support bitwise operations in formulas

Author: ckrause

CHANGELOG.md

@@ -6,6 +6,7 @@ To install or update LODA, please follow the [installation instructions](https:/
 
 * Improve negativity check in formula generation
 * Simplify formulas generated from `nrt` operations
+* Limited support for bit-wise operations in formulas
 
 ## v24.12.8
 

src/form/formula_gen.cpp

@@ -68,6 +68,17 @@ Expression FormulaGenerator::divToFraction(
   return wrapper;
 }
 
+bool FormulaGenerator::bitfunc(const std::string& name, const Expression& a,
+                               const Expression& b, Expression& res) const {
+  if (ExpressionUtil::canBeNegative(a, offset) ||
+      ExpressionUtil::canBeNegative(b, offset)) {
+    // TODO: remove this limitation
+    return false;
+  }
+  res = Expression(Expression::Type::FUNCTION, name, {a, b});
+  return true;
+}
+
 bool FormulaGenerator::update(const Operation& op) {
   auto source = operandToExpression(op.source);
   auto target = operandToExpression(op.target);
@@ -162,6 +173,18 @@ bool FormulaGenerator::update(const Operation& op) {
       res = Expression(Expression::Type::FUNCTION, "max", {prevTarget, source});
       break;
     }
+    case Operation::Type::BAN: {
+      okay = bitfunc("bitand", prevTarget, source, res);
+      break;
+    }
+    case Operation::Type::BOR: {
+      okay = bitfunc("bitor", prevTarget, source, res);
+      break;
+    }
+    case Operation::Type::BXO: {
+      okay = bitfunc("bitxor", prevTarget, source, res);
+      break;
+    }
     case Operation::Type::SEQ: {
       res = Expression(Expression::Type::FUNCTION,
                        ProgramUtil::idStr(source.value.asInt()), {prevTarget});

src/form/formula_gen.hpp

@@ -37,6 +37,9 @@ class FormulaGenerator {
   Expression divToFraction(const Expression& numerator,
                            const Expression& denominator) const;
 
+  bool bitfunc(const std::string& name, const Expression& a,
+               const Expression& b, Expression& res) const;
+
   bool update(const Operation& op);
 
   bool update(const Program& p);