src/cpu/timing_expr.cc

   1 /*
   2  * Copyright (c) 2013-2014 ARM Limited
   3  * All rights reserved.
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * Authors: Andrew Bardsley
  38  */
  39
  40 #include "base/intmath.hh"
  41 #include "cpu/timing_expr.hh"
  42
  43 TimingExprEvalContext::TimingExprEvalContext (StaticInstPtr inst_,
  44     ThreadContext *thread_,
  45     TimingExprLet *let_) :
  46     inst(inst_), thread(thread_), let(let_)
  47 {
  48     /* Reserve space to hold the results of evaluating the
  49      *  let expressions */
  50     if (let) {
  51         unsigned int num_defns = let->defns.size();
  52
  53         results.resize(num_defns, 0);
  54         resultAvailable.resize(num_defns, false);
  55     }
  56 }
  57
  58 uint64_t TimingExprSrcReg::eval(TimingExprEvalContext &context)
  59 {
  60     return context.inst->srcRegIdx(index);
  61 }
  62
  63 uint64_t TimingExprReadIntReg::eval(TimingExprEvalContext &context)
  64 {
  65     return context.thread->readIntReg(reg->eval(context));
  66 }
  67
  68 uint64_t TimingExprLet::eval(TimingExprEvalContext &context)
  69 {
  70     TimingExprEvalContext new_context(context.inst,
  71         context.thread, this);
  72
  73     return expr->eval(new_context);
  74 }
  75
  76 uint64_t TimingExprRef::eval(TimingExprEvalContext &context)
  77 {
  78     /* Lookup the result, evaluating if necessary.  @todo, this
  79      *  should have more error checking */
  80     if (!context.resultAvailable[index]) {
  81         context.results[index] = context.let->defns[index]->eval(context);
  82         context.resultAvailable[index] = true;
  83     }
  84
  85     return context.results[index];
  86 }
  87
  88 uint64_t TimingExprUn::eval(TimingExprEvalContext &context)
  89 {
  90     uint64_t arg_value = arg->eval(context);
  91     uint64_t ret = 0;
  92
  93     switch (op) {
  94       case Enums::timingExprSizeInBits:
  95         if (arg_value == 0)
  96             ret = 0;
  97         else
  98             ret = ceilLog2(arg_value);
  99         break;
 100       case Enums::timingExprNot:
 101         ret = arg_value != 0;
 102         break;
 103       case Enums::timingExprInvert:
 104         ret = ~arg_value;
 105         break;
 106       case Enums::timingExprSignExtend32To64:
 107         ret = static_cast<int64_t>(
 108             static_cast<int32_t>(arg_value));
 109         break;
 110       case Enums::timingExprAbs:
 111         if (static_cast<int64_t>(arg_value) < 0)
 112             ret = -arg_value;
 113         else
 114             ret = arg_value;
 115         break;
 116       default:
 117         break;
 118     }
 119
 120     return ret;
 121 }
 122
 123 uint64_t TimingExprBin::eval(TimingExprEvalContext &context)
 124 {
 125     uint64_t left_value = left->eval(context);
 126     uint64_t right_value = right->eval(context);
 127     uint64_t ret = 0;
 128
 129     switch (op) {
 130       case Enums::timingExprAdd:
 131           ret = left_value + right_value;
 132           break;
 133       case Enums::timingExprSub:
 134           ret = left_value - right_value;
 135           break;
 136       case Enums::timingExprUMul:
 137           ret = left_value * right_value;
 138           break;
 139       case Enums::timingExprUDiv:
 140           if (right_value != 0) {
 141               ret = left_value / right_value;
 142           }
 143           break;
 144       case Enums::timingExprUCeilDiv:
 145           if (right_value != 0) {
 146               ret = (left_value + (right_value - 1)) / right_value;
 147           }
 148           break;
 149       case Enums::timingExprSMul:
 150           ret = static_cast<int64_t>(left_value) *
 151               static_cast<int64_t>(right_value);
 152           break;
 153       case Enums::timingExprSDiv:
 154           if (right_value != 0) {
 155               ret = static_cast<int64_t>(left_value) /
 156                   static_cast<int64_t>(right_value);
 157           }
 158           break;
 159       case Enums::timingExprEqual:
 160           ret = left_value == right_value;
 161           break;
 162       case Enums::timingExprNotEqual:
 163           ret = left_value != right_value;
 164           break;
 165       case Enums::timingExprULessThan:
 166           ret = left_value < right_value;
 167           break;
 168       case Enums::timingExprUGreaterThan:
 169           ret = left_value > right_value;
 170           break;
 171       case Enums::timingExprSLessThan:
 172           ret = static_cast<int64_t>(left_value) <
 173               static_cast<int64_t>(right_value);
 174           break;
 175       case Enums::timingExprSGreaterThan:
 176           ret = static_cast<int64_t>(left_value) >
 177               static_cast<int64_t>(right_value);
 178           break;
 179       case Enums::timingExprAnd:
 180           ret = (left_value != 0) && (right_value != 0);
 181           break;
 182       case Enums::timingExprOr:
 183           ret = (left_value != 0) || (right_value != 0);
 184           break;
 185       default:
 186           break;
 187     }
 188
 189     return ret;
 190 }
 191
 192 uint64_t TimingExprIf::eval(TimingExprEvalContext &context)
 193 {
 194     uint64_t cond_value = cond->eval(context);
 195
 196     if (cond_value != 0)
 197         return trueExpr->eval(context);
 198     else
 199         return falseExpr->eval(context);
 200 }
 201
 202 TimingExprLiteral *
 203 TimingExprLiteralParams::create()
 204 {
 205     return new TimingExprLiteral(this);
 206 }
 207
 208 TimingExprSrcReg *
 209 TimingExprSrcRegParams::create()
 210 {
 211     return new TimingExprSrcReg(this);
 212 }
 213
 214 TimingExprReadIntReg *
 215 TimingExprReadIntRegParams::create()
 216 {
 217     return new TimingExprReadIntReg(this);
 218 }
 219
 220 TimingExprLet *
 221 TimingExprLetParams::create()
 222 {
 223     return new TimingExprLet(this);
 224 }
 225
 226 TimingExprRef *
 227 TimingExprRefParams::create()
 228 {
 229     return new TimingExprRef(this);
 230 }
 231
 232 TimingExprUn *
 233 TimingExprUnParams::create()
 234 {
 235     return new TimingExprUn(this);
 236 }
 237
 238 TimingExprBin *
 239 TimingExprBinParams::create()
 240 {
 241     return new TimingExprBin(this);
 242 }
 243
 244 TimingExprIf *
 245 TimingExprIfParams::create()
 246 {
 247     return new TimingExprIf(this);
 248 }