static_inst.hh revision 9848:a733a8eb6363
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 "arch/registers.hh" 38#include "arch/types.hh" 39#include "base/misc.hh" 40#include "base/refcnt.hh" 41#include "base/types.hh" 42#include "config/the_isa.hh" 43#include "cpu/op_class.hh" 44#include "cpu/static_inst_fwd.hh" 45#include "cpu/thread_context.hh" 46#include "sim/fault_fwd.hh" 47 48// forward declarations 49class Packet; 50 51struct O3CPUImpl; 52template <class Impl> class BaseO3DynInst; 53typedef BaseO3DynInst<O3CPUImpl> O3DynInst; 54class InOrderDynInst; 55 56class CheckerCPU; 57class AtomicSimpleCPU; 58class TimingSimpleCPU; 59class InorderCPU; 60class SymbolTable; 61 62namespace Trace { 63 class InstRecord; 64} 65 66/** 67 * Base, ISA-independent static instruction class. 68 * 69 * The main component of this class is the vector of flags and the 70 * associated methods for reading them. Any object that can rely 71 * solely on these flags can process instructions without being 72 * recompiled for multiple ISAs. 73 */ 74class StaticInst : public RefCounted 75{ 76 public: 77 /// Binary extended machine instruction type. 78 typedef TheISA::ExtMachInst ExtMachInst; 79 /// Logical register index type. 80 typedef TheISA::RegIndex RegIndex; 81 82 enum { 83 MaxInstSrcRegs = TheISA::MaxInstSrcRegs, //< Max source regs 84 MaxInstDestRegs = TheISA::MaxInstDestRegs //< Max dest regs 85 }; 86 87 /// Set of boolean static instruction properties. 88 /// 89 /// Notes: 90 /// - The IsInteger and IsFloating flags are based on the class of 91 /// registers accessed by the instruction. Although most 92 /// instructions will have exactly one of these two flags set, it 93 /// is possible for an instruction to have neither (e.g., direct 94 /// unconditional branches, memory barriers) or both (e.g., an 95 /// FP/int conversion). 96 /// - If IsMemRef is set, then exactly one of IsLoad or IsStore 97 /// will be set. 98 /// - If IsControl is set, then exactly one of IsDirectControl or 99 /// IsIndirect Control will be set, and exactly one of 100 /// IsCondControl or IsUncondControl will be set. 101 /// - IsSerializing, IsMemBarrier, and IsWriteBarrier are 102 /// implemented as flags since in the current model there's no 103 /// other way for instructions to inject behavior into the 104 /// pipeline outside of fetch. Once we go to an exec-in-exec CPU 105 /// model we should be able to get rid of these flags and 106 /// implement this behavior via the execute() methods. 107 /// 108 enum Flags { 109 IsNop, ///< Is a no-op (no effect at all). 110 111 IsInteger, ///< References integer regs. 112 IsFloating, ///< References FP regs. 113 114 IsMemRef, ///< References memory (load, store, or prefetch). 115 IsLoad, ///< Reads from memory (load or prefetch). 116 IsStore, ///< Writes to memory. 117 IsStoreConditional, ///< Store conditional instruction. 118 IsIndexed, ///< Accesses memory with an indexed address computation 119 IsInstPrefetch, ///< Instruction-cache prefetch. 120 IsDataPrefetch, ///< Data-cache prefetch. 121 122 IsControl, ///< Control transfer instruction. 123 IsDirectControl, ///< PC relative control transfer. 124 IsIndirectControl, ///< Register indirect control transfer. 125 IsCondControl, ///< Conditional control transfer. 126 IsUncondControl, ///< Unconditional control transfer. 127 IsCall, ///< Subroutine call. 128 IsReturn, ///< Subroutine return. 129 130 IsCondDelaySlot,///< Conditional Delay-Slot Instruction 131 132 IsThreadSync, ///< Thread synchronization operation. 133 134 IsSerializing, ///< Serializes pipeline: won't execute until all 135 /// older instructions have committed. 136 IsSerializeBefore, 137 IsSerializeAfter, 138 IsMemBarrier, ///< Is a memory barrier 139 IsWriteBarrier, ///< Is a write barrier 140 IsReadBarrier, ///< Is a read barrier 141 IsERET, /// <- Causes the IFU to stall (MIPS ISA) 142 143 IsNonSpeculative, ///< Should not be executed speculatively 144 IsQuiesce, ///< Is a quiesce instruction 145 146 IsIprAccess, ///< Accesses IPRs 147 IsUnverifiable, ///< Can't be verified by a checker 148 149 IsSyscall, ///< Causes a system call to be emulated in syscall 150 /// emulation mode. 151 152 //Flags for microcode 153 IsMacroop, ///< Is a macroop containing microops 154 IsMicroop, ///< Is a microop 155 IsDelayedCommit, ///< This microop doesn't commit right away 156 IsLastMicroop, ///< This microop ends a microop sequence 157 IsFirstMicroop, ///< This microop begins a microop sequence 158 //This flag doesn't do anything yet 159 IsMicroBranch, ///< This microop branches within the microcode for a macroop 160 IsDspOp, 161 IsSquashAfter, ///< Squash all uncommitted state after executed 162 NumFlags 163 }; 164 165 protected: 166 167 /// Flag values for this instruction. 168 std::bitset<NumFlags> flags; 169 170 /// See opClass(). 171 OpClass _opClass; 172 173 /// See numSrcRegs(). 174 int8_t _numSrcRegs; 175 176 /// See numDestRegs(). 177 int8_t _numDestRegs; 178 179 /// The following are used to track physical register usage 180 /// for machines with separate int & FP reg files. 181 //@{ 182 int8_t _numFPDestRegs; 183 int8_t _numIntDestRegs; 184 //@} 185 186 public: 187 188 /// @name Register information. 189 /// The sum of numFPDestRegs() and numIntDestRegs() equals 190 /// numDestRegs(). The former two functions are used to track 191 /// physical register usage for machines with separate int & FP 192 /// reg files. 193 //@{ 194 /// Number of source registers. 195 int8_t numSrcRegs() const { return _numSrcRegs; } 196 /// Number of destination registers. 197 int8_t numDestRegs() const { return _numDestRegs; } 198 /// Number of floating-point destination regs. 199 int8_t numFPDestRegs() const { return _numFPDestRegs; } 200 /// Number of integer destination regs. 201 int8_t numIntDestRegs() const { return _numIntDestRegs; } 202 //@} 203 204 /// @name Flag accessors. 205 /// These functions are used to access the values of the various 206 /// instruction property flags. See StaticInst::Flags for descriptions 207 /// of the individual flags. 208 //@{ 209 210 bool isNop() const { return flags[IsNop]; } 211 212 bool isMemRef() const { return flags[IsMemRef]; } 213 bool isLoad() const { return flags[IsLoad]; } 214 bool isStore() const { return flags[IsStore]; } 215 bool isStoreConditional() const { return flags[IsStoreConditional]; } 216 bool isInstPrefetch() const { return flags[IsInstPrefetch]; } 217 bool isDataPrefetch() const { return flags[IsDataPrefetch]; } 218 bool isPrefetch() const { return isInstPrefetch() || 219 isDataPrefetch(); } 220 221 bool isInteger() const { return flags[IsInteger]; } 222 bool isFloating() const { return flags[IsFloating]; } 223 224 bool isControl() const { return flags[IsControl]; } 225 bool isCall() const { return flags[IsCall]; } 226 bool isReturn() const { return flags[IsReturn]; } 227 bool isDirectCtrl() const { return flags[IsDirectControl]; } 228 bool isIndirectCtrl() const { return flags[IsIndirectControl]; } 229 bool isCondCtrl() const { return flags[IsCondControl]; } 230 bool isUncondCtrl() const { return flags[IsUncondControl]; } 231 bool isCondDelaySlot() const { return flags[IsCondDelaySlot]; } 232 233 bool isThreadSync() const { return flags[IsThreadSync]; } 234 bool isSerializing() const { return flags[IsSerializing] || 235 flags[IsSerializeBefore] || 236 flags[IsSerializeAfter]; } 237 bool isSerializeBefore() const { return flags[IsSerializeBefore]; } 238 bool isSerializeAfter() const { return flags[IsSerializeAfter]; } 239 bool isSquashAfter() const { return flags[IsSquashAfter]; } 240 bool isMemBarrier() const { return flags[IsMemBarrier]; } 241 bool isWriteBarrier() const { return flags[IsWriteBarrier]; } 242 bool isNonSpeculative() const { return flags[IsNonSpeculative]; } 243 bool isQuiesce() const { return flags[IsQuiesce]; } 244 bool isIprAccess() const { return flags[IsIprAccess]; } 245 bool isUnverifiable() const { return flags[IsUnverifiable]; } 246 bool isSyscall() const { return flags[IsSyscall]; } 247 bool isMacroop() const { return flags[IsMacroop]; } 248 bool isMicroop() const { return flags[IsMicroop]; } 249 bool isDelayedCommit() const { return flags[IsDelayedCommit]; } 250 bool isLastMicroop() const { return flags[IsLastMicroop]; } 251 bool isFirstMicroop() const { return flags[IsFirstMicroop]; } 252 //This flag doesn't do anything yet 253 bool isMicroBranch() const { return flags[IsMicroBranch]; } 254 //@} 255 256 void setLastMicroop() { flags[IsLastMicroop] = true; } 257 void setDelayedCommit() { flags[IsDelayedCommit] = true; } 258 void setFlag(Flags f) { flags[f] = true; } 259 260 /// Operation class. Used to select appropriate function unit in issue. 261 OpClass opClass() const { return _opClass; } 262 263 264 /// Return logical index (architectural reg num) of i'th destination reg. 265 /// Only the entries from 0 through numDestRegs()-1 are valid. 266 RegIndex destRegIdx(int i) const { return _destRegIdx[i]; } 267 268 /// Return logical index (architectural reg num) of i'th source reg. 269 /// Only the entries from 0 through numSrcRegs()-1 are valid. 270 RegIndex srcRegIdx(int i) const { return _srcRegIdx[i]; } 271 272 /// Pointer to a statically allocated "null" instruction object. 273 /// Used to give eaCompInst() and memAccInst() something to return 274 /// when called on non-memory instructions. 275 static StaticInstPtr nullStaticInstPtr; 276 277 /** 278 * Memory references only: returns "fake" instruction representing 279 * the effective address part of the memory operation. Used to 280 * obtain the dependence info (numSrcRegs and srcRegIdx[]) for 281 * just the EA computation. 282 */ 283 virtual const 284 StaticInstPtr &eaCompInst() const { return nullStaticInstPtr; } 285 286 /** 287 * Memory references only: returns "fake" instruction representing 288 * the memory access part of the memory operation. Used to 289 * obtain the dependence info (numSrcRegs and srcRegIdx[]) for 290 * just the memory access (not the EA computation). 291 */ 292 virtual const 293 StaticInstPtr &memAccInst() const { return nullStaticInstPtr; } 294 295 /// The binary machine instruction. 296 const ExtMachInst machInst; 297 298 protected: 299 300 /// See destRegIdx(). 301 RegIndex _destRegIdx[MaxInstDestRegs]; 302 /// See srcRegIdx(). 303 RegIndex _srcRegIdx[MaxInstSrcRegs]; 304 305 /** 306 * Base mnemonic (e.g., "add"). Used by generateDisassembly() 307 * methods. Also useful to readily identify instructions from 308 * within the debugger when #cachedDisassembly has not been 309 * initialized. 310 */ 311 const char *mnemonic; 312 313 /** 314 * String representation of disassembly (lazily evaluated via 315 * disassemble()). 316 */ 317 mutable std::string *cachedDisassembly; 318 319 /** 320 * Internal function to generate disassembly string. 321 */ 322 virtual std::string 323 generateDisassembly(Addr pc, const SymbolTable *symtab) const = 0; 324 325 /// Constructor. 326 /// It's important to initialize everything here to a sane 327 /// default, since the decoder generally only overrides 328 /// the fields that are meaningful for the particular 329 /// instruction. 330 StaticInst(const char *_mnemonic, ExtMachInst _machInst, OpClass __opClass) 331 : _opClass(__opClass), _numSrcRegs(0), _numDestRegs(0), 332 _numFPDestRegs(0), _numIntDestRegs(0), 333 machInst(_machInst), mnemonic(_mnemonic), cachedDisassembly(0) 334 { } 335 336 public: 337 virtual ~StaticInst(); 338 339/** 340 * The execute() signatures are auto-generated by scons based on the 341 * set of CPU models we are compiling in today. 342 */ 343#include "cpu/static_inst_exec_sigs.hh" 344 345 virtual void advancePC(TheISA::PCState &pcState) const = 0; 346 347 /** 348 * Return the microop that goes with a particular micropc. This should 349 * only be defined/used in macroops which will contain microops 350 */ 351 virtual StaticInstPtr fetchMicroop(MicroPC upc) const; 352 353 /** 354 * Return the target address for a PC-relative branch. 355 * Invalid if not a PC-relative branch (i.e. isDirectCtrl() 356 * should be true). 357 */ 358 virtual TheISA::PCState branchTarget(const TheISA::PCState &pc) const; 359 360 /** 361 * Return the target address for an indirect branch (jump). The 362 * register value is read from the supplied thread context, so 363 * the result is valid only if the thread context is about to 364 * execute the branch in question. Invalid if not an indirect 365 * branch (i.e. isIndirectCtrl() should be true). 366 */ 367 virtual TheISA::PCState branchTarget(ThreadContext *tc) const; 368 369 /** 370 * Return true if the instruction is a control transfer, and if so, 371 * return the target address as well. 372 */ 373 bool hasBranchTarget(const TheISA::PCState &pc, ThreadContext *tc, 374 TheISA::PCState &tgt) const; 375 376 /** 377 * Return string representation of disassembled instruction. 378 * The default version of this function will call the internal 379 * virtual generateDisassembly() function to get the string, 380 * then cache it in #cachedDisassembly. If the disassembly 381 * should not be cached, this function should be overridden directly. 382 */ 383 virtual const std::string &disassemble(Addr pc, 384 const SymbolTable *symtab = 0) const; 385 386 /// Return name of machine instruction 387 std::string getName() { return mnemonic; } 388}; 389 390#endif // __CPU_STATIC_INST_HH__ 391