rename_map.hh revision 12105:742d80361989
1/* 2 * Copyright (c) 2015 ARM Limited 3 * All rights reserved. 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2004-2005 The Regents of The University of Michigan 15 * Copyright (c) 2013 Advanced Micro Devices, Inc. 16 * All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions are 20 * met: redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer; 22 * redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution; 25 * neither the name of the copyright holders nor the names of its 26 * contributors may be used to endorse or promote products derived from 27 * this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 40 * 41 * Authors: Kevin Lim 42 * Steve Reinhardt 43 */ 44 45#ifndef __CPU_O3_RENAME_MAP_HH__ 46#define __CPU_O3_RENAME_MAP_HH__ 47 48#include <iostream> 49#include <utility> 50#include <vector> 51 52#include "arch/types.hh" 53#include "config/the_isa.hh" 54#include "cpu/o3/free_list.hh" 55#include "cpu/o3/regfile.hh" 56#include "cpu/reg_class.hh" 57 58/** 59 * Register rename map for a single class of registers (e.g., integer 60 * or floating point). Because the register class is implicitly 61 * determined by the rename map instance being accessed, all 62 * architectural register index parameters and values in this class 63 * are relative (e.g., %fp2 is just index 2). 64 */ 65class SimpleRenameMap 66{ 67 private: 68 69 /** The acutal arch-to-phys register map */ 70 std::vector<PhysRegIdPtr> map; 71 72 /** 73 * Pointer to the free list from which new physical registers 74 * should be allocated in rename() 75 */ 76 SimpleFreeList *freeList; 77 78 /** 79 * The architectural index of the zero register. This register is 80 * mapped but read-only, so we ignore attempts to rename it via 81 * the rename() method. If there is no such register for this map 82 * table, it should be set to an invalid index so that it never 83 * matches. 84 */ 85 RegIndex zeroReg; 86 87 public: 88 89 SimpleRenameMap(); 90 91 ~SimpleRenameMap() {}; 92 93 /** 94 * Because we have an array of rename maps (one per thread) in the CPU, 95 * it's awkward to initialize this object via the constructor. 96 * Instead, this method is used for initialization. 97 */ 98 void init(unsigned size, SimpleFreeList *_freeList, RegIndex _zeroReg); 99 100 /** 101 * Pair of a physical register and a physical register. Used to 102 * return the physical register that a logical register has been 103 * renamed to, and the previous physical register that the same 104 * logical register was previously mapped to. 105 */ 106 typedef std::pair<PhysRegIdPtr, PhysRegIdPtr> RenameInfo; 107 108 /** 109 * Tell rename map to get a new free physical register to remap 110 * the specified architectural register. 111 * @param arch_reg The architectural register to remap. 112 * @return A RenameInfo pair indicating both the new and previous 113 * physical registers. 114 */ 115 RenameInfo rename(RegIndex arch_reg); 116 117 /** 118 * Look up the physical register mapped to an architectural register. 119 * @param arch_reg The architectural register to look up. 120 * @return The physical register it is currently mapped to. 121 */ 122 PhysRegIdPtr lookup(RegIndex arch_reg) const 123 { 124 assert(arch_reg < map.size()); 125 return map[arch_reg]; 126 } 127 128 /** 129 * Update rename map with a specific mapping. Generally used to 130 * roll back to old mappings on a squash. 131 * @param arch_reg The architectural register to remap. 132 * @param phys_reg The physical register to remap it to. 133 */ 134 void setEntry(RegIndex arch_reg, PhysRegIdPtr phys_reg) 135 { 136 map[arch_reg] = phys_reg; 137 } 138 139 /** Return the number of free entries on the associated free list. */ 140 unsigned numFreeEntries() const { return freeList->numFreeRegs(); } 141}; 142 143 144/** 145 * Unified register rename map for all classes of registers. Wraps a 146 * set of class-specific rename maps. Methods that do not specify a 147 * register class (e.g., rename()) take register ids, 148 * while methods that do specify a register class (e.g., renameInt()) 149 * take register indices. 150 */ 151class UnifiedRenameMap 152{ 153 private: 154 155 /** The integer register rename map */ 156 SimpleRenameMap intMap; 157 158 /** The floating-point register rename map */ 159 SimpleRenameMap floatMap; 160 161 /** The condition-code register rename map */ 162 SimpleRenameMap ccMap; 163 164 /** 165 * The register file object is used only to get PhysRegIdPtr 166 * on MiscRegs, as they are stored in it. 167 */ 168 PhysRegFile *regFile; 169 170 public: 171 172 typedef SimpleRenameMap::RenameInfo RenameInfo; 173 174 /** Default constructor. init() must be called prior to use. */ 175 UnifiedRenameMap() : regFile(nullptr) {}; 176 177 /** Destructor. */ 178 ~UnifiedRenameMap() {}; 179 180 /** Initializes rename map with given parameters. */ 181 void init(PhysRegFile *_regFile, 182 RegIndex _intZeroReg, 183 RegIndex _floatZeroReg, 184 UnifiedFreeList *freeList); 185 186 /** 187 * Tell rename map to get a new free physical register to remap 188 * the specified architectural register. This version takes a 189 * flattened architectural register id and calls the 190 * appropriate class-specific rename table. 191 * @param arch_reg The architectural register index to remap. 192 * @return A RenameInfo pair indicating both the new and previous 193 * physical registers. 194 */ 195 RenameInfo rename(RegId arch_reg); 196 197 /** 198 * Perform rename() on an integer register, given a 199 * integer register index. 200 */ 201 RenameInfo renameInt(RegIndex rel_arch_reg) 202 { 203 return intMap.rename(rel_arch_reg); 204 } 205 206 /** 207 * Perform rename() on a floating-point register, given a 208 * floating-point register index. 209 */ 210 RenameInfo renameFloat(RegIndex rel_arch_reg) 211 { 212 return floatMap.rename(rel_arch_reg); 213 } 214 215 /** 216 * Perform rename() on a condition-code register, given a 217 * condition-code register index. 218 */ 219 RenameInfo renameCC(RegIndex rel_arch_reg) 220 { 221 return ccMap.rename(rel_arch_reg); 222 } 223 224 /** 225 * Perform rename() on a misc register, given a 226 * misc register index. 227 */ 228 RenameInfo renameMisc(RegIndex rel_arch_reg) 229 { 230 // misc regs aren't really renamed, just remapped 231 PhysRegIdPtr phys_reg = lookupMisc(rel_arch_reg); 232 // Set the new register to the previous one to keep the same 233 // mapping throughout the execution. 234 return RenameInfo(phys_reg, phys_reg); 235 } 236 237 238 /** 239 * Look up the physical register mapped to an architectural register. 240 * This version takes a flattened architectural register id 241 * and calls the appropriate class-specific rename table. 242 * @param arch_reg The architectural register to look up. 243 * @return The physical register it is currently mapped to. 244 */ 245 PhysRegIdPtr lookup(RegId arch_reg) const; 246 247 /** 248 * Perform lookup() on an integer register, given a 249 * integer register index. 250 */ 251 PhysRegIdPtr lookupInt(RegIndex rel_arch_reg) const 252 { 253 return intMap.lookup(rel_arch_reg); 254 } 255 256 /** 257 * Perform lookup() on a floating-point register, given a 258 * floating-point register index. 259 */ 260 PhysRegIdPtr lookupFloat(RegIndex rel_arch_reg) const 261 { 262 return floatMap.lookup(rel_arch_reg); 263 } 264 265 /** 266 * Perform lookup() on a condition-code register, given a 267 * condition-code register index. 268 */ 269 PhysRegIdPtr lookupCC(RegIndex rel_arch_reg) const 270 { 271 return ccMap.lookup(rel_arch_reg); 272 } 273 274 /** 275 * Perform lookup() on a misc register, given a relative 276 * misc register index. 277 */ 278 PhysRegIdPtr lookupMisc(RegIndex rel_arch_reg) const 279 { 280 // misc regs aren't really renamed, they keep the same 281 // mapping throughout the execution. 282 return regFile->getMiscRegId(rel_arch_reg); 283 } 284 285 /** 286 * Update rename map with a specific mapping. Generally used to 287 * roll back to old mappings on a squash. This version takes a 288 * flattened architectural register id and calls the 289 * appropriate class-specific rename table. 290 * @param arch_reg The architectural register to remap. 291 * @param phys_reg The physical register to remap it to. 292 */ 293 void setEntry(RegId arch_reg, PhysRegIdPtr phys_reg); 294 295 /** 296 * Perform setEntry() on an integer register, given a 297 * integer register index. 298 */ 299 void setIntEntry(RegIndex arch_reg, PhysRegIdPtr phys_reg) 300 { 301 assert(phys_reg->isIntPhysReg()); 302 intMap.setEntry(arch_reg, phys_reg); 303 } 304 305 /** 306 * Perform setEntry() on a floating-point register, given a 307 * floating-point register index. 308 */ 309 void setFloatEntry(RegIndex arch_reg, PhysRegIdPtr phys_reg) 310 { 311 assert(phys_reg->isFloatPhysReg()); 312 floatMap.setEntry(arch_reg, phys_reg); 313 } 314 315 /** 316 * Perform setEntry() on a condition-code register, given a 317 * condition-code register index. 318 */ 319 void setCCEntry(RegIndex arch_reg, PhysRegIdPtr phys_reg) 320 { 321 assert(phys_reg->isCCPhysReg()); 322 ccMap.setEntry(arch_reg, phys_reg); 323 } 324 325 /** 326 * Return the minimum number of free entries across all of the 327 * register classes. The minimum is used so we guarantee that 328 * this number of entries is available regardless of which class 329 * of registers is requested. 330 */ 331 unsigned numFreeEntries() const 332 { 333 return std::min(intMap.numFreeEntries(), floatMap.numFreeEntries()); 334 } 335 336 /** 337 * Return whether there are enough registers to serve the request. 338 */ 339 bool canRename(uint32_t intRegs, uint32_t floatRegs, uint32_t ccRegs) const 340 { 341 return intRegs <= intMap.numFreeEntries() && 342 floatRegs <= floatMap.numFreeEntries() && 343 ccRegs <= ccMap.numFreeEntries(); 344 } 345 346}; 347 348#endif //__CPU_O3_RENAME_MAP_HH__ 349