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Commit 95fa837c authored by Peter Eastman's avatar Peter Eastman
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Implemented more optimizations

parent 119fb95d
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Showing with 45 additions and 20 deletions
libraries/lepton/src/ParsedExpression.cpp
View file @ 95fa837c
...@@ -109,25 +109,25 @@ ExpressionTreeNode ParsedExpression::substituteSimplerExpression(const Expressio ...@@ -109,25 +109,25 @@ ExpressionTreeNode ParsedExpression::substituteSimplerExpression(const Expressio
{ {
double first = getConstantValue(children[0]); double first = getConstantValue(children[0]);
double second = getConstantValue(children[1]); double second = getConstantValue(children[1]);
if (first == 0.0) if (first == 0.0) // Add 0
return children[1]; return children[1];
if (first == 1.0) if (first == 1.0) // Add 1
return ExpressionTreeNode(new Operation::Increment(), children[1]); return ExpressionTreeNode(new Operation::Increment(), children[1]);
if (second == 0.0) if (second == 0.0) // Add 0
return children[0]; return children[0];
if (second == 1.0) if (second == 1.0) // Add 1
return ExpressionTreeNode(new Operation::Increment(), children[0]); return ExpressionTreeNode(new Operation::Increment(), children[0]);
break; break;
} }
case Operation::SUBTRACT: case Operation::SUBTRACT:
{ {
double first = getConstantValue(children[0]); double first = getConstantValue(children[0]);
if (first == 0.0) if (first == 0.0) // Subtract from 0
return ExpressionTreeNode(new Operation::Negate(), children[1]); return ExpressionTreeNode(new Operation::Negate(), children[1]);
double second = getConstantValue(children[1]); double second = getConstantValue(children[1]);
if (second == 0.0) if (second == 0.0) // Subtract 0
return children[0]; return children[0];
if (second == 1.0) if (second == 1.0) // Subtract 1
return ExpressionTreeNode(new Operation::Decrement(), children[0]); return ExpressionTreeNode(new Operation::Decrement(), children[0]);
break; break;
} }
...@@ -135,43 +135,68 @@ ExpressionTreeNode ParsedExpression::substituteSimplerExpression(const Expressio ...@@ -135,43 +135,68 @@ ExpressionTreeNode ParsedExpression::substituteSimplerExpression(const Expressio
{ {
double first = getConstantValue(children[0]); double first = getConstantValue(children[0]);
double second = getConstantValue(children[1]); double second = getConstantValue(children[1]);
if (first == 0.0 || second == 0.0) if (first == 0.0 || second == 0.0) // Multiply by 0
return ExpressionTreeNode(new Operation::Constant(0.0)); return ExpressionTreeNode(new Operation::Constant(0.0));
if (first == 1.0) if (first == 1.0) // Multiply by 1
return children[1]; return children[1];
if (second == 1.0) if (second == 1.0) // Multiply by 1
return children[0]; return children[0];
if (children[0].getOperation().getId() == Operation::CONSTANT) {
if (children[1].getOperation().getId() == Operation::MULTIPLY) {
if (children[1].getChildren()[0].getOperation().getId() == Operation::CONSTANT) // Combine two multiplies into a single one
return ExpressionTreeNode(new Operation::Multiply(), children[1].getChildren()[1], ExpressionTreeNode(new Operation::Constant(getConstantValue(children[1].getChildren()[0])*first)));
if (children[1].getChildren()[1].getOperation().getId() == Operation::CONSTANT) // Combine two multiplies into a single one
return ExpressionTreeNode(new Operation::Multiply(), children[1].getChildren()[0], ExpressionTreeNode(new Operation::Constant(getConstantValue(children[1].getChildren()[1])*first)));
}
}
if (children[1].getOperation().getId() == Operation::CONSTANT) {
if (children[0].getOperation().getId() == Operation::MULTIPLY) {
if (children[0].getChildren()[0].getOperation().getId() == Operation::CONSTANT) // Combine two multiplies into a single one
return ExpressionTreeNode(new Operation::Multiply(), children[0].getChildren()[1], ExpressionTreeNode(new Operation::Constant(getConstantValue(children[0].getChildren()[0])*second)));
if (children[0].getChildren()[1].getOperation().getId() == Operation::CONSTANT) // Combine two multiplies into a single one
return ExpressionTreeNode(new Operation::Multiply(), children[0].getChildren()[0], ExpressionTreeNode(new Operation::Constant(getConstantValue(children[0].getChildren()[1])*second)));
}
}
break; break;
} }
case Operation::DIVIDE: case Operation::DIVIDE:
{ {
double numerator = getConstantValue(children[0]); double numerator = getConstantValue(children[0]);
if (numerator = 0.0) if (numerator = 0.0) // 0 divided by something
return ExpressionTreeNode(new Operation::Constant(0.0)); return ExpressionTreeNode(new Operation::Constant(0.0));
if (numerator == 1.0) if (numerator == 1.0) // 1 divided by something
return ExpressionTreeNode(new Operation::Reciprocal(), children[1]); return ExpressionTreeNode(new Operation::Reciprocal(), children[1]);
double denominator = getConstantValue(children[1]); double denominator = getConstantValue(children[1]);
if (denominator == 1.0) if (denominator == 1.0) // Divide by 1
return children[0]; return children[0];
if (children[1].getOperation().getId() == Operation::CONSTANT) {
if (children[0].getOperation().getId() == Operation::MULTIPLY) {
if (children[0].getChildren()[0].getOperation().getId() == Operation::CONSTANT) // Combine a multiply and a divide into one multiply
return ExpressionTreeNode(new Operation::Multiply(), children[0].getChildren()[1], ExpressionTreeNode(new Operation::Constant(getConstantValue(children[0].getChildren()[0])/denominator)));
if (children[0].getChildren()[1].getOperation().getId() == Operation::CONSTANT) // Combine a multiply and a divide into one multiply
return ExpressionTreeNode(new Operation::Multiply(), children[0].getChildren()[0], ExpressionTreeNode(new Operation::Constant(getConstantValue(children[0].getChildren()[1])/denominator)));
}
return ExpressionTreeNode(new Operation::Multiply(), children[0], ExpressionTreeNode(new Operation::Constant(1.0/denominator))); // Replace a divide with a multiply
}
break; break;
} }
case Operation::POWER: case Operation::POWER:
{ {
double base = getConstantValue(children[0]); double base = getConstantValue(children[0]);
if (base == 0.0) if (base == 0.0) // 0 to any power is 0
return ExpressionTreeNode(new Operation::Constant(0.0)); return ExpressionTreeNode(new Operation::Constant(0.0));
if (base == 1.0) if (base == 1.0) // 1 to any power is 1
return ExpressionTreeNode(new Operation::Constant(1.0)); return ExpressionTreeNode(new Operation::Constant(1.0));
double exponent = getConstantValue(children[1]); double exponent = getConstantValue(children[1]);
if (exponent == 1.0) if (exponent == 1.0) // x^1 = x
return children[0]; return children[0];
if (exponent == -1.0) if (exponent == -1.0) // x^-1 = recip(x)
return ExpressionTreeNode(new Operation::Reciprocal(), children[0]); return ExpressionTreeNode(new Operation::Reciprocal(), children[0]);
if (exponent == 2.0) if (exponent == 2.0) // x^2 = square(x)
return ExpressionTreeNode(new Operation::Square(), children[0]); return ExpressionTreeNode(new Operation::Square(), children[0]);
if (exponent == 3.0) if (exponent == 3.0) // x^3 = cube(x)
return ExpressionTreeNode(new Operation::Cube(), children[0]); return ExpressionTreeNode(new Operation::Cube(), children[0]);
if (exponent == 0.5) if (exponent == 0.5) // x^0.5 = sqrt(x)
return ExpressionTreeNode(new Operation::Sqrt(), children[0]); return ExpressionTreeNode(new Operation::Sqrt(), children[0]);
break; break;
} }
......
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