| /* |
| * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package jdk.vm.ci.code; |
| |
| import jdk.vm.ci.meta.AllocatableValue; |
| import jdk.vm.ci.meta.ValueKind; |
| |
| /** |
| * Represents a compiler spill slot or an outgoing stack-based argument in a method's frame or an |
| * incoming stack-based argument in a method's {@linkplain #isInCallerFrame() caller's frame}. |
| */ |
| public final class StackSlot extends AllocatableValue { |
| |
| private final int offset; |
| private final boolean addFrameSize; |
| |
| /** |
| * Gets a {@link StackSlot} instance representing a stack slot at a given index holding a value |
| * of a given kind. |
| * |
| * @param kind The kind of the value stored in the stack slot. |
| * @param offset The offset of the stack slot (in bytes) |
| * @param addFrameSize Specifies if the offset is relative to the stack pointer, or the |
| * beginning of the frame (stack pointer + total frame size). |
| */ |
| public static StackSlot get(ValueKind<?> kind, int offset, boolean addFrameSize) { |
| assert addFrameSize || offset >= 0; |
| return new StackSlot(kind, offset, addFrameSize); |
| } |
| |
| /** |
| * Private constructor to enforce use of {@link #get(ValueKind, int, boolean)} so that a cache |
| * can be used. |
| */ |
| private StackSlot(ValueKind<?> kind, int offset, boolean addFrameSize) { |
| super(kind); |
| this.offset = offset; |
| this.addFrameSize = addFrameSize; |
| } |
| |
| /** |
| * Gets the offset of this stack slot, relative to the stack pointer. |
| * |
| * @return The offset of this slot (in bytes). |
| */ |
| public int getOffset(int totalFrameSize) { |
| assert totalFrameSize > 0 || !addFrameSize; |
| int result = offset + (addFrameSize ? totalFrameSize : 0); |
| assert result >= 0; |
| return result; |
| } |
| |
| public boolean isInCallerFrame() { |
| return addFrameSize && offset >= 0; |
| } |
| |
| public int getRawOffset() { |
| return offset; |
| } |
| |
| public boolean getRawAddFrameSize() { |
| return addFrameSize; |
| } |
| |
| @Override |
| public String toString() { |
| if (!addFrameSize) { |
| return "out:" + offset + getKindSuffix(); |
| } else if (offset >= 0) { |
| return "in:" + offset + getKindSuffix(); |
| } else { |
| return "stack:" + (-offset) + getKindSuffix(); |
| } |
| } |
| |
| /** |
| * Gets this stack slot used to pass an argument from the perspective of a caller. |
| */ |
| public StackSlot asOutArg() { |
| assert offset >= 0; |
| if (addFrameSize) { |
| return get(getValueKind(), offset, false); |
| } |
| return this; |
| } |
| |
| /** |
| * Gets this stack slot used to pass an argument from the perspective of a callee. |
| */ |
| public StackSlot asInArg() { |
| assert offset >= 0; |
| if (!addFrameSize) { |
| return get(getValueKind(), offset, true); |
| } |
| return this; |
| } |
| |
| @Override |
| public int hashCode() { |
| final int prime = 37; |
| int result = super.hashCode(); |
| result = prime * result + (addFrameSize ? 1231 : 1237); |
| result = prime * result + offset; |
| return result; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj instanceof StackSlot) { |
| StackSlot other = (StackSlot) obj; |
| return super.equals(obj) && addFrameSize == other.addFrameSize && offset == other.offset; |
| } |
| return false; |
| } |
| } |