--- /dev/null 2017-01-22 10:16:57.869617664 -0800 +++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/alloc/lsra/LinearScanAssignLocationsPhase.java 2017-02-15 17:05:27.379576744 -0800 @@ -0,0 +1,239 @@ +/* + * Copyright (c) 2015, 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. + */ +package org.graalvm.compiler.lir.alloc.lsra; + +import static org.graalvm.compiler.core.common.GraalOptions.DetailedAsserts; +import static org.graalvm.compiler.lir.LIRValueUtil.isJavaConstant; +import static org.graalvm.compiler.lir.LIRValueUtil.isStackSlotValue; +import static org.graalvm.compiler.lir.LIRValueUtil.isVariable; +import static org.graalvm.compiler.lir.LIRValueUtil.isVirtualStackSlot; +import static jdk.vm.ci.code.ValueUtil.isIllegal; + +import java.util.Collections; +import java.util.EnumSet; +import java.util.List; + +import org.graalvm.compiler.core.common.cfg.AbstractBlockBase; +import org.graalvm.compiler.debug.Debug; +import org.graalvm.compiler.debug.Indent; +import org.graalvm.compiler.lir.ConstantValue; +import org.graalvm.compiler.lir.InstructionValueProcedure; +import org.graalvm.compiler.lir.LIRFrameState; +import org.graalvm.compiler.lir.LIRInstruction; +import org.graalvm.compiler.lir.LIRInstruction.OperandFlag; +import org.graalvm.compiler.lir.LIRInstruction.OperandMode; +import org.graalvm.compiler.lir.StandardOp; +import org.graalvm.compiler.lir.StandardOp.MoveOp; +import org.graalvm.compiler.lir.StandardOp.ValueMoveOp; +import org.graalvm.compiler.lir.Variable; +import org.graalvm.compiler.lir.gen.LIRGenerationResult; +import org.graalvm.compiler.lir.phases.AllocationPhase; + +import jdk.vm.ci.code.TargetDescription; +import jdk.vm.ci.meta.AllocatableValue; +import jdk.vm.ci.meta.Value; + +/** + * Phase 7: Assign register numbers back to LIR. + */ +public class LinearScanAssignLocationsPhase extends AllocationPhase { + + protected final LinearScan allocator; + + public LinearScanAssignLocationsPhase(LinearScan allocator) { + this.allocator = allocator; + } + + @Override + protected void run(TargetDescription target, LIRGenerationResult lirGenRes, AllocationContext context) { + assignLocations(); + } + + /** + * Assigns the allocated location for an LIR instruction operand back into the instruction. + * + * @param op current {@link LIRInstruction} + * @param operand an LIR instruction operand + * @param mode the usage mode for {@code operand} by the instruction + * @return the location assigned for the operand + */ + protected Value colorLirOperand(LIRInstruction op, Variable operand, OperandMode mode) { + int opId = op.id(); + Interval interval = allocator.intervalFor(operand); + assert interval != null : "interval must exist"; + + if (opId != -1) { + if (DetailedAsserts.getValue()) { + AbstractBlockBase block = allocator.blockForId(opId); + if (block.getSuccessorCount() <= 1 && opId == allocator.getLastLirInstructionId(block)) { + /* + * Check if spill moves could have been appended at the end of this block, but + * before the branch instruction. So the split child information for this branch + * would be incorrect. + */ + LIRInstruction instr = allocator.getLIR().getLIRforBlock(block).get(allocator.getLIR().getLIRforBlock(block).size() - 1); + if (instr instanceof StandardOp.JumpOp) { + if (allocator.getBlockData(block).liveOut.get(allocator.operandNumber(operand))) { + assert false : String.format( + "can't get split child for the last branch of a block because the information would be incorrect (moves are inserted before the branch in resolveDataFlow) block=%s, instruction=%s, operand=%s", + block, instr, operand); + } + } + } + } + + /* + * Operands are not changed when an interval is split during allocation, so search the + * right interval here. + */ + interval = allocator.splitChildAtOpId(interval, opId, mode); + } + + if (isIllegal(interval.location()) && interval.canMaterialize()) { + assert mode != OperandMode.DEF; + return new ConstantValue(interval.kind(), interval.getMaterializedValue()); + } + return interval.location(); + } + + /** + * @param op + * @param operand + * @param valueMode + * @param flags + * @see InstructionValueProcedure#doValue(LIRInstruction, Value, OperandMode, EnumSet) + */ + private Value debugInfoProcedure(LIRInstruction op, Value operand, OperandMode valueMode, EnumSet flags) { + if (isVirtualStackSlot(operand)) { + return operand; + } + int tempOpId = op.id(); + OperandMode mode = OperandMode.USE; + AbstractBlockBase block = allocator.blockForId(tempOpId); + if (block.getSuccessorCount() == 1 && tempOpId == allocator.getLastLirInstructionId(block)) { + /* + * Generating debug information for the last instruction of a block. If this instruction + * is a branch, spill moves are inserted before this branch and so the wrong operand + * would be returned (spill moves at block boundaries are not considered in the live + * ranges of intervals). + * + * Solution: use the first opId of the branch target block instead. + */ + final LIRInstruction instr = allocator.getLIR().getLIRforBlock(block).get(allocator.getLIR().getLIRforBlock(block).size() - 1); + if (instr instanceof StandardOp.JumpOp) { + if (allocator.getBlockData(block).liveOut.get(allocator.operandNumber(operand))) { + tempOpId = allocator.getFirstLirInstructionId(block.getSuccessors()[0]); + mode = OperandMode.DEF; + } + } + } + + /* + * Get current location of operand. The operand must be live because debug information is + * considered when building the intervals if the interval is not live, colorLirOperand will + * cause an assert on failure. + */ + Value result = colorLirOperand(op, (Variable) operand, mode); + assert !allocator.hasCall(tempOpId) || isStackSlotValue(result) || isJavaConstant(result) || !allocator.isCallerSave(result) : "cannot have caller-save register operands at calls"; + return result; + } + + private void computeDebugInfo(final LIRInstruction op, LIRFrameState info) { + info.forEachState(op, this::debugInfoProcedure); + } + + private void assignLocations(List instructions) { + int numInst = instructions.size(); + boolean hasDead = false; + + for (int j = 0; j < numInst; j++) { + final LIRInstruction op = instructions.get(j); + if (op == null) { + /* + * this can happen when spill-moves are removed in eliminateSpillMoves + */ + hasDead = true; + } else if (assignLocations(op)) { + instructions.set(j, null); + hasDead = true; + } + } + + if (hasDead) { + // Remove null values from the list. + instructions.removeAll(Collections.singleton(null)); + } + } + + /** + * Assigns the operand of an {@link LIRInstruction}. + * + * @param op The {@link LIRInstruction} that should be colored. + * @return {@code true} if the instruction should be deleted. + */ + protected boolean assignLocations(LIRInstruction op) { + assert op != null; + + InstructionValueProcedure assignProc = (inst, operand, mode, flags) -> isVariable(operand) ? colorLirOperand(inst, (Variable) operand, mode) : operand; + // remove useless moves + if (op instanceof MoveOp) { + AllocatableValue result = ((MoveOp) op).getResult(); + if (isVariable(result) && allocator.isMaterialized(result, op.id(), OperandMode.DEF)) { + /* + * This happens if a materializable interval is originally not spilled but then + * kicked out in LinearScanWalker.splitForSpilling(). When kicking out such an + * interval this move operation was already generated. + */ + return true; + } + } + + op.forEachInput(assignProc); + op.forEachAlive(assignProc); + op.forEachTemp(assignProc); + op.forEachOutput(assignProc); + + // compute reference map and debug information + op.forEachState((inst, state) -> computeDebugInfo(inst, state)); + + // remove useless moves + if (op instanceof ValueMoveOp) { + ValueMoveOp move = (ValueMoveOp) op; + if (move.getInput().equals(move.getResult())) { + return true; + } + } + return false; + } + + @SuppressWarnings("try") + private void assignLocations() { + try (Indent indent = Debug.logAndIndent("assign locations")) { + for (AbstractBlockBase block : allocator.sortedBlocks()) { + try (Indent indent2 = Debug.logAndIndent("assign locations in block B%d", block.getId())) { + assignLocations(allocator.getLIR().getLIRforBlock(block)); + } + } + } + } +}