1 files changed, 127 insertions, 0 deletions
diff --git a/src/sim/mathexpr.hh b/src/sim/mathexpr.hh
new file mode 100644
index 000000000..8f16cc851
--- /dev/null
+++ b/src/sim/mathexpr.hh
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2015 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 <functional>
+#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
+
+