static_inst.hh revision 2670:9107b8bd08cd
1/* 2 * Copyright (c) 2003-2005 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 * Authors: Steve Reinhardt 29 */ 30 31#ifndef __CPU_STATIC_INST_HH__ 32#define __CPU_STATIC_INST_HH__ 33 34#include <bitset> 35#include <string> 36 37#include "base/hashmap.hh" 38#include "base/misc.hh" 39#include "base/refcnt.hh" 40#include "cpu/op_class.hh" 41#include "sim/host.hh" 42#include "arch/isa_traits.hh" 43 44// forward declarations 45struct AlphaSimpleImpl; 46struct OzoneImpl; 47struct SimpleImpl; 48class ExecContext; 49class DynInst; 50class Packet; 51 52template <class Impl> 53class AlphaDynInst; 54 55template <class Impl> 56class OzoneDynInst; 57 58class CheckerCPU; 59class FastCPU; 60class AtomicSimpleCPU; 61class TimingSimpleCPU; 62class InorderCPU; 63class SymbolTable; 64 65namespace Trace { 66 class InstRecord; 67} 68 69/** 70 * Base, ISA-independent static instruction class. 71 * 72 * The main component of this class is the vector of flags and the 73 * associated methods for reading them. Any object that can rely 74 * solely on these flags can process instructions without being 75 * recompiled for multiple ISAs. 76 */ 77class StaticInstBase : public RefCounted 78{ 79 protected: 80 81 /// Set of boolean static instruction properties. 82 /// 83 /// Notes: 84 /// - The IsInteger and IsFloating flags are based on the class of 85 /// registers accessed by the instruction. Although most 86 /// instructions will have exactly one of these two flags set, it 87 /// is possible for an instruction to have neither (e.g., direct 88 /// unconditional branches, memory barriers) or both (e.g., an 89 /// FP/int conversion). 90 /// - If IsMemRef is set, then exactly one of IsLoad or IsStore 91 /// will be set. 92 /// - If IsControl is set, then exactly one of IsDirectControl or 93 /// IsIndirect Control will be set, and exactly one of 94 /// IsCondControl or IsUncondControl will be set. 95 /// - IsSerializing, IsMemBarrier, and IsWriteBarrier are 96 /// implemented as flags since in the current model there's no 97 /// other way for instructions to inject behavior into the 98 /// pipeline outside of fetch. Once we go to an exec-in-exec CPU 99 /// model we should be able to get rid of these flags and 100 /// implement this behavior via the execute() methods. 101 /// 102 enum Flags { 103 IsNop, ///< Is a no-op (no effect at all). 104 105 IsInteger, ///< References integer regs. 106 IsFloating, ///< References FP regs. 107 108 IsMemRef, ///< References memory (load, store, or prefetch). 109 IsLoad, ///< Reads from memory (load or prefetch). 110 IsStore, ///< Writes to memory. 111 IsStoreConditional, ///< Store conditional instruction. 112 IsInstPrefetch, ///< Instruction-cache prefetch. 113 IsDataPrefetch, ///< Data-cache prefetch. 114 IsCopy, ///< Fast Cache block copy 115 116 IsControl, ///< Control transfer instruction. 117 IsDirectControl, ///< PC relative control transfer. 118 IsIndirectControl, ///< Register indirect control transfer. 119 IsCondControl, ///< Conditional control transfer. 120 IsUncondControl, ///< Unconditional control transfer. 121 IsCall, ///< Subroutine call. 122 IsReturn, ///< Subroutine return. 123 124 IsCondDelaySlot,///< Conditional Delay-Slot Instruction 125 126 IsThreadSync, ///< Thread synchronization operation. 127 128 IsSerializing, ///< Serializes pipeline: won't execute until all 129 /// older instructions have committed. 130 IsSerializeBefore, 131 IsSerializeAfter, 132 IsMemBarrier, ///< Is a memory barrier 133 IsWriteBarrier, ///< Is a write barrier 134 135 IsNonSpeculative, ///< Should not be executed speculatively 136 IsQuiesce, ///< Is a quiesce instruction 137 138 IsIprAccess, ///< Accesses IPRs 139 IsUnverifiable, ///< Can't be verified by a checker 140 141 NumFlags 142 }; 143 144 /// Flag values for this instruction. 145 std::bitset<NumFlags> flags; 146 147 /// See opClass(). 148 OpClass _opClass; 149 150 /// See numSrcRegs(). 151 int8_t _numSrcRegs; 152 153 /// See numDestRegs(). 154 int8_t _numDestRegs; 155 156 /// The following are used to track physical register usage 157 /// for machines with separate int & FP reg files. 158 //@{ 159 int8_t _numFPDestRegs; 160 int8_t _numIntDestRegs; 161 //@} 162 163 /// Constructor. 164 /// It's important to initialize everything here to a sane 165 /// default, since the decoder generally only overrides 166 /// the fields that are meaningful for the particular 167 /// instruction. 168 StaticInstBase(OpClass __opClass) 169 : _opClass(__opClass), _numSrcRegs(0), _numDestRegs(0), 170 _numFPDestRegs(0), _numIntDestRegs(0) 171 { 172 } 173 174 public: 175 176 /// @name Register information. 177 /// The sum of numFPDestRegs() and numIntDestRegs() equals 178 /// numDestRegs(). The former two functions are used to track 179 /// physical register usage for machines with separate int & FP 180 /// reg files. 181 //@{ 182 /// Number of source registers. 183 int8_t numSrcRegs() const { return _numSrcRegs; } 184 /// Number of destination registers. 185 int8_t numDestRegs() const { return _numDestRegs; } 186 /// Number of floating-point destination regs. 187 int8_t numFPDestRegs() const { return _numFPDestRegs; } 188 /// Number of integer destination regs. 189 int8_t numIntDestRegs() const { return _numIntDestRegs; } 190 //@} 191 192 /// @name Flag accessors. 193 /// These functions are used to access the values of the various 194 /// instruction property flags. See StaticInstBase::Flags for descriptions 195 /// of the individual flags. 196 //@{ 197 198 bool isNop() const { return flags[IsNop]; } 199 200 bool isMemRef() const { return flags[IsMemRef]; } 201 bool isLoad() const { return flags[IsLoad]; } 202 bool isStore() const { return flags[IsStore]; } 203 bool isStoreConditional() const { return flags[IsStoreConditional]; } 204 bool isInstPrefetch() const { return flags[IsInstPrefetch]; } 205 bool isDataPrefetch() const { return flags[IsDataPrefetch]; } 206 bool isCopy() const { return flags[IsCopy];} 207 208 bool isInteger() const { return flags[IsInteger]; } 209 bool isFloating() const { return flags[IsFloating]; } 210 211 bool isControl() const { return flags[IsControl]; } 212 bool isCall() const { return flags[IsCall]; } 213 bool isReturn() const { return flags[IsReturn]; } 214 bool isDirectCtrl() const { return flags[IsDirectControl]; } 215 bool isIndirectCtrl() const { return flags[IsIndirectControl]; } 216 bool isCondCtrl() const { return flags[IsCondControl]; } 217 bool isUncondCtrl() const { return flags[IsUncondControl]; } 218 219 bool isThreadSync() const { return flags[IsThreadSync]; } 220 bool isSerializing() const { return flags[IsSerializing] || 221 flags[IsSerializeBefore] || 222 flags[IsSerializeAfter]; } 223 bool isSerializeBefore() const { return flags[IsSerializeBefore]; } 224 bool isSerializeAfter() const { return flags[IsSerializeAfter]; } 225 bool isMemBarrier() const { return flags[IsMemBarrier]; } 226 bool isWriteBarrier() const { return flags[IsWriteBarrier]; } 227 bool isNonSpeculative() const { return flags[IsNonSpeculative]; } 228 bool isQuiesce() const { return flags[IsQuiesce]; } 229 bool isIprAccess() const { return flags[IsIprAccess]; } 230 bool isUnverifiable() const { return flags[IsUnverifiable]; } 231 //@} 232 233 /// Operation class. Used to select appropriate function unit in issue. 234 OpClass opClass() const { return _opClass; } 235}; 236 237 238// forward declaration 239class StaticInstPtr; 240 241/** 242 * Generic yet ISA-dependent static instruction class. 243 * 244 * This class builds on StaticInstBase, defining fields and interfaces 245 * that are generic across all ISAs but that differ in details 246 * according to the specific ISA being used. 247 */ 248class StaticInst : public StaticInstBase 249{ 250 public: 251 252 /// Binary machine instruction type. 253 typedef TheISA::MachInst MachInst; 254 /// Binary extended machine instruction type. 255 typedef TheISA::ExtMachInst ExtMachInst; 256 /// Logical register index type. 257 typedef TheISA::RegIndex RegIndex; 258 259 enum { 260 MaxInstSrcRegs = TheISA::MaxInstSrcRegs, //< Max source regs 261 MaxInstDestRegs = TheISA::MaxInstDestRegs, //< Max dest regs 262 }; 263 264 265 /// Return logical index (architectural reg num) of i'th destination reg. 266 /// Only the entries from 0 through numDestRegs()-1 are valid. 267 RegIndex destRegIdx(int i) const { return _destRegIdx[i]; } 268 269 /// Return logical index (architectural reg num) of i'th source reg. 270 /// Only the entries from 0 through numSrcRegs()-1 are valid. 271 RegIndex srcRegIdx(int i) const { return _srcRegIdx[i]; } 272 273 /// Pointer to a statically allocated "null" instruction object. 274 /// Used to give eaCompInst() and memAccInst() something to return 275 /// when called on non-memory instructions. 276 static StaticInstPtr nullStaticInstPtr; 277 278 /** 279 * Memory references only: returns "fake" instruction representing 280 * the effective address part of the memory operation. Used to 281 * obtain the dependence info (numSrcRegs and srcRegIdx[]) for 282 * just the EA computation. 283 */ 284 virtual const 285 StaticInstPtr &eaCompInst() const { return nullStaticInstPtr; } 286 287 /** 288 * Memory references only: returns "fake" instruction representing 289 * the memory access part of the memory operation. Used to 290 * obtain the dependence info (numSrcRegs and srcRegIdx[]) for 291 * just the memory access (not the EA computation). 292 */ 293 virtual const 294 StaticInstPtr &memAccInst() const { return nullStaticInstPtr; } 295 296 /// The binary machine instruction. 297 const ExtMachInst machInst; 298 299 protected: 300 301 /// See destRegIdx(). 302 RegIndex _destRegIdx[MaxInstDestRegs]; 303 /// See srcRegIdx(). 304 RegIndex _srcRegIdx[MaxInstSrcRegs]; 305 306 /** 307 * Base mnemonic (e.g., "add"). Used by generateDisassembly() 308 * methods. Also useful to readily identify instructions from 309 * within the debugger when #cachedDisassembly has not been 310 * initialized. 311 */ 312 const char *mnemonic; 313 314 /** 315 * String representation of disassembly (lazily evaluated via 316 * disassemble()). 317 */ 318 mutable std::string *cachedDisassembly; 319 320 /** 321 * Internal function to generate disassembly string. 322 */ 323 virtual std::string 324 generateDisassembly(Addr pc, const SymbolTable *symtab) const = 0; 325 326 /// Constructor. 327 StaticInst(const char *_mnemonic, ExtMachInst _machInst, OpClass __opClass) 328 : StaticInstBase(__opClass), 329 machInst(_machInst), mnemonic(_mnemonic), cachedDisassembly(0) 330 { 331 } 332 333 public: 334 335 virtual ~StaticInst() 336 { 337 if (cachedDisassembly) 338 delete cachedDisassembly; 339 } 340 341/** 342 * The execute() signatures are auto-generated by scons based on the 343 * set of CPU models we are compiling in today. 344 */ 345#include "cpu/static_inst_exec_sigs.hh" 346 347 /** 348 * Return the target address for a PC-relative branch. 349 * Invalid if not a PC-relative branch (i.e. isDirectCtrl() 350 * should be true). 351 */ 352 virtual Addr branchTarget(Addr branchPC) const 353 { 354 panic("StaticInst::branchTarget() called on instruction " 355 "that is not a PC-relative branch."); 356 } 357 358 /** 359 * Return the target address for an indirect branch (jump). The 360 * register value is read from the supplied execution context, so 361 * the result is valid only if the execution context is about to 362 * execute the branch in question. Invalid if not an indirect 363 * branch (i.e. isIndirectCtrl() should be true). 364 */ 365 virtual Addr branchTarget(ExecContext *xc) const 366 { 367 panic("StaticInst::branchTarget() called on instruction " 368 "that is not an indirect branch."); 369 } 370 371 /** 372 * Return true if the instruction is a control transfer, and if so, 373 * return the target address as well. 374 */ 375 bool hasBranchTarget(Addr pc, ExecContext *xc, Addr &tgt) const; 376 377 /** 378 * Return string representation of disassembled instruction. 379 * The default version of this function will call the internal 380 * virtual generateDisassembly() function to get the string, 381 * then cache it in #cachedDisassembly. If the disassembly 382 * should not be cached, this function should be overridden directly. 383 */ 384 virtual const std::string &disassemble(Addr pc, 385 const SymbolTable *symtab = 0) const 386 { 387 if (!cachedDisassembly) 388 cachedDisassembly = 389 new std::string(generateDisassembly(pc, symtab)); 390 391 return *cachedDisassembly; 392 } 393 394 /// Decoded instruction cache type. 395 /// For now we're using a generic hash_map; this seems to work 396 /// pretty well. 397 typedef m5::hash_map<ExtMachInst, StaticInstPtr> DecodeCache; 398 399 /// A cache of decoded instruction objects. 400 static DecodeCache decodeCache; 401 402 /** 403 * Dump some basic stats on the decode cache hash map. 404 * Only gets called if DECODE_CACHE_HASH_STATS is defined. 405 */ 406 static void dumpDecodeCacheStats(); 407 408 /// Decode a machine instruction. 409 /// @param mach_inst The binary instruction to decode. 410 /// @retval A pointer to the corresponding StaticInst object. 411 //This is defined as inline below. 412 static StaticInstPtr decode(ExtMachInst mach_inst); 413 414 //MIPS Decoder Debug Functions 415 int getOpcode() { return (machInst & 0xFC000000) >> 26 ; }//31..26 416 int getRs() { return (machInst & 0x03E00000) >> 21; } //25...21 417 int getRt() { return (machInst & 0x001F0000) >> 16; } //20...16 418 int getRd() { return (machInst & 0x0000F800) >> 11; } //15...11 419 int getImm() { return (machInst & 0x0000FFFF); } //15...0 420 int getFunction(){ return (machInst & 0x0000003F); }//5...0 421 int getBranch(){ return (machInst & 0x0000FFFF); }//15...0 422 int getJump(){ return (machInst & 0x03FFFFFF); }//5...0 423 int getHint(){ return (machInst & 0x000007C0) >> 6; } //10...6 424 std::string getName() { return mnemonic; } 425}; 426 427typedef RefCountingPtr<StaticInstBase> StaticInstBasePtr; 428 429/// Reference-counted pointer to a StaticInst object. 430/// This type should be used instead of "StaticInst *" so that 431/// StaticInst objects can be properly reference-counted. 432class StaticInstPtr : public RefCountingPtr<StaticInst> 433{ 434 public: 435 /// Constructor. 436 StaticInstPtr() 437 : RefCountingPtr<StaticInst>() 438 { 439 } 440 441 /// Conversion from "StaticInst *". 442 StaticInstPtr(StaticInst *p) 443 : RefCountingPtr<StaticInst>(p) 444 { 445 } 446 447 /// Copy constructor. 448 StaticInstPtr(const StaticInstPtr &r) 449 : RefCountingPtr<StaticInst>(r) 450 { 451 } 452 453 /// Construct directly from machine instruction. 454 /// Calls StaticInst::decode(). 455 StaticInstPtr(TheISA::ExtMachInst mach_inst) 456 : RefCountingPtr<StaticInst>(StaticInst::decode(mach_inst)) 457 { 458 } 459 460 /// Convert to pointer to StaticInstBase class. 461 operator const StaticInstBasePtr() 462 { 463 return this->get(); 464 } 465}; 466 467inline StaticInstPtr 468StaticInst::decode(StaticInst::ExtMachInst mach_inst) 469{ 470#ifdef DECODE_CACHE_HASH_STATS 471 // Simple stats on decode hash_map. Turns out the default 472 // hash function is as good as anything I could come up with. 473 const int dump_every_n = 10000000; 474 static int decodes_til_dump = dump_every_n; 475 476 if (--decodes_til_dump == 0) { 477 dumpDecodeCacheStats(); 478 decodes_til_dump = dump_every_n; 479 } 480#endif 481 482 DecodeCache::iterator iter = decodeCache.find(mach_inst); 483 if (iter != decodeCache.end()) { 484 return iter->second; 485 } 486 487 StaticInstPtr si = TheISA::decodeInst(mach_inst); 488 decodeCache[mach_inst] = si; 489 return si; 490} 491 492#endif // __CPU_STATIC_INST_HH__ 493