/*
* Copyright (c) 2015, 2016, 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.trace;
import static org.graalvm.compiler.lir.LIRValueUtil.asVariable;
import static org.graalvm.compiler.lir.LIRValueUtil.isVariable;
import static org.graalvm.compiler.lir.alloc.trace.TraceUtil.isTrivialTrace;
import java.util.EnumSet;
import org.graalvm.compiler.core.common.alloc.Trace;
import org.graalvm.compiler.core.common.alloc.TraceBuilderResult;
import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
import org.graalvm.compiler.lir.LIR;
import org.graalvm.compiler.lir.LIRInstruction.OperandFlag;
import org.graalvm.compiler.lir.LIRInstruction.OperandMode;
import org.graalvm.compiler.lir.StandardOp.JumpOp;
import org.graalvm.compiler.lir.StandardOp.LabelOp;
import org.graalvm.compiler.lir.ValueProcedure;
import org.graalvm.compiler.lir.gen.LIRGenerationResult;
import org.graalvm.compiler.lir.ssa.SSAUtil;
import jdk.vm.ci.code.TargetDescription;
import jdk.vm.ci.meta.Value;
/**
* Allocates a trivial trace i.e. a trace consisting of a single block with no instructions other
* than the {@link LabelOp} and the {@link JumpOp}.
*/
final class TrivialTraceAllocator extends TraceAllocationPhase<TraceAllocationPhase.TraceAllocationContext> {
@Override
protected void run(TargetDescription target, LIRGenerationResult lirGenRes, Trace trace, TraceAllocationContext context) {
LIR lir = lirGenRes.getLIR();
TraceBuilderResult resultTraces = context.resultTraces;
assert isTrivialTrace(lir, trace) : "Not a trivial trace! " + trace;
AbstractBlockBase<?> block = trace.getBlocks()[0];
AbstractBlockBase<?> pred = TraceUtil.getBestTraceInterPredecessor(resultTraces, block);
Value[] variableMap = new Value[lir.numVariables()];
GlobalLivenessInfo livenessInfo = context.livenessInfo;
collectMapping(block, pred, livenessInfo, variableMap);
assignLocations(lir, block, livenessInfo, variableMap);
}
/**
* Collects the mapping from variable to location. Additionally the
* {@link GlobalLivenessInfo#setInLocations incoming location array} is set.
*/
private static void collectMapping(AbstractBlockBase<?> block, AbstractBlockBase<?> pred, GlobalLivenessInfo livenessInfo, Value[] variableMap) {
final int[] blockIn = livenessInfo.getBlockIn(block);
final Value[] predLocOut = livenessInfo.getOutLocation(pred);
final Value[] locationIn = new Value[blockIn.length];
for (int i = 0; i < blockIn.length; i++) {
int varNum = blockIn[i];
if (varNum >= 0) {
Value location = predLocOut[i];
variableMap[varNum] = location;
locationIn[i] = location;
} else {
locationIn[i] = Value.ILLEGAL;
}
}
livenessInfo.setInLocations(block, locationIn);
}
/**
* Assigns the outgoing locations according to the {@link #collectMapping variable mapping}.
*/
private static void assignLocations(LIR lir, AbstractBlockBase<?> block, GlobalLivenessInfo livenessInfo, Value[] variableMap) {
final int[] blockOut = livenessInfo.getBlockOut(block);
final Value[] locationOut = new Value[blockOut.length];
for (int i = 0; i < blockOut.length; i++) {
int varNum = blockOut[i];
locationOut[i] = variableMap[varNum];
}
livenessInfo.setOutLocations(block, locationOut);
// handle outgoing phi values
ValueProcedure outputConsumer = new ValueProcedure() {
@Override
public Value doValue(Value value, OperandMode mode, EnumSet<OperandFlag> flags) {
if (isVariable(value)) {
return variableMap[asVariable(value).index];
}
return value;
}
};
JumpOp jump = SSAUtil.phiOut(lir, block);
// Jumps have only alive values (outgoing phi values)
jump.forEachAlive(outputConsumer);
}
}