Mercurial > hg > truffle
diff src/share/vm/opto/lcm.cpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | ba764ed4b6f2 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/lcm.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,934 @@ +/* + * Copyright 1998-2007 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]; + } + + // 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_LoadC: + case Op_LoadD: + case Op_LoadF: + case Op_LoadI: + case Op_LoadL: + case Op_LoadP: + case Op_LoadS: + case Op_LoadKlass: + 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: + 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: + // 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) { + // cannot reason about it; is probably not implicit null exception + } else { + const TypePtr* 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 + uint idx; // 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 + + Node *n = worklist[idx]; // Get the winner + + worklist.map(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 ) { + 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 ) { + 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 { + 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); + } + } + } +}