| /* |
| * Copyright (c) 1999, 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 "c1/c1_Compilation.hpp" |
| #include "c1/c1_FrameMap.hpp" |
| #include "c1/c1_GraphBuilder.hpp" |
| #include "c1/c1_IR.hpp" |
| #include "c1/c1_InstructionPrinter.hpp" |
| #include "c1/c1_Optimizer.hpp" |
| #include "utilities/bitMap.inline.hpp" |
| |
| |
| // Implementation of XHandlers |
| // |
| // Note: This code could eventually go away if we are |
| // just using the ciExceptionHandlerStream. |
| |
| XHandlers::XHandlers(ciMethod* method) : _list(method->exception_table_length()) { |
| ciExceptionHandlerStream s(method); |
| while (!s.is_done()) { |
| _list.append(new XHandler(s.handler())); |
| s.next(); |
| } |
| assert(s.count() == method->exception_table_length(), "exception table lengths inconsistent"); |
| } |
| |
| // deep copy of all XHandler contained in list |
| XHandlers::XHandlers(XHandlers* other) : |
| _list(other->length()) |
| { |
| for (int i = 0; i < other->length(); i++) { |
| _list.append(new XHandler(other->handler_at(i))); |
| } |
| } |
| |
| // Returns whether a particular exception type can be caught. Also |
| // returns true if klass is unloaded or any exception handler |
| // classes are unloaded. type_is_exact indicates whether the throw |
| // is known to be exactly that class or it might throw a subtype. |
| bool XHandlers::could_catch(ciInstanceKlass* klass, bool type_is_exact) const { |
| // the type is unknown so be conservative |
| if (!klass->is_loaded()) { |
| return true; |
| } |
| |
| for (int i = 0; i < length(); i++) { |
| XHandler* handler = handler_at(i); |
| if (handler->is_catch_all()) { |
| // catch of ANY |
| return true; |
| } |
| ciInstanceKlass* handler_klass = handler->catch_klass(); |
| // if it's unknown it might be catchable |
| if (!handler_klass->is_loaded()) { |
| return true; |
| } |
| // if the throw type is definitely a subtype of the catch type |
| // then it can be caught. |
| if (klass->is_subtype_of(handler_klass)) { |
| return true; |
| } |
| if (!type_is_exact) { |
| // If the type isn't exactly known then it can also be caught by |
| // catch statements where the inexact type is a subtype of the |
| // catch type. |
| // given: foo extends bar extends Exception |
| // throw bar can be caught by catch foo, catch bar, and catch |
| // Exception, however it can't be caught by any handlers without |
| // bar in its type hierarchy. |
| if (handler_klass->is_subtype_of(klass)) { |
| return true; |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| |
| bool XHandlers::equals(XHandlers* others) const { |
| if (others == NULL) return false; |
| if (length() != others->length()) return false; |
| |
| for (int i = 0; i < length(); i++) { |
| if (!handler_at(i)->equals(others->handler_at(i))) return false; |
| } |
| return true; |
| } |
| |
| bool XHandler::equals(XHandler* other) const { |
| assert(entry_pco() != -1 && other->entry_pco() != -1, "must have entry_pco"); |
| |
| if (entry_pco() != other->entry_pco()) return false; |
| if (scope_count() != other->scope_count()) return false; |
| if (_desc != other->_desc) return false; |
| |
| assert(entry_block() == other->entry_block(), "entry_block must be equal when entry_pco is equal"); |
| return true; |
| } |
| |
| |
| // Implementation of IRScope |
| BlockBegin* IRScope::build_graph(Compilation* compilation, int osr_bci) { |
| GraphBuilder gm(compilation, this); |
| NOT_PRODUCT(if (PrintValueNumbering && Verbose) gm.print_stats()); |
| if (compilation->bailed_out()) return NULL; |
| return gm.start(); |
| } |
| |
| |
| IRScope::IRScope(Compilation* compilation, IRScope* caller, int caller_bci, ciMethod* method, int osr_bci, bool create_graph) |
| : _callees(2) |
| , _compilation(compilation) |
| , _requires_phi_function(method->max_locals()) |
| { |
| _caller = caller; |
| _level = caller == NULL ? 0 : caller->level() + 1; |
| _method = method; |
| _xhandlers = new XHandlers(method); |
| _number_of_locks = 0; |
| _monitor_pairing_ok = method->has_balanced_monitors(); |
| _wrote_final = false; |
| _wrote_fields = false; |
| _wrote_volatile = false; |
| _start = NULL; |
| |
| if (osr_bci == -1) { |
| _requires_phi_function.clear(); |
| } else { |
| // selective creation of phi functions is not possibel in osr-methods |
| _requires_phi_function.set_range(0, method->max_locals()); |
| } |
| |
| assert(method->holder()->is_loaded() , "method holder must be loaded"); |
| |
| // build graph if monitor pairing is ok |
| if (create_graph && monitor_pairing_ok()) _start = build_graph(compilation, osr_bci); |
| } |
| |
| |
| int IRScope::max_stack() const { |
| int my_max = method()->max_stack(); |
| int callee_max = 0; |
| for (int i = 0; i < number_of_callees(); i++) { |
| callee_max = MAX2(callee_max, callee_no(i)->max_stack()); |
| } |
| return my_max + callee_max; |
| } |
| |
| |
| bool IRScopeDebugInfo::should_reexecute() { |
| ciMethod* cur_method = scope()->method(); |
| int cur_bci = bci(); |
| if (cur_method != NULL && cur_bci != SynchronizationEntryBCI) { |
| Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci); |
| return Interpreter::bytecode_should_reexecute(code); |
| } else |
| return false; |
| } |
| |
| |
| // Implementation of CodeEmitInfo |
| |
| // Stack must be NON-null |
| CodeEmitInfo::CodeEmitInfo(ValueStack* stack, XHandlers* exception_handlers, bool deoptimize_on_exception) |
| : _scope(stack->scope()) |
| , _scope_debug_info(NULL) |
| , _oop_map(NULL) |
| , _stack(stack) |
| , _exception_handlers(exception_handlers) |
| , _is_method_handle_invoke(false) |
| , _deoptimize_on_exception(deoptimize_on_exception) { |
| assert(_stack != NULL, "must be non null"); |
| } |
| |
| |
| CodeEmitInfo::CodeEmitInfo(CodeEmitInfo* info, ValueStack* stack) |
| : _scope(info->_scope) |
| , _exception_handlers(NULL) |
| , _scope_debug_info(NULL) |
| , _oop_map(NULL) |
| , _stack(stack == NULL ? info->_stack : stack) |
| , _is_method_handle_invoke(info->_is_method_handle_invoke) |
| , _deoptimize_on_exception(info->_deoptimize_on_exception) { |
| |
| // deep copy of exception handlers |
| if (info->_exception_handlers != NULL) { |
| _exception_handlers = new XHandlers(info->_exception_handlers); |
| } |
| } |
| |
| |
| void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset) { |
| // record the safepoint before recording the debug info for enclosing scopes |
| recorder->add_safepoint(pc_offset, _oop_map->deep_copy()); |
| _scope_debug_info->record_debug_info(recorder, pc_offset, true/*topmost*/, _is_method_handle_invoke); |
| recorder->end_safepoint(pc_offset); |
| } |
| |
| |
| void CodeEmitInfo::add_register_oop(LIR_Opr opr) { |
| assert(_oop_map != NULL, "oop map must already exist"); |
| assert(opr->is_single_cpu(), "should not call otherwise"); |
| |
| VMReg name = frame_map()->regname(opr); |
| _oop_map->set_oop(name); |
| } |
| |
| // Mirror the stack size calculation in the deopt code |
| // How much stack space would we need at this point in the program in |
| // case of deoptimization? |
| int CodeEmitInfo::interpreter_frame_size() const { |
| ValueStack* state = _stack; |
| int size = 0; |
| int callee_parameters = 0; |
| int callee_locals = 0; |
| int extra_args = state->scope()->method()->max_stack() - state->stack_size(); |
| |
| while (state != NULL) { |
| int locks = state->locks_size(); |
| int temps = state->stack_size(); |
| bool is_top_frame = (state == _stack); |
| ciMethod* method = state->scope()->method(); |
| |
| int frame_size = BytesPerWord * Interpreter::size_activation(method->max_stack(), |
| temps + callee_parameters, |
| extra_args, |
| locks, |
| callee_parameters, |
| callee_locals, |
| is_top_frame); |
| size += frame_size; |
| |
| callee_parameters = method->size_of_parameters(); |
| callee_locals = method->max_locals(); |
| extra_args = 0; |
| state = state->caller_state(); |
| } |
| return size + Deoptimization::last_frame_adjust(0, callee_locals) * BytesPerWord; |
| } |
| |
| // Implementation of IR |
| |
| IR::IR(Compilation* compilation, ciMethod* method, int osr_bci) : |
| _num_loops(0) { |
| // setup IR fields |
| _compilation = compilation; |
| _top_scope = new IRScope(compilation, NULL, -1, method, osr_bci, true); |
| _code = NULL; |
| } |
| |
| |
| void IR::optimize_blocks() { |
| Optimizer opt(this); |
| if (!compilation()->profile_branches()) { |
| if (DoCEE) { |
| opt.eliminate_conditional_expressions(); |
| #ifndef PRODUCT |
| if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after CEE"); print(true); } |
| if (PrintIR || PrintIR1 ) { tty->print_cr("IR after CEE"); print(false); } |
| #endif |
| } |
| if (EliminateBlocks) { |
| opt.eliminate_blocks(); |
| #ifndef PRODUCT |
| if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after block elimination"); print(true); } |
| if (PrintIR || PrintIR1 ) { tty->print_cr("IR after block elimination"); print(false); } |
| #endif |
| } |
| } |
| } |
| |
| void IR::eliminate_null_checks() { |
| Optimizer opt(this); |
| if (EliminateNullChecks) { |
| opt.eliminate_null_checks(); |
| #ifndef PRODUCT |
| if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after null check elimination"); print(true); } |
| if (PrintIR || PrintIR1 ) { tty->print_cr("IR after null check elimination"); print(false); } |
| #endif |
| } |
| } |
| |
| |
| static int sort_pairs(BlockPair** a, BlockPair** b) { |
| if ((*a)->from() == (*b)->from()) { |
| return (*a)->to()->block_id() - (*b)->to()->block_id(); |
| } else { |
| return (*a)->from()->block_id() - (*b)->from()->block_id(); |
| } |
| } |
| |
| |
| class CriticalEdgeFinder: public BlockClosure { |
| BlockPairList blocks; |
| IR* _ir; |
| |
| public: |
| CriticalEdgeFinder(IR* ir): _ir(ir) {} |
| void block_do(BlockBegin* bb) { |
| BlockEnd* be = bb->end(); |
| int nos = be->number_of_sux(); |
| if (nos >= 2) { |
| for (int i = 0; i < nos; i++) { |
| BlockBegin* sux = be->sux_at(i); |
| if (sux->number_of_preds() >= 2) { |
| blocks.append(new BlockPair(bb, sux)); |
| } |
| } |
| } |
| } |
| |
| void split_edges() { |
| BlockPair* last_pair = NULL; |
| blocks.sort(sort_pairs); |
| for (int i = 0; i < blocks.length(); i++) { |
| BlockPair* pair = blocks.at(i); |
| if (last_pair != NULL && pair->is_same(last_pair)) continue; |
| BlockBegin* from = pair->from(); |
| BlockBegin* to = pair->to(); |
| BlockBegin* split = from->insert_block_between(to); |
| #ifndef PRODUCT |
| if ((PrintIR || PrintIR1) && Verbose) { |
| tty->print_cr("Split critical edge B%d -> B%d (new block B%d)", |
| from->block_id(), to->block_id(), split->block_id()); |
| } |
| #endif |
| last_pair = pair; |
| } |
| } |
| }; |
| |
| void IR::split_critical_edges() { |
| CriticalEdgeFinder cef(this); |
| |
| iterate_preorder(&cef); |
| cef.split_edges(); |
| } |
| |
| |
| class UseCountComputer: public ValueVisitor, BlockClosure { |
| private: |
| void visit(Value* n) { |
| // Local instructions and Phis for expression stack values at the |
| // start of basic blocks are not added to the instruction list |
| if (!(*n)->is_linked() && (*n)->can_be_linked()) { |
| assert(false, "a node was not appended to the graph"); |
| Compilation::current()->bailout("a node was not appended to the graph"); |
| } |
| // use n's input if not visited before |
| if (!(*n)->is_pinned() && !(*n)->has_uses()) { |
| // note: a) if the instruction is pinned, it will be handled by compute_use_count |
| // b) if the instruction has uses, it was touched before |
| // => in both cases we don't need to update n's values |
| uses_do(n); |
| } |
| // use n |
| (*n)->_use_count++; |
| } |
| |
| Values* worklist; |
| int depth; |
| enum { |
| max_recurse_depth = 20 |
| }; |
| |
| void uses_do(Value* n) { |
| depth++; |
| if (depth > max_recurse_depth) { |
| // don't allow the traversal to recurse too deeply |
| worklist->push(*n); |
| } else { |
| (*n)->input_values_do(this); |
| // special handling for some instructions |
| if ((*n)->as_BlockEnd() != NULL) { |
| // note on BlockEnd: |
| // must 'use' the stack only if the method doesn't |
| // terminate, however, in those cases stack is empty |
| (*n)->state_values_do(this); |
| } |
| } |
| depth--; |
| } |
| |
| void block_do(BlockBegin* b) { |
| depth = 0; |
| // process all pinned nodes as the roots of expression trees |
| for (Instruction* n = b; n != NULL; n = n->next()) { |
| if (n->is_pinned()) uses_do(&n); |
| } |
| assert(depth == 0, "should have counted back down"); |
| |
| // now process any unpinned nodes which recursed too deeply |
| while (worklist->length() > 0) { |
| Value t = worklist->pop(); |
| if (!t->is_pinned()) { |
| // compute the use count |
| uses_do(&t); |
| |
| // pin the instruction so that LIRGenerator doesn't recurse |
| // too deeply during it's evaluation. |
| t->pin(); |
| } |
| } |
| assert(depth == 0, "should have counted back down"); |
| } |
| |
| UseCountComputer() { |
| worklist = new Values(); |
| depth = 0; |
| } |
| |
| public: |
| static void compute(BlockList* blocks) { |
| UseCountComputer ucc; |
| blocks->iterate_backward(&ucc); |
| } |
| }; |
| |
| |
| // helper macro for short definition of trace-output inside code |
| #ifndef PRODUCT |
| #define TRACE_LINEAR_SCAN(level, code) \ |
| if (TraceLinearScanLevel >= level) { \ |
| code; \ |
| } |
| #else |
| #define TRACE_LINEAR_SCAN(level, code) |
| #endif |
| |
| class ComputeLinearScanOrder : public StackObj { |
| private: |
| int _max_block_id; // the highest block_id of a block |
| int _num_blocks; // total number of blocks (smaller than _max_block_id) |
| int _num_loops; // total number of loops |
| bool _iterative_dominators;// method requires iterative computation of dominatiors |
| |
| BlockList* _linear_scan_order; // the resulting list of blocks in correct order |
| |
| BitMap _visited_blocks; // used for recursive processing of blocks |
| BitMap _active_blocks; // used for recursive processing of blocks |
| BitMap _dominator_blocks; // temproary BitMap used for computation of dominator |
| intArray _forward_branches; // number of incoming forward branches for each block |
| BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges |
| BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop |
| BlockList _work_list; // temporary list (used in mark_loops and compute_order) |
| BlockList _loop_headers; |
| |
| Compilation* _compilation; |
| |
| // accessors for _visited_blocks and _active_blocks |
| void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); } |
| bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); } |
| bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); } |
| void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); } |
| void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); } |
| void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); } |
| |
| // accessors for _forward_branches |
| void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); } |
| int dec_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) - 1); return _forward_branches.at(b->block_id()); } |
| |
| // accessors for _loop_map |
| bool is_block_in_loop (int loop_idx, BlockBegin* b) const { return _loop_map.at(loop_idx, b->block_id()); } |
| void set_block_in_loop (int loop_idx, BlockBegin* b) { _loop_map.set_bit(loop_idx, b->block_id()); } |
| void clear_block_in_loop(int loop_idx, int block_id) { _loop_map.clear_bit(loop_idx, block_id); } |
| |
| // count edges between blocks |
| void count_edges(BlockBegin* cur, BlockBegin* parent); |
| |
| // loop detection |
| void mark_loops(); |
| void clear_non_natural_loops(BlockBegin* start_block); |
| void assign_loop_depth(BlockBegin* start_block); |
| |
| // computation of final block order |
| BlockBegin* common_dominator(BlockBegin* a, BlockBegin* b); |
| void compute_dominator(BlockBegin* cur, BlockBegin* parent); |
| int compute_weight(BlockBegin* cur); |
| bool ready_for_processing(BlockBegin* cur); |
| void sort_into_work_list(BlockBegin* b); |
| void append_block(BlockBegin* cur); |
| void compute_order(BlockBegin* start_block); |
| |
| // fixup of dominators for non-natural loops |
| bool compute_dominators_iter(); |
| void compute_dominators(); |
| |
| // debug functions |
| NOT_PRODUCT(void print_blocks();) |
| DEBUG_ONLY(void verify();) |
| |
| Compilation* compilation() const { return _compilation; } |
| public: |
| ComputeLinearScanOrder(Compilation* c, BlockBegin* start_block); |
| |
| // accessors for final result |
| BlockList* linear_scan_order() const { return _linear_scan_order; } |
| int num_loops() const { return _num_loops; } |
| }; |
| |
| |
| ComputeLinearScanOrder::ComputeLinearScanOrder(Compilation* c, BlockBegin* start_block) : |
| _max_block_id(BlockBegin::number_of_blocks()), |
| _num_blocks(0), |
| _num_loops(0), |
| _iterative_dominators(false), |
| _visited_blocks(_max_block_id), |
| _active_blocks(_max_block_id), |
| _dominator_blocks(_max_block_id), |
| _forward_branches(_max_block_id, 0), |
| _loop_end_blocks(8), |
| _work_list(8), |
| _linear_scan_order(NULL), // initialized later with correct size |
| _loop_map(0, 0), // initialized later with correct size |
| _compilation(c) |
| { |
| TRACE_LINEAR_SCAN(2, tty->print_cr("***** computing linear-scan block order")); |
| |
| init_visited(); |
| count_edges(start_block, NULL); |
| |
| if (compilation()->is_profiling()) { |
| ciMethod *method = compilation()->method(); |
| if (!method->is_accessor()) { |
| ciMethodData* md = method->method_data_or_null(); |
| assert(md != NULL, "Sanity"); |
| md->set_compilation_stats(_num_loops, _num_blocks); |
| } |
| } |
| |
| if (_num_loops > 0) { |
| mark_loops(); |
| clear_non_natural_loops(start_block); |
| assign_loop_depth(start_block); |
| } |
| |
| compute_order(start_block); |
| compute_dominators(); |
| |
| NOT_PRODUCT(print_blocks()); |
| DEBUG_ONLY(verify()); |
| } |
| |
| |
| // Traverse the CFG: |
| // * count total number of blocks |
| // * count all incoming edges and backward incoming edges |
| // * number loop header blocks |
| // * create a list with all loop end blocks |
| void ComputeLinearScanOrder::count_edges(BlockBegin* cur, BlockBegin* parent) { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("Enter count_edges for block B%d coming from B%d", cur->block_id(), parent != NULL ? parent->block_id() : -1)); |
| assert(cur->dominator() == NULL, "dominator already initialized"); |
| |
| if (is_active(cur)) { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch")); |
| assert(is_visited(cur), "block must be visisted when block is active"); |
| assert(parent != NULL, "must have parent"); |
| |
| cur->set(BlockBegin::backward_branch_target_flag); |
| |
| // When a loop header is also the start of an exception handler, then the backward branch is |
| // an exception edge. Because such edges are usually critical edges which cannot be split, the |
| // loop must be excluded here from processing. |
| if (cur->is_set(BlockBegin::exception_entry_flag)) { |
| // Make sure that dominators are correct in this weird situation |
| _iterative_dominators = true; |
| return; |
| } |
| |
| cur->set(BlockBegin::linear_scan_loop_header_flag); |
| parent->set(BlockBegin::linear_scan_loop_end_flag); |
| |
| assert(parent->number_of_sux() == 1 && parent->sux_at(0) == cur, |
| "loop end blocks must have one successor (critical edges are split)"); |
| |
| _loop_end_blocks.append(parent); |
| return; |
| } |
| |
| // increment number of incoming forward branches |
| inc_forward_branches(cur); |
| |
| if (is_visited(cur)) { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("block already visited")); |
| return; |
| } |
| |
| _num_blocks++; |
| set_visited(cur); |
| set_active(cur); |
| |
| // recursive call for all successors |
| int i; |
| for (i = cur->number_of_sux() - 1; i >= 0; i--) { |
| count_edges(cur->sux_at(i), cur); |
| } |
| for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) { |
| count_edges(cur->exception_handler_at(i), cur); |
| } |
| |
| clear_active(cur); |
| |
| // Each loop has a unique number. |
| // When multiple loops are nested, assign_loop_depth assumes that the |
| // innermost loop has the lowest number. This is guaranteed by setting |
| // the loop number after the recursive calls for the successors above |
| // have returned. |
| if (cur->is_set(BlockBegin::linear_scan_loop_header_flag)) { |
| assert(cur->loop_index() == -1, "cannot set loop-index twice"); |
| TRACE_LINEAR_SCAN(3, tty->print_cr("Block B%d is loop header of loop %d", cur->block_id(), _num_loops)); |
| |
| cur->set_loop_index(_num_loops); |
| _loop_headers.append(cur); |
| _num_loops++; |
| } |
| |
| TRACE_LINEAR_SCAN(3, tty->print_cr("Finished count_edges for block B%d", cur->block_id())); |
| } |
| |
| |
| void ComputeLinearScanOrder::mark_loops() { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("----- marking loops")); |
| |
| _loop_map = BitMap2D(_num_loops, _max_block_id); |
| _loop_map.clear(); |
| |
| for (int i = _loop_end_blocks.length() - 1; i >= 0; i--) { |
| BlockBegin* loop_end = _loop_end_blocks.at(i); |
| BlockBegin* loop_start = loop_end->sux_at(0); |
| int loop_idx = loop_start->loop_index(); |
| |
| TRACE_LINEAR_SCAN(3, tty->print_cr("Processing loop from B%d to B%d (loop %d):", loop_start->block_id(), loop_end->block_id(), loop_idx)); |
| assert(loop_end->is_set(BlockBegin::linear_scan_loop_end_flag), "loop end flag must be set"); |
| assert(loop_end->number_of_sux() == 1, "incorrect number of successors"); |
| assert(loop_start->is_set(BlockBegin::linear_scan_loop_header_flag), "loop header flag must be set"); |
| assert(loop_idx >= 0 && loop_idx < _num_loops, "loop index not set"); |
| assert(_work_list.is_empty(), "work list must be empty before processing"); |
| |
| // add the end-block of the loop to the working list |
| _work_list.push(loop_end); |
| set_block_in_loop(loop_idx, loop_end); |
| do { |
| BlockBegin* cur = _work_list.pop(); |
| |
| TRACE_LINEAR_SCAN(3, tty->print_cr(" processing B%d", cur->block_id())); |
| assert(is_block_in_loop(loop_idx, cur), "bit in loop map must be set when block is in work list"); |
| |
| // recursive processing of all predecessors ends when start block of loop is reached |
| if (cur != loop_start && !cur->is_set(BlockBegin::osr_entry_flag)) { |
| for (int j = cur->number_of_preds() - 1; j >= 0; j--) { |
| BlockBegin* pred = cur->pred_at(j); |
| |
| if (!is_block_in_loop(loop_idx, pred) /*&& !pred->is_set(BlockBeginosr_entry_flag)*/) { |
| // this predecessor has not been processed yet, so add it to work list |
| TRACE_LINEAR_SCAN(3, tty->print_cr(" pushing B%d", pred->block_id())); |
| _work_list.push(pred); |
| set_block_in_loop(loop_idx, pred); |
| } |
| } |
| } |
| } while (!_work_list.is_empty()); |
| } |
| } |
| |
| |
| // check for non-natural loops (loops where the loop header does not dominate |
| // all other loop blocks = loops with mulitple entries). |
| // such loops are ignored |
| void ComputeLinearScanOrder::clear_non_natural_loops(BlockBegin* start_block) { |
| for (int i = _num_loops - 1; i >= 0; i--) { |
| if (is_block_in_loop(i, start_block)) { |
| // loop i contains the entry block of the method |
| // -> this is not a natural loop, so ignore it |
| TRACE_LINEAR_SCAN(2, tty->print_cr("Loop %d is non-natural, so it is ignored", i)); |
| |
| BlockBegin *loop_header = _loop_headers.at(i); |
| assert(loop_header->is_set(BlockBegin::linear_scan_loop_header_flag), "Must be loop header"); |
| |
| for (int j = 0; j < loop_header->number_of_preds(); j++) { |
| BlockBegin *pred = loop_header->pred_at(j); |
| pred->clear(BlockBegin::linear_scan_loop_end_flag); |
| } |
| |
| loop_header->clear(BlockBegin::linear_scan_loop_header_flag); |
| |
| for (int block_id = _max_block_id - 1; block_id >= 0; block_id--) { |
| clear_block_in_loop(i, block_id); |
| } |
| _iterative_dominators = true; |
| } |
| } |
| } |
| |
| void ComputeLinearScanOrder::assign_loop_depth(BlockBegin* start_block) { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing loop-depth and weight")); |
| init_visited(); |
| |
| assert(_work_list.is_empty(), "work list must be empty before processing"); |
| _work_list.append(start_block); |
| |
| do { |
| BlockBegin* cur = _work_list.pop(); |
| |
| if (!is_visited(cur)) { |
| set_visited(cur); |
| TRACE_LINEAR_SCAN(4, tty->print_cr("Computing loop depth for block B%d", cur->block_id())); |
| |
| // compute loop-depth and loop-index for the block |
| assert(cur->loop_depth() == 0, "cannot set loop-depth twice"); |
| int i; |
| int loop_depth = 0; |
| int min_loop_idx = -1; |
| for (i = _num_loops - 1; i >= 0; i--) { |
| if (is_block_in_loop(i, cur)) { |
| loop_depth++; |
| min_loop_idx = i; |
| } |
| } |
| cur->set_loop_depth(loop_depth); |
| cur->set_loop_index(min_loop_idx); |
| |
| // append all unvisited successors to work list |
| for (i = cur->number_of_sux() - 1; i >= 0; i--) { |
| _work_list.append(cur->sux_at(i)); |
| } |
| for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) { |
| _work_list.append(cur->exception_handler_at(i)); |
| } |
| } |
| } while (!_work_list.is_empty()); |
| } |
| |
| |
| BlockBegin* ComputeLinearScanOrder::common_dominator(BlockBegin* a, BlockBegin* b) { |
| assert(a != NULL && b != NULL, "must have input blocks"); |
| |
| _dominator_blocks.clear(); |
| while (a != NULL) { |
| _dominator_blocks.set_bit(a->block_id()); |
| assert(a->dominator() != NULL || a == _linear_scan_order->at(0), "dominator must be initialized"); |
| a = a->dominator(); |
| } |
| while (b != NULL && !_dominator_blocks.at(b->block_id())) { |
| assert(b->dominator() != NULL || b == _linear_scan_order->at(0), "dominator must be initialized"); |
| b = b->dominator(); |
| } |
| |
| assert(b != NULL, "could not find dominator"); |
| return b; |
| } |
| |
| void ComputeLinearScanOrder::compute_dominator(BlockBegin* cur, BlockBegin* parent) { |
| if (cur->dominator() == NULL) { |
| TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: initializing dominator of B%d to B%d", cur->block_id(), parent->block_id())); |
| cur->set_dominator(parent); |
| |
| } else if (!(cur->is_set(BlockBegin::linear_scan_loop_header_flag) && parent->is_set(BlockBegin::linear_scan_loop_end_flag))) { |
| TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: computing dominator of B%d: common dominator of B%d and B%d is B%d", cur->block_id(), parent->block_id(), cur->dominator()->block_id(), common_dominator(cur->dominator(), parent)->block_id())); |
| // Does not hold for exception blocks |
| assert(cur->number_of_preds() > 1 || cur->is_set(BlockBegin::exception_entry_flag), ""); |
| cur->set_dominator(common_dominator(cur->dominator(), parent)); |
| } |
| |
| // Additional edge to xhandler of all our successors |
| // range check elimination needs that the state at the end of a |
| // block be valid in every block it dominates so cur must dominate |
| // the exception handlers of its successors. |
| int num_cur_xhandler = cur->number_of_exception_handlers(); |
| for (int j = 0; j < num_cur_xhandler; j++) { |
| BlockBegin* xhandler = cur->exception_handler_at(j); |
| compute_dominator(xhandler, parent); |
| } |
| } |
| |
| |
| int ComputeLinearScanOrder::compute_weight(BlockBegin* cur) { |
| BlockBegin* single_sux = NULL; |
| if (cur->number_of_sux() == 1) { |
| single_sux = cur->sux_at(0); |
| } |
| |
| // limit loop-depth to 15 bit (only for security reason, it will never be so big) |
| int weight = (cur->loop_depth() & 0x7FFF) << 16; |
| |
| // general macro for short definition of weight flags |
| // the first instance of INC_WEIGHT_IF has the highest priority |
| int cur_bit = 15; |
| #define INC_WEIGHT_IF(condition) if ((condition)) { weight |= (1 << cur_bit); } cur_bit--; |
| |
| // this is necessery for the (very rare) case that two successing blocks have |
| // the same loop depth, but a different loop index (can happen for endless loops |
| // with exception handlers) |
| INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_header_flag)); |
| |
| // loop end blocks (blocks that end with a backward branch) are added |
| // after all other blocks of the loop. |
| INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_end_flag)); |
| |
| // critical edge split blocks are prefered because than they have a bigger |
| // proability to be completely empty |
| INC_WEIGHT_IF(cur->is_set(BlockBegin::critical_edge_split_flag)); |
| |
| // exceptions should not be thrown in normal control flow, so these blocks |
| // are added as late as possible |
| INC_WEIGHT_IF(cur->end()->as_Throw() == NULL && (single_sux == NULL || single_sux->end()->as_Throw() == NULL)); |
| INC_WEIGHT_IF(cur->end()->as_Return() == NULL && (single_sux == NULL || single_sux->end()->as_Return() == NULL)); |
| |
| // exceptions handlers are added as late as possible |
| INC_WEIGHT_IF(!cur->is_set(BlockBegin::exception_entry_flag)); |
| |
| // guarantee that weight is > 0 |
| weight |= 1; |
| |
| #undef INC_WEIGHT_IF |
| assert(cur_bit >= 0, "too many flags"); |
| assert(weight > 0, "weight cannot become negative"); |
| |
| return weight; |
| } |
| |
| bool ComputeLinearScanOrder::ready_for_processing(BlockBegin* cur) { |
| // Discount the edge just traveled. |
| // When the number drops to zero, all forward branches were processed |
| if (dec_forward_branches(cur) != 0) { |
| return false; |
| } |
| |
| assert(_linear_scan_order->index_of(cur) == -1, "block already processed (block can be ready only once)"); |
| assert(_work_list.index_of(cur) == -1, "block already in work-list (block can be ready only once)"); |
| return true; |
| } |
| |
| void ComputeLinearScanOrder::sort_into_work_list(BlockBegin* cur) { |
| assert(_work_list.index_of(cur) == -1, "block already in work list"); |
| |
| int cur_weight = compute_weight(cur); |
| |
| // the linear_scan_number is used to cache the weight of a block |
| cur->set_linear_scan_number(cur_weight); |
| |
| #ifndef PRODUCT |
| if (StressLinearScan) { |
| _work_list.insert_before(0, cur); |
| return; |
| } |
| #endif |
| |
| _work_list.append(NULL); // provide space for new element |
| |
| int insert_idx = _work_list.length() - 1; |
| while (insert_idx > 0 && _work_list.at(insert_idx - 1)->linear_scan_number() > cur_weight) { |
| _work_list.at_put(insert_idx, _work_list.at(insert_idx - 1)); |
| insert_idx--; |
| } |
| _work_list.at_put(insert_idx, cur); |
| |
| TRACE_LINEAR_SCAN(3, tty->print_cr("Sorted B%d into worklist. new worklist:", cur->block_id())); |
| TRACE_LINEAR_SCAN(3, for (int i = 0; i < _work_list.length(); i++) tty->print_cr("%8d B%2d weight:%6x", i, _work_list.at(i)->block_id(), _work_list.at(i)->linear_scan_number())); |
| |
| #ifdef ASSERT |
| for (int i = 0; i < _work_list.length(); i++) { |
| assert(_work_list.at(i)->linear_scan_number() > 0, "weight not set"); |
| assert(i == 0 || _work_list.at(i - 1)->linear_scan_number() <= _work_list.at(i)->linear_scan_number(), "incorrect order in worklist"); |
| } |
| #endif |
| } |
| |
| void ComputeLinearScanOrder::append_block(BlockBegin* cur) { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("appending block B%d (weight 0x%6x) to linear-scan order", cur->block_id(), cur->linear_scan_number())); |
| assert(_linear_scan_order->index_of(cur) == -1, "cannot add the same block twice"); |
| |
| // currently, the linear scan order and code emit order are equal. |
| // therefore the linear_scan_number and the weight of a block must also |
| // be equal. |
| cur->set_linear_scan_number(_linear_scan_order->length()); |
| _linear_scan_order->append(cur); |
| } |
| |
| void ComputeLinearScanOrder::compute_order(BlockBegin* start_block) { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing final block order")); |
| |
| // the start block is always the first block in the linear scan order |
| _linear_scan_order = new BlockList(_num_blocks); |
| append_block(start_block); |
| |
| assert(start_block->end()->as_Base() != NULL, "start block must end with Base-instruction"); |
| BlockBegin* std_entry = ((Base*)start_block->end())->std_entry(); |
| BlockBegin* osr_entry = ((Base*)start_block->end())->osr_entry(); |
| |
| BlockBegin* sux_of_osr_entry = NULL; |
| if (osr_entry != NULL) { |
| // special handling for osr entry: |
| // ignore the edge between the osr entry and its successor for processing |
| // the osr entry block is added manually below |
| assert(osr_entry->number_of_sux() == 1, "osr entry must have exactly one successor"); |
| assert(osr_entry->sux_at(0)->number_of_preds() >= 2, "sucessor of osr entry must have two predecessors (otherwise it is not present in normal control flow"); |
| |
| sux_of_osr_entry = osr_entry->sux_at(0); |
| dec_forward_branches(sux_of_osr_entry); |
| |
| compute_dominator(osr_entry, start_block); |
| _iterative_dominators = true; |
| } |
| compute_dominator(std_entry, start_block); |
| |
| // start processing with standard entry block |
| assert(_work_list.is_empty(), "list must be empty before processing"); |
| |
| if (ready_for_processing(std_entry)) { |
| sort_into_work_list(std_entry); |
| } else { |
| assert(false, "the std_entry must be ready for processing (otherwise, the method has no start block)"); |
| } |
| |
| do { |
| BlockBegin* cur = _work_list.pop(); |
| |
| if (cur == sux_of_osr_entry) { |
| // the osr entry block is ignored in normal processing, it is never added to the |
| // work list. Instead, it is added as late as possible manually here. |
| append_block(osr_entry); |
| compute_dominator(cur, osr_entry); |
| } |
| append_block(cur); |
| |
| int i; |
| int num_sux = cur->number_of_sux(); |
| // changed loop order to get "intuitive" order of if- and else-blocks |
| for (i = 0; i < num_sux; i++) { |
| BlockBegin* sux = cur->sux_at(i); |
| compute_dominator(sux, cur); |
| if (ready_for_processing(sux)) { |
| sort_into_work_list(sux); |
| } |
| } |
| num_sux = cur->number_of_exception_handlers(); |
| for (i = 0; i < num_sux; i++) { |
| BlockBegin* sux = cur->exception_handler_at(i); |
| if (ready_for_processing(sux)) { |
| sort_into_work_list(sux); |
| } |
| } |
| } while (_work_list.length() > 0); |
| } |
| |
| |
| bool ComputeLinearScanOrder::compute_dominators_iter() { |
| bool changed = false; |
| int num_blocks = _linear_scan_order->length(); |
| |
| assert(_linear_scan_order->at(0)->dominator() == NULL, "must not have dominator"); |
| assert(_linear_scan_order->at(0)->number_of_preds() == 0, "must not have predecessors"); |
| for (int i = 1; i < num_blocks; i++) { |
| BlockBegin* block = _linear_scan_order->at(i); |
| |
| BlockBegin* dominator = block->pred_at(0); |
| int num_preds = block->number_of_preds(); |
| |
| TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: Processing B%d", block->block_id())); |
| |
| for (int j = 0; j < num_preds; j++) { |
| |
| BlockBegin *pred = block->pred_at(j); |
| TRACE_LINEAR_SCAN(4, tty->print_cr(" DOM: Subrocessing B%d", pred->block_id())); |
| |
| if (block->is_set(BlockBegin::exception_entry_flag)) { |
| dominator = common_dominator(dominator, pred); |
| int num_pred_preds = pred->number_of_preds(); |
| for (int k = 0; k < num_pred_preds; k++) { |
| dominator = common_dominator(dominator, pred->pred_at(k)); |
| } |
| } else { |
| dominator = common_dominator(dominator, pred); |
| } |
| } |
| |
| if (dominator != block->dominator()) { |
| TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: updating dominator of B%d from B%d to B%d", block->block_id(), block->dominator()->block_id(), dominator->block_id())); |
| |
| block->set_dominator(dominator); |
| changed = true; |
| } |
| } |
| return changed; |
| } |
| |
| void ComputeLinearScanOrder::compute_dominators() { |
| TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing dominators (iterative computation reqired: %d)", _iterative_dominators)); |
| |
| // iterative computation of dominators is only required for methods with non-natural loops |
| // and OSR-methods. For all other methods, the dominators computed when generating the |
| // linear scan block order are correct. |
| if (_iterative_dominators) { |
| do { |
| TRACE_LINEAR_SCAN(1, tty->print_cr("DOM: next iteration of fix-point calculation")); |
| } while (compute_dominators_iter()); |
| } |
| |
| // check that dominators are correct |
| assert(!compute_dominators_iter(), "fix point not reached"); |
| |
| // Add Blocks to dominates-Array |
| int num_blocks = _linear_scan_order->length(); |
| for (int i = 0; i < num_blocks; i++) { |
| BlockBegin* block = _linear_scan_order->at(i); |
| |
| BlockBegin *dom = block->dominator(); |
| if (dom) { |
| assert(dom->dominator_depth() != -1, "Dominator must have been visited before"); |
| dom->dominates()->append(block); |
| block->set_dominator_depth(dom->dominator_depth() + 1); |
| } else { |
| block->set_dominator_depth(0); |
| } |
| } |
| } |
| |
| |
| #ifndef PRODUCT |
| void ComputeLinearScanOrder::print_blocks() { |
| if (TraceLinearScanLevel >= 2) { |
| tty->print_cr("----- loop information:"); |
| for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) { |
| BlockBegin* cur = _linear_scan_order->at(block_idx); |
| |
| tty->print("%4d: B%2d: ", cur->linear_scan_number(), cur->block_id()); |
| for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) { |
| tty->print ("%d ", is_block_in_loop(loop_idx, cur)); |
| } |
| tty->print_cr(" -> loop_index: %2d, loop_depth: %2d", cur->loop_index(), cur->loop_depth()); |
| } |
| } |
| |
| if (TraceLinearScanLevel >= 1) { |
| tty->print_cr("----- linear-scan block order:"); |
| for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) { |
| BlockBegin* cur = _linear_scan_order->at(block_idx); |
| tty->print("%4d: B%2d loop: %2d depth: %2d", cur->linear_scan_number(), cur->block_id(), cur->loop_index(), cur->loop_depth()); |
| |
| tty->print(cur->is_set(BlockBegin::exception_entry_flag) ? " ex" : " "); |
| tty->print(cur->is_set(BlockBegin::critical_edge_split_flag) ? " ce" : " "); |
| tty->print(cur->is_set(BlockBegin::linear_scan_loop_header_flag) ? " lh" : " "); |
| tty->print(cur->is_set(BlockBegin::linear_scan_loop_end_flag) ? " le" : " "); |
| |
| if (cur->dominator() != NULL) { |
| tty->print(" dom: B%d ", cur->dominator()->block_id()); |
| } else { |
| tty->print(" dom: NULL "); |
| } |
| |
| if (cur->number_of_preds() > 0) { |
| tty->print(" preds: "); |
| for (int j = 0; j < cur->number_of_preds(); j++) { |
| BlockBegin* pred = cur->pred_at(j); |
| tty->print("B%d ", pred->block_id()); |
| } |
| } |
| if (cur->number_of_sux() > 0) { |
| tty->print(" sux: "); |
| for (int j = 0; j < cur->number_of_sux(); j++) { |
| BlockBegin* sux = cur->sux_at(j); |
| tty->print("B%d ", sux->block_id()); |
| } |
| } |
| if (cur->number_of_exception_handlers() > 0) { |
| tty->print(" ex: "); |
| for (int j = 0; j < cur->number_of_exception_handlers(); j++) { |
| BlockBegin* ex = cur->exception_handler_at(j); |
| tty->print("B%d ", ex->block_id()); |
| } |
| } |
| tty->cr(); |
| } |
| } |
| } |
| #endif |
| |
| #ifdef ASSERT |
| void ComputeLinearScanOrder::verify() { |
| assert(_linear_scan_order->length() == _num_blocks, "wrong number of blocks in list"); |
| |
| if (StressLinearScan) { |
| // blocks are scrambled when StressLinearScan is used |
| return; |
| } |
| |
| // check that all successors of a block have a higher linear-scan-number |
| // and that all predecessors of a block have a lower linear-scan-number |
| // (only backward branches of loops are ignored) |
| int i; |
| for (i = 0; i < _linear_scan_order->length(); i++) { |
| BlockBegin* cur = _linear_scan_order->at(i); |
| |
| assert(cur->linear_scan_number() == i, "incorrect linear_scan_number"); |
| assert(cur->linear_scan_number() >= 0 && cur->linear_scan_number() == _linear_scan_order->index_of(cur), "incorrect linear_scan_number"); |
| |
| int j; |
| for (j = cur->number_of_sux() - 1; j >= 0; j--) { |
| BlockBegin* sux = cur->sux_at(j); |
| |
| assert(sux->linear_scan_number() >= 0 && sux->linear_scan_number() == _linear_scan_order->index_of(sux), "incorrect linear_scan_number"); |
| if (!sux->is_set(BlockBegin::backward_branch_target_flag)) { |
| assert(cur->linear_scan_number() < sux->linear_scan_number(), "invalid order"); |
| } |
| if (cur->loop_depth() == sux->loop_depth()) { |
| assert(cur->loop_index() == sux->loop_index() || sux->is_set(BlockBegin::linear_scan_loop_header_flag), "successing blocks with same loop depth must have same loop index"); |
| } |
| } |
| |
| for (j = cur->number_of_preds() - 1; j >= 0; j--) { |
| BlockBegin* pred = cur->pred_at(j); |
| |
| assert(pred->linear_scan_number() >= 0 && pred->linear_scan_number() == _linear_scan_order->index_of(pred), "incorrect linear_scan_number"); |
| if (!cur->is_set(BlockBegin::backward_branch_target_flag)) { |
| assert(cur->linear_scan_number() > pred->linear_scan_number(), "invalid order"); |
| } |
| if (cur->loop_depth() == pred->loop_depth()) { |
| assert(cur->loop_index() == pred->loop_index() || cur->is_set(BlockBegin::linear_scan_loop_header_flag), "successing blocks with same loop depth must have same loop index"); |
| } |
| |
| assert(cur->dominator()->linear_scan_number() <= cur->pred_at(j)->linear_scan_number(), "dominator must be before predecessors"); |
| } |
| |
| // check dominator |
| if (i == 0) { |
| assert(cur->dominator() == NULL, "first block has no dominator"); |
| } else { |
| assert(cur->dominator() != NULL, "all but first block must have dominator"); |
| } |
| // Assertion does not hold for exception handlers |
| assert(cur->number_of_preds() != 1 || cur->dominator() == cur->pred_at(0) || cur->is_set(BlockBegin::exception_entry_flag), "Single predecessor must also be dominator"); |
| } |
| |
| // check that all loops are continuous |
| for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) { |
| int block_idx = 0; |
| assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "the first block must not be present in any loop"); |
| |
| // skip blocks before the loop |
| while (block_idx < _num_blocks && !is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) { |
| block_idx++; |
| } |
| // skip blocks of loop |
| while (block_idx < _num_blocks && is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) { |
| block_idx++; |
| } |
| // after the first non-loop block, there must not be another loop-block |
| while (block_idx < _num_blocks) { |
| assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "loop not continuous in linear-scan order"); |
| block_idx++; |
| } |
| } |
| } |
| #endif |
| |
| |
| void IR::compute_code() { |
| assert(is_valid(), "IR must be valid"); |
| |
| ComputeLinearScanOrder compute_order(compilation(), start()); |
| _num_loops = compute_order.num_loops(); |
| _code = compute_order.linear_scan_order(); |
| } |
| |
| |
| void IR::compute_use_counts() { |
| // make sure all values coming out of this block get evaluated. |
| int num_blocks = _code->length(); |
| for (int i = 0; i < num_blocks; i++) { |
| _code->at(i)->end()->state()->pin_stack_for_linear_scan(); |
| } |
| |
| // compute use counts |
| UseCountComputer::compute(_code); |
| } |
| |
| |
| void IR::iterate_preorder(BlockClosure* closure) { |
| assert(is_valid(), "IR must be valid"); |
| start()->iterate_preorder(closure); |
| } |
| |
| |
| void IR::iterate_postorder(BlockClosure* closure) { |
| assert(is_valid(), "IR must be valid"); |
| start()->iterate_postorder(closure); |
| } |
| |
| void IR::iterate_linear_scan_order(BlockClosure* closure) { |
| linear_scan_order()->iterate_forward(closure); |
| } |
| |
| |
| #ifndef PRODUCT |
| class BlockPrinter: public BlockClosure { |
| private: |
| InstructionPrinter* _ip; |
| bool _cfg_only; |
| bool _live_only; |
| |
| public: |
| BlockPrinter(InstructionPrinter* ip, bool cfg_only, bool live_only = false) { |
| _ip = ip; |
| _cfg_only = cfg_only; |
| _live_only = live_only; |
| } |
| |
| virtual void block_do(BlockBegin* block) { |
| if (_cfg_only) { |
| _ip->print_instr(block); tty->cr(); |
| } else { |
| block->print_block(*_ip, _live_only); |
| } |
| } |
| }; |
| |
| |
| void IR::print(BlockBegin* start, bool cfg_only, bool live_only) { |
| ttyLocker ttyl; |
| InstructionPrinter ip(!cfg_only); |
| BlockPrinter bp(&ip, cfg_only, live_only); |
| start->iterate_preorder(&bp); |
| tty->cr(); |
| } |
| |
| void IR::print(bool cfg_only, bool live_only) { |
| if (is_valid()) { |
| print(start(), cfg_only, live_only); |
| } else { |
| tty->print_cr("invalid IR"); |
| } |
| } |
| |
| |
| define_array(BlockListArray, BlockList*) |
| define_stack(BlockListList, BlockListArray) |
| |
| class PredecessorValidator : public BlockClosure { |
| private: |
| BlockListList* _predecessors; |
| BlockList* _blocks; |
| |
| static int cmp(BlockBegin** a, BlockBegin** b) { |
| return (*a)->block_id() - (*b)->block_id(); |
| } |
| |
| public: |
| PredecessorValidator(IR* hir) { |
| ResourceMark rm; |
| _predecessors = new BlockListList(BlockBegin::number_of_blocks(), NULL); |
| _blocks = new BlockList(); |
| |
| int i; |
| hir->start()->iterate_preorder(this); |
| if (hir->code() != NULL) { |
| assert(hir->code()->length() == _blocks->length(), "must match"); |
| for (i = 0; i < _blocks->length(); i++) { |
| assert(hir->code()->contains(_blocks->at(i)), "should be in both lists"); |
| } |
| } |
| |
| for (i = 0; i < _blocks->length(); i++) { |
| BlockBegin* block = _blocks->at(i); |
| BlockList* preds = _predecessors->at(block->block_id()); |
| if (preds == NULL) { |
| assert(block->number_of_preds() == 0, "should be the same"); |
| continue; |
| } |
| |
| // clone the pred list so we can mutate it |
| BlockList* pred_copy = new BlockList(); |
| int j; |
| for (j = 0; j < block->number_of_preds(); j++) { |
| pred_copy->append(block->pred_at(j)); |
| } |
| // sort them in the same order |
| preds->sort(cmp); |
| pred_copy->sort(cmp); |
| int length = MIN2(preds->length(), block->number_of_preds()); |
| for (j = 0; j < block->number_of_preds(); j++) { |
| assert(preds->at(j) == pred_copy->at(j), "must match"); |
| } |
| |
| assert(preds->length() == block->number_of_preds(), "should be the same"); |
| } |
| } |
| |
| virtual void block_do(BlockBegin* block) { |
| _blocks->append(block); |
| BlockEnd* be = block->end(); |
| int n = be->number_of_sux(); |
| int i; |
| for (i = 0; i < n; i++) { |
| BlockBegin* sux = be->sux_at(i); |
| assert(!sux->is_set(BlockBegin::exception_entry_flag), "must not be xhandler"); |
| |
| BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL); |
| if (preds == NULL) { |
| preds = new BlockList(); |
| _predecessors->at_put(sux->block_id(), preds); |
| } |
| preds->append(block); |
| } |
| |
| n = block->number_of_exception_handlers(); |
| for (i = 0; i < n; i++) { |
| BlockBegin* sux = block->exception_handler_at(i); |
| assert(sux->is_set(BlockBegin::exception_entry_flag), "must be xhandler"); |
| |
| BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL); |
| if (preds == NULL) { |
| preds = new BlockList(); |
| _predecessors->at_put(sux->block_id(), preds); |
| } |
| preds->append(block); |
| } |
| } |
| }; |
| |
| class VerifyBlockBeginField : public BlockClosure { |
| |
| public: |
| |
| virtual void block_do(BlockBegin *block) { |
| for ( Instruction *cur = block; cur != NULL; cur = cur->next()) { |
| assert(cur->block() == block, "Block begin is not correct"); |
| } |
| } |
| }; |
| |
| void IR::verify() { |
| #ifdef ASSERT |
| PredecessorValidator pv(this); |
| VerifyBlockBeginField verifier; |
| this->iterate_postorder(&verifier); |
| #endif |
| } |
| |
| #endif // PRODUCT |
| |
| void SubstitutionResolver::visit(Value* v) { |
| Value v0 = *v; |
| if (v0) { |
| Value vs = v0->subst(); |
| if (vs != v0) { |
| *v = v0->subst(); |
| } |
| } |
| } |
| |
| #ifdef ASSERT |
| class SubstitutionChecker: public ValueVisitor { |
| void visit(Value* v) { |
| Value v0 = *v; |
| if (v0) { |
| Value vs = v0->subst(); |
| assert(vs == v0, "missed substitution"); |
| } |
| } |
| }; |
| #endif |
| |
| |
| void SubstitutionResolver::block_do(BlockBegin* block) { |
| Instruction* last = NULL; |
| for (Instruction* n = block; n != NULL;) { |
| n->values_do(this); |
| // need to remove this instruction from the instruction stream |
| if (n->subst() != n) { |
| assert(last != NULL, "must have last"); |
| last->set_next(n->next()); |
| } else { |
| last = n; |
| } |
| n = last->next(); |
| } |
| |
| #ifdef ASSERT |
| SubstitutionChecker check_substitute; |
| if (block->state()) block->state()->values_do(&check_substitute); |
| block->block_values_do(&check_substitute); |
| if (block->end() && block->end()->state()) block->end()->state()->values_do(&check_substitute); |
| #endif |
| } |