1 /*
2 * Copyright (c) 2015, 2016, 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
24 package org.graalvm.compiler.core.amd64;
25
26 import jdk.vm.ci.meta.JavaConstant;
27
28 import org.graalvm.compiler.core.common.NumUtil;
29 import org.graalvm.compiler.asm.amd64.AMD64Address.Scale;
30 import org.graalvm.compiler.core.common.type.IntegerStamp;
31 import org.graalvm.compiler.nodes.ValueNode;
32 import org.graalvm.compiler.nodes.calc.AddNode;
33 import org.graalvm.compiler.nodes.calc.LeftShiftNode;
34 import org.graalvm.compiler.nodes.calc.ZeroExtendNode;
35 import org.graalvm.compiler.nodes.memory.address.AddressNode;
36 import org.graalvm.compiler.phases.common.AddressLoweringPhase.AddressLowering;
37
38 public class AMD64AddressLowering extends AddressLowering {
39
40 @Override
41 public AddressNode lower(ValueNode address) {
42 return lower(address, null);
43 }
44
45 @Override
46 public AddressNode lower(ValueNode base, ValueNode offset) {
47 AMD64AddressNode ret = new AMD64AddressNode(base, offset);
48 boolean changed;
49 do {
50 changed = improve(ret);
51 } while (changed);
52 return base.graph().unique(ret);
53 }
54
55 protected boolean improve(AMD64AddressNode ret) {
56 ValueNode newBase = improveInput(ret, ret.getBase(), 0);
57 if (newBase != ret.getBase()) {
58 ret.setBase(newBase);
59 return true;
60 }
61
62 ValueNode newIdx = improveInput(ret, ret.getIndex(), ret.getScale().log2);
63 if (newIdx != ret.getIndex()) {
64 ret.setIndex(newIdx);
65 return true;
66 }
67
68 if (ret.getIndex() instanceof LeftShiftNode) {
69 LeftShiftNode shift = (LeftShiftNode) ret.getIndex();
70 if (shift.getY().isConstant()) {
71 int amount = ret.getScale().log2 + shift.getY().asJavaConstant().asInt();
72 Scale scale = Scale.fromShift(amount);
73 if (scale != null) {
74 ret.setIndex(shift.getX());
75 ret.setScale(scale);
76 return true;
77 }
78 }
79 }
80
81 if (ret.getScale() == Scale.Times1) {
82 if (ret.getBase() == null || ret.getIndex() == null) {
83 if (ret.getBase() instanceof AddNode) {
84 AddNode add = (AddNode) ret.getBase();
85 ret.setBase(add.getX());
86 ret.setIndex(add.getY());
87 return true;
88 } else if (ret.getIndex() instanceof AddNode) {
89 AddNode add = (AddNode) ret.getIndex();
90 ret.setBase(add.getX());
91 ret.setIndex(add.getY());
92 return true;
93 }
94 }
95
96 if (ret.getBase() instanceof LeftShiftNode && !(ret.getIndex() instanceof LeftShiftNode)) {
97 ValueNode tmp = ret.getBase();
98 ret.setBase(ret.getIndex());
99 ret.setIndex(tmp);
100 return true;
101 }
102 }
103
104 return false;
105 }
106
107 private static ValueNode improveInput(AMD64AddressNode address, ValueNode node, int shift) {
108 if (node == null) {
109 return null;
110 }
111
112 JavaConstant c = node.asJavaConstant();
113 if (c != null) {
114 return improveConstDisp(address, node, c, null, shift);
115 } else {
116 if (node.stamp() instanceof IntegerStamp && ((IntegerStamp) node.stamp()).getBits() == 64) {
117 if (node instanceof ZeroExtendNode) {
118 if (((ZeroExtendNode) node).getInputBits() == 32) {
119 /*
120 * We can just swallow a zero-extend from 32 bit to 64 bit because the upper
121 * half of the register will always be zero.
122 */
123 return ((ZeroExtendNode) node).getValue();
124 }
125 } else if (node instanceof AddNode) {
126 AddNode add = (AddNode) node;
127 if (add.getX().isConstant()) {
128 return improveConstDisp(address, node, add.getX().asJavaConstant(), add.getY(), shift);
129 } else if (add.getY().isConstant()) {
130 return improveConstDisp(address, node, add.getY().asJavaConstant(), add.getX(), shift);
131 }
132 }
133 }
134 }
135
136 return node;
137 }
138
139 private static ValueNode improveConstDisp(AMD64AddressNode address, ValueNode original, JavaConstant c, ValueNode other, int shift) {
140 if (c.getJavaKind().isNumericInteger()) {
141 long disp = address.getDisplacement();
142 disp += c.asLong() << shift;
143 if (NumUtil.isInt(disp)) {
144 address.setDisplacement((int) disp);
145 return other;
146 }
147 }
148 return original;
149 }
150 }