1 /* 2 * Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package jdk.vm.ci.code; 24 25 import java.util.*; 26 27 /** 28 * A collection of register attributes. The specific attribute values for a register may be local to 29 * a compilation context. For example, a {@link RegisterConfig} in use during a compilation will 30 * determine which registers are callee saved. 31 */ 32 public class RegisterAttributes { 33 34 private final boolean callerSave; 35 private final boolean calleeSave; 36 private final boolean allocatable; 37 38 public RegisterAttributes(boolean isCallerSave, boolean isCalleeSave, boolean isAllocatable) { 39 this.callerSave = isCallerSave; 40 this.calleeSave = isCalleeSave; 41 this.allocatable = isAllocatable; 42 } 43 44 public static final RegisterAttributes NONE = new RegisterAttributes(false, false, false); 45 46 /** 47 * Creates a map from register {@linkplain Register#number numbers} to register 48 * {@linkplain RegisterAttributes attributes} for a given register configuration and set of 49 * registers. 50 * 51 * @param registerConfig a register configuration 52 * @param registers a set of registers 53 * @return an array whose length is the max register number in {@code registers} plus 1. An 54 * element at index i holds the attributes of the register whose number is i. 55 */ 56 public static RegisterAttributes[] createMap(RegisterConfig registerConfig, Register[] registers) { 57 RegisterAttributes[] map = new RegisterAttributes[registers.length]; 58 for (Register reg : registers) { 59 if (reg != null) { 60 Register[] csr = registerConfig.getCalleeSaveRegisters(); 61 RegisterAttributes attr = new RegisterAttributes(Arrays.asList(registerConfig.getCallerSaveRegisters()).contains(reg), csr == null ? false : Arrays.asList(csr).contains(reg), 62 Arrays.asList(registerConfig.getAllocatableRegisters()).contains(reg)); 63 if (map.length <= reg.number) { 64 map = Arrays.copyOf(map, reg.number + 1); 65 } 66 map[reg.number] = attr; 67 } 68 } 69 for (int i = 0; i < map.length; i++) { 70 if (map[i] == null) { 71 map[i] = NONE; 72 } 73 } 74 return map; 75 } 76 77 /** 78 * @return Denotes a register that is available for use by a register allocator. 79 */ 80 public boolean isAllocatable() { 81 return allocatable; 82 } 83 84 /** 85 * @return Denotes a register whose value preservation (if required) across a call is the 86 * responsibility of the callee. 87 */ 88 public boolean isCalleeSave() { 89 return calleeSave; 90 } 91 92 /** 93 * @return Denotes a register whose value preservation (if required) across a call is the 94 * responsibility of the caller. 95 */ 96 public boolean isCallerSave() { 97 return callerSave; 98 } 99 }