static_inst.hh revision 12768:9a299ec956ac 
1/*
2 * Copyright (c) 2003-2005 The Regents of The University of Michigan
3 * Copyright (c) 2013 Advanced Micro Devices, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Steve Reinhardt
30 */
31
32#ifndef __CPU_STATIC_INST_HH__
33#define __CPU_STATIC_INST_HH__
34
35#include <bitset>
36#include <memory>
37#include <string>
38
39#include "arch/registers.hh"
40#include "arch/types.hh"
41#include "base/logging.hh"
42#include "base/refcnt.hh"
43#include "base/types.hh"
44#include "config/the_isa.hh"
45#include "cpu/op_class.hh"
46#include "cpu/reg_class.hh"
47#include "cpu/reg_class_impl.hh"
48#include "cpu/static_inst_fwd.hh"
49#include "cpu/thread_context.hh"
50#include "enums/StaticInstFlags.hh"
51#include "sim/byteswap.hh"
52
53// forward declarations
54class Packet;
55
56class ExecContext;
57
58class SymbolTable;
59
60namespace Trace {
61    class InstRecord;
62}
63
64/**
65 * Base, ISA-independent static instruction class.
66 *
67 * The main component of this class is the vector of flags and the
68 * associated methods for reading them.  Any object that can rely
69 * solely on these flags can process instructions without being
70 * recompiled for multiple ISAs.
71 */
72class StaticInst : public RefCounted, public StaticInstFlags
73{
74  public:
75    /// Binary extended machine instruction type.
76    typedef TheISA::ExtMachInst ExtMachInst;
77
78    enum {
79        MaxInstSrcRegs = TheISA::MaxInstSrcRegs,        //< Max source regs
80        MaxInstDestRegs = TheISA::MaxInstDestRegs       //< Max dest regs
81    };
82
83  protected:
84
85    /// Flag values for this instruction.
86    std::bitset<Num_Flags> flags;
87
88    /// See opClass().
89    OpClass _opClass;
90
91    /// See numSrcRegs().
92    int8_t _numSrcRegs;
93
94    /// See numDestRegs().
95    int8_t _numDestRegs;
96
97    /// The following are used to track physical register usage
98    /// for machines with separate int & FP reg files.
99    //@{
100    int8_t _numFPDestRegs;
101    int8_t _numIntDestRegs;
102    int8_t _numCCDestRegs;
103    //@}
104
105    /** To use in architectures with vector register file. */
106    /** @{ */
107    int8_t _numVecDestRegs;
108    int8_t _numVecElemDestRegs;
109    /** @} */
110
111  public:
112
113    /// @name Register information.
114    /// The sum of numFPDestRegs(), numIntDestRegs(), numVecDestRegs() and
115    /// numVecelemDestRegs() equals numDestRegs().  The former two functions
116    /// are used to track physical register usage for machines with separate
117    /// int & FP reg files, the next two is for machines with vector register
118    /// file.
119    //@{
120    /// Number of source registers.
121    int8_t numSrcRegs()  const { return _numSrcRegs; }
122    /// Number of destination registers.
123    int8_t numDestRegs() const { return _numDestRegs; }
124    /// Number of floating-point destination regs.
125    int8_t numFPDestRegs()  const { return _numFPDestRegs; }
126    /// Number of integer destination regs.
127    int8_t numIntDestRegs() const { return _numIntDestRegs; }
128    /// Number of vector destination regs.
129    int8_t numVecDestRegs() const { return _numVecDestRegs; }
130    /// Number of vector element destination regs.
131    int8_t numVecElemDestRegs() const { return _numVecElemDestRegs; }
132    /// Number of coprocesor destination regs.
133    int8_t numCCDestRegs() const { return _numCCDestRegs; }
134    //@}
135
136    /// @name Flag accessors.
137    /// These functions are used to access the values of the various
138    /// instruction property flags.  See StaticInst::Flags for descriptions
139    /// of the individual flags.
140    //@{
141
142    bool isNop()          const { return flags[IsNop]; }
143
144    bool isMemRef()       const { return flags[IsMemRef]; }
145    bool isLoad()         const { return flags[IsLoad]; }
146    bool isStore()        const { return flags[IsStore]; }
147    bool isAtomic()       const { return flags[IsAtomic]; }
148    bool isStoreConditional()     const { return flags[IsStoreConditional]; }
149    bool isInstPrefetch() const { return flags[IsInstPrefetch]; }
150    bool isDataPrefetch() const { return flags[IsDataPrefetch]; }
151    bool isPrefetch()     const { return isInstPrefetch() ||
152                                         isDataPrefetch(); }
153
154    bool isInteger()      const { return flags[IsInteger]; }
155    bool isFloating()     const { return flags[IsFloating]; }
156    bool isVector()       const { return flags[IsVector]; }
157    bool isCC()           const { return flags[IsCC]; }
158
159    bool isControl()      const { return flags[IsControl]; }
160    bool isCall()         const { return flags[IsCall]; }
161    bool isReturn()       const { return flags[IsReturn]; }
162    bool isDirectCtrl()   const { return flags[IsDirectControl]; }
163    bool isIndirectCtrl() const { return flags[IsIndirectControl]; }
164    bool isCondCtrl()     const { return flags[IsCondControl]; }
165    bool isUncondCtrl()   const { return flags[IsUncondControl]; }
166    bool isCondDelaySlot() const { return flags[IsCondDelaySlot]; }
167
168    bool isThreadSync()   const { return flags[IsThreadSync]; }
169    bool isSerializing()  const { return flags[IsSerializing] ||
170                                      flags[IsSerializeBefore] ||
171                                      flags[IsSerializeAfter]; }
172    bool isSerializeBefore() const { return flags[IsSerializeBefore]; }
173    bool isSerializeAfter() const { return flags[IsSerializeAfter]; }
174    bool isSquashAfter() const { return flags[IsSquashAfter]; }
175    bool isMemBarrier()   const { return flags[IsMemBarrier]; }
176    bool isWriteBarrier() const { return flags[IsWriteBarrier]; }
177    bool isNonSpeculative() const { return flags[IsNonSpeculative]; }
178    bool isQuiesce() const { return flags[IsQuiesce]; }
179    bool isIprAccess() const { return flags[IsIprAccess]; }
180    bool isUnverifiable() const { return flags[IsUnverifiable]; }
181    bool isSyscall() const { return flags[IsSyscall]; }
182    bool isMacroop() const { return flags[IsMacroop]; }
183    bool isMicroop() const { return flags[IsMicroop]; }
184    bool isDelayedCommit() const { return flags[IsDelayedCommit]; }
185    bool isLastMicroop() const { return flags[IsLastMicroop]; }
186    bool isFirstMicroop() const { return flags[IsFirstMicroop]; }
187    //This flag doesn't do anything yet
188    bool isMicroBranch() const { return flags[IsMicroBranch]; }
189    //@}
190
191    void setFirstMicroop() { flags[IsFirstMicroop] = true; }
192    void setLastMicroop() { flags[IsLastMicroop] = true; }
193    void setDelayedCommit() { flags[IsDelayedCommit] = true; }
194    void setFlag(Flags f) { flags[f] = true; }
195
196    /// Operation class.  Used to select appropriate function unit in issue.
197    OpClass opClass()     const { return _opClass; }
198
199
200    /// Return logical index (architectural reg num) of i'th destination reg.
201    /// Only the entries from 0 through numDestRegs()-1 are valid.
202    const RegId& destRegIdx(int i) const { return _destRegIdx[i]; }
203
204    /// Return logical index (architectural reg num) of i'th source reg.
205    /// Only the entries from 0 through numSrcRegs()-1 are valid.
206    const RegId& srcRegIdx(int i)  const { return _srcRegIdx[i]; }
207
208    /// Pointer to a statically allocated "null" instruction object.
209    static StaticInstPtr nullStaticInstPtr;
210
211    /// Pointer to a statically allocated generic "nop" instruction object.
212    static StaticInstPtr nopStaticInstPtr;
213
214    /// The binary machine instruction.
215    const ExtMachInst machInst;
216
217  protected:
218
219    /// See destRegIdx().
220    RegId _destRegIdx[MaxInstDestRegs];
221    /// See srcRegIdx().
222    RegId _srcRegIdx[MaxInstSrcRegs];
223
224    /**
225     * Base mnemonic (e.g., "add").  Used by generateDisassembly()
226     * methods.  Also useful to readily identify instructions from
227     * within the debugger when #cachedDisassembly has not been
228     * initialized.
229     */
230    const char *mnemonic;
231
232    /**
233     * String representation of disassembly (lazily evaluated via
234     * disassemble()).
235     */
236    mutable std::string *cachedDisassembly;
237
238    /**
239     * Internal function to generate disassembly string.
240     */
241    virtual std::string
242    generateDisassembly(Addr pc, const SymbolTable *symtab) const = 0;
243
244    /// Constructor.
245    /// It's important to initialize everything here to a sane
246    /// default, since the decoder generally only overrides
247    /// the fields that are meaningful for the particular
248    /// instruction.
249    StaticInst(const char *_mnemonic, ExtMachInst _machInst, OpClass __opClass)
250        : _opClass(__opClass), _numSrcRegs(0), _numDestRegs(0),
251          _numFPDestRegs(0), _numIntDestRegs(0), _numCCDestRegs(0),
252          _numVecDestRegs(0), _numVecElemDestRegs(0), machInst(_machInst),
253          mnemonic(_mnemonic), cachedDisassembly(0)
254    { }
255
256  public:
257    virtual ~StaticInst();
258
259    virtual Fault execute(ExecContext *xc,
260                          Trace::InstRecord *traceData) const = 0;
261
262    virtual Fault initiateAcc(ExecContext *xc,
263                              Trace::InstRecord *traceData) const
264    {
265        panic("initiateAcc not defined!");
266    }
267
268    virtual Fault completeAcc(Packet *pkt, ExecContext *xc,
269                              Trace::InstRecord *traceData) const
270    {
271        panic("completeAcc not defined!");
272    }
273
274    virtual void advancePC(TheISA::PCState &pcState) const = 0;
275
276    /**
277     * Return the microop that goes with a particular micropc. This should
278     * only be defined/used in macroops which will contain microops
279     */
280    virtual StaticInstPtr fetchMicroop(MicroPC upc) const;
281
282    /**
283     * Return the target address for a PC-relative branch.
284     * Invalid if not a PC-relative branch (i.e. isDirectCtrl()
285     * should be true).
286     */
287    virtual TheISA::PCState branchTarget(const TheISA::PCState &pc) const;
288
289    /**
290     * Return the target address for an indirect branch (jump).  The
291     * register value is read from the supplied thread context, so
292     * the result is valid only if the thread context is about to
293     * execute the branch in question.  Invalid if not an indirect
294     * branch (i.e. isIndirectCtrl() should be true).
295     */
296    virtual TheISA::PCState branchTarget(ThreadContext *tc) const;
297
298    /**
299     * Return true if the instruction is a control transfer, and if so,
300     * return the target address as well.
301     */
302    bool hasBranchTarget(const TheISA::PCState &pc, ThreadContext *tc,
303                         TheISA::PCState &tgt) const;
304
305    /**
306     * Return string representation of disassembled instruction.
307     * The default version of this function will call the internal
308     * virtual generateDisassembly() function to get the string,
309     * then cache it in #cachedDisassembly.  If the disassembly
310     * should not be cached, this function should be overridden directly.
311     */
312    virtual const std::string &disassemble(Addr pc,
313        const SymbolTable *symtab = 0) const;
314
315    /**
316     * Print a separator separated list of this instruction's set flag
317     * names on the given stream.
318     */
319    void printFlags(std::ostream &outs, const std::string &separator) const;
320
321    /// Return name of machine instruction
322    std::string getName() { return mnemonic; }
323
324  protected:
325    template<typename T>
326    size_t
327    simpleAsBytes(void *buf, size_t max_size, const T &t)
328    {
329        size_t size = sizeof(T);
330        if (size <= max_size)
331            *reinterpret_cast<T *>(buf) = htole<T>(t);
332        return size;
333    }
334
335  public:
336    /**
337     * Instruction classes can override this function to return a
338     * a representation of themselves as a blob of bytes, generally assumed to
339     * be that instructions ExtMachInst.
340     *
341     * buf is a buffer to hold the bytes.
342     * max_size is the size allocated for that buffer by the caller.
343     * The return value is how much data was actually put into the buffer,
344     * zero if no data was put in the buffer, or the necessary size of the
345     * buffer if there wasn't enough space.
346     */
347    virtual size_t asBytes(void *buf, size_t max_size) { return 0; }
348};
349
350#endif // __CPU_STATIC_INST_HH__
351