633 // | |
1634 ProjNode* PhaseIdealLoop::insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj) { | |
1635 IfNode* iff = proj->in(0)->as_If(); | |
1636 IdealLoopTree *loop = get_loop(proj); | |
1637 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj(); | |
1638 int ddepth = dom_depth(proj); | |
1639 | |
1640 _igvn.hash_delete(iff); | |
1641 _igvn._worklist.push(iff); | |
1642 _igvn.hash_delete(proj); | |
1643 _igvn._worklist.push(proj); | |
1644 | |
1645 proj->set_req(0, NULL); // temporary disconnect | |
1646 ProjNode* proj2 = proj_clone(proj, iff); | |
1647 register_node(proj2, loop, iff, ddepth); | |
1648 | |
1649 Node* cmp = Signed ? (Node*) new (C,3)CmpINode(left, right) : (Node*) new (C,3)CmpUNode(left, right); | |
1650 register_node(cmp, loop, proj2, ddepth); | |
1651 | |
1652 BoolNode* bol = new (C,2)BoolNode(cmp, relop); | |
1653 register_node(bol, loop, proj2, ddepth); | |
1654 | |
1655 IfNode* new_if = new (C,2)IfNode(proj2, bol, iff->_prob, iff->_fcnt); | |
1656 register_node(new_if, loop, proj2, ddepth); | |
1657 | |
1658 proj->set_req(0, new_if); // reattach | |
1659 set_idom(proj, new_if, ddepth); | |
1660 | |
1661 ProjNode* new_exit = proj_clone(other_proj, new_if)->as_Proj(); | |
1662 register_node(new_exit, get_loop(other_proj), new_if, ddepth); | |
1663 | |
1664 return new_exit; | |
1665 } | |
1666 | |
1667 //------------------------------ insert_region_before_proj ------------------------------------- | |
1668 // Insert a region before an if projection (* - new node) | |
1669 // | |
1670 // before | |
1671 // if(test) | |
1672 // / | | |
1673 // v | | |
1674 // proj v | |
1675 // other-proj | |
1676 // | |
1677 // after | |
1678 // if(test) | |
1679 // / | | |
1680 // v | | |
1681 // * proj-clone v | |
1682 // | other-proj | |
1683 // v | |
1684 // * new-region | |
1685 // | | |
1686 // v | |
1687 // * dum_if | |
1688 // / \ | |
1689 // v \ | |
1690 // * dum-proj v | |
1691 // proj | |
1692 // | |
1693 RegionNode* PhaseIdealLoop::insert_region_before_proj(ProjNode* proj) { | |
1694 IfNode* iff = proj->in(0)->as_If(); | |
1695 IdealLoopTree *loop = get_loop(proj); | |
1696 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj(); | |
1697 int ddepth = dom_depth(proj); | |
1698 | |
1699 _igvn.hash_delete(iff); | |
1700 _igvn._worklist.push(iff); | |
1701 _igvn.hash_delete(proj); | |
1702 _igvn._worklist.push(proj); | |
1703 | |
1704 proj->set_req(0, NULL); // temporary disconnect | |
1705 ProjNode* proj2 = proj_clone(proj, iff); | |
1706 register_node(proj2, loop, iff, ddepth); | |
1707 | |
1708 RegionNode* reg = new (C,2)RegionNode(2); | |
1709 reg->set_req(1, proj2); | |
1710 register_node(reg, loop, iff, ddepth); | |
1711 | |
1712 IfNode* dum_if = new (C,2)IfNode(reg, short_circuit_if(NULL, proj), iff->_prob, iff->_fcnt); | |
1713 register_node(dum_if, loop, reg, ddepth); | |
1714 | |
1715 proj->set_req(0, dum_if); // reattach | |
1716 set_idom(proj, dum_if, ddepth); | |
1717 | |
1718 ProjNode* dum_proj = proj_clone(other_proj, dum_if); | |
1719 register_node(dum_proj, loop, dum_if, ddepth); | |
1720 | |
1721 return reg; | |
1722 } | |
1723 | |
1724 //------------------------------ insert_cmpi_loop_exit ------------------------------------- | |
1725 // Clone a signed compare loop exit from an unsigned compare and | |
1726 // insert it before the unsigned cmp on the stay-in-loop path. | |
1727 // All new nodes inserted in the dominator tree between the original | |
1728 // if and it's projections. The original if test is replaced with | |
1729 // a constant to force the stay-in-loop path. | |
1730 // | |
1731 // This is done to make sure that the original if and it's projections | |
1732 // still dominate the same set of control nodes, that the ctrl() relation | |
1733 // from data nodes to them is preserved, and that their loop nesting is | |
1734 // preserved. | |
1735 // | |
1736 // before | |
1737 // if(i <u limit) unsigned compare loop exit | |
1738 // / | | |
1739 // v v | |
1740 // exit-proj stay-in-loop-proj | |
1741 // | |
1742 // after | |
1743 // if(stay-in-loop-const) original if | |
1744 // / | | |
1745 // / v | |
1746 // / if(i < limit) new signed test | |
1747 // / / | | |
1748 // / / v | |
1749 // / / if(i <u limit) new cloned unsigned test | |
1750 // / / / | | |
1751 // v v v | | |
1752 // region | | |
1753 // | | | |
1754 // dum-if | | |
1755 // / | | | |
1756 // ether | | | |
1757 // v v | |
1758 // exit-proj stay-in-loop-proj | |
1759 // | |
1760 IfNode* PhaseIdealLoop::insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop) { | |
1761 const bool Signed = true; | |
1762 const bool Unsigned = false; | |
1763 | |
1764 BoolNode* bol = if_cmpu->in(1)->as_Bool(); | |
1765 if (bol->_test._test != BoolTest::lt) return NULL; | |
1766 CmpNode* cmpu = bol->in(1)->as_Cmp(); | |
1767 if (cmpu->Opcode() != Op_CmpU) return NULL; | |
1768 int stride = stride_of_possible_iv(if_cmpu); | |
1769 if (stride == 0) return NULL; | |
1770 | |
1771 ProjNode* lp_continue = stay_in_loop(if_cmpu, loop)->as_Proj(); | |
1772 ProjNode* lp_exit = if_cmpu->proj_out(!lp_continue->is_IfTrue())->as_Proj(); | |
1773 | |
1774 Node* limit = NULL; | |
1775 if (stride > 0) { | |
1776 limit = cmpu->in(2); | |
1777 } else { | |
1778 limit = _igvn.makecon(TypeInt::ZERO); | |
1779 set_ctrl(limit, C->root()); | |
1780 } | |
1781 // Create a new region on the exit path | |
1782 RegionNode* reg = insert_region_before_proj(lp_exit); | |
1783 | |
1784 // Clone the if-cmpu-true-false using a signed compare | |
1785 BoolTest::mask rel_i = stride > 0 ? bol->_test._test : BoolTest::ge; | |
1786 ProjNode* cmpi_exit = insert_if_before_proj(cmpu->in(1), Signed, rel_i, limit, lp_continue); | |
1787 reg->add_req(cmpi_exit); | |
1788 | |
1789 // Clone the if-cmpu-true-false | |
1790 BoolTest::mask rel_u = bol->_test._test; | |
1791 ProjNode* cmpu_exit = insert_if_before_proj(cmpu->in(1), Unsigned, rel_u, cmpu->in(2), lp_continue); | |
1792 reg->add_req(cmpu_exit); | |
1793 | |
1794 // Force original if to stay in loop. | |
1795 short_circuit_if(if_cmpu, lp_continue); | |
1796 | |
1797 return cmpi_exit->in(0)->as_If(); | |
1798 } | |
1799 | |
1800 //------------------------------ remove_cmpi_loop_exit ------------------------------------- | |
1801 // Remove a previously inserted signed compare loop exit. | |
1802 void PhaseIdealLoop::remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop) { | |
1803 Node* lp_proj = stay_in_loop(if_cmp, loop); | |
1804 assert(if_cmp->in(1)->in(1)->Opcode() == Op_CmpI && | |
1805 stay_in_loop(lp_proj, loop)->is_If() && | |
1806 stay_in_loop(lp_proj, loop)->in(1)->in(1)->Opcode() == Op_CmpU, "inserted cmpi before cmpu"); | |
1807 Node *con = _igvn.makecon(lp_proj->is_IfTrue() ? TypeInt::ONE : TypeInt::ZERO); | |
1808 set_ctrl(con, C->root()); | |
1809 if_cmp->set_req(1, con); | |
1810 } | |
1811 | |
1812 //------------------------------ scheduled_nodelist ------------------------------------- | |
1813 // Create a post order schedule of nodes that are in the | |
1814 // "member" set. The list is returned in "sched". | |
1815 // The first node in "sched" is the loop head, followed by | |
1816 // nodes which have no inputs in the "member" set, and then | |
1817 // followed by the nodes that have an immediate input dependence | |
1818 // on a node in "sched". | |
1819 void PhaseIdealLoop::scheduled_nodelist( IdealLoopTree *loop, VectorSet& member, Node_List &sched ) { | |
1820 | |
1821 assert(member.test(loop->_head->_idx), "loop head must be in member set"); | |
1822 Arena *a = Thread::current()->resource_area(); | |
1823 VectorSet visited(a); | |
1824 Node_Stack nstack(a, loop->_body.size()); | |
1825 | |
1826 Node* n = loop->_head; // top of stack is cached in "n" | |
1827 uint idx = 0; | |
1828 visited.set(n->_idx); | |
1829 | |
1830 // Initially push all with no inputs from within member set | |
1831 for(uint i = 0; i < loop->_body.size(); i++ ) { | |
1832 Node *elt = loop->_body.at(i); | |
1833 if (member.test(elt->_idx)) { | |
1834 bool found = false; | |
1835 for (uint j = 0; j < elt->req(); j++) { | |
1836 Node* def = elt->in(j); | |
1837 if (def && member.test(def->_idx) && def != elt) { | |
1838 found = true; | |
1839 break; | |
1840 } | |
1841 } | |
1842 if (!found && elt != loop->_head) { | |
1843 nstack.push(n, idx); | |
1844 n = elt; | |
1845 assert(!visited.test(n->_idx), "not seen yet"); | |
1846 visited.set(n->_idx); | |
1847 } | |
1848 } | |
1849 } | |
1850 | |
1851 // traverse out's that are in the member set | |
1852 while (true) { | |
1853 if (idx < n->outcnt()) { | |
1854 Node* use = n->raw_out(idx); | |
1855 idx++; | |
1856 if (!visited.test_set(use->_idx)) { | |
1857 if (member.test(use->_idx)) { | |
1858 nstack.push(n, idx); | |
1859 n = use; | |
1860 idx = 0; | |
1861 } | |
1862 } | |
1863 } else { | |
1864 // All outputs processed | |
1865 sched.push(n); | |
1866 if (nstack.is_empty()) break; | |
1867 n = nstack.node(); | |
1868 idx = nstack.index(); | |
1869 nstack.pop(); | |
1870 } | |
1871 } | |
1872 } | |
1873 | |
1874 | |
1875 //------------------------------ has_use_in_set ------------------------------------- | |
1876 // Has a use in the vector set | |
1877 bool PhaseIdealLoop::has_use_in_set( Node* n, VectorSet& vset ) { | |
1878 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1879 Node* use = n->fast_out(j); | |
1880 if (vset.test(use->_idx)) { | |
1881 return true; | |
1882 } | |
1883 } | |
1884 return false; | |
1885 } | |
1886 | |
1887 | |
1888 //------------------------------ has_use_internal_to_set ------------------------------------- | |
1889 // Has use internal to the vector set (ie. not in a phi at the loop head) | |
1890 bool PhaseIdealLoop::has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop ) { | |
1891 Node* head = loop->_head; | |
1892 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1893 Node* use = n->fast_out(j); | |
1894 if (vset.test(use->_idx) && !(use->is_Phi() && use->in(0) == head)) { | |
1895 return true; | |
1896 } | |
1897 } | |
1898 return false; | |
1899 } | |
1900 | |
1901 | |
1902 //------------------------------ clone_for_use_outside_loop ------------------------------------- | |
1903 // clone "n" for uses that are outside of loop | |
1904 void PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) { | |
1905 | |
1906 assert(worklist.size() == 0, "should be empty"); | |
1907 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1908 Node* use = n->fast_out(j); | |
1909 if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) { | |
1910 worklist.push(use); | |
1911 } | |
1912 } | |
1913 while( worklist.size() ) { | |
1914 Node *use = worklist.pop(); | |
1915 if (!has_node(use) || use->in(0) == C->top()) continue; | |
1916 uint j; | |
1917 for (j = 0; j < use->req(); j++) { | |
1918 if (use->in(j) == n) break; | |
1919 } | |
1920 assert(j < use->req(), "must be there"); | |
1921 | |
1922 // clone "n" and insert it between the inputs of "n" and the use outside the loop | |
1923 Node* n_clone = n->clone(); | |
1924 _igvn.hash_delete(use); | |
1925 use->set_req(j, n_clone); | |
1926 _igvn._worklist.push(use); | |
251 | 1927 Node* use_c; |
0 | 1928 if (!use->is_Phi()) { |
251 | 1929 use_c = has_ctrl(use) ? get_ctrl(use) : use->in(0); |
0 | 1930 } else { |
1931 // Use in a phi is considered a use in the associated predecessor block | |
251 | 1932 use_c = use->in(0)->in(j); |
0 | 1933 } |
251 | 1934 set_ctrl(n_clone, use_c); |
1935 assert(!loop->is_member(get_loop(use_c)), "should be outside loop"); | |
1936 get_loop(use_c)->_body.push(n_clone); | |
0 | 1937 _igvn.register_new_node_with_optimizer(n_clone); |
1938 #if !defined(PRODUCT) | |
1939 if (TracePartialPeeling) { | |
1940 tty->print_cr("loop exit cloning old: %d new: %d newbb: %d", n->_idx, n_clone->_idx, get_ctrl(n_clone)->_idx); | |
1941 } | |
1942 #endif | |
1943 } | |
1944 } | |
1945 | |
1946 | |
1947 //------------------------------ clone_for_special_use_inside_loop ------------------------------------- | |
1948 // clone "n" for special uses that are in the not_peeled region. | |
1949 // If these def-uses occur in separate blocks, the code generator | |
1950 // marks the method as not compilable. For example, if a "BoolNode" | |
1951 // is in a different basic block than the "IfNode" that uses it, then | |
1952 // the compilation is aborted in the code generator. | |
1953 void PhaseIdealLoop::clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n, | |
1954 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist ) { | |
1955 if (n->is_Phi() || n->is_Load()) { | |
1956 return; | |
1957 } | |
1958 assert(worklist.size() == 0, "should be empty"); | |
1959 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
1960 Node* use = n->fast_out(j); | |
1961 if ( not_peel.test(use->_idx) && | |
1962 (use->is_If() || use->is_CMove() || use->is_Bool()) && | |
1963 use->in(1) == n) { | |
1964 worklist.push(use); | |
1965 } | |
1966 } | |
1967 if (worklist.size() > 0) { | |
1968 // clone "n" and insert it between inputs of "n" and the use | |
1969 Node* n_clone = n->clone(); | |
1970 loop->_body.push(n_clone); | |
1971 _igvn.register_new_node_with_optimizer(n_clone); | |
1972 set_ctrl(n_clone, get_ctrl(n)); | |
1973 sink_list.push(n_clone); | |
1974 not_peel <<= n_clone->_idx; // add n_clone to not_peel set. | |
1975 #if !defined(PRODUCT) | |
1976 if (TracePartialPeeling) { | |
1977 tty->print_cr("special not_peeled cloning old: %d new: %d", n->_idx, n_clone->_idx); | |
1978 } | |
1979 #endif | |
1980 while( worklist.size() ) { | |
1981 Node *use = worklist.pop(); | |
1982 _igvn.hash_delete(use); | |
1983 _igvn._worklist.push(use); | |
1984 for (uint j = 1; j < use->req(); j++) { | |
1985 if (use->in(j) == n) { | |
1986 use->set_req(j, n_clone); | |
1987 } | |
1988 } | |
1989 } | |
1990 } | |
1991 } | |
1992 | |
1993 | |
1994 //------------------------------ insert_phi_for_loop ------------------------------------- | |
1995 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist | |
1996 void PhaseIdealLoop::insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp ) { | |
1997 Node *phi = PhiNode::make(lp, back_edge_val); | |
1998 phi->set_req(LoopNode::EntryControl, lp_entry_val); | |
1999 // Use existing phi if it already exists | |
2000 Node *hit = _igvn.hash_find_insert(phi); | |
2001 if( hit == NULL ) { | |
2002 _igvn.register_new_node_with_optimizer(phi); | |
2003 set_ctrl(phi, lp); | |
2004 } else { | |
2005 // Remove the new phi from the graph and use the hit | |
2006 _igvn.remove_dead_node(phi); | |
2007 phi = hit; | |
2008 } | |
2009 _igvn.hash_delete(use); | |
2010 _igvn._worklist.push(use); | |
2011 use->set_req(idx, phi); | |
2012 } | |
2013 | |
2014 #ifdef ASSERT | |
2015 //------------------------------ is_valid_loop_partition ------------------------------------- | |
2016 // Validate the loop partition sets: peel and not_peel | |
2017 bool PhaseIdealLoop::is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list, | |
2018 VectorSet& not_peel ) { | |
2019 uint i; | |
2020 // Check that peel_list entries are in the peel set | |
2021 for (i = 0; i < peel_list.size(); i++) { | |
2022 if (!peel.test(peel_list.at(i)->_idx)) { | |
2023 return false; | |
2024 } | |
2025 } | |
2026 // Check at loop members are in one of peel set or not_peel set | |
2027 for (i = 0; i < loop->_body.size(); i++ ) { | |
2028 Node *def = loop->_body.at(i); | |
2029 uint di = def->_idx; | |
2030 // Check that peel set elements are in peel_list | |
2031 if (peel.test(di)) { | |
2032 if (not_peel.test(di)) { | |
2033 return false; | |
2034 } | |
2035 // Must be in peel_list also | |
2036 bool found = false; | |
2037 for (uint j = 0; j < peel_list.size(); j++) { | |
2038 if (peel_list.at(j)->_idx == di) { | |
2039 found = true; | |
2040 break; | |
2041 } | |
2042 } | |
2043 if (!found) { | |
2044 return false; | |
2045 } | |
2046 } else if (not_peel.test(di)) { | |
2047 if (peel.test(di)) { | |
2048 return false; | |
2049 } | |
2050 } else { | |
2051 return false; | |
2052 } | |
2053 } | |
2054 return true; | |
2055 } | |
2056 | |
2057 //------------------------------ is_valid_clone_loop_exit_use ------------------------------------- | |
2058 // Ensure a use outside of loop is of the right form | |
2059 bool PhaseIdealLoop::is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx) { | |
2060 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
2061 return (use->is_Phi() && | |
2062 use_c->is_Region() && use_c->req() == 3 && | |
2063 (use_c->in(exit_idx)->Opcode() == Op_IfTrue || | |
2064 use_c->in(exit_idx)->Opcode() == Op_IfFalse || | |
2065 use_c->in(exit_idx)->Opcode() == Op_JumpProj) && | |
2066 loop->is_member( get_loop( use_c->in(exit_idx)->in(0) ) ) ); | |
2067 } | |
2068 | |
2069 //------------------------------ is_valid_clone_loop_form ------------------------------------- | |
2070 // Ensure that all uses outside of loop are of the right form | |
2071 bool PhaseIdealLoop::is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list, | |
2072 uint orig_exit_idx, uint clone_exit_idx) { | |
2073 uint len = peel_list.size(); | |
2074 for (uint i = 0; i < len; i++) { | |
2075 Node *def = peel_list.at(i); | |
2076 | |
2077 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) { | |
2078 Node *use = def->fast_out(j); | |
2079 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
2080 if (!loop->is_member(get_loop(use_c))) { | |
2081 // use is not in the loop, check for correct structure | |
2082 if (use->in(0) == def) { | |
2083 // Okay | |
2084 } else if (!is_valid_clone_loop_exit_use(loop, use, orig_exit_idx)) { | |
2085 return false; | |
2086 } | |
2087 } | |
2088 } | |
2089 } | |
2090 return true; | |
2091 } | |
2092 #endif | |
2093 | |
2094 //------------------------------ partial_peel ------------------------------------- | |
2095 // Partially peel (aka loop rotation) the top portion of a loop (called | |
2096 // the peel section below) by cloning it and placing one copy just before | |
2097 // the new loop head and the other copy at the bottom of the new loop. | |
2098 // | |
2099 // before after where it came from | |
2100 // | |
2101 // stmt1 stmt1 | |
2102 // loop: stmt2 clone | |
2103 // stmt2 if condA goto exitA clone | |
2104 // if condA goto exitA new_loop: new | |
2105 // stmt3 stmt3 clone | |
2106 // if !condB goto loop if condB goto exitB clone | |
2107 // exitB: stmt2 orig | |
2108 // stmt4 if !condA goto new_loop orig | |
2109 // exitA: goto exitA | |
2110 // exitB: | |
2111 // stmt4 | |
2112 // exitA: | |
2113 // | |
2114 // Step 1: find the cut point: an exit test on probable | |
2115 // induction variable. | |
2116 // Step 2: schedule (with cloning) operations in the peel | |
2117 // section that can be executed after the cut into | |
2118 // the section that is not peeled. This may need | |
2119 // to clone operations into exit blocks. For | |
2120 // instance, a reference to A[i] in the not-peel | |
2121 // section and a reference to B[i] in an exit block | |
2122 // may cause a left-shift of i by 2 to be placed | |
2123 // in the peel block. This step will clone the left | |
2124 // shift into the exit block and sink the left shift | |
2125 // from the peel to the not-peel section. | |
2126 // Step 3: clone the loop, retarget the control, and insert | |
2127 // phis for values that are live across the new loop | |
2128 // head. This is very dependent on the graph structure | |
2129 // from clone_loop. It creates region nodes for | |
2130 // exit control and associated phi nodes for values | |
2131 // flow out of the loop through that exit. The region | |
2132 // node is dominated by the clone's control projection. | |
2133 // So the clone's peel section is placed before the | |
2134 // new loop head, and the clone's not-peel section is | |
2135 // forms the top part of the new loop. The original | |
2136 // peel section forms the tail of the new loop. | |
2137 // Step 4: update the dominator tree and recompute the | |
2138 // dominator depth. | |
2139 // | |
2140 // orig | |
2141 // | |
2445 | 2142 // stmt1 |
2143 // | | |
2144 // v | |
2145 // loop predicate | |
2146 // | | |
2147 // v | |
0 | 2148 // loop<----+ |
2149 // | | | |
2150 // stmt2 | | |
2151 // | | | |
2152 // v | | |
2153 // ifA | | |
2154 // / | | | |
2155 // v v | | |
2156 // false true ^ <-- last_peel | |
2157 // / | | | |
2158 // / ===|==cut | | |
2159 // / stmt3 | <-- first_not_peel | |
2160 // / | | | |
2161 // | v | | |
2162 // v ifB | | |
2163 // exitA: / \ | | |
2164 // / \ | | |
2165 // v v | | |
2166 // false true | | |
2167 // / \ | | |
2168 // / ----+ | |
2169 // | | |
2170 // v | |
2171 // exitB: | |
2172 // stmt4 | |
2173 // | |
2174 // | |
2175 // after clone loop | |
2176 // | |
2177 // stmt1 | |
2445 | 2178 // | |
2179 // v | |
2180 // loop predicate | |
0 | 2181 // / \ |
2182 // clone / \ orig | |
2183 // / \ | |
2184 // / \ | |
2185 // v v | |
2186 // +---->loop loop<----+ | |
2187 // | | | | | |
2188 // | stmt2 stmt2 | | |
2189 // | | | | | |
2190 // | v v | | |
2191 // | ifA ifA | | |
2192 // | | \ / | | | |
2193 // | v v v v | | |
2194 // ^ true false false true ^ <-- last_peel | |
2195 // | | ^ \ / | | | |
2196 // | cut==|== \ \ / ===|==cut | | |
2197 // | stmt3 \ \ / stmt3 | <-- first_not_peel | |
2198 // | | dom | | | | | |
2199 // | v \ 1v v2 v | | |
2200 // | ifB regionA ifB | | |
2201 // | / \ | / \ | | |
2202 // | / \ v / \ | | |
2203 // | v v exitA: v v | | |
2204 // | true false false true | | |
2205 // | / ^ \ / \ | | |
2206 // +---- \ \ / ----+ | |
2207 // dom \ / | |
2208 // \ 1v v2 | |
2209 // regionB | |
2210 // | | |
2211 // v | |
2212 // exitB: | |
2213 // stmt4 | |
2214 // | |
2215 // | |
2216 // after partial peel | |
2217 // | |
2218 // stmt1 | |
2445 | 2219 // | |
2220 // v | |
2221 // loop predicate | |
0 | 2222 // / |
2223 // clone / orig | |
2224 // / TOP | |
2225 // / \ | |
2226 // v v | |
2445 | 2227 // TOP->loop loop----+ |
0 | 2228 // | | | |
2229 // stmt2 stmt2 | | |
2230 // | | | | |
2231 // v v | | |
2232 // ifA ifA | | |
2233 // | \ / | | | |
2234 // v v v v | | |
2235 // true false false true | <-- last_peel | |
2236 // | ^ \ / +------|---+ | |
2237 // +->newloop \ \ / === ==cut | | | |
2238 // | stmt3 \ \ / TOP | | | |
2239 // | | dom | | stmt3 | | <-- first_not_peel | |
2240 // | v \ 1v v2 v | | | |
2241 // | ifB regionA ifB ^ v | |
2242 // | / \ | / \ | | | |
2243 // | / \ v / \ | | | |
2244 // | v v exitA: v v | | | |
2245 // | true false false true | | | |
2246 // | / ^ \ / \ | | | |
2247 // | | \ \ / v | | | |
2248 // | | dom \ / TOP | | | |
2249 // | | \ 1v v2 | | | |
2250 // ^ v regionB | | | |
2251 // | | | | | | |
2252 // | | v ^ v | |
2253 // | | exitB: | | | |
2254 // | | stmt4 | | | |
2255 // | +------------>-----------------+ | | |
2256 // | | | |
2257 // +-----------------<---------------------+ | |
2258 // | |
2259 // | |
2260 // final graph | |
2261 // | |
2262 // stmt1 | |
2263 // | | |
2264 // v | |
2445 | 2265 // stmt2 clone |
2266 // | | |
2267 // v | |
0 | 2268 // ........> ifA clone |
2269 // : / | | |
2270 // dom / | | |
2271 // : v v | |
2272 // : false true | |
2273 // : | | | |
2445 | 2274 // : | v |
2275 // : | loop predicate | |
0 | 2276 // : | | |
2277 // : | v | |
2278 // : | newloop<-----+ | |
2279 // : | | | | |
2280 // : | stmt3 clone | | |
2281 // : | | | | |
2282 // : | v | | |
2283 // : | ifB | | |
2284 // : | / \ | | |
2285 // : | v v | | |
2286 // : | false true | | |
2287 // : | | | | | |
2288 // : | v stmt2 | | |
2289 // : | exitB: | | | |
2290 // : | stmt4 v | | |
2291 // : | ifA orig | | |
2292 // : | / \ | | |
2293 // : | / \ | | |
2294 // : | v v | | |
2295 // : | false true | | |
2296 // : | / \ | | |
2297 // : v v -----+ | |
2298 // RegionA | |
2299 // | | |
2300 // v | |
2301 // exitA | |
2302 // | |
2303 bool PhaseIdealLoop::partial_peel( IdealLoopTree *loop, Node_List &old_new ) { | |
2304 | |
2445 | 2305 assert(!loop->_head->is_CountedLoop(), "Non-counted loop only"); |
108 | 2306 if (!loop->_head->is_Loop()) { |
2307 return false; } | |
2308 | |
0 | 2309 LoopNode *head = loop->_head->as_Loop(); |
2310 | |
2311 if (head->is_partial_peel_loop() || head->partial_peel_has_failed()) { | |
2312 return false; | |
2313 } | |
2314 | |
2315 // Check for complex exit control | |
2316 for(uint ii = 0; ii < loop->_body.size(); ii++ ) { | |
2317 Node *n = loop->_body.at(ii); | |
2318 int opc = n->Opcode(); | |
2319 if (n->is_Call() || | |
2320 opc == Op_Catch || | |
2321 opc == Op_CatchProj || | |
2322 opc == Op_Jump || | |
2323 opc == Op_JumpProj) { | |
2324 #if !defined(PRODUCT) | |
2325 if (TracePartialPeeling) { | |
2326 tty->print_cr("\nExit control too complex: lp: %d", head->_idx); | |
2327 } | |
2328 #endif | |
2329 return false; | |
2330 } | |
2331 } | |
2332 | |
2445 | 2333 Node* entry = head->in(LoopNode::EntryControl); |
0 | 2334 int dd = dom_depth(head); |
2335 | |
2336 // Step 1: find cut point | |
2337 | |
2338 // Walk up dominators to loop head looking for first loop exit | |
2339 // which is executed on every path thru loop. | |
2340 IfNode *peel_if = NULL; | |
2341 IfNode *peel_if_cmpu = NULL; | |
2342 | |
2343 Node *iff = loop->tail(); | |
2344 while( iff != head ) { | |
2345 if( iff->is_If() ) { | |
2346 Node *ctrl = get_ctrl(iff->in(1)); | |
2347 if (ctrl->is_top()) return false; // Dead test on live IF. | |
2348 // If loop-varying exit-test, check for induction variable | |
2349 if( loop->is_member(get_loop(ctrl)) && | |
2350 loop->is_loop_exit(iff) && | |
2351 is_possible_iv_test(iff)) { | |
2352 Node* cmp = iff->in(1)->in(1); | |
2353 if (cmp->Opcode() == Op_CmpI) { | |
2354 peel_if = iff->as_If(); | |
2355 } else { | |
2356 assert(cmp->Opcode() == Op_CmpU, "must be CmpI or CmpU"); | |
2357 peel_if_cmpu = iff->as_If(); | |
2358 } | |
2359 } | |
2360 } | |
2361 iff = idom(iff); | |
2362 } | |
2363 // Prefer signed compare over unsigned compare. | |
2364 IfNode* new_peel_if = NULL; | |
2365 if (peel_if == NULL) { | |
2366 if (!PartialPeelAtUnsignedTests || peel_if_cmpu == NULL) { | |
2367 return false; // No peel point found | |
2368 } | |
2369 new_peel_if = insert_cmpi_loop_exit(peel_if_cmpu, loop); | |
2370 if (new_peel_if == NULL) { | |
2371 return false; // No peel point found | |
2372 } | |
2373 peel_if = new_peel_if; | |
2374 } | |
2375 Node* last_peel = stay_in_loop(peel_if, loop); | |
2376 Node* first_not_peeled = stay_in_loop(last_peel, loop); | |
2377 if (first_not_peeled == NULL || first_not_peeled == head) { | |
2378 return false; | |
2379 } | |
2380 | |
2381 #if !defined(PRODUCT) | |
2383
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2382 if (TraceLoopOpts) { |
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2383 tty->print("PartialPeel "); |
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2384 loop->dump_head(); |
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|
2385 } |
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|
2386 |
0 | 2387 if (TracePartialPeeling) { |
2388 tty->print_cr("before partial peel one iteration"); | |
2389 Node_List wl; | |
2390 Node* t = head->in(2); | |
2391 while (true) { | |
2392 wl.push(t); | |
2393 if (t == head) break; | |
2394 t = idom(t); | |
2395 } | |
2396 while (wl.size() > 0) { | |
2397 Node* tt = wl.pop(); | |
2398 tt->dump(); | |
2399 if (tt == last_peel) tty->print_cr("-- cut --"); | |
2400 } | |
2401 } | |
2402 #endif | |
2403 ResourceArea *area = Thread::current()->resource_area(); | |
2404 VectorSet peel(area); | |
2405 VectorSet not_peel(area); | |
2406 Node_List peel_list(area); | |
2407 Node_List worklist(area); | |
2408 Node_List sink_list(area); | |
2409 | |
2410 // Set of cfg nodes to peel are those that are executable from | |
2411 // the head through last_peel. | |
2412 assert(worklist.size() == 0, "should be empty"); | |
2413 worklist.push(head); | |
2414 peel.set(head->_idx); | |
2415 while (worklist.size() > 0) { | |
2416 Node *n = worklist.pop(); | |
2417 if (n != last_peel) { | |
2418 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
2419 Node* use = n->fast_out(j); | |
2420 if (use->is_CFG() && | |
2421 loop->is_member(get_loop(use)) && | |
2422 !peel.test_set(use->_idx)) { | |
2423 worklist.push(use); | |
2424 } | |
2425 } | |
2426 } | |
2427 } | |
2428 | |
2429 // Set of non-cfg nodes to peel are those that are control | |
2430 // dependent on the cfg nodes. | |
2431 uint i; | |
2432 for(i = 0; i < loop->_body.size(); i++ ) { | |
2433 Node *n = loop->_body.at(i); | |
2434 Node *n_c = has_ctrl(n) ? get_ctrl(n) : n; | |
2435 if (peel.test(n_c->_idx)) { | |
2436 peel.set(n->_idx); | |
2437 } else { | |
2438 not_peel.set(n->_idx); | |
2439 } | |
2440 } | |
2441 | |
2442 // Step 2: move operations from the peeled section down into the | |
2443 // not-peeled section | |
2444 | |
2445 // Get a post order schedule of nodes in the peel region | |
2446 // Result in right-most operand. | |
2447 scheduled_nodelist(loop, peel, peel_list ); | |
2448 | |
2449 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition"); | |
2450 | |
2451 // For future check for too many new phis | |
2452 uint old_phi_cnt = 0; | |
2453 for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) { | |
2454 Node* use = head->fast_out(j); | |
2455 if (use->is_Phi()) old_phi_cnt++; | |
2456 } | |
2457 | |
2458 #if !defined(PRODUCT) | |
2459 if (TracePartialPeeling) { | |
2460 tty->print_cr("\npeeled list"); | |
2461 } | |
2462 #endif | |
2463 | |
2464 // Evacuate nodes in peel region into the not_peeled region if possible | |
2465 uint new_phi_cnt = 0; | |
2466 for (i = 0; i < peel_list.size();) { | |
2467 Node* n = peel_list.at(i); | |
2468 #if !defined(PRODUCT) | |
2469 if (TracePartialPeeling) n->dump(); | |
2470 #endif | |
2471 bool incr = true; | |
2472 if ( !n->is_CFG() ) { | |
2473 | |
2474 if ( has_use_in_set(n, not_peel) ) { | |
2475 | |
2476 // If not used internal to the peeled region, | |
2477 // move "n" from peeled to not_peeled region. | |
2478 | |
2479 if ( !has_use_internal_to_set(n, peel, loop) ) { | |
2480 | |
2481 // if not pinned and not a load (which maybe anti-dependent on a store) | |
2482 // and not a CMove (Matcher expects only bool->cmove). | |
2483 if ( n->in(0) == NULL && !n->is_Load() && !n->is_CMove() ) { | |
2484 clone_for_use_outside_loop( loop, n, worklist ); | |
2485 | |
2486 sink_list.push(n); | |
2487 peel >>= n->_idx; // delete n from peel set. | |
2488 not_peel <<= n->_idx; // add n to not_peel set. | |
2489 peel_list.remove(i); | |
2490 incr = false; | |
2491 #if !defined(PRODUCT) | |
2492 if (TracePartialPeeling) { | |
2493 tty->print_cr("sink to not_peeled region: %d newbb: %d", | |
2494 n->_idx, get_ctrl(n)->_idx); | |
2495 } | |
2496 #endif | |
2497 } | |
2498 } else { | |
2499 // Otherwise check for special def-use cases that span | |
2500 // the peel/not_peel boundary such as bool->if | |
2501 clone_for_special_use_inside_loop( loop, n, not_peel, sink_list, worklist ); | |
2502 new_phi_cnt++; | |
2503 } | |
2504 } | |
2505 } | |
2506 if (incr) i++; | |
2507 } | |
2508 | |
2509 if (new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta) { | |
2510 #if !defined(PRODUCT) | |
2511 if (TracePartialPeeling) { | |
2512 tty->print_cr("\nToo many new phis: %d old %d new cmpi: %c", | |
2513 new_phi_cnt, old_phi_cnt, new_peel_if != NULL?'T':'F'); | |
2514 } | |
2515 #endif | |
2516 if (new_peel_if != NULL) { | |
2517 remove_cmpi_loop_exit(new_peel_if, loop); | |
2518 } | |
2519 // Inhibit more partial peeling on this loop | |
2520 assert(!head->is_partial_peel_loop(), "not partial peeled"); | |
2521 head->mark_partial_peel_failed(); | |
2522 return false; | |
2523 } | |
2524 | |
2525 // Step 3: clone loop, retarget control, and insert new phis | |
2526 | |
2527 // Create new loop head for new phis and to hang | |
2528 // the nodes being moved (sinked) from the peel region. | |
2529 LoopNode* new_head = new (C, 3) LoopNode(last_peel, last_peel); | |
2383
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2530 new_head->set_unswitch_count(head->unswitch_count()); // Preserve |
0 | 2531 _igvn.register_new_node_with_optimizer(new_head); |
2532 assert(first_not_peeled->in(0) == last_peel, "last_peel <- first_not_peeled"); | |
2533 first_not_peeled->set_req(0, new_head); | |
2534 set_loop(new_head, loop); | |
2535 loop->_body.push(new_head); | |
2536 not_peel.set(new_head->_idx); | |
2537 set_idom(new_head, last_peel, dom_depth(first_not_peeled)); | |
2538 set_idom(first_not_peeled, new_head, dom_depth(first_not_peeled)); | |
2539 | |
2540 while (sink_list.size() > 0) { | |
2541 Node* n = sink_list.pop(); | |
2542 set_ctrl(n, new_head); | |
2543 } | |
2544 | |
2545 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition"); | |
2546 | |
2547 clone_loop( loop, old_new, dd ); | |
2548 | |
2549 const uint clone_exit_idx = 1; | |
2550 const uint orig_exit_idx = 2; | |
2551 assert(is_valid_clone_loop_form( loop, peel_list, orig_exit_idx, clone_exit_idx ), "bad clone loop"); | |
2552 | |
2553 Node* head_clone = old_new[head->_idx]; | |
2554 LoopNode* new_head_clone = old_new[new_head->_idx]->as_Loop(); | |
2555 Node* orig_tail_clone = head_clone->in(2); | |
2556 | |
2557 // Add phi if "def" node is in peel set and "use" is not | |
2558 | |
2559 for(i = 0; i < peel_list.size(); i++ ) { | |
2560 Node *def = peel_list.at(i); | |
2561 if (!def->is_CFG()) { | |
2562 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) { | |
2563 Node *use = def->fast_out(j); | |
2564 if (has_node(use) && use->in(0) != C->top() && | |
2565 (!peel.test(use->_idx) || | |
2566 (use->is_Phi() && use->in(0) == head)) ) { | |
2567 worklist.push(use); | |
2568 } | |
2569 } | |
2570 while( worklist.size() ) { | |
2571 Node *use = worklist.pop(); | |
2572 for (uint j = 1; j < use->req(); j++) { | |
2573 Node* n = use->in(j); | |
2574 if (n == def) { | |
2575 | |
2576 // "def" is in peel set, "use" is not in peel set | |
2577 // or "use" is in the entry boundary (a phi) of the peel set | |
2578 | |
2579 Node* use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
2580 | |
2581 if ( loop->is_member(get_loop( use_c )) ) { | |
2582 // use is in loop | |
2583 if (old_new[use->_idx] != NULL) { // null for dead code | |
2584 Node* use_clone = old_new[use->_idx]; | |
2585 _igvn.hash_delete(use); | |
2586 use->set_req(j, C->top()); | |
2587 _igvn._worklist.push(use); | |
2588 insert_phi_for_loop( use_clone, j, old_new[def->_idx], def, new_head_clone ); | |
2589 } | |
2590 } else { | |
2591 assert(is_valid_clone_loop_exit_use(loop, use, orig_exit_idx), "clone loop format"); | |
2592 // use is not in the loop, check if the live range includes the cut | |
2593 Node* lp_if = use_c->in(orig_exit_idx)->in(0); | |
2594 if (not_peel.test(lp_if->_idx)) { | |
2595 assert(j == orig_exit_idx, "use from original loop"); | |
2596 insert_phi_for_loop( use, clone_exit_idx, old_new[def->_idx], def, new_head_clone ); | |
2597 } | |
2598 } | |
2599 } | |
2600 } | |
2601 } | |
2602 } | |
2603 } | |
2604 | |
2605 // Step 3b: retarget control | |
2606 | |
2607 // Redirect control to the new loop head if a cloned node in | |
2608 // the not_peeled region has control that points into the peeled region. | |
2609 // This necessary because the cloned peeled region will be outside | |
2610 // the loop. | |
2611 // from to | |
2612 // cloned-peeled <---+ | |
2613 // new_head_clone: | <--+ | |
2614 // cloned-not_peeled in(0) in(0) | |
2615 // orig-peeled | |
2616 | |
2617 for(i = 0; i < loop->_body.size(); i++ ) { | |
2618 Node *n = loop->_body.at(i); | |
2619 if (!n->is_CFG() && n->in(0) != NULL && | |
2620 not_peel.test(n->_idx) && peel.test(n->in(0)->_idx)) { | |
2621 Node* n_clone = old_new[n->_idx]; | |
2622 _igvn.hash_delete(n_clone); | |
2623 n_clone->set_req(0, new_head_clone); | |
2624 _igvn._worklist.push(n_clone); | |
2625 } | |
2626 } | |
2627 | |
2628 // Backedge of the surviving new_head (the clone) is original last_peel | |
2629 _igvn.hash_delete(new_head_clone); | |
2445 | 2630 Node* new_entry = move_loop_predicates(entry, new_head_clone->in(LoopNode::EntryControl)); |
2631 new_head_clone->set_req(LoopNode::EntryControl, new_entry); | |
0 | 2632 new_head_clone->set_req(LoopNode::LoopBackControl, last_peel); |
2633 _igvn._worklist.push(new_head_clone); | |
2634 | |
2635 // Cut first node in original not_peel set | |
2636 _igvn.hash_delete(new_head); | |
2637 new_head->set_req(LoopNode::EntryControl, C->top()); | |
2638 new_head->set_req(LoopNode::LoopBackControl, C->top()); | |
2639 _igvn._worklist.push(new_head); | |
2640 | |
2641 // Copy head_clone back-branch info to original head | |
2642 // and remove original head's loop entry and | |
2643 // clone head's back-branch | |
2644 _igvn.hash_delete(head); | |
2645 _igvn.hash_delete(head_clone); | |
2646 head->set_req(LoopNode::EntryControl, head_clone->in(LoopNode::LoopBackControl)); | |
2647 head->set_req(LoopNode::LoopBackControl, C->top()); | |
2648 head_clone->set_req(LoopNode::LoopBackControl, C->top()); | |
2649 _igvn._worklist.push(head); | |
2650 _igvn._worklist.push(head_clone); | |
2651 | |
2652 // Similarly modify the phis | |
2653 for (DUIterator_Fast kmax, k = head->fast_outs(kmax); k < kmax; k++) { | |
2654 Node* use = head->fast_out(k); | |
2655 if (use->is_Phi() && use->outcnt() > 0) { | |
2656 Node* use_clone = old_new[use->_idx]; | |
2657 _igvn.hash_delete(use); | |
2658 _igvn.hash_delete(use_clone); | |
2659 use->set_req(LoopNode::EntryControl, use_clone->in(LoopNode::LoopBackControl)); | |
2660 use->set_req(LoopNode::LoopBackControl, C->top()); | |
2661 use_clone->set_req(LoopNode::LoopBackControl, C->top()); | |
2662 _igvn._worklist.push(use); | |
2663 _igvn._worklist.push(use_clone); | |
2664 } | |
2665 } | |
2666 | |
2667 // Step 4: update dominator tree and dominator depth | |
2668 | |
2669 set_idom(head, orig_tail_clone, dd); | |
2670 recompute_dom_depth(); | |
2671 | |
2672 // Inhibit more partial peeling on this loop | |
2673 new_head_clone->set_partial_peel_loop(); | |
2674 C->set_major_progress(); | |
2675 | |
2676 #if !defined(PRODUCT) | |
2677 if (TracePartialPeeling) { | |
2678 tty->print_cr("\nafter partial peel one iteration"); | |
2679 Node_List wl(area); | |
2680 Node* t = last_peel; | |
2681 while (true) { | |
2682 wl.push(t); | |
2683 if (t == head_clone) break; | |
2684 t = idom(t); | |
2685 } | |
2686 while (wl.size() > 0) { | |
2687 Node* tt = wl.pop(); | |
2688 if (tt == head) tty->print_cr("orig head"); | |
2689 else if (tt == new_head_clone) tty->print_cr("new head"); | |
2690 else if (tt == head_clone) tty->print_cr("clone head"); | |
2691 tt->dump(); | |
2692 } | |
2693 } | |
2694 #endif | |
2695 return true; | |
2696 } | |
2697 | |
2698 //------------------------------reorg_offsets---------------------------------- | |
2699 // Reorganize offset computations to lower register pressure. Mostly | |
2700 // prevent loop-fallout uses of the pre-incremented trip counter (which are | |
2701 // then alive with the post-incremented trip counter forcing an extra | |
2702 // register move) | |
2383
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diff
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|
2703 void PhaseIdealLoop::reorg_offsets(IdealLoopTree *loop) { |
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diff
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|
2704 // Perform it only for canonical counted loops. |
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|
2705 // Loop's shape could be messed up by iteration_split_impl. |
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2706 if (!loop->_head->is_CountedLoop()) |
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|
2707 return; |
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|
2708 if (!loop->_head->as_Loop()->is_valid_counted_loop()) |
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7008866: Missing loop predicate for loop with multiple entries
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|
2709 return; |
0 | 2710 |
2711 CountedLoopNode *cl = loop->_head->as_CountedLoop(); | |
2712 CountedLoopEndNode *cle = cl->loopexit(); | |
2713 Node *exit = cle->proj_out(false); | |
2383
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|
2714 Node *phi = cl->phi(); |
0 | 2715 |
2716 // Check for the special case of folks using the pre-incremented | |
2717 // trip-counter on the fall-out path (forces the pre-incremented | |
2718 // and post-incremented trip counter to be live at the same time). | |
2719 // Fix this by adjusting to use the post-increment trip counter. | |
367
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2720 |
0 | 2721 bool progress = true; |
2722 while (progress) { | |
2723 progress = false; | |
2724 for (DUIterator_Fast imax, i = phi->fast_outs(imax); i < imax; i++) { | |
2725 Node* use = phi->fast_out(i); // User of trip-counter | |
2726 if (!has_ctrl(use)) continue; | |
2727 Node *u_ctrl = get_ctrl(use); | |
2383
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|
2728 if (use->is_Phi()) { |
0 | 2729 u_ctrl = NULL; |
2383
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|
2730 for (uint j = 1; j < use->req(); j++) |
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|
2731 if (use->in(j) == phi) |
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|
2732 u_ctrl = dom_lca(u_ctrl, use->in(0)->in(j)); |
0 | 2733 } |
2734 IdealLoopTree *u_loop = get_loop(u_ctrl); | |
2735 // Look for loop-invariant use | |
2383
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2736 if (u_loop == loop) continue; |
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|
2737 if (loop->is_member(u_loop)) continue; |
0 | 2738 // Check that use is live out the bottom. Assuming the trip-counter |
2739 // update is right at the bottom, uses of of the loop middle are ok. | |
2383
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diff
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|
2740 if (dom_lca(exit, u_ctrl) != exit) continue; |
0 | 2741 // Hit! Refactor use to use the post-incremented tripcounter. |
2742 // Compute a post-increment tripcounter. | |
216
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2743 Node *opaq = new (C, 2) Opaque2Node( C, cle->incr() ); |
0 | 2744 register_new_node( opaq, u_ctrl ); |
2745 Node *neg_stride = _igvn.intcon(-cle->stride_con()); | |
2746 set_ctrl(neg_stride, C->root()); | |
2747 Node *post = new (C, 3) AddINode( opaq, neg_stride); | |
2748 register_new_node( post, u_ctrl ); | |
2749 _igvn.hash_delete(use); | |
2750 _igvn._worklist.push(use); | |
2383
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|
2751 for (uint j = 1; j < use->req(); j++) { |
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diff
changeset
|
2752 if (use->in(j) == phi) |
0 | 2753 use->set_req(j, post); |
2383
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diff
changeset
|
2754 } |
0 | 2755 // Since DU info changed, rerun loop |
2756 progress = true; | |
2757 break; | |
2758 } | |
2759 } | |
2760 | |
2761 } |