1 /* 2 * Copyright (c) 2009, 2012, 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 static jdk.vm.ci.code.ValueUtil.*; 26 27 import jdk.vm.ci.meta.*; 28 29 /** 30 * A calling convention describes the locations in which the arguments for a call are placed and the 31 * location in which the return value is placed if the call is not void. 32 */ 33 public class CallingConvention { 34 35 /** 36 * Constants denoting the type of a call for which a calling convention is requested. 37 */ 38 public enum Type { 39 /** 40 * A request for the outgoing argument locations at a call site to Java code. 41 */ 42 JavaCall(true), 43 44 /** 45 * A request for the incoming argument locations. 46 */ 47 JavaCallee(false), 48 49 /** 50 * A request for the outgoing argument locations at a call site to external native code that 51 * complies with the platform ABI. 52 */ 53 NativeCall(true); 54 55 /** 56 * Determines if this is a request for the outgoing argument locations at a call site. 57 */ 58 public final boolean out; 59 60 public static final Type[] VALUES = values(); 61 62 private Type(boolean out) { 63 this.out = out; 64 } 65 } 66 67 /** 68 * The amount of stack space (in bytes) required for the stack-based arguments of the call. 69 */ 70 private final int stackSize; 71 72 private final AllocatableValue returnLocation; 73 74 /** 75 * The ordered locations in which the arguments are placed. 76 */ 77 private final AllocatableValue[] argumentLocations; 78 79 /** 80 * Creates a description of the registers and stack locations used by a call. 81 * 82 * @param stackSize amount of stack space (in bytes) required for the stack-based arguments of 83 * the call 84 * @param returnLocation the location for the return value or {@link Value#ILLEGAL} if a void 85 * call 86 * @param argumentLocations the ordered locations in which the arguments are placed 87 */ 88 public CallingConvention(int stackSize, AllocatableValue returnLocation, AllocatableValue... argumentLocations) { 89 assert argumentLocations != null; 90 assert returnLocation != null; 91 this.argumentLocations = argumentLocations; 92 this.stackSize = stackSize; 93 this.returnLocation = returnLocation; 94 assert verify(); 95 } 96 97 /** 98 * Gets the location for the return value or {@link Value#ILLEGAL} if a void call. 99 */ 100 public AllocatableValue getReturn() { 101 return returnLocation; 102 } 103 104 /** 105 * Gets the location for the {@code index}'th argument. 106 */ 107 public AllocatableValue getArgument(int index) { 108 return argumentLocations[index]; 109 } 110 111 /** 112 * Gets the amount of stack space (in bytes) required for the stack-based arguments of the call. 113 */ 114 public int getStackSize() { 115 return stackSize; 116 } 117 118 /** 119 * Gets the number of locations required for the arguments. 120 */ 121 public int getArgumentCount() { 122 return argumentLocations.length; 123 } 124 125 /** 126 * Gets the locations required for the arguments. 127 */ 128 public AllocatableValue[] getArguments() { 129 if (argumentLocations.length == 0) { 130 return argumentLocations; 131 } 132 return argumentLocations.clone(); 133 } 134 135 @Override 136 public String toString() { 137 StringBuilder sb = new StringBuilder(); 138 sb.append("CallingConvention["); 139 String sep = ""; 140 for (Value op : argumentLocations) { 141 sb.append(sep).append(op); 142 sep = ", "; 143 } 144 if (!returnLocation.equals(Value.ILLEGAL)) { 145 sb.append(" -> ").append(returnLocation); 146 } 147 sb.append("]"); 148 return sb.toString(); 149 } 150 151 private boolean verify() { 152 for (int i = 0; i < argumentLocations.length; i++) { 153 Value location = argumentLocations[i]; 154 assert isStackSlot(location) || isAllocatableValue(location); 155 } 156 return true; 157 } 158 }