truffle: src/share/vm/opto/lcm.cpp comparison

comparison src/share/vm/opto/lcm.cpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	ba764ed4b6f2

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--1:000000000000
+:a61af66fc99e
+/*
+* 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);
+}
+}
+}
+}

Mercurial > hg > truffle

comparison src/share/vm/opto/lcm.cpp @ 0:a61af66fc99e jdk7-b24