Mercurial > hg > graal-jvmci-8
view graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/alloc/MoveResolver.java @ 13639:f41881157b13
Properly handle illegal locations in MoveResolver verification.
author | Roland Schatz <roland.schatz@oracle.com> |
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date | Wed, 15 Jan 2014 15:01:39 +0100 |
parents | 622af5fb8c58 |
children | 38c881305352 |
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/* * Copyright (c) 2009, 2012, 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. */ package com.oracle.graal.compiler.alloc; import static com.oracle.graal.api.code.ValueUtil.*; import java.util.*; import com.oracle.graal.api.code.*; import com.oracle.graal.api.meta.*; import com.oracle.graal.debug.*; import com.oracle.graal.lir.*; /** */ final class MoveResolver { private final LinearScan allocator; private int insertIdx; private LIRInsertionBuffer insertionBuffer; // buffer where moves are inserted private final List<Interval> mappingFrom; private final List<Value> mappingFromOpr; private final List<Interval> mappingTo; private boolean multipleReadsAllowed; private final int[] registerBlocked; private int registerBlocked(int reg) { return registerBlocked[reg]; } private void setRegisterBlocked(int reg, int direction) { assert direction == 1 || direction == -1 : "out of bounds"; registerBlocked[reg] += direction; } void setMultipleReadsAllowed() { multipleReadsAllowed = true; } boolean hasMappings() { return mappingFrom.size() > 0; } MoveResolver(LinearScan allocator) { this.allocator = allocator; this.multipleReadsAllowed = false; this.mappingFrom = new ArrayList<>(8); this.mappingFromOpr = new ArrayList<>(8); this.mappingTo = new ArrayList<>(8); this.insertIdx = -1; this.insertionBuffer = new LIRInsertionBuffer(); this.registerBlocked = new int[allocator.registers.length]; assert checkEmpty(); } boolean checkEmpty() { assert mappingFrom.size() == 0 && mappingFromOpr.size() == 0 && mappingTo.size() == 0 : "list must be empty before and after processing"; for (int i = 0; i < allocator.registers.length; i++) { assert registerBlocked(i) == 0 : "register map must be empty before and after processing"; } assert !multipleReadsAllowed : "must have default value"; return true; } private boolean verifyBeforeResolve() { assert mappingFrom.size() == mappingFromOpr.size() : "length must be equal"; assert mappingFrom.size() == mappingTo.size() : "length must be equal"; assert insertIdx != -1 : "insert position not set"; int i; int j; if (!multipleReadsAllowed) { for (i = 0; i < mappingFrom.size(); i++) { for (j = i + 1; j < mappingFrom.size(); j++) { assert mappingFrom.get(i) == null || mappingFrom.get(i) != mappingFrom.get(j) : "cannot read from same interval twice"; } } } for (i = 0; i < mappingTo.size(); i++) { for (j = i + 1; j < mappingTo.size(); j++) { assert mappingTo.get(i) != mappingTo.get(j) : "cannot write to same interval twice"; } } HashSet<Value> usedRegs = new HashSet<>(); if (!multipleReadsAllowed) { for (i = 0; i < mappingFrom.size(); i++) { Interval interval = mappingFrom.get(i); if (interval != null && !isIllegal(interval.location())) { boolean unique = usedRegs.add(interval.location()); assert unique : "cannot read from same register twice"; } } } usedRegs.clear(); for (i = 0; i < mappingTo.size(); i++) { Interval interval = mappingTo.get(i); if (isIllegal(interval.location())) { // After insertion the location may become illegal, so don't check it since multiple // intervals might be illegal. continue; } boolean unique = usedRegs.add(interval.location()); assert unique : "cannot write to same register twice"; } usedRegs.clear(); for (i = 0; i < mappingFrom.size(); i++) { Interval interval = mappingFrom.get(i); if (interval != null && !isRegister(interval.location())) { usedRegs.add(interval.location()); } } for (i = 0; i < mappingTo.size(); i++) { Interval interval = mappingTo.get(i); assert !usedRegs.contains(interval.location()) || interval.location().equals(mappingFrom.get(i).location()) : "stack slots used in mappingFrom must be disjoint to mappingTo"; } return true; } // mark assignedReg and assignedRegHi of the interval as blocked private void blockRegisters(Interval interval) { Value location = interval.location(); if (isRegister(location)) { int reg = asRegister(location).number; assert multipleReadsAllowed || registerBlocked(reg) == 0 : "register already marked as used"; setRegisterBlocked(reg, 1); } } // mark assignedReg and assignedRegHi of the interval as unblocked private void unblockRegisters(Interval interval) { Value location = interval.location(); if (isRegister(location)) { int reg = asRegister(location).number; assert registerBlocked(reg) > 0 : "register already marked as unused"; setRegisterBlocked(reg, -1); } } /** * Checks if the {@linkplain Interval#location() location} of {@code to} is not blocked or is * only blocked by {@code from}. */ private boolean safeToProcessMove(Interval from, Interval to) { Value fromReg = from != null ? from.location() : null; Value reg = to.location(); if (isRegister(reg)) { if (registerBlocked(asRegister(reg).number) > 1 || (registerBlocked(asRegister(reg).number) == 1 && !reg.equals(fromReg))) { return false; } } return true; } private void createInsertionBuffer(List<LIRInstruction> list) { assert !insertionBuffer.initialized() : "overwriting existing buffer"; insertionBuffer.init(list); } private void appendInsertionBuffer() { if (insertionBuffer.initialized()) { insertionBuffer.finish(); } assert !insertionBuffer.initialized() : "must be uninitialized now"; insertIdx = -1; } private void insertMove(Interval fromInterval, Interval toInterval) { assert !fromInterval.operand.equals(toInterval.operand) : "from and to interval equal: " + fromInterval; assert fromInterval.kind() == toInterval.kind() : "move between different types"; assert insertIdx != -1 : "must setup insert position first"; AllocatableValue fromOpr = fromInterval.operand; AllocatableValue toOpr = toInterval.operand; insertionBuffer.append(insertIdx, allocator.ir.spillMoveFactory.createMove(toOpr, fromOpr)); Debug.log("insert move from %s to %s at %d", fromInterval, toInterval, insertIdx); } private void insertMove(Value fromOpr, Interval toInterval) { assert fromOpr.getPlatformKind() == toInterval.kind() : "move between different types"; assert insertIdx != -1 : "must setup insert position first"; AllocatableValue toOpr = toInterval.operand; insertionBuffer.append(insertIdx, allocator.ir.spillMoveFactory.createMove(toOpr, fromOpr)); Debug.log("insert move from value %s to %s at %d", fromOpr, toInterval, insertIdx); } private void resolveMappings() { assert verifyBeforeResolve(); // Block all registers that are used as input operands of a move. // When a register is blocked, no move to this register is emitted. // This is necessary for detecting cycles in moves. int i; for (i = mappingFrom.size() - 1; i >= 0; i--) { Interval fromInterval = mappingFrom.get(i); if (fromInterval != null) { blockRegisters(fromInterval); } } int spillCandidate = -1; while (mappingFrom.size() > 0) { boolean processedInterval = false; for (i = mappingFrom.size() - 1; i >= 0; i--) { Interval fromInterval = mappingFrom.get(i); Interval toInterval = mappingTo.get(i); if (safeToProcessMove(fromInterval, toInterval)) { // this interval can be processed because target is free if (fromInterval != null) { insertMove(fromInterval, toInterval); unblockRegisters(fromInterval); } else { insertMove(mappingFromOpr.get(i), toInterval); } mappingFrom.remove(i); mappingFromOpr.remove(i); mappingTo.remove(i); processedInterval = true; } else if (fromInterval != null && isRegister(fromInterval.location())) { // this interval cannot be processed now because target is not free // it starts in a register, so it is a possible candidate for spilling spillCandidate = i; } } if (!processedInterval) { // no move could be processed because there is a cycle in the move list // (e.g. r1 . r2, r2 . r1), so one interval must be spilled to memory assert spillCandidate != -1 : "no interval in register for spilling found"; // create a new spill interval and assign a stack slot to it Interval fromInterval = mappingFrom.get(spillCandidate); Interval spillInterval = allocator.createDerivedInterval(fromInterval); spillInterval.setKind(fromInterval.kind()); // add a dummy range because real position is difficult to calculate // Note: this range is a special case when the integrity of the allocation is // checked spillInterval.addRange(1, 2); // do not allocate a new spill slot for temporary interval, but // use spill slot assigned to fromInterval. Otherwise moves from // one stack slot to another can happen (not allowed by LIRAssembler StackSlot spillSlot = fromInterval.spillSlot(); if (spillSlot == null) { spillSlot = allocator.frameMap.allocateSpillSlot(spillInterval.kind()); fromInterval.setSpillSlot(spillSlot); } spillInterval.assignLocation(spillSlot); Debug.log("created new Interval for spilling: %s", spillInterval); // insert a move from register to stack and update the mapping insertMove(fromInterval, spillInterval); mappingFrom.set(spillCandidate, spillInterval); unblockRegisters(fromInterval); } } // reset to default value multipleReadsAllowed = false; // check that all intervals have been processed assert checkEmpty(); } void setInsertPosition(List<LIRInstruction> insertList, int insertIdx) { assert this.insertIdx == -1 : "use moveInsertPosition instead of setInsertPosition when data already set"; createInsertionBuffer(insertList); this.insertIdx = insertIdx; } void moveInsertPosition(List<LIRInstruction> newInsertList, int newInsertIdx) { if (insertionBuffer.lirList() != null && (insertionBuffer.lirList() != newInsertList || this.insertIdx != newInsertIdx)) { // insert position changed . resolve current mappings resolveMappings(); } if (insertionBuffer.lirList() != newInsertList) { // block changed . append insertionBuffer because it is // bound to a specific block and create a new insertionBuffer appendInsertionBuffer(); createInsertionBuffer(newInsertList); } this.insertIdx = newInsertIdx; } void addMapping(Interval fromInterval, Interval toInterval) { if (isIllegal(toInterval.location()) && toInterval.canMaterialize()) { Debug.log("no store to rematerializable interval %s needed", toInterval); return; } if (isIllegal(fromInterval.location()) && fromInterval.canMaterialize()) { // Instead of a reload, re-materialize the value Value rematValue = fromInterval.getMaterializedValue(); addMapping(rematValue, toInterval); return; } Debug.log("add move mapping from %s to %s", fromInterval, toInterval); assert !fromInterval.operand.equals(toInterval.operand) : "from and to interval equal: " + fromInterval; assert fromInterval.kind() == toInterval.kind(); mappingFrom.add(fromInterval); mappingFromOpr.add(Value.ILLEGAL); mappingTo.add(toInterval); } void addMapping(Value fromOpr, Interval toInterval) { Debug.log("add move mapping from %s to %s", fromOpr, toInterval); assert isConstant(fromOpr) : "only for constants"; mappingFrom.add(null); mappingFromOpr.add(fromOpr); mappingTo.add(toInterval); } void resolveAndAppendMoves() { if (hasMappings()) { resolveMappings(); } appendInsertionBuffer(); } }