rename_map.cc revision 2632:1bb2f91485ea
1/* 2 * Copyright (c) 2004-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <vector> 30 31#include "cpu/o3/rename_map.hh" 32 33using namespace std; 34 35// Todo: Consider making functions inline. Avoid having things that are 36// using the zero register or misc registers from adding on the registers 37// to the free list. Possibly remove the direct communication between 38// this and the freelist. Considering making inline bool functions that 39// determine if the register is a logical int, logical fp, physical int, 40// physical fp, etc. 41 42SimpleRenameMap::SimpleRenameMap(unsigned _numLogicalIntRegs, 43 unsigned _numPhysicalIntRegs, 44 unsigned _numLogicalFloatRegs, 45 unsigned _numPhysicalFloatRegs, 46 unsigned _numMiscRegs, 47 RegIndex _intZeroReg, 48 RegIndex _floatZeroReg) 49 : numLogicalIntRegs(_numLogicalIntRegs), 50 numPhysicalIntRegs(_numPhysicalIntRegs), 51 numLogicalFloatRegs(_numLogicalFloatRegs), 52 numPhysicalFloatRegs(_numPhysicalFloatRegs), 53 numMiscRegs(_numMiscRegs), 54 intZeroReg(_intZeroReg), 55 floatZeroReg(_floatZeroReg) 56{ 57 DPRINTF(Rename, "Rename: Creating rename map. Phys: %i / %i, Float: " 58 "%i / %i.\n", numLogicalIntRegs, numPhysicalIntRegs, 59 numLogicalFloatRegs, numPhysicalFloatRegs); 60 61 numLogicalRegs = numLogicalIntRegs + numLogicalFloatRegs; 62 63 numPhysicalRegs = numPhysicalIntRegs + numPhysicalFloatRegs; 64 65 //Create the rename maps, and their scoreboards. 66 intRenameMap = new RenameEntry[numLogicalIntRegs]; 67 floatRenameMap = new RenameEntry[numLogicalRegs]; 68 69 // Should combine this into one scoreboard. 70 intScoreboard.resize(numPhysicalIntRegs); 71 floatScoreboard.resize(numPhysicalRegs); 72 miscScoreboard.resize(numPhysicalRegs + numMiscRegs); 73 74 // Initialize the entries in the integer rename map to point to the 75 // physical registers of the same index, and consider each register 76 // ready until the first rename occurs. 77 for (RegIndex index = 0; index < numLogicalIntRegs; ++index) 78 { 79 intRenameMap[index].physical_reg = index; 80 intScoreboard[index] = 1; 81 } 82 83 // Initialize the rest of the physical registers (the ones that don't 84 // directly map to a logical register) as unready. 85 for (PhysRegIndex index = numLogicalIntRegs; 86 index < numPhysicalIntRegs; 87 ++index) 88 { 89 intScoreboard[index] = 0; 90 } 91 92 int float_reg_idx = numPhysicalIntRegs; 93 94 // Initialize the entries in the floating point rename map to point to 95 // the physical registers of the same index, and consider each register 96 // ready until the first rename occurs. 97 // Although the index refers purely to architected registers, because 98 // the floating reg indices come after the integer reg indices, they 99 // may exceed the size of a normal RegIndex (short). 100 for (PhysRegIndex index = numLogicalIntRegs; 101 index < numLogicalRegs; ++index) 102 { 103 floatRenameMap[index].physical_reg = float_reg_idx++; 104 } 105 106 for (PhysRegIndex index = numPhysicalIntRegs; 107 index < numPhysicalIntRegs + numLogicalFloatRegs; ++index) 108 { 109 floatScoreboard[index] = 1; 110 } 111 112 // Initialize the rest of the physical registers (the ones that don't 113 // directly map to a logical register) as unready. 114 for (PhysRegIndex index = numPhysicalIntRegs + numLogicalFloatRegs; 115 index < numPhysicalRegs; 116 ++index) 117 { 118 floatScoreboard[index] = 0; 119 } 120 121 // Initialize the entries in the misc register scoreboard to be ready. 122 for (PhysRegIndex index = numPhysicalRegs; 123 index < numPhysicalRegs + numMiscRegs; ++index) 124 { 125 miscScoreboard[index] = 1; 126 } 127} 128 129SimpleRenameMap::~SimpleRenameMap() 130{ 131 // Delete the rename maps as they were allocated with new. 132 delete [] intRenameMap; 133 delete [] floatRenameMap; 134} 135 136void 137SimpleRenameMap::setFreeList(SimpleFreeList *fl_ptr) 138{ 139 //Setup the interface to the freelist. 140 freeList = fl_ptr; 141} 142 143 144// Don't allow this stage to fault; force that check to the rename stage. 145// Simply ask to rename a logical register and get back a new physical 146// register index. 147SimpleRenameMap::RenameInfo 148SimpleRenameMap::rename(RegIndex arch_reg) 149{ 150 PhysRegIndex renamed_reg; 151 PhysRegIndex prev_reg; 152 153 if (arch_reg < numLogicalIntRegs) { 154 155 // Record the current physical register that is renamed to the 156 // requested architected register. 157 prev_reg = intRenameMap[arch_reg].physical_reg; 158 159 // If it's not referencing the zero register, then mark the register 160 // as not ready. 161 if (arch_reg != intZeroReg) { 162 // Get a free physical register to rename to. 163 renamed_reg = freeList->getIntReg(); 164 165 // Update the integer rename map. 166 intRenameMap[arch_reg].physical_reg = renamed_reg; 167 168 assert(renamed_reg >= 0 && renamed_reg < numPhysicalIntRegs); 169 170 // Mark register as not ready. 171 intScoreboard[renamed_reg] = false; 172 } else { 173 // Otherwise return the zero register so nothing bad happens. 174 renamed_reg = intZeroReg; 175 } 176 } else if (arch_reg < numLogicalRegs) { 177 // Subtract off the base offset for floating point registers. 178// arch_reg = arch_reg - numLogicalIntRegs; 179 180 // Record the current physical register that is renamed to the 181 // requested architected register. 182 prev_reg = floatRenameMap[arch_reg].physical_reg; 183 184 // If it's not referencing the zero register, then mark the register 185 // as not ready. 186 if (arch_reg != floatZeroReg) { 187 // Get a free floating point register to rename to. 188 renamed_reg = freeList->getFloatReg(); 189 190 // Update the floating point rename map. 191 floatRenameMap[arch_reg].physical_reg = renamed_reg; 192 193 assert(renamed_reg < numPhysicalRegs && 194 renamed_reg >= numPhysicalIntRegs); 195 196 // Mark register as not ready. 197 floatScoreboard[renamed_reg] = false; 198 } else { 199 // Otherwise return the zero register so nothing bad happens. 200 renamed_reg = floatZeroReg; 201 } 202 } else { 203 // Subtract off the base offset for miscellaneous registers. 204 arch_reg = arch_reg - numLogicalRegs; 205 206 // No renaming happens to the misc. registers. They are simply the 207 // registers that come after all the physical registers; thus 208 // take the base architected register and add the physical registers 209 // to it. 210 renamed_reg = arch_reg + numPhysicalRegs; 211 212 // Set the previous register to the same register; mainly it must be 213 // known that the prev reg was outside the range of normal registers 214 // so the free list can avoid adding it. 215 prev_reg = renamed_reg; 216 217 assert(renamed_reg < numPhysicalRegs + numMiscRegs); 218 219 miscScoreboard[renamed_reg] = false; 220 } 221 222 return RenameInfo(renamed_reg, prev_reg); 223} 224 225//Perhaps give this a pair as a return value, of the physical register 226//and whether or not it's ready. 227PhysRegIndex 228SimpleRenameMap::lookup(RegIndex arch_reg) 229{ 230 if (arch_reg < numLogicalIntRegs) { 231 return intRenameMap[arch_reg].physical_reg; 232 } else if (arch_reg < numLogicalRegs) { 233 // Subtract off the base FP offset. 234// arch_reg = arch_reg - numLogicalIntRegs; 235 236 return floatRenameMap[arch_reg].physical_reg; 237 } else { 238 // Subtract off the misc registers offset. 239 arch_reg = arch_reg - numLogicalRegs; 240 241 // Misc. regs don't rename, so simply add the base arch reg to 242 // the number of physical registers. 243 return numPhysicalRegs + arch_reg; 244 } 245} 246 247bool 248SimpleRenameMap::isReady(PhysRegIndex phys_reg) 249{ 250 if (phys_reg < numPhysicalIntRegs) { 251 return intScoreboard[phys_reg]; 252 } else if (phys_reg < numPhysicalRegs) { 253 254 // Subtract off the base FP offset. 255// phys_reg = phys_reg - numPhysicalIntRegs; 256 257 return floatScoreboard[phys_reg]; 258 } else { 259 // Subtract off the misc registers offset. 260// phys_reg = phys_reg - numPhysicalRegs; 261 262 return miscScoreboard[phys_reg]; 263 } 264} 265 266// In this implementation the miscellaneous registers do not actually rename, 267// so this function does not allow you to try to change their mappings. 268void 269SimpleRenameMap::setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg) 270{ 271 if (arch_reg < numLogicalIntRegs) { 272 DPRINTF(Rename, "Rename Map: Integer register %i being set to %i.\n", 273 (int)arch_reg, renamed_reg); 274 275 intRenameMap[arch_reg].physical_reg = renamed_reg; 276 } else { 277 assert(arch_reg < (numLogicalIntRegs + numLogicalFloatRegs)); 278 279 DPRINTF(Rename, "Rename Map: Float register %i being set to %i.\n", 280 (int)arch_reg - numLogicalIntRegs, renamed_reg); 281 282 floatRenameMap[arch_reg].physical_reg = renamed_reg; 283 } 284} 285 286void 287SimpleRenameMap::squash(vector<RegIndex> freed_regs, 288 vector<UnmapInfo> unmaps) 289{ 290 panic("Not sure this function should be called."); 291 292 // Not sure the rename map should be able to access the free list 293 // like this. 294 while (!freed_regs.empty()) { 295 RegIndex free_register = freed_regs.back(); 296 297 if (free_register < numPhysicalIntRegs) { 298 freeList->addIntReg(free_register); 299 } else { 300 // Subtract off the base FP dependence tag. 301 free_register = free_register - numPhysicalIntRegs; 302 freeList->addFloatReg(free_register); 303 } 304 305 freed_regs.pop_back(); 306 } 307 308 // Take unmap info and roll back the rename map. 309} 310 311void 312SimpleRenameMap::markAsReady(PhysRegIndex ready_reg) 313{ 314 DPRINTF(Rename, "Rename map: Marking register %i as ready.\n", 315 (int)ready_reg); 316 317 if (ready_reg < numPhysicalIntRegs) { 318 assert(ready_reg >= 0); 319 320 intScoreboard[ready_reg] = 1; 321 } else if (ready_reg < numPhysicalRegs) { 322 323 // Subtract off the base FP offset. 324// ready_reg = ready_reg - numPhysicalIntRegs; 325 326 floatScoreboard[ready_reg] = 1; 327 } else { 328 //Subtract off the misc registers offset. 329// ready_reg = ready_reg - numPhysicalRegs; 330 331 miscScoreboard[ready_reg] = 1; 332 } 333} 334 335int 336SimpleRenameMap::numFreeEntries() 337{ 338 int free_int_regs = freeList->numFreeIntRegs(); 339 int free_float_regs = freeList->numFreeFloatRegs(); 340 341 if (free_int_regs < free_float_regs) { 342 return free_int_regs; 343 } else { 344 return free_float_regs; 345 } 346} 347