1407 lines
48 KiB
C++
1407 lines
48 KiB
C++
/*
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* Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "c1/c1_Compilation.hpp"
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#include "c1/c1_FrameMap.hpp"
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#include "c1/c1_GraphBuilder.hpp"
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#include "c1/c1_IR.hpp"
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#include "c1/c1_InstructionPrinter.hpp"
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#include "c1/c1_Optimizer.hpp"
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#include "utilities/bitMap.inline.hpp"
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// Implementation of XHandlers
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//
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// Note: This code could eventually go away if we are
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// just using the ciExceptionHandlerStream.
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XHandlers::XHandlers(ciMethod* method) : _list(method->exception_table_length()) {
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ciExceptionHandlerStream s(method);
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while (!s.is_done()) {
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_list.append(new XHandler(s.handler()));
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s.next();
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}
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assert(s.count() == method->exception_table_length(), "exception table lengths inconsistent");
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}
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// deep copy of all XHandler contained in list
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XHandlers::XHandlers(XHandlers* other) :
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_list(other->length())
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{
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for (int i = 0; i < other->length(); i++) {
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_list.append(new XHandler(other->handler_at(i)));
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}
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}
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// Returns whether a particular exception type can be caught. Also
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// returns true if klass is unloaded or any exception handler
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// classes are unloaded. type_is_exact indicates whether the throw
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// is known to be exactly that class or it might throw a subtype.
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bool XHandlers::could_catch(ciInstanceKlass* klass, bool type_is_exact) const {
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// the type is unknown so be conservative
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if (!klass->is_loaded()) {
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return true;
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}
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for (int i = 0; i < length(); i++) {
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XHandler* handler = handler_at(i);
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if (handler->is_catch_all()) {
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// catch of ANY
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return true;
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}
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ciInstanceKlass* handler_klass = handler->catch_klass();
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// if it's unknown it might be catchable
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if (!handler_klass->is_loaded()) {
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return true;
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}
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// if the throw type is definitely a subtype of the catch type
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// then it can be caught.
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if (klass->is_subtype_of(handler_klass)) {
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return true;
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}
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if (!type_is_exact) {
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// If the type isn't exactly known then it can also be caught by
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// catch statements where the inexact type is a subtype of the
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// catch type.
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// given: foo extends bar extends Exception
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// throw bar can be caught by catch foo, catch bar, and catch
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// Exception, however it can't be caught by any handlers without
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// bar in its type hierarchy.
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if (handler_klass->is_subtype_of(klass)) {
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return true;
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}
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}
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}
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return false;
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}
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bool XHandlers::equals(XHandlers* others) const {
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if (others == NULL) return false;
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if (length() != others->length()) return false;
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for (int i = 0; i < length(); i++) {
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if (!handler_at(i)->equals(others->handler_at(i))) return false;
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}
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return true;
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}
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bool XHandler::equals(XHandler* other) const {
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assert(entry_pco() != -1 && other->entry_pco() != -1, "must have entry_pco");
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if (entry_pco() != other->entry_pco()) return false;
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if (scope_count() != other->scope_count()) return false;
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if (_desc != other->_desc) return false;
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assert(entry_block() == other->entry_block(), "entry_block must be equal when entry_pco is equal");
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return true;
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}
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// Implementation of IRScope
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BlockBegin* IRScope::build_graph(Compilation* compilation, int osr_bci) {
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GraphBuilder gm(compilation, this);
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NOT_PRODUCT(if (PrintValueNumbering && Verbose) gm.print_stats());
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if (compilation->bailed_out()) return NULL;
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return gm.start();
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}
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IRScope::IRScope(Compilation* compilation, IRScope* caller, int caller_bci, ciMethod* method, int osr_bci, bool create_graph)
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: _callees(2)
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, _compilation(compilation)
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, _requires_phi_function(method->max_locals())
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{
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_caller = caller;
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_level = caller == NULL ? 0 : caller->level() + 1;
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_method = method;
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_xhandlers = new XHandlers(method);
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_number_of_locks = 0;
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_monitor_pairing_ok = method->has_balanced_monitors();
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_wrote_final = false;
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_wrote_fields = false;
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_wrote_volatile = false;
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_start = NULL;
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if (osr_bci == -1) {
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_requires_phi_function.clear();
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} else {
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// selective creation of phi functions is not possibel in osr-methods
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_requires_phi_function.set_range(0, method->max_locals());
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}
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assert(method->holder()->is_loaded() , "method holder must be loaded");
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// build graph if monitor pairing is ok
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if (create_graph && monitor_pairing_ok()) _start = build_graph(compilation, osr_bci);
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}
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int IRScope::max_stack() const {
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int my_max = method()->max_stack();
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int callee_max = 0;
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for (int i = 0; i < number_of_callees(); i++) {
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callee_max = MAX2(callee_max, callee_no(i)->max_stack());
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}
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return my_max + callee_max;
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}
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bool IRScopeDebugInfo::should_reexecute() {
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ciMethod* cur_method = scope()->method();
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int cur_bci = bci();
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if (cur_method != NULL && cur_bci != SynchronizationEntryBCI) {
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Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
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return Interpreter::bytecode_should_reexecute(code);
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} else
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return false;
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}
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// Implementation of CodeEmitInfo
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// Stack must be NON-null
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CodeEmitInfo::CodeEmitInfo(ValueStack* stack, XHandlers* exception_handlers, bool deoptimize_on_exception)
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: _scope(stack->scope())
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, _scope_debug_info(NULL)
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, _oop_map(NULL)
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, _stack(stack)
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, _exception_handlers(exception_handlers)
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, _is_method_handle_invoke(false)
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, _deoptimize_on_exception(deoptimize_on_exception) {
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assert(_stack != NULL, "must be non null");
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}
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CodeEmitInfo::CodeEmitInfo(CodeEmitInfo* info, ValueStack* stack)
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: _scope(info->_scope)
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, _exception_handlers(NULL)
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, _scope_debug_info(NULL)
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, _oop_map(NULL)
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, _stack(stack == NULL ? info->_stack : stack)
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, _is_method_handle_invoke(info->_is_method_handle_invoke)
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, _deoptimize_on_exception(info->_deoptimize_on_exception) {
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// deep copy of exception handlers
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if (info->_exception_handlers != NULL) {
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_exception_handlers = new XHandlers(info->_exception_handlers);
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}
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}
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void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset) {
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// record the safepoint before recording the debug info for enclosing scopes
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recorder->add_safepoint(pc_offset, _oop_map->deep_copy());
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_scope_debug_info->record_debug_info(recorder, pc_offset, true/*topmost*/, _is_method_handle_invoke);
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recorder->end_safepoint(pc_offset);
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}
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void CodeEmitInfo::add_register_oop(LIR_Opr opr) {
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assert(_oop_map != NULL, "oop map must already exist");
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assert(opr->is_single_cpu(), "should not call otherwise");
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VMReg name = frame_map()->regname(opr);
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_oop_map->set_oop(name);
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}
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// Mirror the stack size calculation in the deopt code
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// How much stack space would we need at this point in the program in
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// case of deoptimization?
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int CodeEmitInfo::interpreter_frame_size() const {
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ValueStack* state = _stack;
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int size = 0;
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int callee_parameters = 0;
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int callee_locals = 0;
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int extra_args = state->scope()->method()->max_stack() - state->stack_size();
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while (state != NULL) {
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int locks = state->locks_size();
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int temps = state->stack_size();
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bool is_top_frame = (state == _stack);
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ciMethod* method = state->scope()->method();
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int frame_size = BytesPerWord * Interpreter::size_activation(method->max_stack(),
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temps + callee_parameters,
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extra_args,
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locks,
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callee_parameters,
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callee_locals,
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is_top_frame);
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size += frame_size;
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callee_parameters = method->size_of_parameters();
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callee_locals = method->max_locals();
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extra_args = 0;
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state = state->caller_state();
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}
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return size + Deoptimization::last_frame_adjust(0, callee_locals) * BytesPerWord;
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}
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// Implementation of IR
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IR::IR(Compilation* compilation, ciMethod* method, int osr_bci) :
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_num_loops(0) {
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// setup IR fields
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_compilation = compilation;
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_top_scope = new IRScope(compilation, NULL, -1, method, osr_bci, true);
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_code = NULL;
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}
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void IR::optimize_blocks() {
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Optimizer opt(this);
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if (!compilation()->profile_branches()) {
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if (DoCEE) {
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opt.eliminate_conditional_expressions();
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#ifndef PRODUCT
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if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after CEE"); print(true); }
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if (PrintIR || PrintIR1 ) { tty->print_cr("IR after CEE"); print(false); }
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#endif
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}
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if (EliminateBlocks) {
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opt.eliminate_blocks();
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#ifndef PRODUCT
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if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after block elimination"); print(true); }
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if (PrintIR || PrintIR1 ) { tty->print_cr("IR after block elimination"); print(false); }
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#endif
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}
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}
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}
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void IR::eliminate_null_checks() {
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Optimizer opt(this);
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if (EliminateNullChecks) {
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opt.eliminate_null_checks();
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#ifndef PRODUCT
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if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after null check elimination"); print(true); }
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if (PrintIR || PrintIR1 ) { tty->print_cr("IR after null check elimination"); print(false); }
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#endif
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}
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}
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static int sort_pairs(BlockPair** a, BlockPair** b) {
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if ((*a)->from() == (*b)->from()) {
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return (*a)->to()->block_id() - (*b)->to()->block_id();
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} else {
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return (*a)->from()->block_id() - (*b)->from()->block_id();
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}
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}
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class CriticalEdgeFinder: public BlockClosure {
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BlockPairList blocks;
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IR* _ir;
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public:
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CriticalEdgeFinder(IR* ir): _ir(ir) {}
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void block_do(BlockBegin* bb) {
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BlockEnd* be = bb->end();
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int nos = be->number_of_sux();
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if (nos >= 2) {
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for (int i = 0; i < nos; i++) {
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BlockBegin* sux = be->sux_at(i);
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if (sux->number_of_preds() >= 2) {
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blocks.append(new BlockPair(bb, sux));
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}
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}
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}
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}
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void split_edges() {
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BlockPair* last_pair = NULL;
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blocks.sort(sort_pairs);
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for (int i = 0; i < blocks.length(); i++) {
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BlockPair* pair = blocks.at(i);
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if (last_pair != NULL && pair->is_same(last_pair)) continue;
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BlockBegin* from = pair->from();
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BlockBegin* to = pair->to();
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BlockBegin* split = from->insert_block_between(to);
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#ifndef PRODUCT
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if ((PrintIR || PrintIR1) && Verbose) {
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tty->print_cr("Split critical edge B%d -> B%d (new block B%d)",
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from->block_id(), to->block_id(), split->block_id());
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}
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#endif
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last_pair = pair;
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}
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}
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};
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void IR::split_critical_edges() {
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CriticalEdgeFinder cef(this);
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iterate_preorder(&cef);
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cef.split_edges();
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}
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class UseCountComputer: public ValueVisitor, BlockClosure {
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private:
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void visit(Value* n) {
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// Local instructions and Phis for expression stack values at the
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// start of basic blocks are not added to the instruction list
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if (!(*n)->is_linked() && (*n)->can_be_linked()) {
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assert(false, "a node was not appended to the graph");
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Compilation::current()->bailout("a node was not appended to the graph");
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}
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// use n's input if not visited before
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if (!(*n)->is_pinned() && !(*n)->has_uses()) {
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// note: a) if the instruction is pinned, it will be handled by compute_use_count
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// b) if the instruction has uses, it was touched before
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// => in both cases we don't need to update n's values
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uses_do(n);
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}
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// use n
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(*n)->_use_count++;
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}
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Values* worklist;
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int depth;
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enum {
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max_recurse_depth = 20
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};
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void uses_do(Value* n) {
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depth++;
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if (depth > max_recurse_depth) {
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// don't allow the traversal to recurse too deeply
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worklist->push(*n);
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} else {
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(*n)->input_values_do(this);
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// special handling for some instructions
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if ((*n)->as_BlockEnd() != NULL) {
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// note on BlockEnd:
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// must 'use' the stack only if the method doesn't
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// terminate, however, in those cases stack is empty
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(*n)->state_values_do(this);
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}
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}
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depth--;
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}
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void block_do(BlockBegin* b) {
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depth = 0;
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// process all pinned nodes as the roots of expression trees
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for (Instruction* n = b; n != NULL; n = n->next()) {
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if (n->is_pinned()) uses_do(&n);
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}
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assert(depth == 0, "should have counted back down");
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// now process any unpinned nodes which recursed too deeply
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while (worklist->length() > 0) {
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Value t = worklist->pop();
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if (!t->is_pinned()) {
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// compute the use count
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uses_do(&t);
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// pin the instruction so that LIRGenerator doesn't recurse
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// too deeply during it's evaluation.
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t->pin();
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}
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}
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assert(depth == 0, "should have counted back down");
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}
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UseCountComputer() {
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worklist = new Values();
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depth = 0;
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}
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public:
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static void compute(BlockList* blocks) {
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UseCountComputer ucc;
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blocks->iterate_backward(&ucc);
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}
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};
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// helper macro for short definition of trace-output inside code
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#ifndef PRODUCT
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#define TRACE_LINEAR_SCAN(level, code) \
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if (TraceLinearScanLevel >= level) { \
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code; \
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}
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#else
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#define TRACE_LINEAR_SCAN(level, code)
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#endif
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class ComputeLinearScanOrder : public StackObj {
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private:
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int _max_block_id; // the highest block_id of a block
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int _num_blocks; // total number of blocks (smaller than _max_block_id)
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int _num_loops; // total number of loops
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bool _iterative_dominators;// method requires iterative computation of dominatiors
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BlockList* _linear_scan_order; // the resulting list of blocks in correct order
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BitMap _visited_blocks; // used for recursive processing of blocks
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BitMap _active_blocks; // used for recursive processing of blocks
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BitMap _dominator_blocks; // temproary BitMap used for computation of dominator
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intArray _forward_branches; // number of incoming forward branches for each block
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BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges
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BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop
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BlockList _work_list; // temporary list (used in mark_loops and compute_order)
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BlockList _loop_headers;
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Compilation* _compilation;
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// accessors for _visited_blocks and _active_blocks
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void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); }
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bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); }
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bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); }
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void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); }
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void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); }
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void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); }
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// accessors for _forward_branches
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void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); }
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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()); }
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// accessors for _loop_map
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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::linear_scan_loop_header_flag);
|
|
cur->set(BlockBegin::backward_branch_target_flag);
|
|
|
|
parent->set(BlockBegin::linear_scan_loop_end_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;
|
|
}
|
|
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);
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if (block->end() && block->end()->state()) block->end()->state()->values_do(&check_substitute);
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#endif
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}
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