1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.dx.ssa.back; 18 19 import com.android.dx.ssa.BasicRegisterMapper; 20 import com.android.dx.ssa.RegisterMapper; 21 import com.android.dx.ssa.SsaMethod; 22 23 import java.util.BitSet; 24 import java.util.ArrayList; 25 26 /** 27 * A register allocator that maps SSA register n to Rop register 2*n, 28 * essentially preserving the original mapping and remaining agnostic 29 * about normal or wide categories. Used for debugging. 30 */ 31 public class NullRegisterAllocator extends RegisterAllocator { 32 /** {@inheritDoc} */ NullRegisterAllocator(SsaMethod ssaMeth, InterferenceGraph interference)33 public NullRegisterAllocator(SsaMethod ssaMeth, 34 InterferenceGraph interference) { 35 super(ssaMeth, interference); 36 } 37 38 /** {@inheritDoc} */ 39 @Override wantsParamsMovedHigh()40 public boolean wantsParamsMovedHigh() { 41 // We're not smart enough for this. 42 return false; 43 } 44 45 /** {@inheritDoc} */ 46 @Override allocateRegisters()47 public RegisterMapper allocateRegisters() { 48 int oldRegCount = ssaMeth.getRegCount(); 49 50 BasicRegisterMapper mapper = new BasicRegisterMapper(oldRegCount); 51 52 for (int i = 0; i < oldRegCount; i++) { 53 mapper.addMapping(i, i*2, 2); 54 } 55 56 return mapper; 57 } 58 } 59