Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/opto/node.cpp
src/share/vm/opto/node.cpp
- changeset 740
- ab075d07f1ba
- parent 670
- 9c2ecc2ffb12
- child 1040
- 98cb887364d3
equal
deleted
inserted
replaced
| 739:dc7f315e41f7 | 740:ab075d07f1ba |
|---|---|
| 1164 //------------------------------remove_dead_region----------------------------- | 1164 //------------------------------remove_dead_region----------------------------- |
| 1165 // This control node is dead. Follow the subgraph below it making everything | 1165 // This control node is dead. Follow the subgraph below it making everything |
| 1166 // using it dead as well. This will happen normally via the usual IterGVN | 1166 // using it dead as well. This will happen normally via the usual IterGVN |
| 1167 // worklist but this call is more efficient. Do not update use-def info | 1167 // worklist but this call is more efficient. Do not update use-def info |
| 1168 // inside the dead region, just at the borders. | 1168 // inside the dead region, just at the borders. |
| 1169 static bool kill_dead_code( Node *dead, PhaseIterGVN *igvn ) { | 1169 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) { |
| 1170 // Con's are a popular node to re-hit in the hash table again. | 1170 // Con's are a popular node to re-hit in the hash table again. |
| 1171 if( dead->is_Con() ) return false; | 1171 if( dead->is_Con() ) return; |
| 1172 | 1172 |
| 1173 // Can't put ResourceMark here since igvn->_worklist uses the same arena | 1173 // Can't put ResourceMark here since igvn->_worklist uses the same arena |
| 1174 // for verify pass with +VerifyOpto and we add/remove elements in it here. | 1174 // for verify pass with +VerifyOpto and we add/remove elements in it here. |
| 1175 Node_List nstack(Thread::current()->resource_area()); | 1175 Node_List nstack(Thread::current()->resource_area()); |
| 1176 | 1176 |
| 1177 Node *top = igvn->C->top(); | 1177 Node *top = igvn->C->top(); |
| 1178 bool progress = false; | |
| 1179 nstack.push(dead); | 1178 nstack.push(dead); |
| 1180 | 1179 |
| 1181 while (nstack.size() > 0) { | 1180 while (nstack.size() > 0) { |
| 1182 dead = nstack.pop(); | 1181 dead = nstack.pop(); |
| 1183 if (dead->outcnt() > 0) { | 1182 if (dead->outcnt() > 0) { |
| 1212 } | 1211 } |
| 1213 // Kill all inputs to the dead guy | 1212 // Kill all inputs to the dead guy |
| 1214 for (uint i=0; i < dead->req(); i++) { | 1213 for (uint i=0; i < dead->req(); i++) { |
| 1215 Node *n = dead->in(i); // Get input to dead guy | 1214 Node *n = dead->in(i); // Get input to dead guy |
| 1216 if (n != NULL && !n->is_top()) { // Input is valid? | 1215 if (n != NULL && !n->is_top()) { // Input is valid? |
| 1217 progress = true; | |
| 1218 dead->set_req(i, top); // Smash input away | 1216 dead->set_req(i, top); // Smash input away |
| 1219 if (n->outcnt() == 0) { // Input also goes dead? | 1217 if (n->outcnt() == 0) { // Input also goes dead? |
| 1220 if (!n->is_Con()) | 1218 if (!n->is_Con()) |
| 1221 nstack.push(n); // Clear it out as well | 1219 nstack.push(n); // Clear it out as well |
| 1222 } else if (n->outcnt() == 1 && | 1220 } else if (n->outcnt() == 1 && |
| 1231 } | 1229 } |
| 1232 } | 1230 } |
| 1233 } | 1231 } |
| 1234 } // (dead->outcnt() == 0) | 1232 } // (dead->outcnt() == 0) |
| 1235 } // while (nstack.size() > 0) for outputs | 1233 } // while (nstack.size() > 0) for outputs |
| 1236 return progress; | 1234 return; |
| 1237 } | 1235 } |
| 1238 | 1236 |
| 1239 //------------------------------remove_dead_region----------------------------- | 1237 //------------------------------remove_dead_region----------------------------- |
| 1240 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) { | 1238 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) { |
| 1241 Node *n = in(0); | 1239 Node *n = in(0); |
| 1242 if( !n ) return false; | 1240 if( !n ) return false; |
| 1243 // Lost control into this guy? I.e., it became unreachable? | 1241 // Lost control into this guy? I.e., it became unreachable? |
| 1244 // Aggressively kill all unreachable code. | 1242 // Aggressively kill all unreachable code. |
| 1245 if (can_reshape && n->is_top()) { | 1243 if (can_reshape && n->is_top()) { |
| 1246 return kill_dead_code(this, phase->is_IterGVN()); | 1244 kill_dead_code(this, phase->is_IterGVN()); |
| 1245 return false; // Node is dead. | |
| 1247 } | 1246 } |
| 1248 | 1247 |
| 1249 if( n->is_Region() && n->as_Region()->is_copy() ) { | 1248 if( n->is_Region() && n->as_Region()->is_copy() ) { |
| 1250 Node *m = n->nonnull_req(); | 1249 Node *m = n->nonnull_req(); |
| 1251 set_req(0, m); | 1250 set_req(0, m); |
