jdk8-mips64-public/hotspot: src/share/vm/opto/lcm.cpp@bd441136a5ce (annotated)

src/share/vm/opto/lcm.cpp@bd441136a5ce (annotated)

src/share/vm/opto/lcm.cpp

Thu, 19 Mar 2009 09:13:24 -0700

author: kvn
date: Thu, 19 Mar 2009 09:13:24 -0700
changeset 1082: bd441136a5ce
parent 1014: 0fbdb4381b99
parent 1077: 660978a2a31a
child 1116: fbde8ec322d0
permissions: -rw-r--r--

Merge

 /*
  * Copyright 1998-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 // Optimization - Graph Style
 #include "incls/_precompiled.incl"
 #include "incls/_lcm.cpp.incl"
 //------------------------------implicit_null_check----------------------------
 // Detect implicit-null-check opportunities.  Basically, find NULL checks
 // with suitable memory ops nearby.  Use the memory op to do the NULL check.
 // I can generate a memory op if there is not one nearby.
 // The proj is the control projection for the not-null case.
 // The val is the pointer being checked for nullness.
 void Block::implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons) {
   // Assume if null check need for 0 offset then always needed
   // Intel solaris doesn't support any null checks yet and no
   // mechanism exists (yet) to set the switches at an os_cpu level
   if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return;
   // Make sure the ptr-is-null path appears to be uncommon!
   float f = end()->as_MachIf()->_prob;
   if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f;
   if( f > PROB_UNLIKELY_MAG(4) ) return;
   uint bidx = 0;                // Capture index of value into memop
   bool was_store;               // Memory op is a store op
   // Get the successor block for if the test ptr is non-null
   Block* not_null_block;  // this one goes with the proj
   Block* null_block;
   if (_nodes[_nodes.size()-1] == proj) {
     null_block     = _succs[0];
     not_null_block = _succs[1];
   } else {
     assert(_nodes[_nodes.size()-2] == proj, "proj is one or the other");
     not_null_block = _succs[0];
     null_block     = _succs[1];
   }
   while (null_block->is_Empty() == Block::empty_with_goto) {
     null_block     = null_block->_succs[0];
   }
   // Search the exception block for an uncommon trap.
   // (See Parse::do_if and Parse::do_ifnull for the reason
   // we need an uncommon trap.  Briefly, we need a way to
   // detect failure of this optimization, as in 6366351.)
   {
     bool found_trap = false;
     for (uint i1 = 0; i1 < null_block->_nodes.size(); i1++) {
       Node* nn = null_block->_nodes[i1];
       if (nn->is_MachCall() &&
           nn->as_MachCall()->entry_point() ==
           SharedRuntime::uncommon_trap_blob()->instructions_begin()) {
         const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type();
         if (trtype->isa_int() && trtype->is_int()->is_con()) {
           jint tr_con = trtype->is_int()->get_con();
           Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con);
           Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con);
           assert((int)reason < (int)BitsPerInt, "recode bit map");
           if (is_set_nth_bit(allowed_reasons, (int) reason)
               && action != Deoptimization::Action_none) {
             // This uncommon trap is sure to recompile, eventually.
             // When that happens, C->too_many_traps will prevent
             // this transformation from happening again.
             found_trap = true;
           }
         }
         break;
       }
     }
     if (!found_trap) {
       // We did not find an uncommon trap.
       return;
     }
   }
   // Search the successor block for a load or store who's base value is also
   // the tested value.  There may be several.
   Node_List *out = new Node_List(Thread::current()->resource_area());
   MachNode *best = NULL;        // Best found so far
   for (DUIterator i = val->outs(); val->has_out(i); i++) {
     Node *m = val->out(i);
     if( !m->is_Mach() ) continue;
     MachNode *mach = m->as_Mach();
     was_store = false;
     switch( mach->ideal_Opcode() ) {
     case Op_LoadB:
     case Op_LoadUS:
     case Op_LoadD:
     case Op_LoadF:
     case Op_LoadI:
     case Op_LoadL:
     case Op_LoadP:
     case Op_LoadN:
     case Op_LoadS:
     case Op_LoadKlass:
     case Op_LoadNKlass:
     case Op_LoadRange:
     case Op_LoadD_unaligned:
     case Op_LoadL_unaligned:
       break;
     case Op_StoreB:
     case Op_StoreC:
     case Op_StoreCM:
     case Op_StoreD:
     case Op_StoreF:
     case Op_StoreI:
     case Op_StoreL:
     case Op_StoreP:
     case Op_StoreN:
       was_store = true;         // Memory op is a store op
       // Stores will have their address in slot 2 (memory in slot 1).
       // If the value being nul-checked is in another slot, it means we
       // are storing the checked value, which does NOT check the value!
       if( mach->in(2) != val ) continue;
       break;                    // Found a memory op?
     case Op_StrComp:
     case Op_AryEq:
       // Not a legit memory op for implicit null check regardless of
       // embedded loads
       continue;
     default:                    // Also check for embedded loads
       if( !mach->needs_anti_dependence_check() )
         continue;               // Not an memory op; skip it
       break;
     }
     // check if the offset is not too high for implicit exception
     {
       intptr_t offset = 0;
       const TypePtr *adr_type = NULL;  // Do not need this return value here
       const Node* base = mach->get_base_and_disp(offset, adr_type);
       if (base == NULL || base == NodeSentinel) {
         // Narrow oop address doesn't have base, only index
         if( val->bottom_type()->isa_narrowoop() &&
             MacroAssembler::needs_explicit_null_check(offset) )
           continue;             // Give up if offset is beyond page size
         // cannot reason about it; is probably not implicit null exception
       } else {
         const TypePtr* tptr;
         if (UseCompressedOops && Universe::narrow_oop_shift() == 0) {
           // 32-bits narrow oop can be the base of address expressions
           tptr = base->bottom_type()->make_ptr();
         } else {
           // only regular oops are expected here
           tptr = base->bottom_type()->is_ptr();
         }
         // Give up if offset is not a compile-time constant
         if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot )
           continue;
         offset += tptr->_offset; // correct if base is offseted
         if( MacroAssembler::needs_explicit_null_check(offset) )
           continue;             // Give up is reference is beyond 4K page size
       }
     }
     // Check ctrl input to see if the null-check dominates the memory op
     Block *cb = cfg->_bbs[mach->_idx];
     cb = cb->_idom;             // Always hoist at least 1 block
     if( !was_store ) {          // Stores can be hoisted only one block
       while( cb->_dom_depth > (_dom_depth + 1))
         cb = cb->_idom;         // Hoist loads as far as we want
       // The non-null-block should dominate the memory op, too. Live
       // range spilling will insert a spill in the non-null-block if it is
       // needs to spill the memory op for an implicit null check.
       if (cb->_dom_depth == (_dom_depth + 1)) {
         if (cb != not_null_block) continue;
         cb = cb->_idom;
       }
     }
     if( cb != this ) continue;
     // Found a memory user; see if it can be hoisted to check-block
     uint vidx = 0;              // Capture index of value into memop
     uint j;
     for( j = mach->req()-1; j > 0; j-- ) {
       if( mach->in(j) == val ) vidx = j;
       // Block of memory-op input
       Block *inb = cfg->_bbs[mach->in(j)->_idx];
       Block *b = this;          // Start from nul check
       while( b != inb && b->_dom_depth > inb->_dom_depth )
         b = b->_idom;           // search upwards for input
       // See if input dominates null check
       if( b != inb )
         break;
     }
     if( j > 0 )
       continue;
     Block *mb = cfg->_bbs[mach->_idx];
     // Hoisting stores requires more checks for the anti-dependence case.
     // Give up hoisting if we have to move the store past any load.
     if( was_store ) {
       Block *b = mb;            // Start searching here for a local load
       // mach use (faulting) trying to hoist
       // n might be blocker to hoisting
       while( b != this ) {
         uint k;
         for( k = 1; k < b->_nodes.size(); k++ ) {
           Node *n = b->_nodes[k];
           if( n->needs_anti_dependence_check() &&
               n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) )
             break;              // Found anti-dependent load
         }
         if( k < b->_nodes.size() )
           break;                // Found anti-dependent load
         // Make sure control does not do a merge (would have to check allpaths)
         if( b->num_preds() != 2 ) break;
         b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block
       }
       if( b != this ) continue;
     }
     // Make sure this memory op is not already being used for a NullCheck
     Node *e = mb->end();
     if( e->is_MachNullCheck() && e->in(1) == mach )
       continue;                 // Already being used as a NULL check
     // Found a candidate!  Pick one with least dom depth - the highest
     // in the dom tree should be closest to the null check.
     if( !best ||
         cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) {
       best = mach;
       bidx = vidx;
     }
   }
   // No candidate!
   if( !best ) return;
   // ---- Found an implicit null check
   extern int implicit_null_checks;
   implicit_null_checks++;
   // Hoist the memory candidate up to the end of the test block.
   Block *old_block = cfg->_bbs[best->_idx];
   old_block->find_remove(best);
   add_inst(best);
   cfg->_bbs.map(best->_idx,this);
   // Move the control dependence
   if (best->in(0) && best->in(0) == old_block->_nodes[0])
     best->set_req(0, _nodes[0]);
   // Check for flag-killing projections that also need to be hoisted
   // Should be DU safe because no edge updates.
   for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) {
     Node* n = best->fast_out(j);
     if( n->Opcode() == Op_MachProj ) {
       cfg->_bbs[n->_idx]->find_remove(n);
       add_inst(n);
       cfg->_bbs.map(n->_idx,this);
     }
   }
   Compile *C = cfg->C;
   // proj==Op_True --> ne test; proj==Op_False --> eq test.
   // One of two graph shapes got matched:
   //   (IfTrue  (If (Bool NE (CmpP ptr NULL))))
   //   (IfFalse (If (Bool EQ (CmpP ptr NULL))))
   // NULL checks are always branch-if-eq.  If we see a IfTrue projection
   // then we are replacing a 'ne' test with a 'eq' NULL check test.
   // We need to flip the projections to keep the same semantics.
   if( proj->Opcode() == Op_IfTrue ) {
     // Swap order of projections in basic block to swap branch targets
     Node *tmp1 = _nodes[end_idx()+1];
     Node *tmp2 = _nodes[end_idx()+2];
     _nodes.map(end_idx()+1, tmp2);
     _nodes.map(end_idx()+2, tmp1);
     Node *tmp = new (C, 1) Node(C->top()); // Use not NULL input
     tmp1->replace_by(tmp);
     tmp2->replace_by(tmp1);
     tmp->replace_by(tmp2);
     tmp->destruct();
   }
   // Remove the existing null check; use a new implicit null check instead.
   // Since schedule-local needs precise def-use info, we need to correct
   // it as well.
   Node *old_tst = proj->in(0);
   MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx);
   _nodes.map(end_idx(),nul_chk);
   cfg->_bbs.map(nul_chk->_idx,this);
   // Redirect users of old_test to nul_chk
   for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2)
     old_tst->last_out(i2)->set_req(0, nul_chk);
   // Clean-up any dead code
   for (uint i3 = 0; i3 < old_tst->req(); i3++)
     old_tst->set_req(i3, NULL);
   cfg->latency_from_uses(nul_chk);
   cfg->latency_from_uses(best);
 }
 //------------------------------select-----------------------------------------
 // Select a nice fellow from the worklist to schedule next. If there is only
 // one choice, then use it. Projections take top priority for correctness
 // reasons - if I see a projection, then it is next.  There are a number of
 // other special cases, for instructions that consume condition codes, et al.
 // These are chosen immediately. Some instructions are required to immediately
 // precede the last instruction in the block, and these are taken last. Of the
 // remaining cases (most), choose the instruction with the greatest latency
 // (that is, the most number of pseudo-cycles required to the end of the
 // routine). If there is a tie, choose the instruction with the most inputs.
 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, int *ready_cnt, VectorSet &next_call, uint sched_slot) {
   // If only a single entry on the stack, use it
   uint cnt = worklist.size();
   if (cnt == 1) {
     Node *n = worklist[0];
     worklist.map(0,worklist.pop());
     return n;
   }
   uint choice  = 0; // Bigger is most important
   uint latency = 0; // Bigger is scheduled first
   uint score   = 0; // Bigger is better
   int idx = -1;     // Index in worklist
   for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist
     // Order in worklist is used to break ties.
     // See caller for how this is used to delay scheduling
     // of induction variable increments to after the other
     // uses of the phi are scheduled.
     Node *n = worklist[i];      // Get Node on worklist
     int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0;
     if( n->is_Proj() ||         // Projections always win
         n->Opcode()== Op_Con || // So does constant 'Top'
         iop == Op_CreateEx ||   // Create-exception must start block
         iop == Op_CheckCastPP
         ) {
       worklist.map(i,worklist.pop());
       return n;
     }
     // Final call in a block must be adjacent to 'catch'
     Node *e = end();
     if( e->is_Catch() && e->in(0)->in(0) == n )
       continue;
     // Memory op for an implicit null check has to be at the end of the block
     if( e->is_MachNullCheck() && e->in(1) == n )
       continue;
     uint n_choice  = 2;
     // See if this instruction is consumed by a branch. If so, then (as the
     // branch is the last instruction in the basic block) force it to the
     // end of the basic block
     if ( must_clone[iop] ) {
       // See if any use is a branch
       bool found_machif = false;
       for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
         Node* use = n->fast_out(j);
         // The use is a conditional branch, make them adjacent
         if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) {
           found_machif = true;
           break;
         }
         // More than this instruction pending for successor to be ready,
         // don't choose this if other opportunities are ready
         if (ready_cnt[use->_idx] > 1)
           n_choice = 1;
       }
       // loop terminated, prefer not to use this instruction
       if (found_machif)
         continue;
     }
     // See if this has a predecessor that is "must_clone", i.e. sets the
     // condition code. If so, choose this first
     for (uint j = 0; j < n->req() ; j++) {
       Node *inn = n->in(j);
       if (inn) {
         if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) {
           n_choice = 3;
           break;
         }
       }
     }
     // MachTemps should be scheduled last so they are near their uses
     if (n->is_MachTemp()) {
       n_choice = 1;
     }
     uint n_latency = cfg->_node_latency.at_grow(n->_idx);
     uint n_score   = n->req();   // Many inputs get high score to break ties
     // Keep best latency found
     if( choice < n_choice ||
         ( choice == n_choice &&
           ( latency < n_latency ||
             ( latency == n_latency &&
               ( score < n_score ))))) {
       choice  = n_choice;
       latency = n_latency;
       score   = n_score;
       idx     = i;               // Also keep index in worklist
     }
   } // End of for all ready nodes in worklist
   assert(idx >= 0, "index should be set");
   Node *n = worklist[(uint)idx];      // Get the winner
   worklist.map((uint)idx, worklist.pop());     // Compress worklist
   return n;
 }
 //------------------------------set_next_call----------------------------------
 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) {
   if( next_call.test_set(n->_idx) ) return;
   for( uint i=0; i<n->len(); i++ ) {
     Node *m = n->in(i);
     if( !m ) continue;  // must see all nodes in block that precede call
     if( bbs[m->_idx] == this )
       set_next_call( m, next_call, bbs );
   }
 }
 //------------------------------needed_for_next_call---------------------------
 // Set the flag 'next_call' for each Node that is needed for the next call to
 // be scheduled.  This flag lets me bias scheduling so Nodes needed for the
 // next subroutine call get priority - basically it moves things NOT needed
 // for the next call till after the call.  This prevents me from trying to
 // carry lots of stuff live across a call.
 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) {
   // Find the next control-defining Node in this block
   Node* call = NULL;
   for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
     Node* m = this_call->fast_out(i);
     if( bbs[m->_idx] == this && // Local-block user
         m != this_call &&       // Not self-start node
         m->is_Call() )
       call = m;
       break;
   }
   if (call == NULL)  return;    // No next call (e.g., block end is near)
   // Set next-call for all inputs to this call
   set_next_call(call, next_call, bbs);
 }
 //------------------------------sched_call-------------------------------------
 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, int *ready_cnt, MachCallNode *mcall, VectorSet &next_call ) {
   RegMask regs;
   // Schedule all the users of the call right now.  All the users are
   // projection Nodes, so they must be scheduled next to the call.
   // Collect all the defined registers.
   for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
     Node* n = mcall->fast_out(i);
     assert( n->Opcode()==Op_MachProj, "" );
     --ready_cnt[n->_idx];
     assert( !ready_cnt[n->_idx], "" );
     // Schedule next to call
     _nodes.map(node_cnt++, n);
     // Collect defined registers
     regs.OR(n->out_RegMask());
     // Check for scheduling the next control-definer
     if( n->bottom_type() == Type::CONTROL )
       // Warm up next pile of heuristic bits
       needed_for_next_call(n, next_call, bbs);
     // Children of projections are now all ready
     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
       Node* m = n->fast_out(j); // Get user
       if( bbs[m->_idx] != this ) continue;
       if( m->is_Phi() ) continue;
       if( !--ready_cnt[m->_idx] )
         worklist.push(m);
     }
   }
   // Act as if the call defines the Frame Pointer.
   // Certainly the FP is alive and well after the call.
   regs.Insert(matcher.c_frame_pointer());
   // Set all registers killed and not already defined by the call.
   uint r_cnt = mcall->tf()->range()->cnt();
   int op = mcall->ideal_Opcode();
   MachProjNode *proj = new (matcher.C, 1) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
   bbs.map(proj->_idx,this);
   _nodes.insert(node_cnt++, proj);
   // Select the right register save policy.
   const char * save_policy;
   switch (op) {
     case Op_CallRuntime:
     case Op_CallLeaf:
     case Op_CallLeafNoFP:
       // Calling C code so use C calling convention
       save_policy = matcher._c_reg_save_policy;
       break;
     case Op_CallStaticJava:
     case Op_CallDynamicJava:
       // Calling Java code so use Java calling convention
       save_policy = matcher._register_save_policy;
       break;
     default:
       ShouldNotReachHere();
   }
   // When using CallRuntime mark SOE registers as killed by the call
   // so values that could show up in the RegisterMap aren't live in a
   // callee saved register since the register wouldn't know where to
   // find them.  CallLeaf and CallLeafNoFP are ok because they can't
   // have debug info on them.  Strictly speaking this only needs to be
   // done for oops since idealreg2debugmask takes care of debug info
   // references but there no way to handle oops differently than other
   // pointers as far as the kill mask goes.
   bool exclude_soe = op == Op_CallRuntime;
   // Fill in the kill mask for the call
   for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
     if( !regs.Member(r) ) {     // Not already defined by the call
       // Save-on-call register?
       if ((save_policy[r] == 'C') ||
           (save_policy[r] == 'A') ||
           ((save_policy[r] == 'E') && exclude_soe)) {
         proj->_rout.Insert(r);
       }
     }
   }
   return node_cnt;
 }
 //------------------------------schedule_local---------------------------------
 // Topological sort within a block.  Someday become a real scheduler.
 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, int *ready_cnt, VectorSet &next_call) {
   // Already "sorted" are the block start Node (as the first entry), and
   // the block-ending Node and any trailing control projections.  We leave
   // these alone.  PhiNodes and ParmNodes are made to follow the block start
   // Node.  Everything else gets topo-sorted.
 #ifndef PRODUCT
     if (cfg->trace_opto_pipelining()) {
       tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order);
       for (uint i = 0;i < _nodes.size();i++) {
         tty->print("# ");
         _nodes[i]->fast_dump();
       }
       tty->print_cr("#");
     }
 #endif
   // RootNode is already sorted
   if( _nodes.size() == 1 ) return true;
   // Move PhiNodes and ParmNodes from 1 to cnt up to the start
   uint node_cnt = end_idx();
   uint phi_cnt = 1;
   uint i;
   for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
     Node *n = _nodes[i];
     if( n->is_Phi() ||          // Found a PhiNode or ParmNode
         (n->is_Proj()  && n->in(0) == head()) ) {
       // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
       _nodes.map(i,_nodes[phi_cnt]);
       _nodes.map(phi_cnt++,n);  // swap Phi/Parm up front
     } else {                    // All others
       // Count block-local inputs to 'n'
       uint cnt = n->len();      // Input count
       uint local = 0;
       for( uint j=0; j<cnt; j++ ) {
         Node *m = n->in(j);
         if( m && cfg->_bbs[m->_idx] == this && !m->is_top() )
           local++;              // One more block-local input
       }
       ready_cnt[n->_idx] = local; // Count em up
       // A few node types require changing a required edge to a precedence edge
       // before allocation.
       if( UseConcMarkSweepGC || UseG1GC ) {
         if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
           // Note: Required edges with an index greater than oper_input_base
           // are not supported by the allocator.
           // Note2: Can only depend on unmatched edge being last,
           // can not depend on its absolute position.
           Node *oop_store = n->in(n->req() - 1);
           n->del_req(n->req() - 1);
           n->add_prec(oop_store);
           assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
         }
       }
       if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire &&
           n->req() > TypeFunc::Parms ) {
         // MemBarAcquire could be created without Precedent edge.
         // del_req() replaces the specified edge with the last input edge
         // and then removes the last edge. If the specified edge > number of
         // edges the last edge will be moved outside of the input edges array
         // and the edge will be lost. This is why this code should be
         // executed only when Precedent (== TypeFunc::Parms) edge is present.
         Node *x = n->in(TypeFunc::Parms);
         n->del_req(TypeFunc::Parms);
         n->add_prec(x);
       }
     }
   }
   for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count
     ready_cnt[_nodes[i2]->_idx] = 0;
   // All the prescheduled guys do not hold back internal nodes
   uint i3;
   for(i3 = 0; i3<phi_cnt; i3++ ) {  // For all pre-scheduled
     Node *n = _nodes[i3];       // Get pre-scheduled
     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
       Node* m = n->fast_out(j);
       if( cfg->_bbs[m->_idx] ==this ) // Local-block user
         ready_cnt[m->_idx]--;   // Fix ready count
     }
   }
   Node_List delay;
   // Make a worklist
   Node_List worklist;
   for(uint i4=i3; i4<node_cnt; i4++ ) {    // Put ready guys on worklist
     Node *m = _nodes[i4];
     if( !ready_cnt[m->_idx] ) {   // Zero ready count?
       if (m->is_iteratively_computed()) {
         // Push induction variable increments last to allow other uses
         // of the phi to be scheduled first. The select() method breaks
         // ties in scheduling by worklist order.
         delay.push(m);
       } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) {
         // Force the CreateEx to the top of the list so it's processed
         // first and ends up at the start of the block.
         worklist.insert(0, m);
       } else {
         worklist.push(m);         // Then on to worklist!
       }
     }
   }
   while (delay.size()) {
     Node* d = delay.pop();
     worklist.push(d);
   }
   // Warm up the 'next_call' heuristic bits
   needed_for_next_call(_nodes[0], next_call, cfg->_bbs);
 #ifndef PRODUCT
     if (cfg->trace_opto_pipelining()) {
       for (uint j=0; j<_nodes.size(); j++) {
         Node     *n = _nodes[j];
         int     idx = n->_idx;
         tty->print("#   ready cnt:%3d  ", ready_cnt[idx]);
         tty->print("latency:%3d  ", cfg->_node_latency.at_grow(idx));
         tty->print("%4d: %s\n", idx, n->Name());
       }
     }
 #endif
   // Pull from worklist and schedule
   while( worklist.size() ) {    // Worklist is not ready
 #ifndef PRODUCT
     if (cfg->trace_opto_pipelining()) {
       tty->print("#   ready list:");
       for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
         Node *n = worklist[i];      // Get Node on worklist
         tty->print(" %d", n->_idx);
       }
       tty->cr();
     }
 #endif
     // Select and pop a ready guy from worklist
     Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt);
     _nodes.map(phi_cnt++,n);    // Schedule him next
 #ifndef PRODUCT
     if (cfg->trace_opto_pipelining()) {
       tty->print("#    select %d: %s", n->_idx, n->Name());
       tty->print(", latency:%d", cfg->_node_latency.at_grow(n->_idx));
       n->dump();
       if (Verbose) {
         tty->print("#   ready list:");
         for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
           Node *n = worklist[i];      // Get Node on worklist
           tty->print(" %d", n->_idx);
         }
         tty->cr();
       }
     }
 #endif
     if( n->is_MachCall() ) {
       MachCallNode *mcall = n->as_MachCall();
       phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call);
       continue;
     }
     // Children are now all ready
     for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
       Node* m = n->fast_out(i5); // Get user
       if( cfg->_bbs[m->_idx] != this ) continue;
       if( m->is_Phi() ) continue;
       if( !--ready_cnt[m->_idx] )
         worklist.push(m);
     }
   }
   if( phi_cnt != end_idx() ) {
     // did not schedule all.  Retry, Bailout, or Die
     Compile* C = matcher.C;
     if (C->subsume_loads() == true && !C->failing()) {
       // Retry with subsume_loads == false
       // If this is the first failure, the sentinel string will "stick"
       // to the Compile object, and the C2Compiler will see it and retry.
       C->record_failure(C2Compiler::retry_no_subsuming_loads());
     }
     // assert( phi_cnt == end_idx(), "did not schedule all" );
     return false;
   }
 #ifndef PRODUCT
   if (cfg->trace_opto_pipelining()) {
     tty->print_cr("#");
     tty->print_cr("# after schedule_local");
     for (uint i = 0;i < _nodes.size();i++) {
       tty->print("# ");
       _nodes[i]->fast_dump();
     }
     tty->cr();
   }
 #endif
   return true;
 }
 //--------------------------catch_cleanup_fix_all_inputs-----------------------
 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
   for (uint l = 0; l < use->len(); l++) {
     if (use->in(l) == old_def) {
       if (l < use->req()) {
         use->set_req(l, new_def);
       } else {
         use->rm_prec(l);
         use->add_prec(new_def);
         l--;
       }
     }
   }
 }
 //------------------------------catch_cleanup_find_cloned_def------------------
 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
   assert( use_blk != def_blk, "Inter-block cleanup only");
   // The use is some block below the Catch.  Find and return the clone of the def
   // that dominates the use. If there is no clone in a dominating block, then
   // create a phi for the def in a dominating block.
   // Find which successor block dominates this use.  The successor
   // blocks must all be single-entry (from the Catch only; I will have
   // split blocks to make this so), hence they all dominate.
   while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
     use_blk = use_blk->_idom;
   // Find the successor
   Node *fixup = NULL;
   uint j;
   for( j = 0; j < def_blk->_num_succs; j++ )
     if( use_blk == def_blk->_succs[j] )
       break;
   if( j == def_blk->_num_succs ) {
     // Block at same level in dom-tree is not a successor.  It needs a
     // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
     Node_Array inputs = new Node_List(Thread::current()->resource_area());
     for(uint k = 1; k < use_blk->num_preds(); k++) {
       inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx));
     }
     // Check to see if the use_blk already has an identical phi inserted.
     // If it exists, it will be at the first position since all uses of a
     // def are processed together.
     Node *phi = use_blk->_nodes[1];
     if( phi->is_Phi() ) {
       fixup = phi;
       for (uint k = 1; k < use_blk->num_preds(); k++) {
         if (phi->in(k) != inputs[k]) {
           // Not a match
           fixup = NULL;
           break;
         }
       }
     }
     // If an existing PhiNode was not found, make a new one.
     if (fixup == NULL) {
       Node *new_phi = PhiNode::make(use_blk->head(), def);
       use_blk->_nodes.insert(1, new_phi);
       bbs.map(new_phi->_idx, use_blk);
       for (uint k = 1; k < use_blk->num_preds(); k++) {
         new_phi->set_req(k, inputs[k]);
       }
       fixup = new_phi;
     }
   } else {
     // Found the use just below the Catch.  Make it use the clone.
     fixup = use_blk->_nodes[n_clone_idx];
   }
   return fixup;
 }
 //--------------------------catch_cleanup_intra_block--------------------------
 // Fix all input edges in use that reference "def".  The use is in the same
 // block as the def and both have been cloned in each successor block.
 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
   // Both the use and def have been cloned. For each successor block,
   // get the clone of the use, and make its input the clone of the def
   // found in that block.
   uint use_idx = blk->find_node(use);
   uint offset_idx = use_idx - beg;
   for( uint k = 0; k < blk->_num_succs; k++ ) {
     // Get clone in each successor block
     Block *sb = blk->_succs[k];
     Node *clone = sb->_nodes[offset_idx+1];
     assert( clone->Opcode() == use->Opcode(), "" );
     // Make use-clone reference the def-clone
     catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]);
   }
 }
 //------------------------------catch_cleanup_inter_block---------------------
 // Fix all input edges in use that reference "def".  The use is in a different
 // block than the def.
 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
   if( !use_blk ) return;        // Can happen if the use is a precedence edge
   Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx);
   catch_cleanup_fix_all_inputs(use, def, new_def);
 }
 //------------------------------call_catch_cleanup-----------------------------
 // If we inserted any instructions between a Call and his CatchNode,
 // clone the instructions on all paths below the Catch.
 void Block::call_catch_cleanup(Block_Array &bbs) {
   // End of region to clone
   uint end = end_idx();
   if( !_nodes[end]->is_Catch() ) return;
   // Start of region to clone
   uint beg = end;
   while( _nodes[beg-1]->Opcode() != Op_MachProj ||
         !_nodes[beg-1]->in(0)->is_Call() ) {
     beg--;
     assert(beg > 0,"Catch cleanup walking beyond block boundary");
   }
   // Range of inserted instructions is [beg, end)
   if( beg == end ) return;
   // Clone along all Catch output paths.  Clone area between the 'beg' and
   // 'end' indices.
   for( uint i = 0; i < _num_succs; i++ ) {
     Block *sb = _succs[i];
     // Clone the entire area; ignoring the edge fixup for now.
     for( uint j = end; j > beg; j-- ) {
       Node *clone = _nodes[j-1]->clone();
       sb->_nodes.insert( 1, clone );
       bbs.map(clone->_idx,sb);
     }
   }
   // Fixup edges.  Check the def-use info per cloned Node
   for(uint i2 = beg; i2 < end; i2++ ) {
     uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
     Node *n = _nodes[i2];        // Node that got cloned
     // Need DU safe iterator because of edge manipulation in calls.
     Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
     for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
       out->push(n->fast_out(j1));
     }
     uint max = out->size();
     for (uint j = 0; j < max; j++) {// For all users
       Node *use = out->pop();
       Block *buse = bbs[use->_idx];
       if( use->is_Phi() ) {
         for( uint k = 1; k < use->req(); k++ )
           if( use->in(k) == n ) {
             Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx);
             use->set_req(k, fixup);
           }
       } else {
         if (this == buse) {
           catch_cleanup_intra_block(use, n, this, beg, n_clone_idx);
         } else {
           catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx);
         }
       }
     } // End for all users
   } // End of for all Nodes in cloned area
   // Remove the now-dead cloned ops
   for(uint i3 = beg; i3 < end; i3++ ) {
     _nodes[beg]->disconnect_inputs(NULL);
     _nodes.remove(beg);
   }
   // If the successor blocks have a CreateEx node, move it back to the top
   for(uint i4 = 0; i4 < _num_succs; i4++ ) {
     Block *sb = _succs[i4];
     uint new_cnt = end - beg;
     // Remove any newly created, but dead, nodes.
     for( uint j = new_cnt; j > 0; j-- ) {
       Node *n = sb->_nodes[j];
       if (n->outcnt() == 0 &&
           (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
         n->disconnect_inputs(NULL);
         sb->_nodes.remove(j);
         new_cnt--;
       }
     }
     // If any newly created nodes remain, move the CreateEx node to the top
     if (new_cnt > 0) {
       Node *cex = sb->_nodes[1+new_cnt];
       if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
         sb->_nodes.remove(1+new_cnt);
         sb->_nodes.insert(1,cex);
       }
     }
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/lcm.cpp@bd441136a5ce (annotated)

src/share/vm/opto/lcm.cpp