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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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*
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* 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.
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package org.graalvm.compiler.lir.aarch64;
import static jdk.vm.ci.code.ValueUtil.asAllocatableValue;
import static jdk.vm.ci.code.ValueUtil.asRegister;
import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.HINT;
import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
import java.util.function.Function;
import org.graalvm.compiler.asm.Label;
import org.graalvm.compiler.core.common.NumUtil;
import org.graalvm.compiler.asm.aarch64.AArch64Assembler;
import org.graalvm.compiler.asm.aarch64.AArch64Assembler.ConditionFlag;
import org.graalvm.compiler.asm.aarch64.AArch64Assembler.ExtendType;
import org.graalvm.compiler.asm.aarch64.AArch64MacroAssembler;
import org.graalvm.compiler.code.CompilationResult.JumpTable;
import org.graalvm.compiler.core.common.LIRKind;
import org.graalvm.compiler.core.common.calc.Condition;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.lir.ConstantValue;
import org.graalvm.compiler.lir.LIRInstructionClass;
import org.graalvm.compiler.lir.LabelRef;
import org.graalvm.compiler.lir.Opcode;
import org.graalvm.compiler.lir.StandardOp;
import org.graalvm.compiler.lir.SwitchStrategy;
import org.graalvm.compiler.lir.SwitchStrategy.BaseSwitchClosure;
import org.graalvm.compiler.lir.Variable;
import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
import jdk.vm.ci.aarch64.AArch64Kind;
import jdk.vm.ci.code.Register;
import jdk.vm.ci.meta.Constant;
import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.Value;
public class AArch64ControlFlow {
/**
* Compares integer register to 0 and branches if condition is true. Condition may only be equal
* or non-equal.
*/
// TODO (das) where do we need this?
// public static class CompareAndBranchOp extends AArch64LIRInstruction implements
// StandardOp.BranchOp {
// private final ConditionFlag condition;
// private final LabelRef destination;
// @Use({REG}) private Value x;
//
// public CompareAndBranchOp(Condition condition, LabelRef destination, Value x) {
// assert condition == Condition.EQ || condition == Condition.NE;
// assert ARMv8.isGpKind(x.getKind());
// this.condition = condition == Condition.EQ ? ConditionFlag.EQ : ConditionFlag.NE;
// this.destination = destination;
// this.x = x;
// }
//
// @Override
// public void emitCode(CompilationResultBuilder crb, ARMv8MacroAssembler masm) {
// int size = ARMv8.bitsize(x.getKind());
// if (condition == ConditionFlag.EQ) {
// masm.cbz(size, asRegister(x), destination.label());
// } else {
// masm.cbnz(size, asRegister(x), destination.label());
// }
// }
// }
public static class BranchOp extends AArch64BlockEndOp implements StandardOp.BranchOp {
public static final LIRInstructionClass<BranchOp> TYPE = LIRInstructionClass.create(BranchOp.class);
private final AArch64Assembler.ConditionFlag condition;
private final LabelRef trueDestination;
private final LabelRef falseDestination;
private final double trueDestinationProbability;
public BranchOp(AArch64Assembler.ConditionFlag condition, LabelRef trueDestination, LabelRef falseDestination, double trueDestinationProbability) {
super(TYPE);
this.condition = condition;
this.trueDestination = trueDestination;
this.falseDestination = falseDestination;
this.trueDestinationProbability = trueDestinationProbability;
}
@Override
public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
/*
* Explanation: Depending on what the successor edge is, we can use the fall-through to
* optimize the generated code. If neither is a successor edge, use the branch
* probability to try to take the conditional jump as often as possible to avoid
* executing two instructions instead of one.
*/
if (crb.isSuccessorEdge(trueDestination)) {
masm.branchConditionally(condition.negate(), falseDestination.label());
} else if (crb.isSuccessorEdge(falseDestination)) {
masm.branchConditionally(condition, trueDestination.label());
} else if (trueDestinationProbability < 0.5) {
masm.branchConditionally(condition.negate(), falseDestination.label());
masm.jmp(trueDestination.label());
} else {
masm.branchConditionally(condition, trueDestination.label());
masm.jmp(falseDestination.label());
}
}
}
@Opcode("CMOVE")
public static class CondMoveOp extends AArch64LIRInstruction {
public static final LIRInstructionClass<CondMoveOp> TYPE = LIRInstructionClass.create(CondMoveOp.class);
@Def protected Value result;
@Use protected Value trueValue;
@Use protected Value falseValue;
private final AArch64Assembler.ConditionFlag condition;
public CondMoveOp(Variable result, AArch64Assembler.ConditionFlag condition, Value trueValue, Value falseValue) {
super(TYPE);
assert trueValue.getPlatformKind() == falseValue.getPlatformKind() && trueValue.getPlatformKind() == result.getPlatformKind();
this.result = result;
this.condition = condition;
this.trueValue = trueValue;
this.falseValue = falseValue;
}
@Override
public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
AArch64Kind kind = (AArch64Kind) trueValue.getPlatformKind();
int size = kind.getSizeInBytes() * Byte.SIZE;
if (kind.isInteger()) {
masm.cmov(size, asRegister(result), asRegister(trueValue), asRegister(falseValue), condition);
} else {
masm.fcmov(size, asRegister(result), asRegister(trueValue), asRegister(falseValue), condition);
}
}
}
public static class StrategySwitchOp extends AArch64BlockEndOp implements StandardOp.BlockEndOp {
public static final LIRInstructionClass<StrategySwitchOp> TYPE = LIRInstructionClass.create(StrategySwitchOp.class);
private final Constant[] keyConstants;
protected final SwitchStrategy strategy;
private final Function<Condition, ConditionFlag> converter;
private final LabelRef[] keyTargets;
private final LabelRef defaultTarget;
@Alive protected Value key;
// TODO (das) This could be optimized: We only need the scratch register in case of a
// datapatch, or too large immediates.
@Temp protected Value scratch;
public StrategySwitchOp(SwitchStrategy strategy, LabelRef[] keyTargets, LabelRef defaultTarget, Value key, Value scratch,
Function<Condition, ConditionFlag> converter) {
this(TYPE, strategy, keyTargets, defaultTarget, key, scratch, converter);
}
protected StrategySwitchOp(LIRInstructionClass<? extends StrategySwitchOp> c, SwitchStrategy strategy, LabelRef[] keyTargets, LabelRef defaultTarget, Value key, Value scratch,
Function<Condition, ConditionFlag> converter) {
super(c);
this.strategy = strategy;
this.converter = converter;
this.keyConstants = strategy.getKeyConstants();
this.keyTargets = keyTargets;
this.defaultTarget = defaultTarget;
this.key = key;
this.scratch = scratch;
assert keyConstants.length == keyTargets.length;
assert keyConstants.length == strategy.keyProbabilities.length;
}
@Override
public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
strategy.run(new SwitchClosure(asRegister(key), crb, masm));
}
public class SwitchClosure extends BaseSwitchClosure {
protected final Register keyRegister;
protected final CompilationResultBuilder crb;
protected final AArch64MacroAssembler masm;
protected SwitchClosure(Register keyRegister, CompilationResultBuilder crb, AArch64MacroAssembler masm) {
super(crb, masm, keyTargets, defaultTarget);
this.keyRegister = keyRegister;
this.crb = crb;
this.masm = masm;
}
protected void emitComparison(Constant c) {
JavaConstant jc = (JavaConstant) c;
ConstantValue constVal = new ConstantValue(LIRKind.value(key.getPlatformKind()), c);
switch (jc.getJavaKind()) {
case Int:
long lc = jc.asLong();
assert NumUtil.isInt(lc);
emitCompare(crb, masm, key, scratch, constVal);
break;
case Long:
emitCompare(crb, masm, key, scratch, constVal);
break;
case Object:
emitCompare(crb, masm, key, scratch, constVal);
break;
default:
throw new GraalError("switch only supported for int, long and object");
}
}
@Override
protected void conditionalJump(int index, Condition condition, Label target) {
emitComparison(keyConstants[index]);
masm.branchConditionally(converter.apply(condition), target);
}
}
}
public static final class TableSwitchOp extends AArch64BlockEndOp {
public static final LIRInstructionClass<TableSwitchOp> TYPE = LIRInstructionClass.create(TableSwitchOp.class);
private final int lowKey;
private final LabelRef defaultTarget;
private final LabelRef[] targets;
@Use protected Value index;
@Temp({REG, HINT}) protected Value idxScratch;
@Temp protected Value scratch;
public TableSwitchOp(final int lowKey, final LabelRef defaultTarget, final LabelRef[] targets, Value index, Variable scratch, Variable idxScratch) {
super(TYPE);
this.lowKey = lowKey;
this.defaultTarget = defaultTarget;
this.targets = targets;
this.index = index;
this.scratch = scratch;
this.idxScratch = idxScratch;
}
@Override
public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
Register indexReg = asRegister(index, AArch64Kind.DWORD);
Register idxScratchReg = asRegister(idxScratch, AArch64Kind.DWORD);
Register scratchReg = asRegister(scratch, AArch64Kind.QWORD);
// Compare index against jump table bounds
int highKey = lowKey + targets.length - 1;
masm.sub(32, idxScratchReg, indexReg, lowKey);
masm.cmp(32, idxScratchReg, highKey - lowKey);
// Jump to default target if index is not within the jump table
if (defaultTarget != null) {
masm.branchConditionally(ConditionFlag.HI, defaultTarget.label());
}
Label jumpTable = new Label();
masm.adr(scratchReg, jumpTable);
masm.add(64, scratchReg, scratchReg, idxScratchReg, ExtendType.UXTW, 2);
masm.jmp(scratchReg);
masm.bind(jumpTable);
// emit jump table entries
for (LabelRef target : targets) {
masm.jmp(target.label());
}
JumpTable jt = new JumpTable(jumpTable.position(), lowKey, highKey - 1, 4);
crb.compilationResult.addAnnotation(jt);
}
}
private static void emitCompare(CompilationResultBuilder crb, AArch64MacroAssembler masm, Value key, Value scratchValue, ConstantValue c) {
long imm = c.getJavaConstant().asLong();
final int size = key.getPlatformKind().getSizeInBytes() * Byte.SIZE;
if (AArch64MacroAssembler.isComparisonImmediate(imm)) {
masm.cmp(size, asRegister(key), (int) imm);
} else {
AArch64Move.move(crb, masm, asAllocatableValue(scratchValue), c);
masm.cmp(size, asRegister(key), asRegister(scratchValue));
}
}
}