benchmarking: started tuning benchmarking results. found some errors that need fixing

package/src/ExpressionExecutorCuda.jl

@@ -58,21 +58,34 @@ end
 
 
 # Evaluate Expressions on the CPU
-function interpret_cpu(exprs::Vector{Expr}, X::Matrix{Float32}, p::Vector{Vector{Float32}}; repetitions=1)::Matrix{Float32}
+function interpret_cpu(exprs::Vector{Expr}, X::Matrix{Float32}, p::Vector{Vector{Float32}}; repetitions=1, parallel=false)::Matrix{Float32}
 	@assert axes(exprs) == axes(p)
 	nrows = size(X, 1)
 	
 	# each column of the matrix has the result for an expr
 	res = Matrix{Float32}(undef, nrows, length(exprs))
 
-	for i in eachindex(exprs) 
-		# The interpreter holds the postfix code and buffers for evaluation. It is costly to create
-		interpreter = CpuInterpreter.Interpreter{Float32}(exprs[i], length(p[i])) 
-
-		# If an expression has to be evaluated multiple times (e.g. for different parameters),
-		# it is worthwhile to reuse the interpreter to reduce the number of allocations
-		for rep in 1:repetitions
-			CpuInterpreter.interpret!((@view res[:,i]), interpreter, X, p[i])
+	if parallel
+		Threads.@threads for i in eachindex(exprs) 
+			# The interpreter holds the postfix code and buffers for evaluation. It is costly to create
+			interpreter = CpuInterpreter.Interpreter{Float32}(exprs[i], length(p[i])) 
+	
+			# If an expression has to be evaluated multiple times (e.g. for different parameters),
+			# it is worthwhile to reuse the interpreter to reduce the number of allocations
+			for rep in 1:repetitions
+				CpuInterpreter.interpret!((@view res[:,i]), interpreter, X, p[i])
+			end
+		end
+	else
+		for i in eachindex(exprs) 
+			# The interpreter holds the postfix code and buffers for evaluation. It is costly to create
+			interpreter = CpuInterpreter.Interpreter{Float32}(exprs[i], length(p[i])) 
+			
+			# If an expression has to be evaluated multiple times (e.g. for different parameters),
+			# it is worthwhile to reuse the interpreter to reduce the number of allocations
+			for rep in 1:repetitions
+				CpuInterpreter.interpret!((@view res[:,i]), interpreter, X, p[i])
+			end
 		end
 	end
 

package/src/ExpressionProcessing.jl

@@ -100,7 +100,7 @@ function get_operator(op::Symbol)::Operator
 	elseif op == :sqrt
 		return SQRT
 	else
-		throw("Operator unknown")
+		throw("Operator unknown. Operator was $op")
 	end
 end