1/* 2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2017, Red Hat Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25package org.graalvm.compiler.core.aarch64; 26 27import jdk.vm.ci.aarch64.AArch64Kind; 28import jdk.vm.ci.meta.JavaConstant; 29import org.graalvm.compiler.asm.aarch64.AArch64Address; 30import org.graalvm.compiler.core.common.LIRKind; 31import org.graalvm.compiler.core.common.NumUtil; 32import org.graalvm.compiler.core.common.type.Stamp; 33import org.graalvm.compiler.nodes.ValueNode; 34import org.graalvm.compiler.nodes.calc.AddNode; 35import org.graalvm.compiler.nodes.memory.address.AddressNode; 36import org.graalvm.compiler.nodes.memory.address.OffsetAddressNode; 37import org.graalvm.compiler.nodes.memory.address.RawAddressNode; 38import org.graalvm.compiler.phases.common.AddressLoweringByUsePhase; 39 40public class AArch64AddressLoweringByUse extends AddressLoweringByUsePhase.AddressLoweringByUse { 41 private AArch64LIRKindTool kindtool; 42 43 public AArch64AddressLoweringByUse(AArch64LIRKindTool kindtool) { 44 this.kindtool = kindtool; 45 } 46 47 @Override 48 public AddressNode lower(ValueNode use, Stamp stamp, AddressNode address) { 49 if (address instanceof RawAddressNode) { 50 return doLower(stamp, address.getBase(), null); 51 } else if (address instanceof OffsetAddressNode) { 52 OffsetAddressNode offsetAddress = (OffsetAddressNode) address; 53 return doLower(stamp, offsetAddress.getBase(), offsetAddress.getOffset()); 54 } else { 55 // must be an already transformed AArch64AddressNode 56 return address; 57 } 58 } 59 60 @Override 61 public AddressNode lower(AddressNode address) { 62 return lower(null, null, address); 63 } 64 65 private AddressNode doLower(Stamp stamp, ValueNode base, ValueNode index) { 66 AArch64AddressNode ret = new AArch64AddressNode(base, index); 67 AArch64Kind aarch64Kind = (stamp == null ? null : getAArch64Kind(stamp)); 68 69 // improve the address as much as possible 70 boolean changed; 71 do { 72 changed = improve(aarch64Kind, ret); 73 } while (changed); 74 75 // avoid duplicates 76 return base.graph().unique(ret); 77 } 78 79 protected boolean improve(AArch64Kind kind, AArch64AddressNode ret) { 80 AArch64Address.AddressingMode mode = ret.getAddressingMode(); 81 // if we have already set a displacement or set to base only mode then we are done 82 if (isDisplacementMode(mode) || isBaseOnlyMode(mode)) { 83 return false; 84 } 85 ValueNode base = ret.getBase(); 86 ValueNode index = ret.getIndex(); 87 88 // avoid a constant or null base if possible 89 if (base == null) { 90 ret.setBase(index); 91 ret.setIndex(base); 92 return true; 93 } 94 // make sure any integral JavaConstant 95 // is the index rather than the base 96 // strictly we don't need the conditions on index 97 // as we ought not to see two JavaConstant values 98 if (base.isJavaConstant() && base.asJavaConstant().getJavaKind().isNumericInteger() && 99 index != null && !index.isJavaConstant()) { 100 ret.setBase(index); 101 ret.setIndex(base); 102 return true; 103 } 104 105 // if the base is an add then move it up 106 if (index == null && base instanceof AddNode) { 107 AddNode add = (AddNode) base; 108 ret.setBase(add.getX()); 109 ret.setIndex(add.getY()); 110 return true; 111 } 112 113 // we can try to fold a JavaConstant index into a displacement 114 if (index != null && index.isJavaConstant()) { 115 JavaConstant javaConstant = index.asJavaConstant(); 116 if (javaConstant.getJavaKind().isNumericInteger()) { 117 long disp = javaConstant.asLong(); 118 mode = immediateMode(kind, disp); 119 if (isDisplacementMode(mode)) { 120 index = null; 121 // we can fold this in as a displacement 122 // but first see if we can pull up any additional 123 // constants added into the base 124 boolean tryNextBase = (base instanceof AddNode); 125 while (tryNextBase) { 126 AddNode add = (AddNode) base; 127 tryNextBase = false; 128 ValueNode child = add.getX(); 129 if (child.isJavaConstant() && child.asJavaConstant().getJavaKind().isNumericInteger()) { 130 long newDisp = disp + child.asJavaConstant().asLong(); 131 AArch64Address.AddressingMode newMode = immediateMode(kind, newDisp); 132 if (newMode != AArch64Address.AddressingMode.REGISTER_OFFSET) { 133 disp = newDisp; 134 mode = newMode; 135 base = add.getY(); 136 ret.setBase(base); 137 tryNextBase = (base instanceof AddNode); 138 } 139 } else { 140 child = add.getY(); 141 if (child.isJavaConstant() && child.asJavaConstant().getJavaKind().isNumericInteger()) { 142 long newDisp = disp + child.asJavaConstant().asLong(); 143 AArch64Address.AddressingMode newMode = immediateMode(kind, newDisp); 144 if (newMode != AArch64Address.AddressingMode.REGISTER_OFFSET) { 145 disp = newDisp; 146 mode = newMode; 147 base = add.getX(); 148 ret.setBase(base); 149 tryNextBase = (base instanceof AddNode); 150 } 151 } 152 } 153 } 154 if (disp != 0) { 155 // ok now set the displacement in place of an index 156 ret.setIndex(null); 157 int scaleFactor = computeScaleFactor(kind, mode); 158 ret.setDisplacement(disp, scaleFactor, mode); 159 } else { 160 // reset to base register only 161 ret.setIndex(null); 162 ret.setDisplacement(0, 1, AArch64Address.AddressingMode.BASE_REGISTER_ONLY); 163 } 164 return true; 165 } 166 } 167 } 168 // nope cannot improve this any more 169 return false; 170 } 171 172 private AArch64Kind getAArch64Kind(Stamp stamp) { 173 LIRKind lirKind = stamp.getLIRKind(kindtool); 174 if (!lirKind.isValue()) { 175 if (!lirKind.isReference(0) || lirKind.getReferenceCount() != 1) { 176 return null; 177 } 178 } 179 180 return (AArch64Kind) lirKind.getPlatformKind(); 181 } 182 183 private static AArch64Address.AddressingMode immediateMode(AArch64Kind kind, long value) { 184 if (kind != null) { 185 int size = kind.getSizeInBytes(); 186 // this next test should never really fail 187 if ((value & (size - 1)) == 0) { 188 long encodedValue = value / size; 189 // assert value % size == 0 190 // we can try for a 12 bit scaled offset 191 if (NumUtil.isUnsignedNbit(12, encodedValue)) { 192 return AArch64Address.AddressingMode.IMMEDIATE_SCALED; 193 } 194 } 195 } 196 197 // we can try for a 9 bit unscaled offset 198 if (NumUtil.isSignedNbit(9, value)) { 199 return AArch64Address.AddressingMode.IMMEDIATE_UNSCALED; 200 } 201 202 // nope this index needs to be passed via offset register 203 return AArch64Address.AddressingMode.REGISTER_OFFSET; 204 } 205 206 private static int computeScaleFactor(AArch64Kind kind, AArch64Address.AddressingMode mode) { 207 if (mode == AArch64Address.AddressingMode.IMMEDIATE_SCALED) { 208 return kind.getSizeInBytes(); 209 } 210 return 1; 211 } 212 213 boolean isBaseOnlyMode(AArch64Address.AddressingMode addressingMode) { 214 return addressingMode == AArch64Address.AddressingMode.BASE_REGISTER_ONLY; 215 } 216 217 private static boolean isDisplacementMode(AArch64Address.AddressingMode addressingMode) { 218 switch (addressingMode) { 219 case IMMEDIATE_POST_INDEXED: 220 case IMMEDIATE_PRE_INDEXED: 221 case IMMEDIATE_SCALED: 222 case IMMEDIATE_UNSCALED: 223 return true; 224 } 225 return false; 226 } 227} 228