timing_expr.hh

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/*
 * Copyright (c) 2013-2014 ARM Limited
 * All rights reserved.
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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/*
 * These classes define an expression language over uint64_t with only
 * a few operators.  This can be used to form expressions for the extra
 * delay required in variable execution time instructions.
 *
 * Expressions, in evaluation, will have access to the ThreadContext and
 * a StaticInst.
 */
 
#ifndef __CPU_TIMING_EXPR_HH__
#define __CPU_TIMING_EXPR_HH__
 
#include "cpu/static_inst.hh"
#include "cpu/thread_context.hh"
#include "enums/TimingExprOp.hh"
#include "params/TimingExpr.hh"
#include "params/TimingExprBin.hh"
#include "params/TimingExprIf.hh"
#include "params/TimingExprLet.hh"
#include "params/TimingExprLiteral.hh"
#include "params/TimingExprRef.hh"
#include "params/TimingExprSrcReg.hh"
#include "params/TimingExprUn.hh"
#include "sim/sim_object.hh"
 
namespace gem5
{
 
class TimingExprLet;
 
class TimingExprEvalContext
{
  public:
    const StaticInstPtr &inst;
    ThreadContext *thread;
 
    TimingExprLet *let;
    std::vector<uint64_t> results;
    std::vector<bool > resultAvailable;
 
    TimingExprEvalContext(const StaticInstPtr &inst_,
        ThreadContext *thread_, TimingExprLet *let_);
};
 
class TimingExpr : public SimObject
{
  public:
    TimingExpr(const TimingExprParams &params) :
        SimObject(params)
    { }
 
    virtual uint64_t eval(TimingExprEvalContext &context) = 0;
};
 
class TimingExprLiteral : public TimingExpr
{
  public:
    uint64_t value;
 
    TimingExprLiteral(const TimingExprLiteralParams &params) :
        TimingExpr(params),
        value(params.value)
    { }
 
    uint64_t eval(TimingExprEvalContext &context) { return value; }
};
 
class TimingExprSrcReg : public TimingExpr
{
  public:
    unsigned int index;
 
    TimingExprSrcReg(const TimingExprSrcRegParams &params) :
        TimingExpr(params),
        index(params.index)
    { }
 
    uint64_t eval(TimingExprEvalContext &context);
};
 
class TimingExprLet : public TimingExpr
{
  public:
    std::vector<TimingExpr *> defns;
    TimingExpr *expr;
 
    TimingExprLet(const TimingExprLetParams &params) :
        TimingExpr(params),
        defns(params.defns),
        expr(params.expr)
    { }
 
    uint64_t eval(TimingExprEvalContext &context);
};
 
class TimingExprRef : public TimingExpr
{
  public:
    unsigned int index;
 
    TimingExprRef(const TimingExprRefParams &params) :
        TimingExpr(params),
        index(params.index)
    { }
 
    uint64_t eval(TimingExprEvalContext &context);
};
 
class TimingExprUn : public TimingExpr
{
  public:
    enums::TimingExprOp op;
    TimingExpr *arg;
 
    TimingExprUn(const TimingExprUnParams &params) :
        TimingExpr(params),
        op(params.op),
        arg(params.arg)
    { }
 
    uint64_t eval(TimingExprEvalContext &context);
};
 
class TimingExprBin : public TimingExpr
{
  public:
    enums::TimingExprOp op;
    TimingExpr *left;
    TimingExpr *right;
 
    TimingExprBin(const TimingExprBinParams &params) :
        TimingExpr(params),
        op(params.op),
        left(params.left),
        right(params.right)
    { }
 
    uint64_t eval(TimingExprEvalContext &context);
};
 
class TimingExprIf : public TimingExpr
{
  public:
    TimingExpr *cond;
    TimingExpr *trueExpr;
    TimingExpr *falseExpr;
 
    TimingExprIf(const TimingExprIfParams &params) :
        TimingExpr(params),
        cond(params.cond),
        trueExpr(params.trueExpr),
        falseExpr(params.falseExpr)
    { }
 
    uint64_t eval(TimingExprEvalContext &context);
};
 
} // namespace gem5
 
#endif