Mercurial > hg > truffle
annotate src/share/vm/opto/loopopts.cpp @ 4062:83d0b5cd1438
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Reviewed-by: jrose, kvn, never
| author | twisti |
|---|---|
| date | Wed, 09 Nov 2011 00:42:33 -0800 |
| parents | d8cb48376797 |
| children | 670a74b863fc |
| rev | line source |
|---|---|
| 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" | |
| 4047 | 31 #include "opto/matcher.hpp" |
| 1972 | 32 #include "opto/mulnode.hpp" |
| 33 #include "opto/rootnode.hpp" | |
| 34 #include "opto/subnode.hpp" | |
| 0 | 35 |
| 36 //============================================================================= | |
| 37 //------------------------------split_thru_phi--------------------------------- | |
| 38 // Split Node 'n' through merge point if there is enough win. | |
| 39 Node *PhaseIdealLoop::split_thru_phi( Node *n, Node *region, int policy ) { | |
| 69 | 40 if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) { |
| 41 // ConvI2L may have type information on it which is unsafe to push up | |
| 42 // so disable this for now | |
| 43 return NULL; | |
| 44 } | |
| 0 | 45 int wins = 0; |
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46 assert(!n->is_CFG(), ""); |
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47 assert(region->is_Region(), ""); |
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48 |
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49 const Type* type = n->bottom_type(); |
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50 const TypeOopPtr *t_oop = _igvn.type(n)->isa_oopptr(); |
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51 Node *phi; |
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52 if (t_oop != NULL && t_oop->is_known_instance_field()) { |
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53 int iid = t_oop->instance_id(); |
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54 int index = C->get_alias_index(t_oop); |
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55 int offset = t_oop->offset(); |
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56 phi = new (C,region->req()) PhiNode(region, type, NULL, iid, index, offset); |
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57 } else { |
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58 phi = PhiNode::make_blank(region, n); |
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59 } |
| 0 | 60 uint old_unique = C->unique(); |
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61 for (uint i = 1; i < region->req(); i++) { |
| 0 | 62 Node *x; |
| 63 Node* the_clone = NULL; | |
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64 if (region->in(i) == C->top()) { |
| 0 | 65 x = C->top(); // Dead path? Use a dead data op |
| 66 } else { | |
| 67 x = n->clone(); // Else clone up the data op | |
| 68 the_clone = x; // Remember for possible deletion. | |
| 69 // Alter data node to use pre-phi inputs | |
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70 if (n->in(0) == region) |
| 0 | 71 x->set_req( 0, region->in(i) ); |
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72 for (uint j = 1; j < n->req(); j++) { |
| 0 | 73 Node *in = n->in(j); |
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74 if (in->is_Phi() && in->in(0) == region) |
| 0 | 75 x->set_req( j, in->in(i) ); // Use pre-Phi input for the clone |
| 76 } | |
| 77 } | |
| 78 // Check for a 'win' on some paths | |
| 79 const Type *t = x->Value(&_igvn); | |
| 80 | |
| 81 bool singleton = t->singleton(); | |
| 82 | |
| 83 // A TOP singleton indicates that there are no possible values incoming | |
| 84 // along a particular edge. In most cases, this is OK, and the Phi will | |
| 85 // be eliminated later in an Ideal call. However, we can't allow this to | |
| 86 // happen if the singleton occurs on loop entry, as the elimination of | |
| 87 // the PhiNode may cause the resulting node to migrate back to a previous | |
| 88 // loop iteration. | |
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89 if (singleton && t == Type::TOP) { |
| 0 | 90 // Is_Loop() == false does not confirm the absence of a loop (e.g., an |
| 91 // irreducible loop may not be indicated by an affirmative is_Loop()); | |
| 92 // therefore, the only top we can split thru a phi is on a backedge of | |
| 93 // a loop. | |
| 94 singleton &= region->is_Loop() && (i != LoopNode::EntryControl); | |
| 95 } | |
| 96 | |
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97 if (singleton) { |
| 0 | 98 wins++; |
| 99 x = ((PhaseGVN&)_igvn).makecon(t); | |
| 100 } else { | |
| 101 // We now call Identity to try to simplify the cloned node. | |
| 102 // Note that some Identity methods call phase->type(this). | |
| 103 // Make sure that the type array is big enough for | |
| 104 // our new node, even though we may throw the node away. | |
| 105 // (Note: This tweaking with igvn only works because x is a new node.) | |
| 106 _igvn.set_type(x, t); | |
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107 // If x is a TypeNode, capture any more-precise type permanently into Node |
| 605 | 108 // otherwise it will be not updated during igvn->transform since |
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109 // igvn->type(x) is set to x->Value() already. |
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110 x->raise_bottom_type(t); |
| 0 | 111 Node *y = x->Identity(&_igvn); |
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112 if (y != x) { |
| 0 | 113 wins++; |
| 114 x = y; | |
| 115 } else { | |
| 116 y = _igvn.hash_find(x); | |
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117 if (y) { |
| 0 | 118 wins++; |
| 119 x = y; | |
| 120 } else { | |
| 121 // Else x is a new node we are keeping | |
| 122 // We do not need register_new_node_with_optimizer | |
| 123 // because set_type has already been called. | |
| 124 _igvn._worklist.push(x); | |
| 125 } | |
| 126 } | |
| 127 } | |
| 128 if (x != the_clone && the_clone != NULL) | |
| 129 _igvn.remove_dead_node(the_clone); | |
| 130 phi->set_req( i, x ); | |
| 131 } | |
| 132 // Too few wins? | |
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133 if (wins <= policy) { |
| 0 | 134 _igvn.remove_dead_node(phi); |
| 135 return NULL; | |
| 136 } | |
| 137 | |
| 138 // Record Phi | |
| 139 register_new_node( phi, region ); | |
| 140 | |
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141 for (uint i2 = 1; i2 < phi->req(); i2++) { |
| 0 | 142 Node *x = phi->in(i2); |
| 143 // If we commoned up the cloned 'x' with another existing Node, | |
| 144 // the existing Node picks up a new use. We need to make the | |
| 145 // existing Node occur higher up so it dominates its uses. | |
| 146 Node *old_ctrl; | |
| 147 IdealLoopTree *old_loop; | |
| 148 | |
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149 if (x->is_Con()) { |
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150 // Constant's control is always root. |
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151 set_ctrl(x, C->root()); |
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152 continue; |
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153 } |
| 0 | 154 // The occasional new node |
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155 if (x->_idx >= old_unique) { // Found a new, unplaced node? |
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156 old_ctrl = NULL; |
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157 old_loop = NULL; // Not in any prior loop |
| 0 | 158 } else { |
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159 old_ctrl = get_ctrl(x); |
| 0 | 160 old_loop = get_loop(old_ctrl); // Get prior loop |
| 161 } | |
| 162 // New late point must dominate new use | |
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163 Node *new_ctrl = dom_lca(old_ctrl, region->in(i2)); |
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164 if (new_ctrl == old_ctrl) // Nothing is changed |
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165 continue; |
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166 |
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167 IdealLoopTree *new_loop = get_loop(new_ctrl); |
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168 |
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169 // Don't move x into a loop if its uses are |
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170 // outside of loop. Otherwise x will be cloned |
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171 // for each use outside of this loop. |
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172 IdealLoopTree *use_loop = get_loop(region); |
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173 if (!new_loop->is_member(use_loop) && |
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174 (old_loop == NULL || !new_loop->is_member(old_loop))) { |
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175 // Take early control, later control will be recalculated |
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176 // during next iteration of loop optimizations. |
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177 new_ctrl = get_early_ctrl(x); |
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178 new_loop = get_loop(new_ctrl); |
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179 } |
| 0 | 180 // Set new location |
| 181 set_ctrl(x, new_ctrl); | |
| 182 // If changing loop bodies, see if we need to collect into new body | |
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183 if (old_loop != new_loop) { |
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184 if (old_loop && !old_loop->_child) |
| 0 | 185 old_loop->_body.yank(x); |
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186 if (!new_loop->_child) |
| 0 | 187 new_loop->_body.push(x); // Collect body info |
| 188 } | |
| 189 } | |
| 190 | |
| 191 return phi; | |
| 192 } | |
| 193 | |
| 194 //------------------------------dominated_by------------------------------------ | |
| 195 // Replace the dominated test with an obvious true or false. Place it on the | |
| 196 // IGVN worklist for later cleanup. Move control-dependent data Nodes on the | |
| 197 // live path up to the dominating control. | |
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198 void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff, bool flip, bool exclude_loop_predicate ) { |
| 0 | 199 #ifndef PRODUCT |
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200 if (VerifyLoopOptimizations && PrintOpto) tty->print_cr("dominating test"); |
| 0 | 201 #endif |
| 202 | |
| 203 | |
| 204 // prevdom is the dominating projection of the dominating test. | |
| 205 assert( iff->is_If(), "" ); | |
| 206 assert( iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd, "Check this code when new subtype is added"); | |
| 207 int pop = prevdom->Opcode(); | |
| 208 assert( pop == Op_IfFalse || pop == Op_IfTrue, "" ); | |
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209 if (flip) { |
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210 if (pop == Op_IfTrue) |
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211 pop = Op_IfFalse; |
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212 else |
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213 pop = Op_IfTrue; |
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214 } |
| 0 | 215 // 'con' is set to true or false to kill the dominated test. |
| 216 Node *con = _igvn.makecon(pop == Op_IfTrue ? TypeInt::ONE : TypeInt::ZERO); | |
| 217 set_ctrl(con, C->root()); // Constant gets a new use | |
| 218 // Hack the dominated test | |
| 219 _igvn.hash_delete(iff); | |
| 220 iff->set_req(1, con); | |
| 221 _igvn._worklist.push(iff); | |
| 222 | |
| 223 // If I dont have a reachable TRUE and FALSE path following the IfNode then | |
| 224 // I can assume this path reaches an infinite loop. In this case it's not | |
| 225 // important to optimize the data Nodes - either the whole compilation will | |
| 226 // be tossed or this path (and all data Nodes) will go dead. | |
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227 if (iff->outcnt() != 2) return; |
| 0 | 228 |
| 229 // Make control-dependent data Nodes on the live path (path that will remain | |
| 230 // once the dominated IF is removed) become control-dependent on the | |
| 231 // dominating projection. | |
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232 Node* dp = iff->as_If()->proj_out(pop == Op_IfTrue); |
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233 |
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234 // Loop predicates may have depending checks which should not |
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235 // be skipped. For example, range check predicate has two checks |
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236 // for lower and upper bounds. |
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237 ProjNode* unc_proj = iff->as_If()->proj_out(1 - dp->as_Proj()->_con)->as_Proj(); |
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238 if (exclude_loop_predicate && |
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239 is_uncommon_trap_proj(unc_proj, Deoptimization::Reason_predicate)) |
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240 return; // Let IGVN transformation change control dependence. |
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241 |
| 0 | 242 IdealLoopTree *old_loop = get_loop(dp); |
| 243 | |
| 244 for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) { | |
| 245 Node* cd = dp->fast_out(i); // Control-dependent node | |
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246 if (cd->depends_only_on_test()) { |
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247 assert(cd->in(0) == dp, ""); |
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248 _igvn.hash_delete(cd); |
| 0 | 249 cd->set_req(0, prevdom); |
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250 set_early_ctrl(cd); |
| 0 | 251 _igvn._worklist.push(cd); |
| 252 IdealLoopTree *new_loop = get_loop(get_ctrl(cd)); | |
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253 if (old_loop != new_loop) { |
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254 if (!old_loop->_child) old_loop->_body.yank(cd); |
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255 if (!new_loop->_child) new_loop->_body.push(cd); |
| 0 | 256 } |
| 257 --i; | |
| 258 --imax; | |
| 259 } | |
| 260 } | |
| 261 } | |
| 262 | |
| 263 //------------------------------has_local_phi_input---------------------------- | |
| 264 // Return TRUE if 'n' has Phi inputs from its local block and no other | |
| 265 // block-local inputs (all non-local-phi inputs come from earlier blocks) | |
| 266 Node *PhaseIdealLoop::has_local_phi_input( Node *n ) { | |
| 267 Node *n_ctrl = get_ctrl(n); | |
| 268 // See if some inputs come from a Phi in this block, or from before | |
| 269 // this block. | |
| 270 uint i; | |
| 271 for( i = 1; i < n->req(); i++ ) { | |
| 272 Node *phi = n->in(i); | |
| 273 if( phi->is_Phi() && phi->in(0) == n_ctrl ) | |
| 274 break; | |
| 275 } | |
| 276 if( i >= n->req() ) | |
| 277 return NULL; // No Phi inputs; nowhere to clone thru | |
| 278 | |
| 279 // Check for inputs created between 'n' and the Phi input. These | |
| 280 // must split as well; they have already been given the chance | |
| 281 // (courtesy of a post-order visit) and since they did not we must | |
| 282 // recover the 'cost' of splitting them by being very profitable | |
| 283 // when splitting 'n'. Since this is unlikely we simply give up. | |
| 284 for( i = 1; i < n->req(); i++ ) { | |
| 285 Node *m = n->in(i); | |
| 286 if( get_ctrl(m) == n_ctrl && !m->is_Phi() ) { | |
| 287 // We allow the special case of AddP's with no local inputs. | |
| 288 // This allows us to split-up address expressions. | |
| 289 if (m->is_AddP() && | |
| 290 get_ctrl(m->in(2)) != n_ctrl && | |
| 291 get_ctrl(m->in(3)) != n_ctrl) { | |
| 292 // Move the AddP up to dominating point | |
| 293 set_ctrl_and_loop(m, find_non_split_ctrl(idom(n_ctrl))); | |
| 294 continue; | |
| 295 } | |
| 296 return NULL; | |
| 297 } | |
| 298 } | |
| 299 | |
| 300 return n_ctrl; | |
| 301 } | |
| 302 | |
| 303 //------------------------------remix_address_expressions---------------------- | |
| 304 // Rework addressing expressions to get the most loop-invariant stuff | |
| 305 // moved out. We'd like to do all associative operators, but it's especially | |
| 306 // important (common) to do address expressions. | |
| 307 Node *PhaseIdealLoop::remix_address_expressions( Node *n ) { | |
| 308 if (!has_ctrl(n)) return NULL; | |
| 309 Node *n_ctrl = get_ctrl(n); | |
| 310 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
| 311 | |
| 312 // See if 'n' mixes loop-varying and loop-invariant inputs and | |
| 313 // itself is loop-varying. | |
| 314 | |
| 315 // Only interested in binary ops (and AddP) | |
| 316 if( n->req() < 3 || n->req() > 4 ) return NULL; | |
| 317 | |
| 318 Node *n1_ctrl = get_ctrl(n->in( 1)); | |
| 319 Node *n2_ctrl = get_ctrl(n->in( 2)); | |
| 320 Node *n3_ctrl = get_ctrl(n->in(n->req() == 3 ? 2 : 3)); | |
| 321 IdealLoopTree *n1_loop = get_loop( n1_ctrl ); | |
| 322 IdealLoopTree *n2_loop = get_loop( n2_ctrl ); | |
| 323 IdealLoopTree *n3_loop = get_loop( n3_ctrl ); | |
| 324 | |
| 325 // Does one of my inputs spin in a tighter loop than self? | |
| 326 if( (n_loop->is_member( n1_loop ) && n_loop != n1_loop) || | |
| 327 (n_loop->is_member( n2_loop ) && n_loop != n2_loop) || | |
| 328 (n_loop->is_member( n3_loop ) && n_loop != n3_loop) ) | |
| 329 return NULL; // Leave well enough alone | |
| 330 | |
| 331 // Is at least one of my inputs loop-invariant? | |
| 332 if( n1_loop == n_loop && | |
| 333 n2_loop == n_loop && | |
| 334 n3_loop == n_loop ) | |
| 335 return NULL; // No loop-invariant inputs | |
| 336 | |
| 337 | |
| 338 int n_op = n->Opcode(); | |
| 339 | |
| 340 // Replace expressions like ((V+I) << 2) with (V<<2 + I<<2). | |
| 341 if( n_op == Op_LShiftI ) { | |
| 342 // Scale is loop invariant | |
| 343 Node *scale = n->in(2); | |
| 344 Node *scale_ctrl = get_ctrl(scale); | |
| 345 IdealLoopTree *scale_loop = get_loop(scale_ctrl ); | |
| 346 if( n_loop == scale_loop || !scale_loop->is_member( n_loop ) ) | |
| 347 return NULL; | |
| 348 const TypeInt *scale_t = scale->bottom_type()->isa_int(); | |
| 349 if( scale_t && scale_t->is_con() && scale_t->get_con() >= 16 ) | |
| 350 return NULL; // Dont bother with byte/short masking | |
| 351 // Add must vary with loop (else shift would be loop-invariant) | |
| 352 Node *add = n->in(1); | |
| 353 Node *add_ctrl = get_ctrl(add); | |
| 354 IdealLoopTree *add_loop = get_loop(add_ctrl); | |
| 355 //assert( n_loop == add_loop, "" ); | |
| 356 if( n_loop != add_loop ) return NULL; // happens w/ evil ZKM loops | |
| 357 | |
| 358 // Convert I-V into I+ (0-V); same for V-I | |
| 359 if( add->Opcode() == Op_SubI && | |
| 360 _igvn.type( add->in(1) ) != TypeInt::ZERO ) { | |
| 361 Node *zero = _igvn.intcon(0); | |
| 362 set_ctrl(zero, C->root()); | |
| 363 Node *neg = new (C, 3) SubINode( _igvn.intcon(0), add->in(2) ); | |
| 364 register_new_node( neg, get_ctrl(add->in(2) ) ); | |
| 365 add = new (C, 3) AddINode( add->in(1), neg ); | |
| 366 register_new_node( add, add_ctrl ); | |
| 367 } | |
| 368 if( add->Opcode() != Op_AddI ) return NULL; | |
| 369 // See if one add input is loop invariant | |
| 370 Node *add_var = add->in(1); | |
| 371 Node *add_var_ctrl = get_ctrl(add_var); | |
| 372 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl ); | |
| 373 Node *add_invar = add->in(2); | |
| 374 Node *add_invar_ctrl = get_ctrl(add_invar); | |
| 375 IdealLoopTree *add_invar_loop = get_loop(add_invar_ctrl ); | |
| 376 if( add_var_loop == n_loop ) { | |
| 377 } else if( add_invar_loop == n_loop ) { | |
| 378 // Swap to find the invariant part | |
| 379 add_invar = add_var; | |
| 380 add_invar_ctrl = add_var_ctrl; | |
| 381 add_invar_loop = add_var_loop; | |
| 382 add_var = add->in(2); | |
| 383 Node *add_var_ctrl = get_ctrl(add_var); | |
| 384 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl ); | |
| 385 } else // Else neither input is loop invariant | |
| 386 return NULL; | |
| 387 if( n_loop == add_invar_loop || !add_invar_loop->is_member( n_loop ) ) | |
| 388 return NULL; // No invariant part of the add? | |
| 389 | |
| 390 // Yes! Reshape address expression! | |
| 391 Node *inv_scale = new (C, 3) LShiftINode( add_invar, scale ); | |
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392 Node *inv_scale_ctrl = |
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393 dom_depth(add_invar_ctrl) > dom_depth(scale_ctrl) ? |
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394 add_invar_ctrl : scale_ctrl; |
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395 register_new_node( inv_scale, inv_scale_ctrl ); |
| 0 | 396 Node *var_scale = new (C, 3) LShiftINode( add_var, scale ); |
| 397 register_new_node( var_scale, n_ctrl ); | |
| 398 Node *var_add = new (C, 3) AddINode( var_scale, inv_scale ); | |
| 399 register_new_node( var_add, n_ctrl ); | |
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400 _igvn.replace_node( n, var_add ); |
| 0 | 401 return var_add; |
| 402 } | |
| 403 | |
| 404 // Replace (I+V) with (V+I) | |
| 405 if( n_op == Op_AddI || | |
| 406 n_op == Op_AddL || | |
| 407 n_op == Op_AddF || | |
| 408 n_op == Op_AddD || | |
| 409 n_op == Op_MulI || | |
| 410 n_op == Op_MulL || | |
| 411 n_op == Op_MulF || | |
| 412 n_op == Op_MulD ) { | |
| 413 if( n2_loop == n_loop ) { | |
| 414 assert( n1_loop != n_loop, "" ); | |
| 415 n->swap_edges(1, 2); | |
| 416 } | |
| 417 } | |
| 418 | |
| 419 // Replace ((I1 +p V) +p I2) with ((I1 +p I2) +p V), | |
| 420 // but not if I2 is a constant. | |
| 421 if( n_op == Op_AddP ) { | |
| 422 if( n2_loop == n_loop && n3_loop != n_loop ) { | |
| 423 if( n->in(2)->Opcode() == Op_AddP && !n->in(3)->is_Con() ) { | |
| 424 Node *n22_ctrl = get_ctrl(n->in(2)->in(2)); | |
| 425 Node *n23_ctrl = get_ctrl(n->in(2)->in(3)); | |
| 426 IdealLoopTree *n22loop = get_loop( n22_ctrl ); | |
| 427 IdealLoopTree *n23_loop = get_loop( n23_ctrl ); | |
| 428 if( n22loop != n_loop && n22loop->is_member(n_loop) && | |
| 429 n23_loop == n_loop ) { | |
| 430 Node *add1 = new (C, 4) AddPNode( n->in(1), n->in(2)->in(2), n->in(3) ); | |
| 431 // Stuff new AddP in the loop preheader | |
| 432 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) ); | |
| 433 Node *add2 = new (C, 4) AddPNode( n->in(1), add1, n->in(2)->in(3) ); | |
| 434 register_new_node( add2, n_ctrl ); | |
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435 _igvn.replace_node( n, add2 ); |
| 0 | 436 return add2; |
| 437 } | |
| 438 } | |
| 439 } | |
| 440 | |
| 441 // Replace (I1 +p (I2 + V)) with ((I1 +p I2) +p V) | |
| 442 if( n2_loop != n_loop && n3_loop == n_loop ) { | |
| 443 if( n->in(3)->Opcode() == Op_AddI ) { | |
| 444 Node *V = n->in(3)->in(1); | |
| 445 Node *I = n->in(3)->in(2); | |
| 446 if( is_member(n_loop,get_ctrl(V)) ) { | |
| 447 } else { | |
| 448 Node *tmp = V; V = I; I = tmp; | |
| 449 } | |
| 450 if( !is_member(n_loop,get_ctrl(I)) ) { | |
| 451 Node *add1 = new (C, 4) AddPNode( n->in(1), n->in(2), I ); | |
| 452 // Stuff new AddP in the loop preheader | |
| 453 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) ); | |
| 454 Node *add2 = new (C, 4) AddPNode( n->in(1), add1, V ); | |
| 455 register_new_node( add2, n_ctrl ); | |
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456 _igvn.replace_node( n, add2 ); |
| 0 | 457 return add2; |
| 458 } | |
| 459 } | |
| 460 } | |
| 461 } | |
| 462 | |
| 463 return NULL; | |
| 464 } | |
| 465 | |
| 466 //------------------------------conditional_move------------------------------- | |
| 467 // Attempt to replace a Phi with a conditional move. We have some pretty | |
| 468 // strict profitability requirements. All Phis at the merge point must | |
| 469 // be converted, so we can remove the control flow. We need to limit the | |
| 470 // number of c-moves to a small handful. All code that was in the side-arms | |
| 471 // of the CFG diamond is now speculatively executed. This code has to be | |
| 472 // "cheap enough". We are pretty much limited to CFG diamonds that merge | |
| 473 // 1 or 2 items with a total of 1 or 2 ops executed speculatively. | |
| 474 Node *PhaseIdealLoop::conditional_move( Node *region ) { | |
| 475 | |
| 4047 | 476 assert(region->is_Region(), "sanity check"); |
| 477 if (region->req() != 3) return NULL; | |
| 0 | 478 |
| 479 // Check for CFG diamond | |
| 480 Node *lp = region->in(1); | |
| 481 Node *rp = region->in(2); | |
| 4047 | 482 if (!lp || !rp) return NULL; |
| 0 | 483 Node *lp_c = lp->in(0); |
| 4047 | 484 if (lp_c == NULL || lp_c != rp->in(0) || !lp_c->is_If()) return NULL; |
| 0 | 485 IfNode *iff = lp_c->as_If(); |
| 486 | |
| 487 // Check for ops pinned in an arm of the diamond. | |
| 488 // Can't remove the control flow in this case | |
| 4047 | 489 if (lp->outcnt() > 1) return NULL; |
| 490 if (rp->outcnt() > 1) return NULL; | |
| 491 | |
| 492 IdealLoopTree* r_loop = get_loop(region); | |
| 493 assert(r_loop == get_loop(iff), "sanity"); | |
| 494 // Always convert to CMOVE if all results are used only outside this loop. | |
| 495 bool used_inside_loop = (r_loop == _ltree_root); | |
| 0 | 496 |
| 497 // Check profitability | |
| 498 int cost = 0; | |
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499 int phis = 0; |
| 0 | 500 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
| 501 Node *out = region->fast_out(i); | |
| 4047 | 502 if (!out->is_Phi()) continue; // Ignore other control edges, etc |
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503 phis++; |
| 0 | 504 PhiNode* phi = out->as_Phi(); |
| 4047 | 505 BasicType bt = phi->type()->basic_type(); |
| 506 switch (bt) { | |
| 507 case T_FLOAT: | |
| 508 case T_DOUBLE: { | |
| 509 cost += Matcher::float_cmove_cost(); // Could be very expensive | |
| 510 break; | |
| 511 } | |
| 512 case T_LONG: { | |
| 513 cost += Matcher::long_cmove_cost(); // May encodes as 2 CMOV's | |
| 514 } | |
| 0 | 515 case T_INT: // These all CMOV fine |
| 4047 | 516 case T_ADDRESS: { // (RawPtr) |
| 0 | 517 cost++; |
| 518 break; | |
| 4047 | 519 } |
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520 case T_NARROWOOP: // Fall through |
| 0 | 521 case T_OBJECT: { // Base oops are OK, but not derived oops |
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522 const TypeOopPtr *tp = phi->type()->make_ptr()->isa_oopptr(); |
| 0 | 523 // Derived pointers are Bad (tm): what's the Base (for GC purposes) of a |
| 524 // CMOVE'd derived pointer? It's a CMOVE'd derived base. Thus | |
| 525 // CMOVE'ing a derived pointer requires we also CMOVE the base. If we | |
| 526 // have a Phi for the base here that we convert to a CMOVE all is well | |
| 527 // and good. But if the base is dead, we'll not make a CMOVE. Later | |
| 528 // the allocator will have to produce a base by creating a CMOVE of the | |
| 529 // relevant bases. This puts the allocator in the business of | |
| 530 // manufacturing expensive instructions, generally a bad plan. | |
| 531 // Just Say No to Conditionally-Moved Derived Pointers. | |
| 4047 | 532 if (tp && tp->offset() != 0) |
| 0 | 533 return NULL; |
| 534 cost++; | |
| 535 break; | |
| 536 } | |
| 537 default: | |
| 538 return NULL; // In particular, can't do memory or I/O | |
| 539 } | |
| 540 // Add in cost any speculative ops | |
| 4047 | 541 for (uint j = 1; j < region->req(); j++) { |
| 0 | 542 Node *proj = region->in(j); |
| 543 Node *inp = phi->in(j); | |
| 544 if (get_ctrl(inp) == proj) { // Found local op | |
| 545 cost++; | |
| 546 // Check for a chain of dependent ops; these will all become | |
| 547 // speculative in a CMOV. | |
| 4047 | 548 for (uint k = 1; k < inp->req(); k++) |
| 0 | 549 if (get_ctrl(inp->in(k)) == proj) |
| 4047 | 550 cost += ConditionalMoveLimit; // Too much speculative goo |
| 0 | 551 } |
| 552 } | |
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553 // See if the Phi is used by a Cmp or Narrow oop Decode/Encode. |
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554 // This will likely Split-If, a higher-payoff operation. |
| 0 | 555 for (DUIterator_Fast kmax, k = phi->fast_outs(kmax); k < kmax; k++) { |
| 556 Node* use = phi->fast_out(k); | |
| 4047 | 557 if (use->is_Cmp() || use->is_DecodeN() || use->is_EncodeP()) |
| 558 cost += ConditionalMoveLimit; | |
| 559 // Is there a use inside the loop? | |
| 560 // Note: check only basic types since CMoveP is pinned. | |
| 561 if (!used_inside_loop && is_java_primitive(bt)) { | |
| 562 IdealLoopTree* u_loop = get_loop(has_ctrl(use) ? get_ctrl(use) : use); | |
| 563 if (r_loop == u_loop || r_loop->is_member(u_loop)) { | |
| 564 used_inside_loop = true; | |
| 565 } | |
| 566 } | |
| 0 | 567 } |
| 568 } | |
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569 Node* bol = iff->in(1); |
| 4047 | 570 assert(bol->Opcode() == Op_Bool, ""); |
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571 int cmp_op = bol->in(1)->Opcode(); |
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572 // It is expensive to generate flags from a float compare. |
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573 // Avoid duplicated float compare. |
| 4047 | 574 if (phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL; |
| 575 | |
| 576 float infrequent_prob = PROB_UNLIKELY_MAG(3); | |
| 577 // Ignore cost and blocks frequency if CMOVE can be moved outside the loop. | |
| 578 if (used_inside_loop) { | |
| 579 if (cost >= ConditionalMoveLimit) return NULL; // Too much goo | |
| 580 | |
| 581 // BlockLayoutByFrequency optimization moves infrequent branch | |
| 582 // from hot path. No point in CMOV'ing in such case (110 is used | |
| 583 // instead of 100 to take into account not exactness of float value). | |
| 584 if (BlockLayoutByFrequency) { | |
| 585 infrequent_prob = MAX2(infrequent_prob, (float)BlockLayoutMinDiamondPercentage/110.0f); | |
| 586 } | |
| 587 } | |
| 588 // Check for highly predictable branch. No point in CMOV'ing if | |
| 589 // we are going to predict accurately all the time. | |
| 590 if (iff->_prob < infrequent_prob || | |
| 591 iff->_prob > (1.0f - infrequent_prob)) | |
| 592 return NULL; | |
| 0 | 593 |
| 594 // -------------- | |
| 595 // Now replace all Phis with CMOV's | |
| 596 Node *cmov_ctrl = iff->in(0); | |
| 597 uint flip = (lp->Opcode() == Op_IfTrue); | |
| 4047 | 598 while (1) { |
| 0 | 599 PhiNode* phi = NULL; |
| 600 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { | |
| 601 Node *out = region->fast_out(i); | |
| 602 if (out->is_Phi()) { | |
| 603 phi = out->as_Phi(); | |
| 604 break; | |
| 605 } | |
| 606 } | |
| 607 if (phi == NULL) break; | |
| 608 #ifndef PRODUCT | |
| 4047 | 609 if (PrintOpto && VerifyLoopOptimizations) tty->print_cr("CMOV"); |
| 0 | 610 #endif |
| 611 // Move speculative ops | |
| 4047 | 612 for (uint j = 1; j < region->req(); j++) { |
| 0 | 613 Node *proj = region->in(j); |
| 614 Node *inp = phi->in(j); | |
| 615 if (get_ctrl(inp) == proj) { // Found local op | |
| 616 #ifndef PRODUCT | |
| 4047 | 617 if (PrintOpto && VerifyLoopOptimizations) { |
| 0 | 618 tty->print(" speculate: "); |
| 619 inp->dump(); | |
| 620 } | |
| 621 #endif | |
| 622 set_ctrl(inp, cmov_ctrl); | |
| 623 } | |
| 624 } | |
| 625 Node *cmov = CMoveNode::make( C, cmov_ctrl, iff->in(1), phi->in(1+flip), phi->in(2-flip), _igvn.type(phi) ); | |
| 626 register_new_node( cmov, cmov_ctrl ); | |
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627 _igvn.replace_node( phi, cmov ); |
| 0 | 628 #ifndef PRODUCT |
| 4047 | 629 if (TraceLoopOpts) { |
| 630 tty->print("CMOV "); | |
| 631 r_loop->dump_head(); | |
| 632 if (Verbose) | |
| 633 bol->in(1)->dump(1); | |
| 634 cmov->dump(1); | |
| 635 } | |
| 636 if (VerifyLoopOptimizations) verify(); | |
| 0 | 637 #endif |
| 638 } | |
| 639 | |
| 640 // The useless CFG diamond will fold up later; see the optimization in | |
| 641 // RegionNode::Ideal. | |
| 642 _igvn._worklist.push(region); | |
| 643 | |
| 644 return iff->in(1); | |
| 645 } | |
| 646 | |
| 647 //------------------------------split_if_with_blocks_pre----------------------- | |
| 648 // Do the real work in a non-recursive function. Data nodes want to be | |
| 649 // cloned in the pre-order so they can feed each other nicely. | |
| 650 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) { | |
| 651 // Cloning these guys is unlikely to win | |
| 652 int n_op = n->Opcode(); | |
| 653 if( n_op == Op_MergeMem ) return n; | |
| 654 if( n->is_Proj() ) return n; | |
| 655 // Do not clone-up CmpFXXX variations, as these are always | |
| 656 // followed by a CmpI | |
| 657 if( n->is_Cmp() ) return n; | |
| 658 // Attempt to use a conditional move instead of a phi/branch | |
| 659 if( ConditionalMoveLimit > 0 && n_op == Op_Region ) { | |
| 660 Node *cmov = conditional_move( n ); | |
| 661 if( cmov ) return cmov; | |
| 662 } | |
|
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663 if( n->is_CFG() || n->is_LoadStore() ) |
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664 return n; |
| 0 | 665 if( n_op == Op_Opaque1 || // Opaque nodes cannot be mod'd |
| 666 n_op == Op_Opaque2 ) { | |
| 667 if( !C->major_progress() ) // If chance of no more loop opts... | |
| 668 _igvn._worklist.push(n); // maybe we'll remove them | |
| 669 return n; | |
| 670 } | |
| 671 | |
| 672 if( n->is_Con() ) return n; // No cloning for Con nodes | |
| 673 | |
| 674 Node *n_ctrl = get_ctrl(n); | |
| 675 if( !n_ctrl ) return n; // Dead node | |
| 676 | |
| 677 // Attempt to remix address expressions for loop invariants | |
| 678 Node *m = remix_address_expressions( n ); | |
| 679 if( m ) return m; | |
| 680 | |
| 681 // Determine if the Node has inputs from some local Phi. | |
| 682 // Returns the block to clone thru. | |
| 683 Node *n_blk = has_local_phi_input( n ); | |
| 684 if( !n_blk ) return n; | |
| 685 // Do not clone the trip counter through on a CountedLoop | |
| 686 // (messes up the canonical shape). | |
| 687 if( n_blk->is_CountedLoop() && n->Opcode() == Op_AddI ) return n; | |
| 688 | |
| 689 // Check for having no control input; not pinned. Allow | |
| 690 // dominating control. | |
| 691 if( n->in(0) ) { | |
| 692 Node *dom = idom(n_blk); | |
| 693 if( dom_lca( n->in(0), dom ) != n->in(0) ) | |
| 694 return n; | |
| 695 } | |
| 696 // Policy: when is it profitable. You must get more wins than | |
| 697 // policy before it is considered profitable. Policy is usually 0, | |
| 698 // so 1 win is considered profitable. Big merges will require big | |
| 699 // cloning, so get a larger policy. | |
| 700 int policy = n_blk->req() >> 2; | |
| 701 | |
| 702 // If the loop is a candidate for range check elimination, | |
| 703 // delay splitting through it's phi until a later loop optimization | |
| 704 if (n_blk->is_CountedLoop()) { | |
| 705 IdealLoopTree *lp = get_loop(n_blk); | |
| 706 if (lp && lp->_rce_candidate) { | |
| 707 return n; | |
| 708 } | |
| 709 } | |
| 710 | |
| 711 // Use same limit as split_if_with_blocks_post | |
| 712 if( C->unique() > 35000 ) return n; // Method too big | |
| 713 | |
| 714 // Split 'n' through the merge point if it is profitable | |
| 715 Node *phi = split_thru_phi( n, n_blk, policy ); | |
| 4047 | 716 if (!phi) return n; |
| 0 | 717 |
| 718 // Found a Phi to split thru! | |
| 719 // Replace 'n' with the new phi | |
|
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720 _igvn.replace_node( n, phi ); |
| 0 | 721 // Moved a load around the loop, 'en-registering' something. |
| 4047 | 722 if (n_blk->is_Loop() && n->is_Load() && |
| 723 !phi->in(LoopNode::LoopBackControl)->is_Load()) | |
| 0 | 724 C->set_major_progress(); |
| 725 | |
| 726 return phi; | |
| 727 } | |
| 728 | |
| 729 static bool merge_point_too_heavy(Compile* C, Node* region) { | |
| 730 // Bail out if the region and its phis have too many users. | |
| 731 int weight = 0; | |
| 732 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { | |
| 733 weight += region->fast_out(i)->outcnt(); | |
| 734 } | |
| 735 int nodes_left = MaxNodeLimit - C->unique(); | |
| 736 if (weight * 8 > nodes_left) { | |
| 737 #ifndef PRODUCT | |
| 738 if (PrintOpto) | |
| 739 tty->print_cr("*** Split-if bails out: %d nodes, region weight %d", C->unique(), weight); | |
| 740 #endif | |
| 741 return true; | |
| 742 } else { | |
| 743 return false; | |
| 744 } | |
| 745 } | |
| 746 | |
| 747 static bool merge_point_safe(Node* region) { | |
| 748 // 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode | |
| 749 // having a PhiNode input. This sidesteps the dangerous case where the split | |
| 750 // ConvI2LNode may become TOP if the input Value() does not | |
| 751 // overlap the ConvI2L range, leaving a node which may not dominate its | |
| 752 // uses. | |
| 753 // A better fix for this problem can be found in the BugTraq entry, but | |
| 754 // expediency for Mantis demands this hack. | |
|
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755 // 6855164: If the merge point has a FastLockNode with a PhiNode input, we stop |
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756 // split_if_with_blocks from splitting a block because we could not move around |
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757 // the FastLockNode. |
| 0 | 758 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
| 759 Node* n = region->fast_out(i); | |
| 760 if (n->is_Phi()) { | |
| 761 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
| 762 Node* m = n->fast_out(j); | |
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763 if (m->is_FastLock()) |
| 0 | 764 return false; |
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765 #ifdef _LP64 |
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766 if (m->Opcode() == Op_ConvI2L) |
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767 return false; |
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768 #endif |
| 0 | 769 } |
| 770 } | |
| 771 } | |
| 772 return true; | |
| 773 } | |
| 774 | |
| 775 | |
| 776 //------------------------------place_near_use--------------------------------- | |
| 777 // Place some computation next to use but not inside inner loops. | |
| 778 // For inner loop uses move it to the preheader area. | |
| 779 Node *PhaseIdealLoop::place_near_use( Node *useblock ) const { | |
| 780 IdealLoopTree *u_loop = get_loop( useblock ); | |
| 781 return (u_loop->_irreducible || u_loop->_child) | |
| 782 ? useblock | |
| 783 : u_loop->_head->in(LoopNode::EntryControl); | |
| 784 } | |
| 785 | |
| 786 | |
| 787 //------------------------------split_if_with_blocks_post---------------------- | |
| 788 // Do the real work in a non-recursive function. CFG hackery wants to be | |
| 789 // in the post-order, so it can dirty the I-DOM info and not use the dirtied | |
| 790 // info. | |
| 791 void PhaseIdealLoop::split_if_with_blocks_post( Node *n ) { | |
| 792 | |
| 793 // Cloning Cmp through Phi's involves the split-if transform. | |
| 794 // FastLock is not used by an If | |
| 795 if( n->is_Cmp() && !n->is_FastLock() ) { | |
| 796 if( C->unique() > 35000 ) return; // Method too big | |
| 797 | |
| 798 // Do not do 'split-if' if irreducible loops are present. | |
| 799 if( _has_irreducible_loops ) | |
| 800 return; | |
| 801 | |
| 802 Node *n_ctrl = get_ctrl(n); | |
| 803 // Determine if the Node has inputs from some local Phi. | |
| 804 // Returns the block to clone thru. | |
| 805 Node *n_blk = has_local_phi_input( n ); | |
| 806 if( n_blk != n_ctrl ) return; | |
| 807 | |
| 808 if( merge_point_too_heavy(C, n_ctrl) ) | |
| 809 return; | |
| 810 | |
| 811 if( n->outcnt() != 1 ) return; // Multiple bool's from 1 compare? | |
| 812 Node *bol = n->unique_out(); | |
| 813 assert( bol->is_Bool(), "expect a bool here" ); | |
| 814 if( bol->outcnt() != 1 ) return;// Multiple branches from 1 compare? | |
| 815 Node *iff = bol->unique_out(); | |
| 816 | |
| 817 // Check some safety conditions | |
| 818 if( iff->is_If() ) { // Classic split-if? | |
| 819 if( iff->in(0) != n_ctrl ) return; // Compare must be in same blk as if | |
| 820 } else if (iff->is_CMove()) { // Trying to split-up a CMOVE | |
| 821 if( get_ctrl(iff->in(2)) == n_ctrl || | |
| 822 get_ctrl(iff->in(3)) == n_ctrl ) | |
| 823 return; // Inputs not yet split-up | |
| 824 if ( get_loop(n_ctrl) != get_loop(get_ctrl(iff)) ) { | |
| 825 return; // Loop-invar test gates loop-varying CMOVE | |
| 826 } | |
| 827 } else { | |
| 828 return; // some other kind of node, such as an Allocate | |
| 829 } | |
| 830 | |
| 831 // Do not do 'split-if' if some paths are dead. First do dead code | |
| 832 // elimination and then see if its still profitable. | |
| 833 for( uint i = 1; i < n_ctrl->req(); i++ ) | |
| 834 if( n_ctrl->in(i) == C->top() ) | |
| 835 return; | |
| 836 | |
| 837 // When is split-if profitable? Every 'win' on means some control flow | |
| 838 // goes dead, so it's almost always a win. | |
| 839 int policy = 0; | |
| 840 // If trying to do a 'Split-If' at the loop head, it is only | |
| 841 // profitable if the cmp folds up on BOTH paths. Otherwise we | |
| 842 // risk peeling a loop forever. | |
| 843 | |
| 844 // CNC - Disabled for now. Requires careful handling of loop | |
| 845 // body selection for the cloned code. Also, make sure we check | |
| 846 // for any input path not being in the same loop as n_ctrl. For | |
| 847 // irreducible loops we cannot check for 'n_ctrl->is_Loop()' | |
| 848 // because the alternative loop entry points won't be converted | |
| 849 // into LoopNodes. | |
| 850 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
| 851 for( uint j = 1; j < n_ctrl->req(); j++ ) | |
| 852 if( get_loop(n_ctrl->in(j)) != n_loop ) | |
| 853 return; | |
| 854 | |
| 855 // Check for safety of the merge point. | |
| 856 if( !merge_point_safe(n_ctrl) ) { | |
| 857 return; | |
| 858 } | |
| 859 | |
| 860 // Split compare 'n' through the merge point if it is profitable | |
| 861 Node *phi = split_thru_phi( n, n_ctrl, policy ); | |
| 862 if( !phi ) return; | |
| 863 | |
| 864 // Found a Phi to split thru! | |
| 865 // Replace 'n' with the new phi | |
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866 _igvn.replace_node( n, phi ); |
| 0 | 867 |
| 868 // Now split the bool up thru the phi | |
| 869 Node *bolphi = split_thru_phi( bol, n_ctrl, -1 ); | |
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870 _igvn.replace_node( bol, bolphi ); |
| 0 | 871 assert( iff->in(1) == bolphi, "" ); |
| 872 if( bolphi->Value(&_igvn)->singleton() ) | |
| 873 return; | |
| 874 | |
| 875 // Conditional-move? Must split up now | |
| 876 if( !iff->is_If() ) { | |
| 877 Node *cmovphi = split_thru_phi( iff, n_ctrl, -1 ); | |
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878 _igvn.replace_node( iff, cmovphi ); |
| 0 | 879 return; |
| 880 } | |
| 881 | |
| 882 // Now split the IF | |
| 883 do_split_if( iff ); | |
| 884 return; | |
| 885 } | |
| 886 | |
| 887 // Check for an IF ready to split; one that has its | |
| 888 // condition codes input coming from a Phi at the block start. | |
| 889 int n_op = n->Opcode(); | |
| 890 | |
| 891 // Check for an IF being dominated by another IF same test | |
| 892 if( n_op == Op_If ) { | |
| 893 Node *bol = n->in(1); | |
| 894 uint max = bol->outcnt(); | |
| 895 // Check for same test used more than once? | |
| 896 if( n_op == Op_If && max > 1 && bol->is_Bool() ) { | |
| 897 // Search up IDOMs to see if this IF is dominated. | |
| 898 Node *cutoff = get_ctrl(bol); | |
| 899 | |
| 900 // Now search up IDOMs till cutoff, looking for a dominating test | |
| 901 Node *prevdom = n; | |
| 902 Node *dom = idom(prevdom); | |
| 903 while( dom != cutoff ) { | |
| 904 if( dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom ) { | |
| 905 // Replace the dominated test with an obvious true or false. | |
| 906 // Place it on the IGVN worklist for later cleanup. | |
| 907 C->set_major_progress(); | |
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908 dominated_by( prevdom, n, false, true ); |
| 0 | 909 #ifndef PRODUCT |
| 910 if( VerifyLoopOptimizations ) verify(); | |
| 911 #endif | |
| 912 return; | |
| 913 } | |
| 914 prevdom = dom; | |
| 915 dom = idom(prevdom); | |
| 916 } | |
| 917 } | |
| 918 } | |
| 919 | |
| 920 // See if a shared loop-varying computation has no loop-varying uses. | |
| 921 // Happens if something is only used for JVM state in uncommon trap exits, | |
| 922 // like various versions of induction variable+offset. Clone the | |
| 923 // computation per usage to allow it to sink out of the loop. | |
| 924 if (has_ctrl(n) && !n->in(0)) {// n not dead and has no control edge (can float about) | |
| 925 Node *n_ctrl = get_ctrl(n); | |
| 926 IdealLoopTree *n_loop = get_loop(n_ctrl); | |
| 927 if( n_loop != _ltree_root ) { | |
| 928 DUIterator_Fast imax, i = n->fast_outs(imax); | |
| 929 for (; i < imax; i++) { | |
| 930 Node* u = n->fast_out(i); | |
| 931 if( !has_ctrl(u) ) break; // Found control user | |
| 932 IdealLoopTree *u_loop = get_loop(get_ctrl(u)); | |
| 933 if( u_loop == n_loop ) break; // Found loop-varying use | |
| 934 if( n_loop->is_member( u_loop ) ) break; // Found use in inner loop | |
| 935 if( u->Opcode() == Op_Opaque1 ) break; // Found loop limit, bugfix for 4677003 | |
| 936 } | |
| 937 bool did_break = (i < imax); // Did we break out of the previous loop? | |
| 938 if (!did_break && n->outcnt() > 1) { // All uses in outer loops! | |
| 939 Node *late_load_ctrl; | |
| 940 if (n->is_Load()) { | |
| 941 // If n is a load, get and save the result from get_late_ctrl(), | |
| 942 // to be later used in calculating the control for n's clones. | |
| 943 clear_dom_lca_tags(); | |
| 944 late_load_ctrl = get_late_ctrl(n, n_ctrl); | |
| 945 } | |
| 946 // If n is a load, and the late control is the same as the current | |
| 947 // control, then the cloning of n is a pointless exercise, because | |
| 948 // GVN will ensure that we end up where we started. | |
| 949 if (!n->is_Load() || late_load_ctrl != n_ctrl) { | |
| 950 for (DUIterator_Last jmin, j = n->last_outs(jmin); j >= jmin; ) { | |
| 951 Node *u = n->last_out(j); // Clone private computation per use | |
| 952 _igvn.hash_delete(u); | |
| 953 _igvn._worklist.push(u); | |
| 954 Node *x = n->clone(); // Clone computation | |
| 955 Node *x_ctrl = NULL; | |
| 956 if( u->is_Phi() ) { | |
| 957 // Replace all uses of normal nodes. Replace Phi uses | |
| 605 | 958 // individually, so the separate Nodes can sink down |
| 0 | 959 // different paths. |
| 960 uint k = 1; | |
| 961 while( u->in(k) != n ) k++; | |
| 962 u->set_req( k, x ); | |
| 963 // x goes next to Phi input path | |
| 964 x_ctrl = u->in(0)->in(k); | |
| 965 --j; | |
| 966 } else { // Normal use | |
| 967 // Replace all uses | |
| 968 for( uint k = 0; k < u->req(); k++ ) { | |
| 969 if( u->in(k) == n ) { | |
| 970 u->set_req( k, x ); | |
| 971 --j; | |
| 972 } | |
| 973 } | |
| 974 x_ctrl = get_ctrl(u); | |
| 975 } | |
| 976 | |
| 977 // Find control for 'x' next to use but not inside inner loops. | |
| 978 // For inner loop uses get the preheader area. | |
| 979 x_ctrl = place_near_use(x_ctrl); | |
| 980 | |
| 981 if (n->is_Load()) { | |
| 982 // For loads, add a control edge to a CFG node outside of the loop | |
| 983 // to force them to not combine and return back inside the loop | |
| 984 // during GVN optimization (4641526). | |
| 985 // | |
| 986 // Because we are setting the actual control input, factor in | |
| 987 // the result from get_late_ctrl() so we respect any | |
| 988 // anti-dependences. (6233005). | |
| 989 x_ctrl = dom_lca(late_load_ctrl, x_ctrl); | |
| 990 | |
| 991 // Don't allow the control input to be a CFG splitting node. | |
| 992 // Such nodes should only have ProjNodes as outs, e.g. IfNode | |
| 993 // should only have IfTrueNode and IfFalseNode (4985384). | |
| 994 x_ctrl = find_non_split_ctrl(x_ctrl); | |
| 995 assert(dom_depth(n_ctrl) <= dom_depth(x_ctrl), "n is later than its clone"); | |
| 996 | |
| 997 x->set_req(0, x_ctrl); | |
| 998 } | |
| 999 register_new_node(x, x_ctrl); | |
| 1000 | |
| 1001 // Some institutional knowledge is needed here: 'x' is | |
| 1002 // yanked because if the optimizer runs GVN on it all the | |
| 1003 // cloned x's will common up and undo this optimization and | |
| 1004 // be forced back in the loop. This is annoying because it | |
| 1005 // makes +VerifyOpto report false-positives on progress. I | |
| 1006 // tried setting control edges on the x's to force them to | |
| 1007 // not combine, but the matching gets worried when it tries | |
| 1008 // to fold a StoreP and an AddP together (as part of an | |
| 1009 // address expression) and the AddP and StoreP have | |
| 1010 // different controls. | |
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1011 if( !x->is_Load() && !x->is_DecodeN() ) _igvn._worklist.yank(x); |
| 0 | 1012 } |
| 1013 _igvn.remove_dead_node(n); | |
| 1014 } | |
| 1015 } | |
| 1016 } | |
| 1017 } | |
| 1018 | |
| 1019 // Check for Opaque2's who's loop has disappeared - who's input is in the | |
| 1020 // same loop nest as their output. Remove 'em, they are no longer useful. | |
| 1021 if( n_op == Op_Opaque2 && | |
| 1022 n->in(1) != NULL && | |
| 1023 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) { | |
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1024 _igvn.replace_node( n, n->in(1) ); |
| 0 | 1025 } |
| 1026 } | |
| 1027 | |
| 1028 //------------------------------split_if_with_blocks--------------------------- | |
| 1029 // Check for aggressive application of 'split-if' optimization, | |
| 1030 // using basic block level info. | |
| 1031 void PhaseIdealLoop::split_if_with_blocks( VectorSet &visited, Node_Stack &nstack ) { | |
| 1032 Node *n = C->root(); | |
| 1033 visited.set(n->_idx); // first, mark node as visited | |
| 1034 // Do pre-visit work for root | |
| 1035 n = split_if_with_blocks_pre( n ); | |
| 1036 uint cnt = n->outcnt(); | |
| 1037 uint i = 0; | |
| 1038 while (true) { | |
| 1039 // Visit all children | |
| 1040 if (i < cnt) { | |
| 1041 Node* use = n->raw_out(i); | |
| 1042 ++i; | |
| 1043 if (use->outcnt() != 0 && !visited.test_set(use->_idx)) { | |
| 1044 // Now do pre-visit work for this use | |
| 1045 use = split_if_with_blocks_pre( use ); | |
| 1046 nstack.push(n, i); // Save parent and next use's index. | |
| 1047 n = use; // Process all children of current use. | |
| 1048 cnt = use->outcnt(); | |
| 1049 i = 0; | |
| 1050 } | |
| 1051 } | |
| 1052 else { | |
| 1053 // All of n's children have been processed, complete post-processing. | |
| 1054 if (cnt != 0 && !n->is_Con()) { | |
| 1055 assert(has_node(n), "no dead nodes"); | |
| 1056 split_if_with_blocks_post( n ); | |
| 1057 } | |
| 1058 if (nstack.is_empty()) { | |
| 1059 // Finished all nodes on stack. | |
| 1060 break; | |
| 1061 } | |
| 1062 // Get saved parent node and next use's index. Visit the rest of uses. | |
| 1063 n = nstack.node(); | |
| 1064 cnt = n->outcnt(); | |
| 1065 i = nstack.index(); | |
| 1066 nstack.pop(); | |
| 1067 } | |
| 1068 } | |
| 1069 } | |
| 1070 | |
| 1071 | |
| 1072 //============================================================================= | |
| 1073 // | |
| 1074 // C L O N E A L O O P B O D Y | |
| 1075 // | |
| 1076 | |
| 1077 //------------------------------clone_iff-------------------------------------- | |
| 1078 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
| 1079 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
| 1080 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
| 1081 // through the Phi recursively, and return a Bool. | |
| 1082 BoolNode *PhaseIdealLoop::clone_iff( PhiNode *phi, IdealLoopTree *loop ) { | |
| 1083 | |
| 1084 // Convert this Phi into a Phi merging Bools | |
| 1085 uint i; | |
| 1086 for( i = 1; i < phi->req(); i++ ) { | |
| 1087 Node *b = phi->in(i); | |
| 1088 if( b->is_Phi() ) { | |
| 1089 _igvn.hash_delete(phi); | |
| 1090 _igvn._worklist.push(phi); | |
| 1091 phi->set_req(i, clone_iff( b->as_Phi(), loop )); | |
| 1092 } else { | |
| 1093 assert( b->is_Bool(), "" ); | |
| 1094 } | |
| 1095 } | |
| 1096 | |
| 1097 Node *sample_bool = phi->in(1); | |
| 1098 Node *sample_cmp = sample_bool->in(1); | |
| 1099 | |
| 1100 // Make Phis to merge the Cmp's inputs. | |
| 1101 int size = phi->in(0)->req(); | |
| 1102 PhiNode *phi1 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
| 1103 PhiNode *phi2 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
| 1104 for( i = 1; i < phi->req(); i++ ) { | |
| 1105 Node *n1 = phi->in(i)->in(1)->in(1); | |
| 1106 Node *n2 = phi->in(i)->in(1)->in(2); | |
| 1107 phi1->set_req( i, n1 ); | |
| 1108 phi2->set_req( i, n2 ); | |
| 1109 phi1->set_type( phi1->type()->meet(n1->bottom_type()) ); | |
| 1110 phi2->set_type( phi2->type()->meet(n2->bottom_type()) ); | |
| 1111 } | |
| 1112 // See if these Phis have been made before. | |
| 1113 // Register with optimizer | |
| 1114 Node *hit1 = _igvn.hash_find_insert(phi1); | |
| 1115 if( hit1 ) { // Hit, toss just made Phi | |
| 1116 _igvn.remove_dead_node(phi1); // Remove new phi | |
| 1117 assert( hit1->is_Phi(), "" ); | |
| 1118 phi1 = (PhiNode*)hit1; // Use existing phi | |
| 1119 } else { // Miss | |
| 1120 _igvn.register_new_node_with_optimizer(phi1); | |
| 1121 } | |
| 1122 Node *hit2 = _igvn.hash_find_insert(phi2); | |
| 1123 if( hit2 ) { // Hit, toss just made Phi | |
| 1124 _igvn.remove_dead_node(phi2); // Remove new phi | |
| 1125 assert( hit2->is_Phi(), "" ); | |
| 1126 phi2 = (PhiNode*)hit2; // Use existing phi | |
| 1127 } else { // Miss | |
| 1128 _igvn.register_new_node_with_optimizer(phi2); | |
| 1129 } | |
| 1130 // Register Phis with loop/block info | |
| 1131 set_ctrl(phi1, phi->in(0)); | |
| 1132 set_ctrl(phi2, phi->in(0)); | |
| 1133 // Make a new Cmp | |
| 1134 Node *cmp = sample_cmp->clone(); | |
| 1135 cmp->set_req( 1, phi1 ); | |
| 1136 cmp->set_req( 2, phi2 ); | |
| 1137 _igvn.register_new_node_with_optimizer(cmp); | |
| 1138 set_ctrl(cmp, phi->in(0)); | |
| 1139 | |
| 1140 // Make a new Bool | |
| 1141 Node *b = sample_bool->clone(); | |
| 1142 b->set_req(1,cmp); | |
| 1143 _igvn.register_new_node_with_optimizer(b); | |
| 1144 set_ctrl(b, phi->in(0)); | |
| 1145 | |
| 1146 assert( b->is_Bool(), "" ); | |
| 1147 return (BoolNode*)b; | |
| 1148 } | |
| 1149 | |
| 1150 //------------------------------clone_bool------------------------------------- | |
| 1151 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
| 1152 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
| 1153 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
| 1154 // through the Phi recursively, and return a Bool. | |
| 1155 CmpNode *PhaseIdealLoop::clone_bool( PhiNode *phi, IdealLoopTree *loop ) { | |
| 1156 uint i; | |
| 1157 // Convert this Phi into a Phi merging Bools | |
| 1158 for( i = 1; i < phi->req(); i++ ) { | |
| 1159 Node *b = phi->in(i); | |
| 1160 if( b->is_Phi() ) { | |
| 1161 _igvn.hash_delete(phi); | |
| 1162 _igvn._worklist.push(phi); | |
| 1163 phi->set_req(i, clone_bool( b->as_Phi(), loop )); | |
| 1164 } else { | |
| 1165 assert( b->is_Cmp() || b->is_top(), "inputs are all Cmp or TOP" ); | |
| 1166 } | |
| 1167 } | |
| 1168 | |
| 1169 Node *sample_cmp = phi->in(1); | |
| 1170 | |
| 1171 // Make Phis to merge the Cmp's inputs. | |
| 1172 int size = phi->in(0)->req(); | |
| 1173 PhiNode *phi1 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
| 1174 PhiNode *phi2 = new (C, size) PhiNode( phi->in(0), Type::TOP ); | |
| 1175 for( uint j = 1; j < phi->req(); j++ ) { | |
| 1176 Node *cmp_top = phi->in(j); // Inputs are all Cmp or TOP | |
| 1177 Node *n1, *n2; | |
| 1178 if( cmp_top->is_Cmp() ) { | |
| 1179 n1 = cmp_top->in(1); | |
| 1180 n2 = cmp_top->in(2); | |
| 1181 } else { | |
| 1182 n1 = n2 = cmp_top; | |
| 1183 } | |
| 1184 phi1->set_req( j, n1 ); | |
| 1185 phi2->set_req( j, n2 ); | |
| 1186 phi1->set_type( phi1->type()->meet(n1->bottom_type()) ); | |
| 1187 phi2->set_type( phi2->type()->meet(n2->bottom_type()) ); | |
| 1188 } | |
| 1189 | |
| 1190 // See if these Phis have been made before. | |
| 1191 // Register with optimizer | |
| 1192 Node *hit1 = _igvn.hash_find_insert(phi1); | |
| 1193 if( hit1 ) { // Hit, toss just made Phi | |
| 1194 _igvn.remove_dead_node(phi1); // Remove new phi | |
| 1195 assert( hit1->is_Phi(), "" ); | |
| 1196 phi1 = (PhiNode*)hit1; // Use existing phi | |
| 1197 } else { // Miss | |
| 1198 _igvn.register_new_node_with_optimizer(phi1); | |
| 1199 } | |
| 1200 Node *hit2 = _igvn.hash_find_insert(phi2); | |
| 1201 if( hit2 ) { // Hit, toss just made Phi | |
| 1202 _igvn.remove_dead_node(phi2); // Remove new phi | |
| 1203 assert( hit2->is_Phi(), "" ); | |
| 1204 phi2 = (PhiNode*)hit2; // Use existing phi | |
| 1205 } else { // Miss | |
| 1206 _igvn.register_new_node_with_optimizer(phi2); | |
| 1207 } | |
| 1208 // Register Phis with loop/block info | |
| 1209 set_ctrl(phi1, phi->in(0)); | |
| 1210 set_ctrl(phi2, phi->in(0)); | |
| 1211 // Make a new Cmp | |
| 1212 Node *cmp = sample_cmp->clone(); | |
| 1213 cmp->set_req( 1, phi1 ); | |
| 1214 cmp->set_req( 2, phi2 ); | |
| 1215 _igvn.register_new_node_with_optimizer(cmp); | |
| 1216 set_ctrl(cmp, phi->in(0)); | |
| 1217 | |
| 1218 assert( cmp->is_Cmp(), "" ); | |
| 1219 return (CmpNode*)cmp; | |
| 1220 } | |
| 1221 | |
| 1222 //------------------------------sink_use--------------------------------------- | |
| 1223 // If 'use' was in the loop-exit block, it now needs to be sunk | |
| 1224 // below the post-loop merge point. | |
| 1225 void PhaseIdealLoop::sink_use( Node *use, Node *post_loop ) { | |
| 1226 if (!use->is_CFG() && get_ctrl(use) == post_loop->in(2)) { | |
| 1227 set_ctrl(use, post_loop); | |
| 1228 for (DUIterator j = use->outs(); use->has_out(j); j++) | |
| 1229 sink_use(use->out(j), post_loop); | |
| 1230 } | |
| 1231 } | |
| 1232 | |
| 1233 //------------------------------clone_loop------------------------------------- | |
| 1234 // | |
| 1235 // C L O N E A L O O P B O D Y | |
| 1236 // | |
| 1237 // This is the basic building block of the loop optimizations. It clones an | |
| 1238 // entire loop body. It makes an old_new loop body mapping; with this mapping | |
| 1239 // you can find the new-loop equivalent to an old-loop node. All new-loop | |
| 1240 // nodes are exactly equal to their old-loop counterparts, all edges are the | |
| 1241 // same. All exits from the old-loop now have a RegionNode that merges the | |
| 1242 // equivalent new-loop path. This is true even for the normal "loop-exit" | |
| 1243 // condition. All uses of loop-invariant old-loop values now come from (one | |
| 1244 // or more) Phis that merge their new-loop equivalents. | |
| 1245 // | |
| 1246 // This operation leaves the graph in an illegal state: there are two valid | |
| 1247 // control edges coming from the loop pre-header to both loop bodies. I'll | |
| 1248 // definitely have to hack the graph after running this transform. | |
| 1249 // | |
| 1250 // From this building block I will further edit edges to perform loop peeling | |
| 1251 // or loop unrolling or iteration splitting (Range-Check-Elimination), etc. | |
| 1252 // | |
| 1253 // Parameter side_by_size_idom: | |
| 1254 // When side_by_size_idom is NULL, the dominator tree is constructed for | |
| 1255 // the clone loop to dominate the original. Used in construction of | |
| 1256 // pre-main-post loop sequence. | |
| 1257 // When nonnull, the clone and original are side-by-side, both are | |
| 1258 // dominated by the side_by_side_idom node. Used in construction of | |
| 1259 // unswitched loops. | |
| 1260 void PhaseIdealLoop::clone_loop( IdealLoopTree *loop, Node_List &old_new, int dd, | |
| 1261 Node* side_by_side_idom) { | |
| 1262 | |
| 1263 // Step 1: Clone the loop body. Make the old->new mapping. | |
| 1264 uint i; | |
| 1265 for( i = 0; i < loop->_body.size(); i++ ) { | |
| 1266 Node *old = loop->_body.at(i); | |
| 1267 Node *nnn = old->clone(); | |
| 1268 old_new.map( old->_idx, nnn ); | |
| 1269 _igvn.register_new_node_with_optimizer(nnn); | |
| 1270 } | |
| 1271 | |
| 1272 | |
| 1273 // Step 2: Fix the edges in the new body. If the old input is outside the | |
| 1274 // loop use it. If the old input is INside the loop, use the corresponding | |
| 1275 // new node instead. | |
| 1276 for( i = 0; i < loop->_body.size(); i++ ) { | |
| 1277 Node *old = loop->_body.at(i); | |
| 1278 Node *nnn = old_new[old->_idx]; | |
| 1279 // Fix CFG/Loop controlling the new node | |
| 1280 if (has_ctrl(old)) { | |
| 1281 set_ctrl(nnn, old_new[get_ctrl(old)->_idx]); | |
| 1282 } else { | |
| 1283 set_loop(nnn, loop->_parent); | |
| 1284 if (old->outcnt() > 0) { | |
| 1285 set_idom( nnn, old_new[idom(old)->_idx], dd ); | |
| 1286 } | |
| 1287 } | |
| 1288 // Correct edges to the new node | |
| 1289 for( uint j = 0; j < nnn->req(); j++ ) { | |
| 1290 Node *n = nnn->in(j); | |
| 1291 if( n ) { | |
| 1292 IdealLoopTree *old_in_loop = get_loop( has_ctrl(n) ? get_ctrl(n) : n ); | |
| 1293 if( loop->is_member( old_in_loop ) ) | |
| 1294 nnn->set_req(j, old_new[n->_idx]); | |
| 1295 } | |
| 1296 } | |
| 1297 _igvn.hash_find_insert(nnn); | |
| 1298 } | |
| 1299 Node *newhead = old_new[loop->_head->_idx]; | |
| 1300 set_idom(newhead, newhead->in(LoopNode::EntryControl), dd); | |
| 1301 | |
| 1302 | |
| 1303 // Step 3: Now fix control uses. Loop varying control uses have already | |
| 1304 // been fixed up (as part of all input edges in Step 2). Loop invariant | |
| 1305 // control uses must be either an IfFalse or an IfTrue. Make a merge | |
| 1306 // point to merge the old and new IfFalse/IfTrue nodes; make the use | |
| 1307 // refer to this. | |
| 1308 ResourceArea *area = Thread::current()->resource_area(); | |
| 1309 Node_List worklist(area); | |
| 1310 uint new_counter = C->unique(); | |
| 1311 for( i = 0; i < loop->_body.size(); i++ ) { | |
| 1312 Node* old = loop->_body.at(i); | |
| 1313 if( !old->is_CFG() ) continue; | |
| 1314 Node* nnn = old_new[old->_idx]; | |
| 1315 | |
| 1316 // Copy uses to a worklist, so I can munge the def-use info | |
| 1317 // with impunity. | |
| 1318 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++) | |
| 1319 worklist.push(old->fast_out(j)); | |
| 1320 | |
| 1321 while( worklist.size() ) { // Visit all uses | |
| 1322 Node *use = worklist.pop(); | |
| 1323 if (!has_node(use)) continue; // Ignore dead nodes | |
| 1324 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use ); | |
| 1325 if( !loop->is_member( use_loop ) && use->is_CFG() ) { | |
| 1326 // Both OLD and USE are CFG nodes here. | |
| 1327 assert( use->is_Proj(), "" ); | |
| 1328 | |
| 1329 // Clone the loop exit control projection | |
| 1330 Node *newuse = use->clone(); | |
| 1331 newuse->set_req(0,nnn); | |
| 1332 _igvn.register_new_node_with_optimizer(newuse); | |
| 1333 set_loop(newuse, use_loop); | |
| 1334 set_idom(newuse, nnn, dom_depth(nnn) + 1 ); | |
| 1335 | |
| 1336 // We need a Region to merge the exit from the peeled body and the | |
| 1337 // exit from the old loop body. | |
| 1338 RegionNode *r = new (C, 3) RegionNode(3); | |
| 1339 // Map the old use to the new merge point | |
| 1340 old_new.map( use->_idx, r ); | |
| 1341 uint dd_r = MIN2(dom_depth(newuse),dom_depth(use)); | |
| 1342 assert( dd_r >= dom_depth(dom_lca(newuse,use)), "" ); | |
| 1343 | |
| 1344 // The original user of 'use' uses 'r' instead. | |
| 1345 for (DUIterator_Last lmin, l = use->last_outs(lmin); l >= lmin;) { | |
| 1346 Node* useuse = use->last_out(l); | |
| 1347 _igvn.hash_delete(useuse); | |
| 1348 _igvn._worklist.push(useuse); | |
| 1349 uint uses_found = 0; | |
| 1350 if( useuse->in(0) == use ) { | |
| 1351 useuse->set_req(0, r); | |
| 1352 uses_found++; | |
| 1353 if( useuse->is_CFG() ) { | |
| 1354 assert( dom_depth(useuse) > dd_r, "" ); | |
| 1355 set_idom(useuse, r, dom_depth(useuse)); | |
| 1356 } | |
| 1357 } | |
| 1358 for( uint k = 1; k < useuse->req(); k++ ) { | |
| 1359 if( useuse->in(k) == use ) { | |
| 1360 useuse->set_req(k, r); | |
| 1361 uses_found++; | |
| 1362 } | |
| 1363 } | |
| 1364 l -= uses_found; // we deleted 1 or more copies of this edge | |
| 1365 } | |
| 1366 | |
| 1367 // Now finish up 'r' | |
| 1368 r->set_req( 1, newuse ); | |
| 1369 r->set_req( 2, use ); | |
| 1370 _igvn.register_new_node_with_optimizer(r); | |
| 1371 set_loop(r, use_loop); | |
| 1372 set_idom(r, !side_by_side_idom ? newuse->in(0) : side_by_side_idom, dd_r); | |
| 1373 } // End of if a loop-exit test | |
| 1374 } | |
| 1375 } | |
| 1376 | |
| 1377 // Step 4: If loop-invariant use is not control, it must be dominated by a | |
| 1378 // loop exit IfFalse/IfTrue. Find "proper" loop exit. Make a Region | |
| 1379 // there if needed. Make a Phi there merging old and new used values. | |
| 1380 Node_List *split_if_set = NULL; | |
| 1381 Node_List *split_bool_set = NULL; | |
| 1382 Node_List *split_cex_set = NULL; | |
| 1383 for( i = 0; i < loop->_body.size(); i++ ) { | |
| 1384 Node* old = loop->_body.at(i); | |
| 1385 Node* nnn = old_new[old->_idx]; | |
| 1386 // Copy uses to a worklist, so I can munge the def-use info | |
| 1387 // with impunity. | |
| 1388 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++) | |
| 1389 worklist.push(old->fast_out(j)); | |
| 1390 | |
| 1391 while( worklist.size() ) { | |
| 1392 Node *use = worklist.pop(); | |
| 1393 if (!has_node(use)) continue; // Ignore dead nodes | |
| 1394 if (use->in(0) == C->top()) continue; | |
| 1395 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use ); | |
| 1396 // Check for data-use outside of loop - at least one of OLD or USE | |
| 1397 // must not be a CFG node. | |
| 1398 if( !loop->is_member( use_loop ) && (!old->is_CFG() || !use->is_CFG())) { | |
| 1399 | |
| 1400 // If the Data use is an IF, that means we have an IF outside of the | |
| 1401 // loop that is switching on a condition that is set inside of the | |
| 1402 // loop. Happens if people set a loop-exit flag; then test the flag | |
| 1403 // in the loop to break the loop, then test is again outside of the | |
| 1404 // loop to determine which way the loop exited. | |
| 1405 if( use->is_If() || use->is_CMove() ) { | |
| 1406 // Since this code is highly unlikely, we lazily build the worklist | |
| 1407 // of such Nodes to go split. | |
| 1408 if( !split_if_set ) | |
| 1409 split_if_set = new Node_List(area); | |
| 1410 split_if_set->push(use); | |
| 1411 } | |
| 1412 if( use->is_Bool() ) { | |
| 1413 if( !split_bool_set ) | |
| 1414 split_bool_set = new Node_List(area); | |
| 1415 split_bool_set->push(use); | |
| 1416 } | |
| 1417 if( use->Opcode() == Op_CreateEx ) { | |
| 1418 if( !split_cex_set ) | |
| 1419 split_cex_set = new Node_List(area); | |
| 1420 split_cex_set->push(use); | |
| 1421 } | |
| 1422 | |
| 1423 | |
| 1424 // Get "block" use is in | |
| 1425 uint idx = 0; | |
| 1426 while( use->in(idx) != old ) idx++; | |
| 1427 Node *prev = use->is_CFG() ? use : get_ctrl(use); | |
| 1428 assert( !loop->is_member( get_loop( prev ) ), "" ); | |
| 1429 Node *cfg = prev->_idx >= new_counter | |
| 1430 ? prev->in(2) | |
| 1431 : idom(prev); | |
| 1432 if( use->is_Phi() ) // Phi use is in prior block | |
| 1433 cfg = prev->in(idx); // NOT in block of Phi itself | |
| 1434 if (cfg->is_top()) { // Use is dead? | |
| 1435 _igvn.hash_delete(use); | |
| 1436 _igvn._worklist.push(use); | |
| 1437 use->set_req(idx, C->top()); | |
| 1438 continue; | |
| 1439 } | |
| 1440 | |
| 1441 while( !loop->is_member( get_loop( cfg ) ) ) { | |
| 1442 prev = cfg; | |
| 1443 cfg = cfg->_idx >= new_counter ? cfg->in(2) : idom(cfg); | |
| 1444 } | |
| 1445 // If the use occurs after merging several exits from the loop, then | |
| 1446 // old value must have dominated all those exits. Since the same old | |
| 1447 // value was used on all those exits we did not need a Phi at this | |
| 1448 // merge point. NOW we do need a Phi here. Each loop exit value | |
| 1449 // is now merged with the peeled body exit; each exit gets its own | |
| 1450 // private Phi and those Phis need to be merged here. | |
| 1451 Node *phi; | |
| 1452 if( prev->is_Region() ) { | |
| 1453 if( idx == 0 ) { // Updating control edge? | |
| 1454 phi = prev; // Just use existing control | |
| 1455 } else { // Else need a new Phi | |
| 1456 phi = PhiNode::make( prev, old ); | |
| 1457 // Now recursively fix up the new uses of old! | |
| 1458 for( uint i = 1; i < prev->req(); i++ ) { | |
| 1459 worklist.push(phi); // Onto worklist once for each 'old' input | |
| 1460 } | |
| 1461 } | |
| 1462 } else { | |
| 1463 // Get new RegionNode merging old and new loop exits | |
| 1464 prev = old_new[prev->_idx]; | |
| 1465 assert( prev, "just made this in step 7" ); | |
| 1466 if( idx == 0 ) { // Updating control edge? | |
| 1467 phi = prev; // Just use existing control | |
| 1468 } else { // Else need a new Phi | |
| 1469 // Make a new Phi merging data values properly | |
| 1470 phi = PhiNode::make( prev, old ); | |
| 1471 phi->set_req( 1, nnn ); | |
| 1472 } | |
| 1473 } | |
| 1474 // If inserting a new Phi, check for prior hits | |
| 1475 if( idx != 0 ) { | |
| 1476 Node *hit = _igvn.hash_find_insert(phi); | |
| 1477 if( hit == NULL ) { | |
| 1478 _igvn.register_new_node_with_optimizer(phi); // Register new phi | |
| 1479 } else { // or | |
| 1480 // Remove the new phi from the graph and use the hit | |
| 1481 _igvn.remove_dead_node(phi); | |
| 1482 phi = hit; // Use existing phi | |
| 1483 } | |
| 1484 set_ctrl(phi, prev); | |
| 1485 } | |
| 1486 // Make 'use' use the Phi instead of the old loop body exit value | |
| 1487 _igvn.hash_delete(use); | |
| 1488 _igvn._worklist.push(use); | |
| 1489 use->set_req(idx, phi); | |
| 1490 if( use->_idx >= new_counter ) { // If updating new phis | |
| 1491 // Not needed for correctness, but prevents a weak assert | |
| 1492 // in AddPNode from tripping (when we end up with different | |
| 1493 // base & derived Phis that will become the same after | |
| 1494 // IGVN does CSE). | |
| 1495 Node *hit = _igvn.hash_find_insert(use); | |
| 1496 if( hit ) // Go ahead and re-hash for hits. | |
|
1621
6027dddc26c6
6677629: PhaseIterGVN::subsume_node() should call hash_delete() and add_users_to_worklist()
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changeset
|
1497 _igvn.replace_node( use, hit ); |
| 0 | 1498 } |
| 1499 | |
| 1500 // If 'use' was in the loop-exit block, it now needs to be sunk | |
| 1501 // below the post-loop merge point. | |
| 1502 sink_use( use, prev ); | |
| 1503 } | |
| 1504 } | |
| 1505 } | |
| 1506 | |
| 1507 // Check for IFs that need splitting/cloning. Happens if an IF outside of | |
| 1508 // the loop uses a condition set in the loop. The original IF probably | |
| 1509 // takes control from one or more OLD Regions (which in turn get from NEW | |
| 1510 // Regions). In any case, there will be a set of Phis for each merge point | |
| 1511 // from the IF up to where the original BOOL def exists the loop. | |
| 1512 if( split_if_set ) { | |
| 1513 while( split_if_set->size() ) { | |
| 1514 Node *iff = split_if_set->pop(); | |
| 1515 if( iff->in(1)->is_Phi() ) { | |
| 1516 BoolNode *b = clone_iff( iff->in(1)->as_Phi(), loop ); | |
| 1517 _igvn.hash_delete(iff); | |
| 1518 _igvn._worklist.push(iff); | |
| 1519 iff->set_req(1, b); | |
| 1520 } | |
| 1521 } | |
| 1522 } | |
| 1523 if( split_bool_set ) { | |
| 1524 while( split_bool_set->size() ) { | |
| 1525 Node *b = split_bool_set->pop(); | |
| 1526 Node *phi = b->in(1); | |
| 1527 assert( phi->is_Phi(), "" ); | |
| 1528 CmpNode *cmp = clone_bool( (PhiNode*)phi, loop ); | |
| 1529 _igvn.hash_delete(b); | |
| 1530 _igvn._worklist.push(b); | |
| 1531 b->set_req(1, cmp); | |
| 1532 } | |
| 1533 } | |
| 1534 if( split_cex_set ) { | |
| 1535 while( split_cex_set->size() ) { | |
| 1536 Node *b = split_cex_set->pop(); | |
| 1537 assert( b->in(0)->is_Region(), "" ); | |
| 1538 assert( b->in(1)->is_Phi(), "" ); | |
| 1539 assert( b->in(0)->in(0) == b->in(1)->in(0), "" ); | |
| 1540 split_up( b, b->in(0), NULL ); | |
| 1541 } | |
| 1542 } | |
| 1543 | |
| 1544 } | |
| 1545 | |
| 1546 | |
| 1547 //---------------------- stride_of_possible_iv ------------------------------------- | |
| 1548 // Looks for an iff/bool/comp with one operand of the compare | |
| 1549 // being a cycle involving an add and a phi, | |
| 1550 // with an optional truncation (left-shift followed by a right-shift) | |
| 1551 // of the add. Returns zero if not an iv. | |
| 1552 int PhaseIdealLoop::stride_of_possible_iv(Node* iff) { | |
| 1553 Node* trunc1 = NULL; | |
| 1554 Node* trunc2 = NULL; | |
| 1555 const TypeInt* ttype = NULL; | |
| 1556 if (!iff->is_If() || iff->in(1) == NULL || !iff->in(1)->is_Bool()) { | |
| 1557 return 0; | |
| 1558 } | |
| 1559 BoolNode* bl = iff->in(1)->as_Bool(); | |
| 1560 Node* cmp = bl->in(1); | |
| 1561 if (!cmp || cmp->Opcode() != Op_CmpI && cmp->Opcode() != Op_CmpU) { | |
| 1562 return 0; | |
| 1563 } | |
| 1564 // Must have an invariant operand | |
| 1565 if (is_member(get_loop(iff), get_ctrl(cmp->in(2)))) { | |
| 1566 return 0; | |
| 1567 } | |
| 1568 Node* add2 = NULL; | |
| 1569 Node* cmp1 = cmp->in(1); | |
| 1570 if (cmp1->is_Phi()) { | |
| 1571 // (If (Bool (CmpX phi:(Phi ...(Optional-trunc(AddI phi add2))) ))) | |
| 1572 Node* phi = cmp1; | |
| 1573 for (uint i = 1; i < phi->req(); i++) { | |
| 1574 Node* in = phi->in(i); | |
| 1575 Node* add = CountedLoopNode::match_incr_with_optional_truncation(in, | |
| 1576 &trunc1, &trunc2, &ttype); | |
| 1577 if (add && add->in(1) == phi) { | |
| 1578 add2 = add->in(2); | |
| 1579 break; | |
| 1580 } | |
| 1581 } | |
| 1582 } else { | |
| 1583 // (If (Bool (CmpX addtrunc:(Optional-trunc((AddI (Phi ...addtrunc...) add2)) ))) | |
| 1584 Node* addtrunc = cmp1; | |
| 1585 Node* add = CountedLoopNode::match_incr_with_optional_truncation(addtrunc, | |
| 1586 &trunc1, &trunc2, &ttype); | |
| 1587 if (add && add->in(1)->is_Phi()) { | |
| 1588 Node* phi = add->in(1); | |
| 1589 for (uint i = 1; i < phi->req(); i++) { | |
| 1590 if (phi->in(i) == addtrunc) { | |
| 1591 add2 = add->in(2); | |
| 1592 break; | |
| 1593 } | |
| 1594 } | |
| 1595 } | |
| 1596 } | |
| 1597 if (add2 != NULL) { | |
| 1598 const TypeInt* add2t = _igvn.type(add2)->is_int(); | |
| 1599 if (add2t->is_con()) { | |
| 1600 return add2t->get_con(); | |
| 1601 } | |
| 1602 } | |
| 1603 return 0; | |
| 1604 } | |
| 1605 | |
| 1606 | |
| 1607 //---------------------- stay_in_loop ------------------------------------- | |
| 1608 // Return the (unique) control output node that's in the loop (if it exists.) | |
| 1609 Node* PhaseIdealLoop::stay_in_loop( Node* n, IdealLoopTree *loop) { | |
| 1610 Node* unique = NULL; | |
| 1611 if (!n) return NULL; | |
| 1612 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { | |
| 1613 Node* use = n->fast_out(i); | |
| 1614 if (!has_ctrl(use) && loop->is_member(get_loop(use))) { | |
| 1615 if (unique != NULL) { | |
| 1616 return NULL; | |
| 1617 } | |
| 1618 unique = use; | |
| 1619 } | |
| 1620 } | |
| 1621 return unique; | |
| 1622 } | |
| 1623 | |
| 1624 //------------------------------ register_node ------------------------------------- | |
| 1625 // Utility to register node "n" with PhaseIdealLoop | |
| 1626 void PhaseIdealLoop::register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth) { | |
| 1627 _igvn.register_new_node_with_optimizer(n); | |
| 1628 loop->_body.push(n); | |
| 1629 if (n->is_CFG()) { | |
| 1630 set_loop(n, loop); | |
| 1631 set_idom(n, pred, ddepth); | |
| 1632 } else { | |
| 1633 set_ctrl(n, pred); | |
| 1634 } | |
| 1635 } | |
| 1636 | |
| 1637 //------------------------------ proj_clone ------------------------------------- | |
| 1638 // Utility to create an if-projection | |
| 1639 ProjNode* PhaseIdealLoop::proj_clone(ProjNode* p, IfNode* iff) { | |
| 1640 ProjNode* c = p->clone()->as_Proj(); | |
| 1641 c->set_req(0, iff); | |
| 1642 return c; | |
| 1643 } | |
| 1644 | |
| 1645 //------------------------------ short_circuit_if ------------------------------------- | |
| 1646 // Force the iff control output to be the live_proj | |
| 1647 Node* PhaseIdealLoop::short_circuit_if(IfNode* iff, ProjNode* live_proj) { | |
| 1648 int proj_con = live_proj->_con; | |
| 1649 assert(proj_con == 0 || proj_con == 1, "false or true projection"); | |
| 1650 Node *con = _igvn.intcon(proj_con); | |
| 1651 set_ctrl(con, C->root()); | |
| 1652 if (iff) { | |
| 1653 iff->set_req(1, con); | |
| 1654 } | |
| 1655 return con; | |
| 1656 } | |
| 1657 | |
| 1658 //------------------------------ insert_if_before_proj ------------------------------------- | |
| 1659 // Insert a new if before an if projection (* - new node) | |
| 1660 // | |
| 1661 // before | |
| 1662 // if(test) | |
| 1663 // / \ | |
| 1664 // v v | |
| 1665 // other-proj proj (arg) | |
| 1666 // | |
| 1667 // after | |
| 1668 // if(test) | |
| 1669 // / \ | |
| 1670 // / v | |
| 1671 // | * proj-clone | |
| 1672 // v | | |
| 1673 // other-proj v | |
| 1674 // * new_if(relop(cmp[IU](left,right))) | |
| 1675 // / \ | |
| 1676 // v v | |
| 1677 // * new-proj proj | |
| 1678 // (returned) | |
| 1679 // | |
| 1680 ProjNode* PhaseIdealLoop::insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj) { | |
| 1681 IfNode* iff = proj->in(0)->as_If(); | |
| 1682 IdealLoopTree *loop = get_loop(proj); | |
| 1683 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj(); | |
| 1684 int ddepth = dom_depth(proj); | |
| 1685 | |
| 1686 _igvn.hash_delete(iff); | |
| 1687 _igvn._worklist.push(iff); | |
| 1688 _igvn.hash_delete(proj); | |
| 1689 _igvn._worklist.push(proj); | |
| 1690 | |
| 1691 proj->set_req(0, NULL); // temporary disconnect | |
| 1692 ProjNode* proj2 = proj_clone(proj, iff); | |
| 1693 register_node(proj2, loop, iff, ddepth); | |
| 1694 | |
| 1695 Node* cmp = Signed ? (Node*) new (C,3)CmpINode(left, right) : (Node*) new (C,3)CmpUNode(left, right); | |
| 1696 register_node(cmp, loop, proj2, ddepth); | |
| 1697 | |
| 1698 BoolNode* bol = new (C,2)BoolNode(cmp, relop); | |
| 1699 register_node(bol, loop, proj2, ddepth); | |
| 1700 | |
| 1701 IfNode* new_if = new (C,2)IfNode(proj2, bol, iff->_prob, iff->_fcnt); | |
| 1702 register_node(new_if, loop, proj2, ddepth); | |
| 1703 | |
| 1704 proj->set_req(0, new_if); // reattach | |
| 1705 set_idom(proj, new_if, ddepth); | |
| 1706 | |
| 1707 ProjNode* new_exit = proj_clone(other_proj, new_if)->as_Proj(); | |
| 1708 register_node(new_exit, get_loop(other_proj), new_if, ddepth); | |
| 1709 | |
| 1710 return new_exit; | |
| 1711 } | |
| 1712 | |
| 1713 //------------------------------ insert_region_before_proj ------------------------------------- | |
| 1714 // Insert a region before an if projection (* - new node) | |
| 1715 // | |
| 1716 // before | |
| 1717 // if(test) | |
| 1718 // / | | |
| 1719 // v | | |
| 1720 // proj v | |
| 1721 // other-proj | |
| 1722 // | |
| 1723 // after | |
| 1724 // if(test) | |
| 1725 // / | | |
| 1726 // v | | |
| 1727 // * proj-clone v | |
| 1728 // | other-proj | |
| 1729 // v | |
| 1730 // * new-region | |
| 1731 // | | |
| 1732 // v | |
| 1733 // * dum_if | |
| 1734 // / \ | |
| 1735 // v \ | |
| 1736 // * dum-proj v | |
| 1737 // proj | |
| 1738 // | |
| 1739 RegionNode* PhaseIdealLoop::insert_region_before_proj(ProjNode* proj) { | |
| 1740 IfNode* iff = proj->in(0)->as_If(); | |
| 1741 IdealLoopTree *loop = get_loop(proj); | |
| 1742 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj(); | |
| 1743 int ddepth = dom_depth(proj); | |
| 1744 | |
| 1745 _igvn.hash_delete(iff); | |
| 1746 _igvn._worklist.push(iff); | |
| 1747 _igvn.hash_delete(proj); | |
| 1748 _igvn._worklist.push(proj); | |
| 1749 | |
| 1750 proj->set_req(0, NULL); // temporary disconnect | |
| 1751 ProjNode* proj2 = proj_clone(proj, iff); | |
| 1752 register_node(proj2, loop, iff, ddepth); | |
| 1753 | |
| 1754 RegionNode* reg = new (C,2)RegionNode(2); | |
| 1755 reg->set_req(1, proj2); | |
| 1756 register_node(reg, loop, iff, ddepth); | |
| 1757 | |
| 1758 IfNode* dum_if = new (C,2)IfNode(reg, short_circuit_if(NULL, proj), iff->_prob, iff->_fcnt); | |
| 1759 register_node(dum_if, loop, reg, ddepth); | |
| 1760 | |
| 1761 proj->set_req(0, dum_if); // reattach | |
| 1762 set_idom(proj, dum_if, ddepth); | |
| 1763 | |
| 1764 ProjNode* dum_proj = proj_clone(other_proj, dum_if); | |
| 1765 register_node(dum_proj, loop, dum_if, ddepth); | |
| 1766 | |
| 1767 return reg; | |
| 1768 } | |
| 1769 | |
| 1770 //------------------------------ insert_cmpi_loop_exit ------------------------------------- | |
| 1771 // Clone a signed compare loop exit from an unsigned compare and | |
| 1772 // insert it before the unsigned cmp on the stay-in-loop path. | |
| 1773 // All new nodes inserted in the dominator tree between the original | |
| 1774 // if and it's projections. The original if test is replaced with | |
| 1775 // a constant to force the stay-in-loop path. | |
| 1776 // | |
| 1777 // This is done to make sure that the original if and it's projections | |
| 1778 // still dominate the same set of control nodes, that the ctrl() relation | |
| 1779 // from data nodes to them is preserved, and that their loop nesting is | |
| 1780 // preserved. | |
| 1781 // | |
| 1782 // before | |
| 1783 // if(i <u limit) unsigned compare loop exit | |
| 1784 // / | | |
| 1785 // v v | |
| 1786 // exit-proj stay-in-loop-proj | |
| 1787 // | |
| 1788 // after | |
| 1789 // if(stay-in-loop-const) original if | |
| 1790 // / | | |
| 1791 // / v | |
| 1792 // / if(i < limit) new signed test | |
| 1793 // / / | | |
| 1794 // / / v | |
| 1795 // / / if(i <u limit) new cloned unsigned test | |
| 1796 // / / / | | |
| 1797 // v v v | | |
| 1798 // region | | |
| 1799 // | | | |
| 1800 // dum-if | | |
| 1801 // / | | | |
| 1802 // ether | | | |
| 1803 // v v | |
| 1804 // exit-proj stay-in-loop-proj | |
| 1805 // | |
| 1806 IfNode* PhaseIdealLoop::insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop) { | |
| 1807 const bool Signed = true; | |
| 1808 const bool Unsigned = false; | |
| 1809 | |
| 1810 BoolNode* bol = if_cmpu->in(1)->as_Bool(); | |
| 1811 if (bol->_test._test != BoolTest::lt) return NULL; | |
| 1812 CmpNode* cmpu = bol->in(1)->as_Cmp(); | |
| 1813 if (cmpu->Opcode() != Op_CmpU) return NULL; | |
| 1814 int stride = stride_of_possible_iv(if_cmpu); | |
| 1815 if (stride == 0) return NULL; | |
| 1816 | |
| 1817 ProjNode* lp_continue = stay_in_loop(if_cmpu, loop)->as_Proj(); | |
| 1818 ProjNode* lp_exit = if_cmpu->proj_out(!lp_continue->is_IfTrue())->as_Proj(); | |
| 1819 | |
| 1820 Node* limit = NULL; | |
| 1821 if (stride > 0) { | |
| 1822 limit = cmpu->in(2); | |
| 1823 } else { | |
| 1824 limit = _igvn.makecon(TypeInt::ZERO); | |
| 1825 set_ctrl(limit, C->root()); | |
| 1826 } | |
| 1827 // Create a new region on the exit path | |
| 1828 RegionNode* reg = insert_region_before_proj(lp_exit); | |
| 1829 | |
| 1830 // Clone the if-cmpu-true-false using a signed compare | |
| 1831 BoolTest::mask rel_i = stride > 0 ? bol->_test._test : BoolTest::ge; | |
| 1832 ProjNode* cmpi_exit = insert_if_before_proj(cmpu->in(1), Signed, rel_i, limit, lp_continue); | |
| 1833 reg->add_req(cmpi_exit); | |
| 1834 | |
| 1835 // Clone the if-cmpu-true-false | |
| 1836 BoolTest::mask rel_u = bol->_test._test; | |
| 1837 ProjNode* cmpu_exit = insert_if_before_proj(cmpu->in(1), Unsigned, rel_u, cmpu->in(2), lp_continue); | |
| 1838 reg->add_req(cmpu_exit); | |
| 1839 | |
| 1840 // Force original if to stay in loop. | |
| 1841 short_circuit_if(if_cmpu, lp_continue); | |
| 1842 | |
| 1843 return cmpi_exit->in(0)->as_If(); | |
| 1844 } | |
| 1845 | |
| 1846 //------------------------------ remove_cmpi_loop_exit ------------------------------------- | |
| 1847 // Remove a previously inserted signed compare loop exit. | |
| 1848 void PhaseIdealLoop::remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop) { | |
| 1849 Node* lp_proj = stay_in_loop(if_cmp, loop); | |
| 1850 assert(if_cmp->in(1)->in(1)->Opcode() == Op_CmpI && | |
| 1851 stay_in_loop(lp_proj, loop)->is_If() && | |
| 1852 stay_in_loop(lp_proj, loop)->in(1)->in(1)->Opcode() == Op_CmpU, "inserted cmpi before cmpu"); | |
| 1853 Node *con = _igvn.makecon(lp_proj->is_IfTrue() ? TypeInt::ONE : TypeInt::ZERO); | |
| 1854 set_ctrl(con, C->root()); | |
| 1855 if_cmp->set_req(1, con); | |
| 1856 } | |
| 1857 | |
| 1858 //------------------------------ scheduled_nodelist ------------------------------------- | |
| 1859 // Create a post order schedule of nodes that are in the | |
| 1860 // "member" set. The list is returned in "sched". | |
| 1861 // The first node in "sched" is the loop head, followed by | |
| 1862 // nodes which have no inputs in the "member" set, and then | |
| 1863 // followed by the nodes that have an immediate input dependence | |
| 1864 // on a node in "sched". | |
| 1865 void PhaseIdealLoop::scheduled_nodelist( IdealLoopTree *loop, VectorSet& member, Node_List &sched ) { | |
| 1866 | |
| 1867 assert(member.test(loop->_head->_idx), "loop head must be in member set"); | |
| 1868 Arena *a = Thread::current()->resource_area(); | |
| 1869 VectorSet visited(a); | |
| 1870 Node_Stack nstack(a, loop->_body.size()); | |
| 1871 | |
| 1872 Node* n = loop->_head; // top of stack is cached in "n" | |
| 1873 uint idx = 0; | |
| 1874 visited.set(n->_idx); | |
| 1875 | |
| 1876 // Initially push all with no inputs from within member set | |
| 1877 for(uint i = 0; i < loop->_body.size(); i++ ) { | |
| 1878 Node *elt = loop->_body.at(i); | |
| 1879 if (member.test(elt->_idx)) { | |
| 1880 bool found = false; | |
| 1881 for (uint j = 0; j < elt->req(); j++) { | |
| 1882 Node* def = elt->in(j); | |
| 1883 if (def && member.test(def->_idx) && def != elt) { | |
| 1884 found = true; | |
| 1885 break; | |
| 1886 } | |
| 1887 } | |
| 1888 if (!found && elt != loop->_head) { | |
| 1889 nstack.push(n, idx); | |
| 1890 n = elt; | |
| 1891 assert(!visited.test(n->_idx), "not seen yet"); | |
| 1892 visited.set(n->_idx); | |
| 1893 } | |
| 1894 } | |
| 1895 } | |
| 1896 | |
| 1897 // traverse out's that are in the member set | |
| 1898 while (true) { | |
| 1899 if (idx < n->outcnt()) { | |
| 1900 Node* use = n->raw_out(idx); | |
| 1901 idx++; | |
| 1902 if (!visited.test_set(use->_idx)) { | |
| 1903 if (member.test(use->_idx)) { | |
| 1904 nstack.push(n, idx); | |
| 1905 n = use; | |
| 1906 idx = 0; | |
| 1907 } | |
| 1908 } | |
| 1909 } else { | |
| 1910 // All outputs processed | |
| 1911 sched.push(n); | |
| 1912 if (nstack.is_empty()) break; | |
| 1913 n = nstack.node(); | |
| 1914 idx = nstack.index(); | |
| 1915 nstack.pop(); | |
| 1916 } | |
| 1917 } | |
| 1918 } | |
| 1919 | |
| 1920 | |
| 1921 //------------------------------ has_use_in_set ------------------------------------- | |
| 1922 // Has a use in the vector set | |
| 1923 bool PhaseIdealLoop::has_use_in_set( Node* n, VectorSet& vset ) { | |
| 1924 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
| 1925 Node* use = n->fast_out(j); | |
| 1926 if (vset.test(use->_idx)) { | |
| 1927 return true; | |
| 1928 } | |
| 1929 } | |
| 1930 return false; | |
| 1931 } | |
| 1932 | |
| 1933 | |
| 1934 //------------------------------ has_use_internal_to_set ------------------------------------- | |
| 1935 // Has use internal to the vector set (ie. not in a phi at the loop head) | |
| 1936 bool PhaseIdealLoop::has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop ) { | |
| 1937 Node* head = loop->_head; | |
| 1938 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
| 1939 Node* use = n->fast_out(j); | |
| 1940 if (vset.test(use->_idx) && !(use->is_Phi() && use->in(0) == head)) { | |
| 1941 return true; | |
| 1942 } | |
| 1943 } | |
| 1944 return false; | |
| 1945 } | |
| 1946 | |
| 1947 | |
| 1948 //------------------------------ clone_for_use_outside_loop ------------------------------------- | |
| 1949 // clone "n" for uses that are outside of loop | |
| 1950 void PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) { | |
| 1951 | |
| 1952 assert(worklist.size() == 0, "should be empty"); | |
| 1953 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
| 1954 Node* use = n->fast_out(j); | |
| 1955 if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) { | |
| 1956 worklist.push(use); | |
| 1957 } | |
| 1958 } | |
| 1959 while( worklist.size() ) { | |
| 1960 Node *use = worklist.pop(); | |
| 1961 if (!has_node(use) || use->in(0) == C->top()) continue; | |
| 1962 uint j; | |
| 1963 for (j = 0; j < use->req(); j++) { | |
| 1964 if (use->in(j) == n) break; | |
| 1965 } | |
| 1966 assert(j < use->req(), "must be there"); | |
| 1967 | |
| 1968 // clone "n" and insert it between the inputs of "n" and the use outside the loop | |
| 1969 Node* n_clone = n->clone(); | |
| 1970 _igvn.hash_delete(use); | |
| 1971 use->set_req(j, n_clone); | |
| 1972 _igvn._worklist.push(use); | |
| 251 | 1973 Node* use_c; |
| 0 | 1974 if (!use->is_Phi()) { |
| 251 | 1975 use_c = has_ctrl(use) ? get_ctrl(use) : use->in(0); |
| 0 | 1976 } else { |
| 1977 // Use in a phi is considered a use in the associated predecessor block | |
| 251 | 1978 use_c = use->in(0)->in(j); |
| 0 | 1979 } |
| 251 | 1980 set_ctrl(n_clone, use_c); |
| 1981 assert(!loop->is_member(get_loop(use_c)), "should be outside loop"); | |
| 1982 get_loop(use_c)->_body.push(n_clone); | |
| 0 | 1983 _igvn.register_new_node_with_optimizer(n_clone); |
| 1984 #if !defined(PRODUCT) | |
| 1985 if (TracePartialPeeling) { | |
| 1986 tty->print_cr("loop exit cloning old: %d new: %d newbb: %d", n->_idx, n_clone->_idx, get_ctrl(n_clone)->_idx); | |
| 1987 } | |
| 1988 #endif | |
| 1989 } | |
| 1990 } | |
| 1991 | |
| 1992 | |
| 1993 //------------------------------ clone_for_special_use_inside_loop ------------------------------------- | |
| 1994 // clone "n" for special uses that are in the not_peeled region. | |
| 1995 // If these def-uses occur in separate blocks, the code generator | |
| 1996 // marks the method as not compilable. For example, if a "BoolNode" | |
| 1997 // is in a different basic block than the "IfNode" that uses it, then | |
| 1998 // the compilation is aborted in the code generator. | |
| 1999 void PhaseIdealLoop::clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n, | |
| 2000 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist ) { | |
| 2001 if (n->is_Phi() || n->is_Load()) { | |
| 2002 return; | |
| 2003 } | |
| 2004 assert(worklist.size() == 0, "should be empty"); | |
| 2005 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
| 2006 Node* use = n->fast_out(j); | |
| 2007 if ( not_peel.test(use->_idx) && | |
| 2008 (use->is_If() || use->is_CMove() || use->is_Bool()) && | |
| 2009 use->in(1) == n) { | |
| 2010 worklist.push(use); | |
| 2011 } | |
| 2012 } | |
| 2013 if (worklist.size() > 0) { | |
| 2014 // clone "n" and insert it between inputs of "n" and the use | |
| 2015 Node* n_clone = n->clone(); | |
| 2016 loop->_body.push(n_clone); | |
| 2017 _igvn.register_new_node_with_optimizer(n_clone); | |
| 2018 set_ctrl(n_clone, get_ctrl(n)); | |
| 2019 sink_list.push(n_clone); | |
| 2020 not_peel <<= n_clone->_idx; // add n_clone to not_peel set. | |
| 2021 #if !defined(PRODUCT) | |
| 2022 if (TracePartialPeeling) { | |
| 2023 tty->print_cr("special not_peeled cloning old: %d new: %d", n->_idx, n_clone->_idx); | |
| 2024 } | |
| 2025 #endif | |
| 2026 while( worklist.size() ) { | |
| 2027 Node *use = worklist.pop(); | |
| 2028 _igvn.hash_delete(use); | |
| 2029 _igvn._worklist.push(use); | |
| 2030 for (uint j = 1; j < use->req(); j++) { | |
| 2031 if (use->in(j) == n) { | |
| 2032 use->set_req(j, n_clone); | |
| 2033 } | |
| 2034 } | |
| 2035 } | |
| 2036 } | |
| 2037 } | |
| 2038 | |
| 2039 | |
| 2040 //------------------------------ insert_phi_for_loop ------------------------------------- | |
| 2041 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist | |
| 2042 void PhaseIdealLoop::insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp ) { | |
| 2043 Node *phi = PhiNode::make(lp, back_edge_val); | |
| 2044 phi->set_req(LoopNode::EntryControl, lp_entry_val); | |
| 2045 // Use existing phi if it already exists | |
| 2046 Node *hit = _igvn.hash_find_insert(phi); | |
| 2047 if( hit == NULL ) { | |
| 2048 _igvn.register_new_node_with_optimizer(phi); | |
| 2049 set_ctrl(phi, lp); | |
| 2050 } else { | |
| 2051 // Remove the new phi from the graph and use the hit | |
| 2052 _igvn.remove_dead_node(phi); | |
| 2053 phi = hit; | |
| 2054 } | |
| 2055 _igvn.hash_delete(use); | |
| 2056 _igvn._worklist.push(use); | |
| 2057 use->set_req(idx, phi); | |
| 2058 } | |
| 2059 | |
| 2060 #ifdef ASSERT | |
| 2061 //------------------------------ is_valid_loop_partition ------------------------------------- | |
| 2062 // Validate the loop partition sets: peel and not_peel | |
| 2063 bool PhaseIdealLoop::is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list, | |
| 2064 VectorSet& not_peel ) { | |
| 2065 uint i; | |
| 2066 // Check that peel_list entries are in the peel set | |
| 2067 for (i = 0; i < peel_list.size(); i++) { | |
| 2068 if (!peel.test(peel_list.at(i)->_idx)) { | |
| 2069 return false; | |
| 2070 } | |
| 2071 } | |
| 2072 // Check at loop members are in one of peel set or not_peel set | |
| 2073 for (i = 0; i < loop->_body.size(); i++ ) { | |
| 2074 Node *def = loop->_body.at(i); | |
| 2075 uint di = def->_idx; | |
| 2076 // Check that peel set elements are in peel_list | |
| 2077 if (peel.test(di)) { | |
| 2078 if (not_peel.test(di)) { | |
| 2079 return false; | |
| 2080 } | |
| 2081 // Must be in peel_list also | |
| 2082 bool found = false; | |
| 2083 for (uint j = 0; j < peel_list.size(); j++) { | |
| 2084 if (peel_list.at(j)->_idx == di) { | |
| 2085 found = true; | |
| 2086 break; | |
| 2087 } | |
| 2088 } | |
| 2089 if (!found) { | |
| 2090 return false; | |
| 2091 } | |
| 2092 } else if (not_peel.test(di)) { | |
| 2093 if (peel.test(di)) { | |
| 2094 return false; | |
| 2095 } | |
| 2096 } else { | |
| 2097 return false; | |
| 2098 } | |
| 2099 } | |
| 2100 return true; | |
| 2101 } | |
| 2102 | |
| 2103 //------------------------------ is_valid_clone_loop_exit_use ------------------------------------- | |
| 2104 // Ensure a use outside of loop is of the right form | |
| 2105 bool PhaseIdealLoop::is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx) { | |
| 2106 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
| 2107 return (use->is_Phi() && | |
| 2108 use_c->is_Region() && use_c->req() == 3 && | |
| 2109 (use_c->in(exit_idx)->Opcode() == Op_IfTrue || | |
| 2110 use_c->in(exit_idx)->Opcode() == Op_IfFalse || | |
| 2111 use_c->in(exit_idx)->Opcode() == Op_JumpProj) && | |
| 2112 loop->is_member( get_loop( use_c->in(exit_idx)->in(0) ) ) ); | |
| 2113 } | |
| 2114 | |
| 2115 //------------------------------ is_valid_clone_loop_form ------------------------------------- | |
| 2116 // Ensure that all uses outside of loop are of the right form | |
| 2117 bool PhaseIdealLoop::is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list, | |
| 2118 uint orig_exit_idx, uint clone_exit_idx) { | |
| 2119 uint len = peel_list.size(); | |
| 2120 for (uint i = 0; i < len; i++) { | |
| 2121 Node *def = peel_list.at(i); | |
| 2122 | |
| 2123 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) { | |
| 2124 Node *use = def->fast_out(j); | |
| 2125 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
| 2126 if (!loop->is_member(get_loop(use_c))) { | |
| 2127 // use is not in the loop, check for correct structure | |
| 2128 if (use->in(0) == def) { | |
| 2129 // Okay | |
| 2130 } else if (!is_valid_clone_loop_exit_use(loop, use, orig_exit_idx)) { | |
| 2131 return false; | |
| 2132 } | |
| 2133 } | |
| 2134 } | |
| 2135 } | |
| 2136 return true; | |
| 2137 } | |
| 2138 #endif | |
| 2139 | |
| 2140 //------------------------------ partial_peel ------------------------------------- | |
| 2141 // Partially peel (aka loop rotation) the top portion of a loop (called | |
| 2142 // the peel section below) by cloning it and placing one copy just before | |
| 2143 // the new loop head and the other copy at the bottom of the new loop. | |
| 2144 // | |
| 2145 // before after where it came from | |
| 2146 // | |
| 2147 // stmt1 stmt1 | |
| 2148 // loop: stmt2 clone | |
| 2149 // stmt2 if condA goto exitA clone | |
| 2150 // if condA goto exitA new_loop: new | |
| 2151 // stmt3 stmt3 clone | |
| 2152 // if !condB goto loop if condB goto exitB clone | |
| 2153 // exitB: stmt2 orig | |
| 2154 // stmt4 if !condA goto new_loop orig | |
| 2155 // exitA: goto exitA | |
| 2156 // exitB: | |
| 2157 // stmt4 | |
| 2158 // exitA: | |
| 2159 // | |
| 2160 // Step 1: find the cut point: an exit test on probable | |
| 2161 // induction variable. | |
| 2162 // Step 2: schedule (with cloning) operations in the peel | |
| 2163 // section that can be executed after the cut into | |
| 2164 // the section that is not peeled. This may need | |
| 2165 // to clone operations into exit blocks. For | |
| 2166 // instance, a reference to A[i] in the not-peel | |
| 2167 // section and a reference to B[i] in an exit block | |
| 2168 // may cause a left-shift of i by 2 to be placed | |
| 2169 // in the peel block. This step will clone the left | |
| 2170 // shift into the exit block and sink the left shift | |
| 2171 // from the peel to the not-peel section. | |
| 2172 // Step 3: clone the loop, retarget the control, and insert | |
| 2173 // phis for values that are live across the new loop | |
| 2174 // head. This is very dependent on the graph structure | |
| 2175 // from clone_loop. It creates region nodes for | |
| 2176 // exit control and associated phi nodes for values | |
| 2177 // flow out of the loop through that exit. The region | |
| 2178 // node is dominated by the clone's control projection. | |
| 2179 // So the clone's peel section is placed before the | |
| 2180 // new loop head, and the clone's not-peel section is | |
| 2181 // forms the top part of the new loop. The original | |
| 2182 // peel section forms the tail of the new loop. | |
| 2183 // Step 4: update the dominator tree and recompute the | |
| 2184 // dominator depth. | |
| 2185 // | |
| 2186 // orig | |
| 2187 // | |
| 2445 | 2188 // stmt1 |
| 2189 // | | |
| 2190 // v | |
| 2191 // loop predicate | |
| 2192 // | | |
| 2193 // v | |
| 0 | 2194 // loop<----+ |
| 2195 // | | | |
| 2196 // stmt2 | | |
| 2197 // | | | |
| 2198 // v | | |
| 2199 // ifA | | |
| 2200 // / | | | |
| 2201 // v v | | |
| 2202 // false true ^ <-- last_peel | |
| 2203 // / | | | |
| 2204 // / ===|==cut | | |
| 2205 // / stmt3 | <-- first_not_peel | |
| 2206 // / | | | |
| 2207 // | v | | |
| 2208 // v ifB | | |
| 2209 // exitA: / \ | | |
| 2210 // / \ | | |
| 2211 // v v | | |
| 2212 // false true | | |
| 2213 // / \ | | |
| 2214 // / ----+ | |
| 2215 // | | |
| 2216 // v | |
| 2217 // exitB: | |
| 2218 // stmt4 | |
| 2219 // | |
| 2220 // | |
| 2221 // after clone loop | |
| 2222 // | |
| 2223 // stmt1 | |
| 2445 | 2224 // | |
| 2225 // v | |
| 2226 // loop predicate | |
| 0 | 2227 // / \ |
| 2228 // clone / \ orig | |
| 2229 // / \ | |
| 2230 // / \ | |
| 2231 // v v | |
| 2232 // +---->loop loop<----+ | |
| 2233 // | | | | | |
| 2234 // | stmt2 stmt2 | | |
| 2235 // | | | | | |
| 2236 // | v v | | |
| 2237 // | ifA ifA | | |
| 2238 // | | \ / | | | |
| 2239 // | v v v v | | |
| 2240 // ^ true false false true ^ <-- last_peel | |
| 2241 // | | ^ \ / | | | |
| 2242 // | cut==|== \ \ / ===|==cut | | |
| 2243 // | stmt3 \ \ / stmt3 | <-- first_not_peel | |
| 2244 // | | dom | | | | | |
| 2245 // | v \ 1v v2 v | | |
| 2246 // | ifB regionA ifB | | |
| 2247 // | / \ | / \ | | |
| 2248 // | / \ v / \ | | |
| 2249 // | v v exitA: v v | | |
| 2250 // | true false false true | | |
| 2251 // | / ^ \ / \ | | |
| 2252 // +---- \ \ / ----+ | |
| 2253 // dom \ / | |
| 2254 // \ 1v v2 | |
| 2255 // regionB | |
| 2256 // | | |
| 2257 // v | |
| 2258 // exitB: | |
| 2259 // stmt4 | |
| 2260 // | |
| 2261 // | |
| 2262 // after partial peel | |
| 2263 // | |
| 2264 // stmt1 | |
| 2445 | 2265 // | |
| 2266 // v | |
| 2267 // loop predicate | |
| 0 | 2268 // / |
| 2269 // clone / orig | |
| 2270 // / TOP | |
| 2271 // / \ | |
| 2272 // v v | |
| 2445 | 2273 // TOP->loop loop----+ |
| 0 | 2274 // | | | |
| 2275 // stmt2 stmt2 | | |
| 2276 // | | | | |
| 2277 // v v | | |
| 2278 // ifA ifA | | |
| 2279 // | \ / | | | |
| 2280 // v v v v | | |
| 2281 // true false false true | <-- last_peel | |
| 2282 // | ^ \ / +------|---+ | |
| 2283 // +->newloop \ \ / === ==cut | | | |
| 2284 // | stmt3 \ \ / TOP | | | |
| 2285 // | | dom | | stmt3 | | <-- first_not_peel | |
| 2286 // | v \ 1v v2 v | | | |
| 2287 // | ifB regionA ifB ^ v | |
| 2288 // | / \ | / \ | | | |
| 2289 // | / \ v / \ | | | |
| 2290 // | v v exitA: v v | | | |
| 2291 // | true false false true | | | |
| 2292 // | / ^ \ / \ | | | |
| 2293 // | | \ \ / v | | | |
| 2294 // | | dom \ / TOP | | | |
| 2295 // | | \ 1v v2 | | | |
| 2296 // ^ v regionB | | | |
| 2297 // | | | | | | |
| 2298 // | | v ^ v | |
| 2299 // | | exitB: | | | |
| 2300 // | | stmt4 | | | |
| 2301 // | +------------>-----------------+ | | |
| 2302 // | | | |
| 2303 // +-----------------<---------------------+ | |
| 2304 // | |
| 2305 // | |
| 2306 // final graph | |
| 2307 // | |
| 2308 // stmt1 | |
| 2309 // | | |
| 2310 // v | |
|
3281
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diff
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|
2311 // loop predicate |
|
273b56978029
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diff
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|
2312 // | |
|
273b56978029
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|
2313 // v |
| 2445 | 2314 // stmt2 clone |
| 2315 // | | |
| 2316 // v | |
| 0 | 2317 // ........> ifA clone |
| 2318 // : / | | |
| 2319 // dom / | | |
| 2320 // : v v | |
| 2321 // : false true | |
| 2322 // : | | | |
| 2445 | 2323 // : | v |
| 0 | 2324 // : | newloop<-----+ |
| 2325 // : | | | | |
| 2326 // : | stmt3 clone | | |
| 2327 // : | | | | |
| 2328 // : | v | | |
| 2329 // : | ifB | | |
| 2330 // : | / \ | | |
| 2331 // : | v v | | |
| 2332 // : | false true | | |
| 2333 // : | | | | | |
| 2334 // : | v stmt2 | | |
| 2335 // : | exitB: | | | |
| 2336 // : | stmt4 v | | |
| 2337 // : | ifA orig | | |
| 2338 // : | / \ | | |
| 2339 // : | / \ | | |
| 2340 // : | v v | | |
| 2341 // : | false true | | |
| 2342 // : | / \ | | |
| 2343 // : v v -----+ | |
| 2344 // RegionA | |
| 2345 // | | |
| 2346 // v | |
| 2347 // exitA | |
| 2348 // | |
| 2349 bool PhaseIdealLoop::partial_peel( IdealLoopTree *loop, Node_List &old_new ) { | |
| 2350 | |
| 2445 | 2351 assert(!loop->_head->is_CountedLoop(), "Non-counted loop only"); |
| 108 | 2352 if (!loop->_head->is_Loop()) { |
| 2353 return false; } | |
| 2354 | |
| 0 | 2355 LoopNode *head = loop->_head->as_Loop(); |
| 2356 | |
| 2357 if (head->is_partial_peel_loop() || head->partial_peel_has_failed()) { | |
| 2358 return false; | |
| 2359 } | |
| 2360 | |
| 2361 // Check for complex exit control | |
| 2362 for(uint ii = 0; ii < loop->_body.size(); ii++ ) { | |
| 2363 Node *n = loop->_body.at(ii); | |
| 2364 int opc = n->Opcode(); | |
| 2365 if (n->is_Call() || | |
| 2366 opc == Op_Catch || | |
| 2367 opc == Op_CatchProj || | |
| 2368 opc == Op_Jump || | |
| 2369 opc == Op_JumpProj) { | |
| 2370 #if !defined(PRODUCT) | |
| 2371 if (TracePartialPeeling) { | |
| 2372 tty->print_cr("\nExit control too complex: lp: %d", head->_idx); | |
| 2373 } | |
| 2374 #endif | |
| 2375 return false; | |
| 2376 } | |
| 2377 } | |
| 2378 | |
| 2379 int dd = dom_depth(head); | |
| 2380 | |
| 2381 // Step 1: find cut point | |
| 2382 | |
| 2383 // Walk up dominators to loop head looking for first loop exit | |
| 2384 // which is executed on every path thru loop. | |
| 2385 IfNode *peel_if = NULL; | |
| 2386 IfNode *peel_if_cmpu = NULL; | |
| 2387 | |
| 2388 Node *iff = loop->tail(); | |
| 2389 while( iff != head ) { | |
| 2390 if( iff->is_If() ) { | |
| 2391 Node *ctrl = get_ctrl(iff->in(1)); | |
| 2392 if (ctrl->is_top()) return false; // Dead test on live IF. | |
| 2393 // If loop-varying exit-test, check for induction variable | |
| 2394 if( loop->is_member(get_loop(ctrl)) && | |
| 2395 loop->is_loop_exit(iff) && | |
| 2396 is_possible_iv_test(iff)) { | |
| 2397 Node* cmp = iff->in(1)->in(1); | |
| 2398 if (cmp->Opcode() == Op_CmpI) { | |
| 2399 peel_if = iff->as_If(); | |
| 2400 } else { | |
| 2401 assert(cmp->Opcode() == Op_CmpU, "must be CmpI or CmpU"); | |
| 2402 peel_if_cmpu = iff->as_If(); | |
| 2403 } | |
| 2404 } | |
| 2405 } | |
| 2406 iff = idom(iff); | |
| 2407 } | |
| 2408 // Prefer signed compare over unsigned compare. | |
| 2409 IfNode* new_peel_if = NULL; | |
| 2410 if (peel_if == NULL) { | |
| 2411 if (!PartialPeelAtUnsignedTests || peel_if_cmpu == NULL) { | |
| 2412 return false; // No peel point found | |
| 2413 } | |
| 2414 new_peel_if = insert_cmpi_loop_exit(peel_if_cmpu, loop); | |
| 2415 if (new_peel_if == NULL) { | |
| 2416 return false; // No peel point found | |
| 2417 } | |
| 2418 peel_if = new_peel_if; | |
| 2419 } | |
| 2420 Node* last_peel = stay_in_loop(peel_if, loop); | |
| 2421 Node* first_not_peeled = stay_in_loop(last_peel, loop); | |
| 2422 if (first_not_peeled == NULL || first_not_peeled == head) { | |
| 2423 return false; | |
| 2424 } | |
| 2425 | |
| 2426 #if !defined(PRODUCT) | |
|
2383
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diff
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|
2427 if (TraceLoopOpts) { |
|
9dc311b8473e
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diff
changeset
|
2428 tty->print("PartialPeel "); |
|
9dc311b8473e
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diff
changeset
|
2429 loop->dump_head(); |
|
9dc311b8473e
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diff
changeset
|
2430 } |
|
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diff
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|
2431 |
| 0 | 2432 if (TracePartialPeeling) { |
| 2433 tty->print_cr("before partial peel one iteration"); | |
| 2434 Node_List wl; | |
| 2435 Node* t = head->in(2); | |
| 2436 while (true) { | |
| 2437 wl.push(t); | |
| 2438 if (t == head) break; | |
| 2439 t = idom(t); | |
| 2440 } | |
| 2441 while (wl.size() > 0) { | |
| 2442 Node* tt = wl.pop(); | |
| 2443 tt->dump(); | |
| 2444 if (tt == last_peel) tty->print_cr("-- cut --"); | |
| 2445 } | |
| 2446 } | |
| 2447 #endif | |
| 2448 ResourceArea *area = Thread::current()->resource_area(); | |
| 2449 VectorSet peel(area); | |
| 2450 VectorSet not_peel(area); | |
| 2451 Node_List peel_list(area); | |
| 2452 Node_List worklist(area); | |
| 2453 Node_List sink_list(area); | |
| 2454 | |
| 2455 // Set of cfg nodes to peel are those that are executable from | |
| 2456 // the head through last_peel. | |
| 2457 assert(worklist.size() == 0, "should be empty"); | |
| 2458 worklist.push(head); | |
| 2459 peel.set(head->_idx); | |
| 2460 while (worklist.size() > 0) { | |
| 2461 Node *n = worklist.pop(); | |
| 2462 if (n != last_peel) { | |
| 2463 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { | |
| 2464 Node* use = n->fast_out(j); | |
| 2465 if (use->is_CFG() && | |
| 2466 loop->is_member(get_loop(use)) && | |
| 2467 !peel.test_set(use->_idx)) { | |
| 2468 worklist.push(use); | |
| 2469 } | |
| 2470 } | |
| 2471 } | |
| 2472 } | |
| 2473 | |
| 2474 // Set of non-cfg nodes to peel are those that are control | |
| 2475 // dependent on the cfg nodes. | |
| 2476 uint i; | |
| 2477 for(i = 0; i < loop->_body.size(); i++ ) { | |
| 2478 Node *n = loop->_body.at(i); | |
| 2479 Node *n_c = has_ctrl(n) ? get_ctrl(n) : n; | |
| 2480 if (peel.test(n_c->_idx)) { | |
| 2481 peel.set(n->_idx); | |
| 2482 } else { | |
| 2483 not_peel.set(n->_idx); | |
| 2484 } | |
| 2485 } | |
| 2486 | |
| 2487 // Step 2: move operations from the peeled section down into the | |
| 2488 // not-peeled section | |
| 2489 | |
| 2490 // Get a post order schedule of nodes in the peel region | |
| 2491 // Result in right-most operand. | |
| 2492 scheduled_nodelist(loop, peel, peel_list ); | |
| 2493 | |
| 2494 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition"); | |
| 2495 | |
| 2496 // For future check for too many new phis | |
| 2497 uint old_phi_cnt = 0; | |
| 2498 for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) { | |
| 2499 Node* use = head->fast_out(j); | |
| 2500 if (use->is_Phi()) old_phi_cnt++; | |
| 2501 } | |
| 2502 | |
| 2503 #if !defined(PRODUCT) | |
| 2504 if (TracePartialPeeling) { | |
| 2505 tty->print_cr("\npeeled list"); | |
| 2506 } | |
| 2507 #endif | |
| 2508 | |
| 2509 // Evacuate nodes in peel region into the not_peeled region if possible | |
| 2510 uint new_phi_cnt = 0; | |
| 2511 for (i = 0; i < peel_list.size();) { | |
| 2512 Node* n = peel_list.at(i); | |
| 2513 #if !defined(PRODUCT) | |
| 2514 if (TracePartialPeeling) n->dump(); | |
| 2515 #endif | |
| 2516 bool incr = true; | |
| 2517 if ( !n->is_CFG() ) { | |
| 2518 | |
| 2519 if ( has_use_in_set(n, not_peel) ) { | |
| 2520 | |
| 2521 // If not used internal to the peeled region, | |
| 2522 // move "n" from peeled to not_peeled region. | |
| 2523 | |
| 2524 if ( !has_use_internal_to_set(n, peel, loop) ) { | |
| 2525 | |
| 2526 // if not pinned and not a load (which maybe anti-dependent on a store) | |
| 2527 // and not a CMove (Matcher expects only bool->cmove). | |
| 2528 if ( n->in(0) == NULL && !n->is_Load() && !n->is_CMove() ) { | |
| 2529 clone_for_use_outside_loop( loop, n, worklist ); | |
| 2530 | |
| 2531 sink_list.push(n); | |
| 2532 peel >>= n->_idx; // delete n from peel set. | |
| 2533 not_peel <<= n->_idx; // add n to not_peel set. | |
| 2534 peel_list.remove(i); | |
| 2535 incr = false; | |
| 2536 #if !defined(PRODUCT) | |
| 2537 if (TracePartialPeeling) { | |
| 2538 tty->print_cr("sink to not_peeled region: %d newbb: %d", | |
| 2539 n->_idx, get_ctrl(n)->_idx); | |
| 2540 } | |
| 2541 #endif | |
| 2542 } | |
| 2543 } else { | |
| 2544 // Otherwise check for special def-use cases that span | |
| 2545 // the peel/not_peel boundary such as bool->if | |
| 2546 clone_for_special_use_inside_loop( loop, n, not_peel, sink_list, worklist ); | |
| 2547 new_phi_cnt++; | |
| 2548 } | |
| 2549 } | |
| 2550 } | |
| 2551 if (incr) i++; | |
| 2552 } | |
| 2553 | |
| 2554 if (new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta) { | |
| 2555 #if !defined(PRODUCT) | |
| 2556 if (TracePartialPeeling) { | |
| 2557 tty->print_cr("\nToo many new phis: %d old %d new cmpi: %c", | |
| 2558 new_phi_cnt, old_phi_cnt, new_peel_if != NULL?'T':'F'); | |
| 2559 } | |
| 2560 #endif | |
| 2561 if (new_peel_if != NULL) { | |
| 2562 remove_cmpi_loop_exit(new_peel_if, loop); | |
| 2563 } | |
| 2564 // Inhibit more partial peeling on this loop | |
| 2565 assert(!head->is_partial_peel_loop(), "not partial peeled"); | |
| 2566 head->mark_partial_peel_failed(); | |
| 2567 return false; | |
| 2568 } | |
| 2569 | |
| 2570 // Step 3: clone loop, retarget control, and insert new phis | |
| 2571 | |
| 2572 // Create new loop head for new phis and to hang | |
| 2573 // the nodes being moved (sinked) from the peel region. | |
| 2574 LoopNode* new_head = new (C, 3) LoopNode(last_peel, last_peel); | |
|
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diff
changeset
|
2575 new_head->set_unswitch_count(head->unswitch_count()); // Preserve |
| 0 | 2576 _igvn.register_new_node_with_optimizer(new_head); |
| 2577 assert(first_not_peeled->in(0) == last_peel, "last_peel <- first_not_peeled"); | |
| 2578 first_not_peeled->set_req(0, new_head); | |
| 2579 set_loop(new_head, loop); | |
| 2580 loop->_body.push(new_head); | |
| 2581 not_peel.set(new_head->_idx); | |
| 2582 set_idom(new_head, last_peel, dom_depth(first_not_peeled)); | |
| 2583 set_idom(first_not_peeled, new_head, dom_depth(first_not_peeled)); | |
| 2584 | |
| 2585 while (sink_list.size() > 0) { | |
| 2586 Node* n = sink_list.pop(); | |
| 2587 set_ctrl(n, new_head); | |
| 2588 } | |
| 2589 | |
| 2590 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition"); | |
| 2591 | |
| 2592 clone_loop( loop, old_new, dd ); | |
| 2593 | |
| 2594 const uint clone_exit_idx = 1; | |
| 2595 const uint orig_exit_idx = 2; | |
| 2596 assert(is_valid_clone_loop_form( loop, peel_list, orig_exit_idx, clone_exit_idx ), "bad clone loop"); | |
| 2597 | |
| 2598 Node* head_clone = old_new[head->_idx]; | |
| 2599 LoopNode* new_head_clone = old_new[new_head->_idx]->as_Loop(); | |
| 2600 Node* orig_tail_clone = head_clone->in(2); | |
| 2601 | |
| 2602 // Add phi if "def" node is in peel set and "use" is not | |
| 2603 | |
| 2604 for(i = 0; i < peel_list.size(); i++ ) { | |
| 2605 Node *def = peel_list.at(i); | |
| 2606 if (!def->is_CFG()) { | |
| 2607 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) { | |
| 2608 Node *use = def->fast_out(j); | |
| 2609 if (has_node(use) && use->in(0) != C->top() && | |
| 2610 (!peel.test(use->_idx) || | |
| 2611 (use->is_Phi() && use->in(0) == head)) ) { | |
| 2612 worklist.push(use); | |
| 2613 } | |
| 2614 } | |
| 2615 while( worklist.size() ) { | |
| 2616 Node *use = worklist.pop(); | |
| 2617 for (uint j = 1; j < use->req(); j++) { | |
| 2618 Node* n = use->in(j); | |
| 2619 if (n == def) { | |
| 2620 | |
| 2621 // "def" is in peel set, "use" is not in peel set | |
| 2622 // or "use" is in the entry boundary (a phi) of the peel set | |
| 2623 | |
| 2624 Node* use_c = has_ctrl(use) ? get_ctrl(use) : use; | |
| 2625 | |
| 2626 if ( loop->is_member(get_loop( use_c )) ) { | |
| 2627 // use is in loop | |
| 2628 if (old_new[use->_idx] != NULL) { // null for dead code | |
| 2629 Node* use_clone = old_new[use->_idx]; | |
| 2630 _igvn.hash_delete(use); | |
| 2631 use->set_req(j, C->top()); | |
| 2632 _igvn._worklist.push(use); | |
| 2633 insert_phi_for_loop( use_clone, j, old_new[def->_idx], def, new_head_clone ); | |
| 2634 } | |
| 2635 } else { | |
| 2636 assert(is_valid_clone_loop_exit_use(loop, use, orig_exit_idx), "clone loop format"); | |
| 2637 // use is not in the loop, check if the live range includes the cut | |
| 2638 Node* lp_if = use_c->in(orig_exit_idx)->in(0); | |
| 2639 if (not_peel.test(lp_if->_idx)) { | |
| 2640 assert(j == orig_exit_idx, "use from original loop"); | |
| 2641 insert_phi_for_loop( use, clone_exit_idx, old_new[def->_idx], def, new_head_clone ); | |
| 2642 } | |
| 2643 } | |
| 2644 } | |
| 2645 } | |
| 2646 } | |
| 2647 } | |
| 2648 } | |
| 2649 | |
| 2650 // Step 3b: retarget control | |
| 2651 | |
| 2652 // Redirect control to the new loop head if a cloned node in | |
| 2653 // the not_peeled region has control that points into the peeled region. | |
| 2654 // This necessary because the cloned peeled region will be outside | |
| 2655 // the loop. | |
| 2656 // from to | |
| 2657 // cloned-peeled <---+ | |
| 2658 // new_head_clone: | <--+ | |
| 2659 // cloned-not_peeled in(0) in(0) | |
| 2660 // orig-peeled | |
| 2661 | |
| 2662 for(i = 0; i < loop->_body.size(); i++ ) { | |
| 2663 Node *n = loop->_body.at(i); | |
| 2664 if (!n->is_CFG() && n->in(0) != NULL && | |
| 2665 not_peel.test(n->_idx) && peel.test(n->in(0)->_idx)) { | |
| 2666 Node* n_clone = old_new[n->_idx]; | |
| 2667 _igvn.hash_delete(n_clone); | |
| 2668 n_clone->set_req(0, new_head_clone); | |
| 2669 _igvn._worklist.push(n_clone); | |
| 2670 } | |
| 2671 } | |
| 2672 | |
| 2673 // Backedge of the surviving new_head (the clone) is original last_peel | |
| 2674 _igvn.hash_delete(new_head_clone); | |
| 2675 new_head_clone->set_req(LoopNode::LoopBackControl, last_peel); | |
| 2676 _igvn._worklist.push(new_head_clone); | |
| 2677 | |
| 2678 // Cut first node in original not_peel set | |
| 2679 _igvn.hash_delete(new_head); | |
| 2680 new_head->set_req(LoopNode::EntryControl, C->top()); | |
| 2681 new_head->set_req(LoopNode::LoopBackControl, C->top()); | |
| 2682 _igvn._worklist.push(new_head); | |
| 2683 | |
| 2684 // Copy head_clone back-branch info to original head | |
| 2685 // and remove original head's loop entry and | |
| 2686 // clone head's back-branch | |
| 2687 _igvn.hash_delete(head); | |
| 2688 _igvn.hash_delete(head_clone); | |
| 2689 head->set_req(LoopNode::EntryControl, head_clone->in(LoopNode::LoopBackControl)); | |
| 2690 head->set_req(LoopNode::LoopBackControl, C->top()); | |
| 2691 head_clone->set_req(LoopNode::LoopBackControl, C->top()); | |
| 2692 _igvn._worklist.push(head); | |
| 2693 _igvn._worklist.push(head_clone); | |
| 2694 | |
| 2695 // Similarly modify the phis | |
| 2696 for (DUIterator_Fast kmax, k = head->fast_outs(kmax); k < kmax; k++) { | |
| 2697 Node* use = head->fast_out(k); | |
| 2698 if (use->is_Phi() && use->outcnt() > 0) { | |
| 2699 Node* use_clone = old_new[use->_idx]; | |
| 2700 _igvn.hash_delete(use); | |
| 2701 _igvn.hash_delete(use_clone); | |
| 2702 use->set_req(LoopNode::EntryControl, use_clone->in(LoopNode::LoopBackControl)); | |
| 2703 use->set_req(LoopNode::LoopBackControl, C->top()); | |
| 2704 use_clone->set_req(LoopNode::LoopBackControl, C->top()); | |
| 2705 _igvn._worklist.push(use); | |
| 2706 _igvn._worklist.push(use_clone); | |
| 2707 } | |
| 2708 } | |
| 2709 | |
| 2710 // Step 4: update dominator tree and dominator depth | |
| 2711 | |
| 2712 set_idom(head, orig_tail_clone, dd); | |
| 2713 recompute_dom_depth(); | |
| 2714 | |
| 2715 // Inhibit more partial peeling on this loop | |
| 2716 new_head_clone->set_partial_peel_loop(); | |
| 2717 C->set_major_progress(); | |
| 2718 | |
| 2719 #if !defined(PRODUCT) | |
| 2720 if (TracePartialPeeling) { | |
| 2721 tty->print_cr("\nafter partial peel one iteration"); | |
| 2722 Node_List wl(area); | |
| 2723 Node* t = last_peel; | |
| 2724 while (true) { | |
| 2725 wl.push(t); | |
| 2726 if (t == head_clone) break; | |
| 2727 t = idom(t); | |
| 2728 } | |
| 2729 while (wl.size() > 0) { | |
| 2730 Node* tt = wl.pop(); | |
| 2731 if (tt == head) tty->print_cr("orig head"); | |
| 2732 else if (tt == new_head_clone) tty->print_cr("new head"); | |
| 2733 else if (tt == head_clone) tty->print_cr("clone head"); | |
| 2734 tt->dump(); | |
| 2735 } | |
| 2736 } | |
| 2737 #endif | |
| 2738 return true; | |
| 2739 } | |
| 2740 | |
| 2741 //------------------------------reorg_offsets---------------------------------- | |
| 2742 // Reorganize offset computations to lower register pressure. Mostly | |
| 2743 // prevent loop-fallout uses of the pre-incremented trip counter (which are | |
| 2744 // then alive with the post-incremented trip counter forcing an extra | |
| 2745 // register move) | |
|
2383
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diff
changeset
|
2746 void PhaseIdealLoop::reorg_offsets(IdealLoopTree *loop) { |
|
9dc311b8473e
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diff
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|
2747 // Perform it only for canonical counted loops. |
|
9dc311b8473e
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diff
changeset
|
2748 // Loop's shape could be messed up by iteration_split_impl. |
|
9dc311b8473e
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diff
changeset
|
2749 if (!loop->_head->is_CountedLoop()) |
|
9dc311b8473e
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kvn
parents:
1972
diff
changeset
|
2750 return; |
|
9dc311b8473e
7008866: Missing loop predicate for loop with multiple entries
kvn
parents:
1972
diff
changeset
|
2751 if (!loop->_head->as_Loop()->is_valid_counted_loop()) |
|
9dc311b8473e
7008866: Missing loop predicate for loop with multiple entries
kvn
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1972
diff
changeset
|
2752 return; |
| 0 | 2753 |
| 2754 CountedLoopNode *cl = loop->_head->as_CountedLoop(); | |
| 2755 CountedLoopEndNode *cle = cl->loopexit(); | |
| 2756 Node *exit = cle->proj_out(false); | |
|
2383
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diff
changeset
|
2757 Node *phi = cl->phi(); |
| 0 | 2758 |
| 2759 // Check for the special case of folks using the pre-incremented | |
| 2760 // trip-counter on the fall-out path (forces the pre-incremented | |
| 2761 // and post-incremented trip counter to be live at the same time). | |
| 2762 // Fix this by adjusting to use the post-increment trip counter. | |
|
367
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never
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318
diff
changeset
|
2763 |
| 0 | 2764 bool progress = true; |
| 2765 while (progress) { | |
| 2766 progress = false; | |
| 2767 for (DUIterator_Fast imax, i = phi->fast_outs(imax); i < imax; i++) { | |
| 2768 Node* use = phi->fast_out(i); // User of trip-counter | |
| 2769 if (!has_ctrl(use)) continue; | |
| 2770 Node *u_ctrl = get_ctrl(use); | |
|
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diff
changeset
|
2771 if (use->is_Phi()) { |
| 0 | 2772 u_ctrl = NULL; |
|
2383
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diff
changeset
|
2773 for (uint j = 1; j < use->req(); j++) |
|
9dc311b8473e
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diff
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|
2774 if (use->in(j) == phi) |
|
9dc311b8473e
7008866: Missing loop predicate for loop with multiple entries
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diff
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|
2775 u_ctrl = dom_lca(u_ctrl, use->in(0)->in(j)); |
| 0 | 2776 } |
| 2777 IdealLoopTree *u_loop = get_loop(u_ctrl); | |
| 2778 // Look for loop-invariant use | |
|
2383
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diff
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|
2779 if (u_loop == loop) continue; |
|
9dc311b8473e
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|
2780 if (loop->is_member(u_loop)) continue; |
| 0 | 2781 // Check that use is live out the bottom. Assuming the trip-counter |
| 2782 // update is right at the bottom, uses of of the loop middle are ok. | |
|
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diff
changeset
|
2783 if (dom_lca(exit, u_ctrl) != exit) continue; |
| 0 | 2784 // Hit! Refactor use to use the post-incremented tripcounter. |
| 2785 // Compute a post-increment tripcounter. | |
|
216
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|
2786 Node *opaq = new (C, 2) Opaque2Node( C, cle->incr() ); |
| 0 | 2787 register_new_node( opaq, u_ctrl ); |
| 2788 Node *neg_stride = _igvn.intcon(-cle->stride_con()); | |
| 2789 set_ctrl(neg_stride, C->root()); | |
| 2790 Node *post = new (C, 3) AddINode( opaq, neg_stride); | |
| 2791 register_new_node( post, u_ctrl ); | |
| 2792 _igvn.hash_delete(use); | |
| 2793 _igvn._worklist.push(use); | |
|
2383
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kvn
parents:
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diff
changeset
|
2794 for (uint j = 1; j < use->req(); j++) { |
|
9dc311b8473e
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diff
changeset
|
2795 if (use->in(j) == phi) |
| 0 | 2796 use->set_req(j, post); |
|
2383
9dc311b8473e
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diff
changeset
|
2797 } |
| 0 | 2798 // Since DU info changed, rerun loop |
| 2799 progress = true; | |
| 2800 break; | |
| 2801 } | |
| 2802 } | |
| 2803 | |
| 2804 } |