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src/hotspot/share/opto/gcm.cpp

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 216         Node* m = node->in(i);
 217         if (m == nullptr) continue;
 218         assert(is_CFG(m), "must be a CFG node");
 219         node->rm_prec(i);
 220         if (n == nullptr) {
 221           n = m;
 222         } else {
 223           assert(is_dominator(n, m) || is_dominator(m, n), "one must dominate the other");
 224           n = is_dominator(n, m) ? m : n;
 225         }
 226       }
 227       if (n != nullptr) {
 228         assert(node->in(0), "control should have been set");
 229         assert(is_dominator(n, node->in(0)) || is_dominator(node->in(0), n), "one must dominate the other");
 230         if (!is_dominator(n, node->in(0))) {
 231           node->set_req(0, n);
 232         }
 233       }
 234 
 235       // process all inputs that are non null
 236       for (int i = node->req()-1; i >= 0; --i) {
 237         if (node->in(i) != nullptr) {
 238           spstack.push(node->in(i));
 239         }
 240       }
 241     }
 242   }
 243 }
 244 
 245 // Assert that new input b2 is dominated by all previous inputs.
 246 // Check this by by seeing that it is dominated by b1, the deepest
 247 // input observed until b2.
 248 static void assert_dom(Block* b1, Block* b2, Node* n, const PhaseCFG* cfg) {
 249   if (b1 == nullptr)  return;
 250   assert(b1->_dom_depth < b2->_dom_depth, "sanity");
 251   Block* tmp = b2;
 252   while (tmp != b1 && tmp != nullptr) {
 253     tmp = tmp->_idom;
 254   }
 255   if (tmp != b1) {
 256 #ifdef ASSERT

1573 
1574 #ifdef ASSERT
1575     // Assert that memory writers (e.g. stores) have a "home" block (the block
1576     // given by their control input), and that this block corresponds to their
1577     // earliest possible placement. This guarantees that
1578     // hoist_to_cheaper_block() will always have at least one valid choice.
1579     if (self->is_memory_writer()) {
1580       assert(find_block_for_node(self->in(0)) == early,
1581              "The home of a memory writer must also be its earliest placement");
1582     }
1583 #endif
1584 
1585     MachNode* mach = self->is_Mach() ? self->as_Mach() : nullptr;
1586     if (mach) {
1587       switch (mach->ideal_Opcode()) {
1588       case Op_CreateEx:
1589         // Don't move exception creation
1590         early->add_inst(self);
1591         continue;
1592         break;



1593       case Op_CheckCastPP: {
1594         // Don't move CheckCastPP nodes away from their input, if the input
1595         // is a rawptr (5071820).
1596         Node *def = self->in(1);
1597         if (def != nullptr && def->bottom_type()->base() == Type::RawPtr) {
1598           early->add_inst(self);
1599 #ifdef ASSERT
1600           _raw_oops.push(def);
1601 #endif
1602           continue;
1603         }
1604         break;
1605       }
1606       default:
1607         break;
1608       }
1609       if (C->has_irreducible_loop() && self->is_memory_writer()) {
1610         // If the CFG is irreducible, place memory writers in their home block.
1611         // This prevents hoist_to_cheaper_block() from accidentally placing such
1612         // nodes into deeper loops, as in the following example:

 216         Node* m = node->in(i);
 217         if (m == nullptr) continue;
 218         assert(is_CFG(m), "must be a CFG node");
 219         node->rm_prec(i);
 220         if (n == nullptr) {
 221           n = m;
 222         } else {
 223           assert(is_dominator(n, m) || is_dominator(m, n), "one must dominate the other");
 224           n = is_dominator(n, m) ? m : n;
 225         }
 226       }
 227       if (n != nullptr) {
 228         assert(node->in(0), "control should have been set");
 229         assert(is_dominator(n, node->in(0)) || is_dominator(node->in(0), n), "one must dominate the other");
 230         if (!is_dominator(n, node->in(0))) {
 231           node->set_req(0, n);
 232         }
 233       }
 234 
 235       // process all inputs that are non null
 236       for (int i = node->len()-1; i >= 0; --i) {
 237         if (node->in(i) != nullptr) {
 238           spstack.push(node->in(i));
 239         }
 240       }
 241     }
 242   }
 243 }
 244 
 245 // Assert that new input b2 is dominated by all previous inputs.
 246 // Check this by by seeing that it is dominated by b1, the deepest
 247 // input observed until b2.
 248 static void assert_dom(Block* b1, Block* b2, Node* n, const PhaseCFG* cfg) {
 249   if (b1 == nullptr)  return;
 250   assert(b1->_dom_depth < b2->_dom_depth, "sanity");
 251   Block* tmp = b2;
 252   while (tmp != b1 && tmp != nullptr) {
 253     tmp = tmp->_idom;
 254   }
 255   if (tmp != b1) {
 256 #ifdef ASSERT

1573 
1574 #ifdef ASSERT
1575     // Assert that memory writers (e.g. stores) have a "home" block (the block
1576     // given by their control input), and that this block corresponds to their
1577     // earliest possible placement. This guarantees that
1578     // hoist_to_cheaper_block() will always have at least one valid choice.
1579     if (self->is_memory_writer()) {
1580       assert(find_block_for_node(self->in(0)) == early,
1581              "The home of a memory writer must also be its earliest placement");
1582     }
1583 #endif
1584 
1585     MachNode* mach = self->is_Mach() ? self->as_Mach() : nullptr;
1586     if (mach) {
1587       switch (mach->ideal_Opcode()) {
1588       case Op_CreateEx:
1589         // Don't move exception creation
1590         early->add_inst(self);
1591         continue;
1592         break;
1593       case Op_CastI2N:
1594         early->add_inst(self);
1595         continue;
1596       case Op_CheckCastPP: {
1597         // Don't move CheckCastPP nodes away from their input, if the input
1598         // is a rawptr (5071820).
1599         Node *def = self->in(1);
1600         if (def != nullptr && def->bottom_type()->base() == Type::RawPtr) {
1601           early->add_inst(self);
1602 #ifdef ASSERT
1603           _raw_oops.push(def);
1604 #endif
1605           continue;
1606         }
1607         break;
1608       }
1609       default:
1610         break;
1611       }
1612       if (C->has_irreducible_loop() && self->is_memory_writer()) {
1613         // If the CFG is irreducible, place memory writers in their home block.
1614         // This prevents hoist_to_cheaper_block() from accidentally placing such
1615         // nodes into deeper loops, as in the following example:
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