Adds common subexpression elimination prototype

This commit is contained in:
Alexey Andreev 2013-12-12 17:37:18 +04:00
parent d9b7a87784
commit 9faf252a8d
2 changed files with 261 additions and 0 deletions

View File

@ -74,6 +74,10 @@ public class Program {
while (basicBlocks.size() > sz) {
basicBlocks.remove(basicBlocks.size() - 1);
}
sz = 0;
for (int i = 0; i < basicBlocks.size(); ++i) {
}
}
public int variableCount() {

View File

@ -0,0 +1,257 @@
package org.teavm.optimization;
import java.util.HashMap;
import java.util.Map;
import org.teavm.common.Graph;
import org.teavm.common.GraphUtils;
import org.teavm.model.BasicBlock;
import org.teavm.model.Instruction;
import org.teavm.model.MethodHolder;
import org.teavm.model.Program;
import org.teavm.model.instructions.*;
import org.teavm.model.util.ProgramUtils;
/**
*
* @author Alexey Andreev
*/
public class CommonSubexpressionElimination implements MethodOptimization {
private Map<String, Integer> knownValues = new HashMap<>();
private Instruction currentInsn;
private int[] map;
private Program program;
@Override
public void optimize(MethodHolder method) {
program = method.getProgram();
Graph cfg = ProgramUtils.buildControlFlowGraph(method.getProgram());
Graph dom = GraphUtils.buildDominatorGraph(GraphUtils.buildDominatorTree(cfg), cfg.size());
map = new int[program.variableCount()];
for (int i = 0; i < map.length; ++i) {
map[i] = i;
}
int[] stack = new int[cfg.size() * 2];
int top = 0;
for (int i = 0; i < cfg.size(); ++i) {
if (cfg.incomingEdgesCount(i) == 0) {
stack[top++] = i;
}
}
while (top > 0) {
int v = stack[--top];
BasicBlock block = program.basicBlockAt(v);
for (int i = 0; i < block.getInstructions().size(); ++i) {
currentInsn = block.getInstructions().get(i);
currentInsn.acceptVisitor(optimizer);
if (currentInsn != null) {
block.getInstructions().set(i, currentInsn);
} else {
block.getInstructions().remove(i--);
}
}
for (int succ : dom.outgoingEdges(v)) {
stack[top++] = succ;
}
}
program.pack();
}
private void bind(int var, String value) {
Integer known = knownValues.get(value);
if (known != null) {
currentInsn = null;
map[var] = known;
} else {
knownValues.put(value, var);
}
}
private InstructionVisitor optimizer = new InstructionVisitor() {
@Override
public void visit(EmptyInstruction insn) {
}
@Override
public void visit(ClassConstantInstruction insn) {
}
@Override
public void visit(NullConstantInstruction insn) {
}
@Override
public void visit(IntegerConstantInstruction insn) {
}
@Override
public void visit(LongConstantInstruction insn) {
}
@Override
public void visit(FloatConstantInstruction insn) {
}
@Override
public void visit(DoubleConstantInstruction insn) {
}
@Override
public void visit(StringConstantInstruction insn) {
}
@Override
public void visit(BinaryInstruction insn) {
int a = map[insn.getFirstOperand().getIndex()];
int b = map[insn.getSecondOperand().getIndex()];
insn.setFirstOperand(program.variableAt(a));
insn.setSecondOperand(program.variableAt(b));
String value;
switch (insn.getOperation()) {
case ADD:
value = "+";
break;
case SUBTRACT:
value = "-";
break;
case MULTIPLY:
value = "*";
break;
case DIVIDE:
value = "/";
break;
case MODULO:
value = "%";
break;
case COMPARE:
value = "$";
break;
case AND:
value = "&";
break;
case OR:
value = "|";
break;
case XOR:
value = "^";
break;
case SHIFT_LEFT:
value = "<<";
break;
case SHIFT_RIGHT:
value = ">>";
break;
case SHIFT_RIGHT_UNSIGNED:
value = ">>>";
break;
default:
return;
}
value = "@" + a + value + "@" + b;
bind(insn.getReceiver().getIndex(), value);
}
@Override
public void visit(NegateInstruction insn) {
int a = map[insn.getOperand().getIndex()];
insn.setOperand(program.variableAt(a));
bind(insn.getReceiver().getIndex(), "-@" + a);
}
@Override
public void visit(AssignInstruction insn) {
map[insn.getReceiver().getIndex()] = insn.getAssignee().getIndex();
currentInsn = null;
}
@Override
public void visit(CastInstruction insn) {
bind(insn.getReceiver().getIndex(), "@" + insn.getValue().getIndex() + " cast " +
insn.getTargetType());
}
@Override
public void visit(CastNumberInstruction insn) {
bind(insn.getReceiver().getIndex(), "@" + insn.getValue().getIndex() + " cast " +
insn.getTargetType());
}
@Override
public void visit(CastIntegerInstruction insn) {
bind(insn.getReceiver().getIndex(), "@" + insn.getValue().getIndex() + " cast " +
insn.getTargetType() + " " + insn.getDirection());
}
@Override
public void visit(BranchingInstruction insn) {
}
@Override
public void visit(BinaryBranchingInstruction insn) {
}
@Override
public void visit(JumpInstruction insn) {
}
@Override
public void visit(SwitchInstruction insn) {
}
@Override
public void visit(ExitInstruction insn) {
}
@Override
public void visit(RaiseInstruction insn) {
}
@Override
public void visit(ConstructArrayInstruction insn) {
}
@Override
public void visit(ConstructInstruction insn) {
}
@Override
public void visit(ConstructMultiArrayInstruction insn) {
}
@Override
public void visit(GetFieldInstruction insn) {
}
@Override
public void visit(PutFieldInstruction insn) {
}
@Override
public void visit(ArrayLengthInstruction insn) {
}
@Override
public void visit(CloneArrayInstruction insn) {
}
@Override
public void visit(UnwrapArrayInstruction insn) {
}
@Override
public void visit(GetElementInstruction insn) {
}
@Override
public void visit(PutElementInstruction insn) {
}
@Override
public void visit(InvokeInstruction insn) {
}
@Override
public void visit(IsInstanceInstruction insn) {
}
};
}