com.android.dx.rop.code.TranslationAdvice Maven / Gradle / Ivy
/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.dx.rop.code;
/**
* Interface for "advice" passed from the late stage of translation back
* to the early stage. This allows for the final target architecture to
* exert its influence early in the translation process without having
* the early stage code be explicitly tied to the target.
*/
public interface TranslationAdvice {
/**
* Returns an indication of whether the target can directly represent an
* instruction with the given opcode operating on the given arguments,
* where the last source argument is used as a constant. (That is, the
* last argument must have a type which indicates it is a known constant.)
* The instruction associated must have exactly two sources.
*
* @param opcode {@code non-null;} the opcode
* @param sourceA {@code non-null;} the first source
* @param sourceB {@code non-null;} the second source
* @return {@code true} iff the target can represent the operation
* using a constant for the last argument
*/
public boolean hasConstantOperation(Rop opcode,
RegisterSpec sourceA, RegisterSpec sourceB);
/**
* Returns true if the translation target requires the sources of the
* specified opcode to be in order and contiguous (eg, for an invoke-range)
*
* @param opcode {@code non-null;} opcode
* @param sources {@code non-null;} source list
* @return {@code true} iff the target requires the sources to be
* in order and contiguous.
*/
public boolean requiresSourcesInOrder(Rop opcode, RegisterSpecList sources);
/**
* Gets the maximum register width that can be represented optimally.
* For example, Dex bytecode does not have instruction forms that take
* register numbers larger than 15 for all instructions so
* DexTranslationAdvice returns 15 here.
*
* @return register count noted above
*/
public int getMaxOptimalRegisterCount();
}