/*
* This file is part of the Jikes RVM project (http://jikesrvm.org).
*
* This file is licensed to You under the Eclipse Public License (EPL);
* You may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.opensource.org/licenses/eclipse-1.0.php
*
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.
*/
package org.jikesrvm.osr;
import org.jikesrvm.compilers.opt.OptOptions;
import org.jikesrvm.compilers.opt.driver.CompilerPhase;
import org.jikesrvm.compilers.opt.driver.OptConstants;
import org.jikesrvm.compilers.opt.inlining.InlineSequence;
import org.jikesrvm.compilers.opt.ir.IR;
import org.jikesrvm.compilers.opt.ir.Instruction;
import org.jikesrvm.compilers.opt.ir.InstructionEnumeration;
/**
* OSR_AdjustBCIndex is an optimizing phase performed on HIR.
* It adjust the byte code index of instructions from specialized
* byte code to its original byte code.
*/
public class AdjustBCIndexes extends CompilerPhase {
public final boolean shouldPerform(OptOptions options) {
return true;
}
/**
* Return this instance of this phase. This phase contains no
* per-compilation instance fields.
* @param ir not used
* @return this
*/
public CompilerPhase newExecution(IR ir) {
return this;
}
public final String getName() { return "AdjustBytecodeIndexes"; }
public final void perform(IR ir) {
if (!ir.method.isForOsrSpecialization()) return;
int offset = ir.method.getOsrPrologueLength();
for (InstructionEnumeration ie = ir.forwardInstrEnumerator(); ie.hasMoreElements();) {
Instruction s = ie.next();
if ((s.position != null) && (s.position.method != ir.method)) {
// also adjust InlineSequence of the direct callee
InlineSequence caller = s.position.caller;
if ((caller != null) && (caller.method == ir.method)) {
// adjust the call site's bcIndex
s.position.bcIndex -= offset;
}
continue;
}
if (s.bcIndex >= offset) {
s.bcIndex -= offset;
} else if (s.bcIndex >= 0) {
s.bcIndex = OptConstants.OSR_PROLOGUE;
}
}
}
}