Chris@82: (*
Chris@82:  * Copyright (c) 1997-1999 Massachusetts Institute of Technology
Chris@82:  * Copyright (c) 2003, 2007-14 Matteo Frigo
Chris@82:  * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
Chris@82:  *
Chris@82:  * This program is free software; you can redistribute it and/or modify
Chris@82:  * it under the terms of the GNU General Public License as published by
Chris@82:  * the Free Software Foundation; either version 2 of the License, or
Chris@82:  * (at your option) any later version.
Chris@82:  *
Chris@82:  * This program is distributed in the hope that it will be useful,
Chris@82:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@82:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@82:  * GNU General Public License for more details.
Chris@82:  *
Chris@82:  * You should have received a copy of the GNU General Public License
Chris@82:  * along with this program; if not, write to the Free Software
Chris@82:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
Chris@82:  *
Chris@82:  *)
Chris@82: 
Chris@82: open Util
Chris@82: open Genutil
Chris@82: open C
Chris@82: 
Chris@82: 
Chris@82: type ditdif = DIT | DIF
Chris@82: let ditdif = ref DIT
Chris@82: let usage = "Usage: " ^ Sys.argv.(0) ^ " -n <number> [ -dit | -dif ]"
Chris@82: 
Chris@82: let urs = ref Stride_variable
Chris@82: 
Chris@82: let speclist = [
Chris@82:   "-dit",
Chris@82:   Arg.Unit(fun () -> ditdif := DIT),
Chris@82:   " generate a DIT codelet";
Chris@82: 
Chris@82:   "-dif",
Chris@82:   Arg.Unit(fun () -> ditdif := DIF),
Chris@82:   " generate a DIF codelet";
Chris@82: 
Chris@82:   "-with-rs",
Chris@82:   Arg.String(fun x -> urs := arg_to_stride x),
Chris@82:   " specialize for given R-stride";
Chris@82: ]
Chris@82: 
Chris@82: let byi = Complex.times Complex.i
Chris@82: let byui = Complex.times (Complex.uminus Complex.i)
Chris@82: 
Chris@82: let sym n f i = if (i < n - i) then f i else Complex.conj (f i)
Chris@82: 
Chris@82: let shuffle_eo fe fo i = if i mod 2 == 0 then fe (i/2) else fo ((i-1)/2)
Chris@82: 
Chris@82: let generate n =
Chris@82:   let rs = "rs"
Chris@82:   and twarray = "W"
Chris@82:   and m = "m" and mb = "mb" and me = "me" and ms = "ms"
Chris@82: 
Chris@82:   (* the array names are from the point of view of the complex array
Chris@82:      (output in R2C, input in C2R) *)
Chris@82:   and arp = "Rp" (* real, positive *)
Chris@82:   and aip = "Ip" (* imag, positive *)
Chris@82:   and arm = "Rm" (* real, negative *)
Chris@82:   and aim = "Im" (* imag, negative *)
Chris@82: 
Chris@82:   in
Chris@82: 
Chris@82:   let sign = !Genutil.sign 
Chris@82:   and name = !Magic.codelet_name 
Chris@82:   and byvl x = choose_simd x (ctimes (CVar "VL", x)) in
Chris@82: 
Chris@82:   let (bytwiddle, num_twiddles, twdesc) = Twiddle.twiddle_policy 1 false in
Chris@82:   let nt = num_twiddles n in
Chris@82: 
Chris@82:   let byw = bytwiddle n sign (twiddle_array nt twarray) in
Chris@82: 
Chris@82:   let vrs = either_stride (!urs) (C.SVar rs) in
Chris@82: 
Chris@82:   (* assume a single location.  No point in doing alias analysis *)
Chris@82:   let the_location = (Unique.make (), Unique.make ()) in
Chris@82:   let locations _ = the_location in
Chris@82: 
Chris@82:   let locr = (locative_array_c n 
Chris@82: 		(C.array_subscript arp vrs)
Chris@82: 		(C.array_subscript arm vrs)
Chris@82: 		locations "BUG")
Chris@82:   and loci = (locative_array_c n 
Chris@82: 		(C.array_subscript aip vrs)
Chris@82: 		(C.array_subscript aim vrs)
Chris@82: 		locations "BUG")
Chris@82:   and locp = (locative_array_c n 
Chris@82: 		(C.array_subscript arp vrs)
Chris@82: 		(C.array_subscript aip vrs)
Chris@82: 		locations "BUG")
Chris@82:   and locm = (locative_array_c n 
Chris@82: 		(C.array_subscript arm vrs)
Chris@82: 		(C.array_subscript aim vrs)
Chris@82: 		locations "BUG")
Chris@82:   in
Chris@82:   let locri i = if i mod 2 == 0 then locr (i/2) else loci ((i-1)/2)
Chris@82:   and locpm i = if i < n - i then locp i else locm (n-1-i)
Chris@82:   in
Chris@82: 
Chris@82:   let asch = 
Chris@82:     match !ditdif with
Chris@82:     | DIT -> 
Chris@82: 	let output = Fft.dft sign n (byw (load_array_c n locri)) in
Chris@82: 	let odag = store_array_c n locpm (sym n output) in
Chris@82: 	  standard_optimizer odag 
Chris@82: 
Chris@82:     | DIF -> 
Chris@82: 	let output = byw (Fft.dft sign n (sym n (load_array_c n locpm))) in
Chris@82: 	let odag = store_array_c n locri output in
Chris@82: 	  standard_optimizer odag 
Chris@82:   in
Chris@82: 
Chris@82:   let vms = CVar "ms" 
Chris@82:   and varp = CVar arp
Chris@82:   and vaip = CVar aip
Chris@82:   and varm = CVar arm
Chris@82:   and vaim = CVar aim
Chris@82:   and vm = CVar m and vmb = CVar mb and vme = CVar me 
Chris@82:   in
Chris@82:   let body = Block (
Chris@82:     [Decl ("INT", m)],
Chris@82:     [For (list_to_comma
Chris@82: 	    [Expr_assign (vm, vmb);
Chris@82: 	     Expr_assign (CVar twarray, 
Chris@82: 			  CPlus [CVar twarray; 
Chris@82: 				 ctimes (CPlus [vmb; CUminus (Integer 1)],
Chris@82: 					 Integer nt)])],
Chris@82: 	  Binop (" < ", vm, vme),
Chris@82: 	  list_to_comma 
Chris@82: 	    [Expr_assign (vm, CPlus [vm; byvl (Integer 1)]);
Chris@82: 	     Expr_assign (varp, CPlus [varp; byvl vms]);
Chris@82: 	     Expr_assign (vaip, CPlus [vaip; byvl vms]);
Chris@82: 	     Expr_assign (varm, CPlus [varm; CUminus (byvl vms)]);
Chris@82: 	     Expr_assign (vaim, CPlus [vaim; CUminus (byvl vms)]);
Chris@82: 	     Expr_assign (CVar twarray, CPlus [CVar twarray; 
Chris@82: 					       byvl (Integer nt)]);
Chris@82: 	     make_volatile_stride (4*n) (CVar rs)
Chris@82: 	   ],
Chris@82: 	  Asch asch)])
Chris@82:   in
Chris@82: 
Chris@82:   let tree = 
Chris@82:     Fcn ("static void", name,
Chris@82: 	 [Decl (C.realtypep, arp);
Chris@82: 	  Decl (C.realtypep, aip);
Chris@82: 	  Decl (C.realtypep, arm);
Chris@82: 	  Decl (C.realtypep, aim);
Chris@82: 	  Decl (C.constrealtypep, twarray);
Chris@82: 	  Decl (C.stridetype, rs);
Chris@82: 	  Decl ("INT", mb);
Chris@82: 	  Decl ("INT", me);
Chris@82: 	  Decl ("INT", ms)],
Chris@82:          finalize_fcn body)
Chris@82:   in
Chris@82:   let twinstr = 
Chris@82:     Printf.sprintf "static const tw_instr twinstr[] = %s;\n\n" 
Chris@82:       (twinstr_to_string "VL" (twdesc n))
Chris@82:   and desc = 
Chris@82:     Printf.sprintf
Chris@82:       "static const hc2c_desc desc = {%d, \"%s\", twinstr, &GENUS, %s};\n\n"
Chris@82:       n name (flops_of tree)
Chris@82:   and register = "X(khc2c_register)"
Chris@82: 
Chris@82:   in
Chris@82:   let init =
Chris@82:     "\n" ^
Chris@82:     twinstr ^ 
Chris@82:     desc ^
Chris@82:     (declare_register_fcn name) ^
Chris@82:     (Printf.sprintf "{\n%s(p, %s, &desc, HC2C_VIA_RDFT);\n}" register name)
Chris@82:   in
Chris@82: 
Chris@82:   (unparse tree) ^ "\n" ^ init
Chris@82: 
Chris@82: 
Chris@82: let main () =
Chris@82:   begin 
Chris@82:     parse (speclist @ Twiddle.speclist) usage;
Chris@82:     print_string (generate (check_size ()));
Chris@82:   end
Chris@82: 
Chris@82: let _ = main()