view Lib/fftw-3.2.1/genfft/expr.ml @ 1:e86e9c111b29

Updates stuff that potentially fixes the memory leak and also makes it work on Windows and Linux (Need to test). Still have to fix fftw include for linux in Jucer.

(*
 * Copyright (c) 1997-1999 Massachusetts Institute of Technology
 * Copyright (c) 2003, 2007-8 Matteo Frigo
 * Copyright (c) 2003, 2007-8 Massachusetts Institute of Technology
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *)

(* Here, we define the data type encapsulating a symbolic arithmetic
   expression, and provide some routines for manipulating it. *)

(* I will regret this hack : *)
(* NEWS: I did *)
type transcendent = I | MULTI_A | MULTI_B | CONJ

type expr =
  | Num of Number.number
  | NaN of transcendent
  | Plus of expr list
  | Times of expr * expr
  | CTimes of expr * expr
  | CTimesJ of expr * expr  (* CTimesJ (a, b) = conj(a) * b *)
  | Uminus of expr
  | Load of Variable.variable
  | Store of Variable.variable * expr

type assignment = Assign of Variable.variable * expr

(* various hash functions *)
let hash_float x = 
  let (mantissa, exponent) = frexp x
  in truncate (float_of_int(exponent) *. 1234.567 +. mantissa *. 10000.0)

let sum_list l = List.fold_right (+) l 0

let transcendent_to_float = function
  | I -> 2.718281828459045235360287471  (* any transcendent number will do *)
  | MULTI_A -> 0.6931471805599453094172321214
  | MULTI_B -> -0.3665129205816643270124391582
  | CONJ -> 0.6019072301972345747375400015

let rec hash = function
  | Num x -> hash_float (Number.to_float x)
  | NaN x -> hash_float (transcendent_to_float x)
  | Load v -> 1 + 1237 * Variable.hash v
  | Store (v, x) -> 2 * Variable.hash v - 2345 * hash x
  | Plus l -> 5 + 23451 * sum_list (List.map Hashtbl.hash l)
  | Times (a, b) -> 41 + 31415 * (Hashtbl.hash a +  Hashtbl.hash b)
  | CTimes (a, b) -> 49 + 3245 * (Hashtbl.hash a +  Hashtbl.hash b)
  | CTimesJ (a, b) -> 31 + 3471 * (Hashtbl.hash a +  Hashtbl.hash b)
  | Uminus x -> 42 + 12345 * (hash x)

(* find all variables *)
let rec find_vars x =
  match x with
  | Load y -> [y]
  | Plus l -> List.flatten (List.map find_vars l)
  | Times (a, b) -> (find_vars a) @ (find_vars b)
  | CTimes (a, b) -> (find_vars a) @ (find_vars b)
  | CTimesJ (a, b) -> (find_vars a) @ (find_vars b)
  | Uminus a -> find_vars a
  | _ -> []


(* TRUE if expression is a constant *)
let is_constant = function
  | Num _ -> true
  | NaN _ -> true
  | Load v -> Variable.is_constant v
  | _ -> false

let is_known_constant = function
  | Num _ -> true
  | NaN _ -> true
  | _ -> false

(* expr to string, used for debugging *)
let rec foldr_string_concat l = 
  match l with
    [] -> ""
  | [a] -> a
  | a :: b -> a ^ " " ^ (foldr_string_concat b)

let string_of_transcendent = function
  | I -> "I"
  | MULTI_A -> "MULTI_A"
  | MULTI_B -> "MULTI_B"
  | CONJ -> "CONJ"

let rec to_string = function
  | Load v -> Variable.unparse v
  | Num n -> string_of_float (Number.to_float n)
  | NaN n -> string_of_transcendent n
  | Plus x -> "(+ " ^ (foldr_string_concat (List.map to_string x)) ^ ")"
  | Times (a, b) -> "(* " ^ (to_string a) ^ " " ^ (to_string b) ^ ")"
  | CTimes (a, b) -> "(c* " ^ (to_string a) ^ " " ^ (to_string b) ^ ")"
  | CTimesJ (a, b) -> "(cj* " ^ (to_string a) ^ " " ^ (to_string b) ^ ")"
  | Uminus a -> "(- " ^ (to_string a) ^ ")"
  | Store (v, a) -> "(:= " ^ (Variable.unparse v) ^ " " ^
      (to_string a) ^ ")"

let rec to_string_a d x = 
  if (d = 0) then "..." else match x with
  | Load v -> Variable.unparse v
  | Num n -> Number.to_konst n
  | NaN n -> string_of_transcendent n
  | Plus x -> "(+ " ^ (foldr_string_concat (List.map (to_string_a (d - 1)) x)) ^ ")"
  | Times (a, b) -> "(* " ^ (to_string_a (d - 1) a) ^ " " ^ (to_string_a (d - 1) b) ^ ")"
  | CTimes (a, b) -> "(c* " ^ (to_string_a (d - 1) a) ^ " " ^ (to_string_a (d - 1) b) ^ ")"
  | CTimesJ (a, b) -> "(cj* " ^ (to_string_a (d - 1) a) ^ " " ^ (to_string_a (d - 1) b) ^ ")"
  | Uminus a -> "(- " ^ (to_string_a (d-1) a) ^ ")"
  | Store (v, a) -> "(:= " ^ (Variable.unparse v) ^ " " ^
      (to_string_a (d-1) a) ^ ")"

let to_string = to_string_a 10

let assignment_to_string = function
  | Assign (v, a) -> "(:= " ^ (Variable.unparse v) ^ " " ^ (to_string a) ^ ")"

let dump print = List.iter (fun x -> print ((assignment_to_string x) ^ "\n"))

(* find all constants in a given expression *)
let rec expr_to_constants = function
  | Num n -> [n]
  | Plus a -> List.flatten (List.map expr_to_constants a)
  | Times (a, b) -> (expr_to_constants a) @ (expr_to_constants b)
  | CTimes (a, b) -> (expr_to_constants a) @ (expr_to_constants b)
  | CTimesJ (a, b) -> (expr_to_constants a) @ (expr_to_constants b)
  | Uminus a -> expr_to_constants a
  | _ -> []


let add_float_key_value list_so_far k = 
  if List.exists (fun k2 -> Number.equal k k2) list_so_far then
    list_so_far
  else
    k :: list_so_far

let unique_constants = List.fold_left add_float_key_value []