| /* |
| * Copyright (c) 1998, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "opto/block.hpp" |
| #include "opto/c2compiler.hpp" |
| #include "opto/callnode.hpp" |
| #include "opto/cfgnode.hpp" |
| #include "opto/machnode.hpp" |
| #include "opto/runtime.hpp" |
| #if defined AD_MD_HPP |
| # include AD_MD_HPP |
| #elif defined TARGET_ARCH_MODEL_x86_32 |
| # include "adfiles/ad_x86_32.hpp" |
| #elif defined TARGET_ARCH_MODEL_x86_64 |
| # include "adfiles/ad_x86_64.hpp" |
| #elif defined TARGET_ARCH_MODEL_sparc |
| # include "adfiles/ad_sparc.hpp" |
| #elif defined TARGET_ARCH_MODEL_zero |
| # include "adfiles/ad_zero.hpp" |
| #elif defined TARGET_ARCH_MODEL_ppc_64 |
| # include "adfiles/ad_ppc_64.hpp" |
| #endif |
| |
| // Optimization - Graph Style |
| |
| // Check whether val is not-null-decoded compressed oop, |
| // i.e. will grab into the base of the heap if it represents NULL. |
| static bool accesses_heap_base_zone(Node *val) { |
| if (Universe::narrow_oop_base() != NULL) { // Implies UseCompressedOops. |
| if (val && val->is_Mach()) { |
| if (val->as_Mach()->ideal_Opcode() == Op_DecodeN) { |
| // This assumes all Decodes with TypePtr::NotNull are matched to nodes that |
| // decode NULL to point to the heap base (Decode_NN). |
| if (val->bottom_type()->is_oopptr()->ptr() == TypePtr::NotNull) { |
| return true; |
| } |
| } |
| // Must recognize load operation with Decode matched in memory operand. |
| // We should not reach here exept for PPC/AIX, as os::zero_page_read_protected() |
| // returns true everywhere else. On PPC, no such memory operands |
| // exist, therefore we did not yet implement a check for such operands. |
| NOT_AIX(Unimplemented()); |
| } |
| } |
| return false; |
| } |
| |
| static bool needs_explicit_null_check_for_read(Node *val) { |
| // On some OSes (AIX) the page at address 0 is only write protected. |
| // If so, only Store operations will trap. |
| if (os::zero_page_read_protected()) { |
| return false; // Implicit null check will work. |
| } |
| // Also a read accessing the base of a heap-based compressed heap will trap. |
| if (accesses_heap_base_zone(val) && // Hits the base zone page. |
| Universe::narrow_oop_use_implicit_null_checks()) { // Base zone page is protected. |
| return false; |
| } |
| |
| return true; |
| } |
| |
| //------------------------------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 or |
| // decodeHeapOop_not_null node if it did not fold into address. |
| void PhaseCFG::implicit_null_check(Block* block, 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 = block->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 (block->get_node(block->number_of_nodes()-1) == proj) { |
| null_block = block->_succs[0]; |
| not_null_block = block->_succs[1]; |
| } else { |
| assert(block->get_node(block->number_of_nodes()-2) == proj, "proj is one or the other"); |
| not_null_block = block->_succs[0]; |
| null_block = 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->number_of_nodes(); i1++) { |
| Node* nn = null_block->get_node(i1); |
| if (nn->is_MachCall() && |
| nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) { |
| 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; |
| } |
| } |
| |
| // Check for decodeHeapOop_not_null node which did not fold into address |
| bool is_decoden = ((intptr_t)val) & 1; |
| val = (Node*)(((intptr_t)val) & ~1); |
| |
| assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() && |
| (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity"); |
| |
| // 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; |
| int iop = mach->ideal_Opcode(); |
| switch( iop ) { |
| case Op_LoadB: |
| case Op_LoadUB: |
| 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: |
| assert(mach->in(2) == val, "should be address"); |
| 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: |
| case Op_StoreNKlass: |
| 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_StrEquals: |
| case Op_StrIndexOf: |
| case Op_AryEq: |
| case Op_EncodeISOArray: |
| // 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 |
| if( must_clone[iop] ) { |
| // Do not move nodes which produce flags because |
| // RA will try to clone it to place near branch and |
| // it will cause recompilation, see clone_node(). |
| continue; |
| } |
| { |
| // Check that value is used in memory address in |
| // instructions with embedded load (CmpP val1,(val2+off)). |
| Node* base; |
| Node* index; |
| const MachOper* oper = mach->memory_inputs(base, index); |
| if (oper == NULL || oper == (MachOper*)-1) { |
| continue; // Not an memory op; skip it |
| } |
| if (val == base || |
| val == index && val->bottom_type()->isa_narrowoop()) { |
| break; // Found it |
| } else { |
| continue; // Skip it |
| } |
| } |
| break; |
| } |
| |
| // On some OSes (AIX) the page at address 0 is only write protected. |
| // If so, only Store operations will trap. |
| // But a read accessing the base of a heap-based compressed heap will trap. |
| if (!was_store && needs_explicit_null_check_for_read(val)) { |
| continue; |
| } |
| |
| // Check that node's control edge is not-null block's head or dominates it, |
| // otherwise we can't hoist it because there are other control dependencies. |
| Node* ctrl = mach->in(0); |
| if (ctrl != NULL && !(ctrl == not_null_block->head() || |
| get_block_for_node(ctrl)->dominates(not_null_block))) { |
| continue; |
| } |
| |
| // 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 || |
| Universe::narrow_klass_shift() == 0)) { |
| // 32-bits narrow oop can be the base of address expressions |
| tptr = base->get_ptr_type(); |
| } 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 = get_block_for_node(mach); |
| cb = cb->_idom; // Always hoist at least 1 block |
| if( !was_store ) { // Stores can be hoisted only one block |
| while( cb->_dom_depth > (block->_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 == (block->_dom_depth + 1)) { |
| if (cb != not_null_block) continue; |
| cb = cb->_idom; |
| } |
| } |
| if( cb != block ) 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; |
| // Ignore DecodeN val which could be hoisted to where needed. |
| if( is_decoden ) continue; |
| } |
| // Block of memory-op input |
| Block *inb = get_block_for_node(mach->in(j)); |
| Block *b = block; // 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 = get_block_for_node(mach); |
| // 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 != block ) { |
| uint k; |
| for( k = 1; k < b->number_of_nodes(); k++ ) { |
| Node *n = b->get_node(k); |
| if( n->needs_anti_dependence_check() && |
| n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) ) |
| break; // Found anti-dependent load |
| } |
| if( k < b->number_of_nodes() ) |
| 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 = get_block_for_node(b->pred(1)); // Move up to predecessor block |
| } |
| if( b != block ) 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 == NULL || get_block_for_node(mach)->_dom_depth < get_block_for_node(best)->_dom_depth) { |
| best = mach; |
| bidx = vidx; |
| } |
| } |
| // No candidate! |
| if (best == NULL) { |
| return; |
| } |
| |
| // ---- Found an implicit null check |
| extern int implicit_null_checks; |
| implicit_null_checks++; |
| |
| if( is_decoden ) { |
| // Check if we need to hoist decodeHeapOop_not_null first. |
| Block *valb = get_block_for_node(val); |
| if( block != valb && block->_dom_depth < valb->_dom_depth ) { |
| // Hoist it up to the end of the test block. |
| valb->find_remove(val); |
| block->add_inst(val); |
| map_node_to_block(val, block); |
| // DecodeN on x86 may kill flags. Check for flag-killing projections |
| // that also need to be hoisted. |
| for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) { |
| Node* n = val->fast_out(j); |
| if( n->is_MachProj() ) { |
| get_block_for_node(n)->find_remove(n); |
| block->add_inst(n); |
| map_node_to_block(n, block); |
| } |
| } |
| } |
| } |
| // Hoist the memory candidate up to the end of the test block. |
| Block *old_block = get_block_for_node(best); |
| old_block->find_remove(best); |
| block->add_inst(best); |
| map_node_to_block(best, block); |
| |
| // Move the control dependence if it is pinned to not-null block. |
| // Don't change it in other cases: NULL or dominating control. |
| if (best->in(0) == not_null_block->head()) { |
| // Set it to control edge of null check. |
| best->set_req(0, proj->in(0)->in(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->is_MachProj() ) { |
| get_block_for_node(n)->find_remove(n); |
| block->add_inst(n); |
| map_node_to_block(n, block); |
| } |
| } |
| |
| // 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 = block->get_node(block->end_idx()+1); |
| Node *tmp2 = block->get_node(block->end_idx()+2); |
| block->map_node(tmp2, block->end_idx()+1); |
| block->map_node(tmp1, block->end_idx()+2); |
| Node *tmp = new (C) 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); |
| block->map_node(nul_chk, block->end_idx()); |
| map_node_to_block(nul_chk, block); |
| // 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++) { |
| Node* in = old_tst->in(i3); |
| old_tst->set_req(i3, NULL); |
| if (in->outcnt() == 0) { |
| // Remove dead input node |
| in->disconnect_inputs(NULL, C); |
| block->find_remove(in); |
| } |
| } |
| |
| latency_from_uses(nul_chk); |
| latency_from_uses(best); |
| |
| // insert anti-dependences to defs in this block |
| if (! best->needs_anti_dependence_check()) { |
| for (uint k = 1; k < block->number_of_nodes(); k++) { |
| Node *n = block->get_node(k); |
| if (n->needs_anti_dependence_check() && |
| n->in(LoadNode::Memory) == best->in(StoreNode::Memory)) { |
| // Found anti-dependent load |
| insert_anti_dependences(block, n); |
| } |
| } |
| } |
| } |
| |
| |
| //------------------------------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* PhaseCFG::select(Block* block, Node_List &worklist, GrowableArray<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 |
| int cand_cnt = 0; // Candidate count |
| |
| 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 = block->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; |
| |
| // Schedule IV increment last. |
| if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd && |
| e->in(1)->in(1) == n && n->is_iteratively_computed()) |
| 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() && get_block_for_node(use) == block) { |
| 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.at(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 = get_latency_for_node(n); |
| uint n_score = n->req(); // Many inputs get high score to break ties |
| |
| // Keep best latency found |
| cand_cnt++; |
| if (choice < n_choice || |
| (choice == n_choice && |
| ((StressLCM && Compile::randomized_select(cand_cnt)) || |
| (!StressLCM && |
| (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 PhaseCFG::set_next_call(Block* block, Node* n, VectorSet& next_call) { |
| 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 (get_block_for_node(m) == block) { |
| set_next_call(block, m, next_call); |
| } |
| } |
| } |
| |
| //------------------------------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 PhaseCFG::needed_for_next_call(Block* block, Node* this_call, VectorSet& next_call) { |
| // 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 (get_block_for_node(m) == block && // Local-block user |
| m != this_call && // Not self-start node |
| m->is_MachCall()) { |
| 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(block, call, next_call); |
| } |
| |
| //------------------------------add_call_kills------------------------------------- |
| // helper function that adds caller save registers to MachProjNode |
| static void add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) { |
| // 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); |
| } |
| } |
| } |
| } |
| |
| |
| //------------------------------sched_call------------------------------------- |
| uint PhaseCFG::sched_call(Block* block, uint node_cnt, Node_List& worklist, GrowableArray<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->is_MachProj(), "" ); |
| int n_cnt = ready_cnt.at(n->_idx)-1; |
| ready_cnt.at_put(n->_idx, n_cnt); |
| assert( n_cnt == 0, "" ); |
| // Schedule next to call |
| block->map_node(n, node_cnt++); |
| // 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(block, n, next_call); |
| |
| // 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(get_block_for_node(m) != block) { |
| continue; |
| } |
| if( m->is_Phi() ) continue; |
| int m_cnt = ready_cnt.at(m->_idx)-1; |
| ready_cnt.at_put(m->_idx, m_cnt); |
| if( m_cnt == 0 ) |
| 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 (C) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj ); |
| map_node_to_block(proj, block); |
| block->insert_node(proj, node_cnt++); |
| |
| // Select the right register save policy. |
| const char *save_policy = NULL; |
| 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; |
| |
| // If the call is a MethodHandle invoke, we need to exclude the |
| // register which is used to save the SP value over MH invokes from |
| // the mask. Otherwise this register could be used for |
| // deoptimization information. |
| if (op == Op_CallStaticJava) { |
| MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall; |
| if (mcallstaticjava->_method_handle_invoke) |
| proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask()); |
| } |
| |
| add_call_kills(proj, regs, save_policy, exclude_soe); |
| |
| return node_cnt; |
| } |
| |
| |
| //------------------------------schedule_local--------------------------------- |
| // Topological sort within a block. Someday become a real scheduler. |
| bool PhaseCFG::schedule_local(Block* block, GrowableArray<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 (trace_opto_pipelining()) { |
| tty->print_cr("# --- schedule_local B%d, before: ---", block->_pre_order); |
| for (uint i = 0;i < block->number_of_nodes(); i++) { |
| tty->print("# "); |
| block->get_node(i)->fast_dump(); |
| } |
| tty->print_cr("#"); |
| } |
| #endif |
| |
| // RootNode is already sorted |
| if (block->number_of_nodes() == 1) { |
| return true; |
| } |
| |
| // Move PhiNodes and ParmNodes from 1 to cnt up to the start |
| uint node_cnt = block->end_idx(); |
| uint phi_cnt = 1; |
| uint i; |
| for( i = 1; i<node_cnt; i++ ) { // Scan for Phi |
| Node *n = block->get_node(i); |
| if( n->is_Phi() || // Found a PhiNode or ParmNode |
| (n->is_Proj() && n->in(0) == block->head()) ) { |
| // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt |
| block->map_node(block->get_node(phi_cnt), i); |
| block->map_node(n, phi_cnt++); // 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 && get_block_for_node(m) == block && !m->is_top() ) |
| local++; // One more block-local input |
| } |
| ready_cnt.at_put(n->_idx, local); // Count em up |
| |
| #ifdef ASSERT |
| if( UseConcMarkSweepGC || UseG1GC ) { |
| if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) { |
| // Check the precedence edges |
| for (uint prec = n->req(); prec < n->len(); prec++) { |
| Node* oop_store = n->in(prec); |
| if (oop_store != NULL) { |
| assert(get_block_for_node(oop_store)->_dom_depth <= block->_dom_depth, "oop_store must dominate card-mark"); |
| } |
| } |
| } |
| } |
| #endif |
| |
| // A few node types require changing a required edge to a precedence edge |
| // before allocation. |
| if( n->is_Mach() && n->req() > TypeFunc::Parms && |
| (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire || |
| n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) { |
| // 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< block->number_of_nodes(); i2++ ) // Trailing guys get zapped count |
| ready_cnt.at_put(block->get_node(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 = block->get_node(i3); // Get pre-scheduled |
| for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { |
| Node* m = n->fast_out(j); |
| if (get_block_for_node(m) == block) { // Local-block user |
| int m_cnt = ready_cnt.at(m->_idx)-1; |
| ready_cnt.at_put(m->_idx, m_cnt); // 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 = block->get_node(i4); |
| if( !ready_cnt.at(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(block, block->head(), next_call); |
| |
| #ifndef PRODUCT |
| if (trace_opto_pipelining()) { |
| for (uint j=0; j< block->number_of_nodes(); j++) { |
| Node *n = block->get_node(j); |
| int idx = n->_idx; |
| tty->print("# ready cnt:%3d ", ready_cnt.at(idx)); |
| tty->print("latency:%3d ", get_latency_for_node(n)); |
| tty->print("%4d: %s\n", idx, n->Name()); |
| } |
| } |
| #endif |
| |
| uint max_idx = (uint)ready_cnt.length(); |
| // Pull from worklist and schedule |
| while( worklist.size() ) { // Worklist is not ready |
| |
| #ifndef PRODUCT |
| if (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(block, worklist, ready_cnt, next_call, phi_cnt); |
| block->map_node(n, phi_cnt++); // Schedule him next |
| |
| #ifndef PRODUCT |
| if (trace_opto_pipelining()) { |
| tty->print("# select %d: %s", n->_idx, n->Name()); |
| tty->print(", latency:%d", get_latency_for_node(n)); |
| 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(block, phi_cnt, worklist, ready_cnt, mcall, next_call); |
| continue; |
| } |
| |
| if (n->is_Mach() && n->as_Mach()->has_call()) { |
| RegMask regs; |
| regs.Insert(_matcher.c_frame_pointer()); |
| regs.OR(n->out_RegMask()); |
| |
| MachProjNode *proj = new (C) MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj ); |
| map_node_to_block(proj, block); |
| block->insert_node(proj, phi_cnt++); |
| |
| add_call_kills(proj, regs, _matcher._c_reg_save_policy, false); |
| } |
| |
| // 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 (get_block_for_node(m) != block) { |
| continue; |
| } |
| if( m->is_Phi() ) continue; |
| if (m->_idx >= max_idx) { // new node, skip it |
| assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types"); |
| continue; |
| } |
| int m_cnt = ready_cnt.at(m->_idx)-1; |
| ready_cnt.at_put(m->_idx, m_cnt); |
| if( m_cnt == 0 ) |
| worklist.push(m); |
| } |
| } |
| |
| if( phi_cnt != block->end_idx() ) { |
| // did not schedule all. Retry, Bailout, or Die |
| 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 (trace_opto_pipelining()) { |
| tty->print_cr("#"); |
| tty->print_cr("# after schedule_local"); |
| for (uint i = 0;i < block->number_of_nodes();i++) { |
| tty->print("# "); |
| block->get_node(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------------------ |
| Node* PhaseCFG::catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, 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++) { |
| Block* block = get_block_for_node(use_blk->pred(k)); |
| inputs.map(k, catch_cleanup_find_cloned_def(block, def, def_blk, 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->get_node(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->insert_node(new_phi, 1); |
| map_node_to_block(new_phi, 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->get_node(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->get_node(offset_idx+1); |
| assert( clone->Opcode() == use->Opcode(), "" ); |
| |
| // Make use-clone reference the def-clone |
| catch_cleanup_fix_all_inputs(clone, def, sb->get_node(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. |
| void PhaseCFG::catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, 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, 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 PhaseCFG::call_catch_cleanup(Block* block) { |
| |
| // End of region to clone |
| uint end = block->end_idx(); |
| if( !block->get_node(end)->is_Catch() ) return; |
| // Start of region to clone |
| uint beg = end; |
| while(!block->get_node(beg-1)->is_MachProj() || |
| !block->get_node(beg-1)->in(0)->is_MachCall() ) { |
| 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 < block->_num_succs; i++ ) { |
| Block *sb = block->_succs[i]; |
| // Clone the entire area; ignoring the edge fixup for now. |
| for( uint j = end; j > beg; j-- ) { |
| Node *clone = block->get_node(j-1)->clone(); |
| sb->insert_node(clone, 1); |
| map_node_to_block(clone, sb); |
| if (clone->needs_anti_dependence_check()) { |
| insert_anti_dependences(sb, clone); |
| } |
| } |
| } |
| |
| |
| // 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 = block->get_node(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 = get_block_for_node(use); |
| if( use->is_Phi() ) { |
| for( uint k = 1; k < use->req(); k++ ) |
| if( use->in(k) == n ) { |
| Block* b = get_block_for_node(buse->pred(k)); |
| Node *fixup = catch_cleanup_find_cloned_def(b, n, block, n_clone_idx); |
| use->set_req(k, fixup); |
| } |
| } else { |
| if (block == buse) { |
| catch_cleanup_intra_block(use, n, block, beg, n_clone_idx); |
| } else { |
| catch_cleanup_inter_block(use, buse, n, block, 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++ ) { |
| block->get_node(beg)->disconnect_inputs(NULL, C); |
| block->remove_node(beg); |
| } |
| |
| // If the successor blocks have a CreateEx node, move it back to the top |
| for(uint i4 = 0; i4 < block->_num_succs; i4++ ) { |
| Block *sb = block->_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->get_node(j); |
| if (n->outcnt() == 0 && |
| (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){ |
| n->disconnect_inputs(NULL, C); |
| sb->remove_node(j); |
| new_cnt--; |
| } |
| } |
| // If any newly created nodes remain, move the CreateEx node to the top |
| if (new_cnt > 0) { |
| Node *cex = sb->get_node(1+new_cnt); |
| if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) { |
| sb->remove_node(1+new_cnt); |
| sb->insert_node(cex, 1); |
| } |
| } |
| } |
| } |
