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Diffstat (limited to 'src/sim/mathexpr.hh')
-rw-r--r-- | src/sim/mathexpr.hh | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/sim/mathexpr.hh b/src/sim/mathexpr.hh new file mode 100644 index 000000000..d857fa512 --- /dev/null +++ b/src/sim/mathexpr.hh @@ -0,0 +1,126 @@ +/* + * Copyright (c) 2016 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 + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: David Guillen Fandos + */ + +#ifndef __SIM_MATHEXPR_HH__ +#define __SIM_MATHEXPR_HH__ + +#include <algorithm> +#include <string> + +class MathExpr { + public: + + MathExpr(std::string expr); + + typedef std::function<double(std::string)> EvalCallback; + + /** + * Prints an ASCII representation of the expression tree + * + * @return A string containing the ASCII representation of the expression + */ + std::string toStr() const { return toStr(root, ""); } + + /** + * Evaluates the expression + * + * @param fn A callback funcion to evaluate variables + * + * @return The value for this expression + */ + double eval(EvalCallback fn) const { return eval(root, fn); } + + private: + enum Operator { + bAdd, bSub, bMul, bDiv, bPow, uNeg, sValue, sVariable, nInvalid + }; + + // Match operators + const int MAX_PRIO = 4; + typedef double (*binOp)(double, double); + struct OpSearch { + bool binary; + Operator op; + int priority; + char c; + binOp fn; + }; + + /** Operator list */ + std::array<OpSearch, uNeg + 1> ops; + + class Node { + public: + Node() : op(nInvalid), l(0), r(0), value(0) {} + std::string toStr() const { + const char opStr[] = {'+', '-', '*', '/', '^', '-'}; + switch (op) { + case nInvalid: + return "INVALID"; + case sVariable: + return variable; + case sValue: + return std::to_string(value); + default: + return std::string(1, opStr[op]); + }; + } + + Operator op; + Node *l, *r; + double value; + std::string variable; + }; + + /** Root node */ + Node * root; + + /** Parse and create nodes from string */ + Node *parse(std::string expr); + + /** Print tree as string */ + std::string toStr(Node *n, std::string prefix) const; + + /** Eval a node */ + double eval(const Node *n, EvalCallback fn) const; +}; + +#endif + + |