comparison src/fftw-3.3.8/genfft/gen_hc2c.ml @ 167:bd3cc4d1df30

Add FFTW 3.3.8 source, and a Linux build

+(*
+ * Copyright (c) 1997-1999 Massachusetts Institute of Technology
+ * Copyright (c) 2003, 2007-14 Matteo Frigo
+ * Copyright (c) 2003, 2007-14 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *)
+
+open Util
+open Genutil
+open C
+
+
+type ditdif = DIT | DIF
+let ditdif = ref DIT
+let usage = "Usage: " ^ Sys.argv.(0) ^ " -n <number> [ -dit | -dif ]"
+
+let urs = ref Stride_variable
+
+let speclist = [
+  "-dit",
+  Arg.Unit(fun () -> ditdif := DIT),
+  " generate a DIT codelet";
+
+  "-dif",
+  Arg.Unit(fun () -> ditdif := DIF),
+  " generate a DIF codelet";
+
+  "-with-rs",
+  Arg.String(fun x -> urs := arg_to_stride x),
+  " specialize for given R-stride";
+]
+
+let byi = Complex.times Complex.i
+let byui = Complex.times (Complex.uminus Complex.i)
+
+let sym n f i = if (i < n - i) then f i else Complex.conj (f i)
+
+let shuffle_eo fe fo i = if i mod 2 == 0 then fe (i/2) else fo ((i-1)/2)
+
+let generate n =
+  let rs = "rs"
+  and twarray = "W"
+  and m = "m" and mb = "mb" and me = "me" and ms = "ms"
+
+  (* the array names are from the point of view of the complex array
+     (output in R2C, input in C2R) *)
+  and arp = "Rp" (* real, positive *)
+  and aip = "Ip" (* imag, positive *)
+  and arm = "Rm" (* real, negative *)
+  and aim = "Im" (* imag, negative *)
+
+  in
+
+  let sign = !Genutil.sign 
+  and name = !Magic.codelet_name 
+  and byvl x = choose_simd x (ctimes (CVar "VL", x)) in
+
+  let (bytwiddle, num_twiddles, twdesc) = Twiddle.twiddle_policy 1 false in
+  let nt = num_twiddles n in
+
+  let byw = bytwiddle n sign (twiddle_array nt twarray) in
+
+  let vrs = either_stride (!urs) (C.SVar rs) in
+
+  (* assume a single location.  No point in doing alias analysis *)
+  let the_location = (Unique.make (), Unique.make ()) in
+  let locations _ = the_location in
+
+  let locr = (locative_array_c n 
+		(C.array_subscript arp vrs)
+		(C.array_subscript arm vrs)
+		locations "BUG")
+  and loci = (locative_array_c n 
+		(C.array_subscript aip vrs)
+		(C.array_subscript aim vrs)
+		locations "BUG")
+  and locp = (locative_array_c n 
+		(C.array_subscript arp vrs)
+		(C.array_subscript aip vrs)
+		locations "BUG")
+  and locm = (locative_array_c n 
+		(C.array_subscript arm vrs)
+		(C.array_subscript aim vrs)
+		locations "BUG")
+  in
+  let locri i = if i mod 2 == 0 then locr (i/2) else loci ((i-1)/2)
+  and locpm i = if i < n - i then locp i else locm (n-1-i)
+  in
+
+  let asch = 
+    match !ditdif with
+    | DIT -> 
+	let output = Fft.dft sign n (byw (load_array_c n locri)) in
+	let odag = store_array_c n locpm (sym n output) in
+	  standard_optimizer odag 
+
+    | DIF -> 
+	let output = byw (Fft.dft sign n (sym n (load_array_c n locpm))) in
+	let odag = store_array_c n locri output in
+	  standard_optimizer odag 
+  in
+
+  let vms = CVar "ms" 
+  and varp = CVar arp
+  and vaip = CVar aip
+  and varm = CVar arm
+  and vaim = CVar aim
+  and vm = CVar m and vmb = CVar mb and vme = CVar me 
+  in
+  let body = Block (
+    [Decl ("INT", m)],
+    [For (list_to_comma
+	    [Expr_assign (vm, vmb);
+	     Expr_assign (CVar twarray, 
+			  CPlus [CVar twarray; 
+				 ctimes (CPlus [vmb; CUminus (Integer 1)],
+					 Integer nt)])],
+	  Binop (" < ", vm, vme),
+	  list_to_comma 
+	    [Expr_assign (vm, CPlus [vm; byvl (Integer 1)]);
+	     Expr_assign (varp, CPlus [varp; byvl vms]);
+	     Expr_assign (vaip, CPlus [vaip; byvl vms]);
+	     Expr_assign (varm, CPlus [varm; CUminus (byvl vms)]);
+	     Expr_assign (vaim, CPlus [vaim; CUminus (byvl vms)]);
+	     Expr_assign (CVar twarray, CPlus [CVar twarray; 
+					       byvl (Integer nt)]);
+	     make_volatile_stride (4*n) (CVar rs)
+	   ],
+	  Asch asch)])
+  in
+
+  let tree = 
+    Fcn ("static void", name,
+	 [Decl (C.realtypep, arp);
+	  Decl (C.realtypep, aip);
+	  Decl (C.realtypep, arm);
+	  Decl (C.realtypep, aim);
+	  Decl (C.constrealtypep, twarray);
+	  Decl (C.stridetype, rs);
+	  Decl ("INT", mb);
+	  Decl ("INT", me);
+	  Decl ("INT", ms)],
+         finalize_fcn body)
+  in
+  let twinstr = 
+    Printf.sprintf "static const tw_instr twinstr[] = %s;\n\n" 
+      (twinstr_to_string "VL" (twdesc n))
+  and desc = 
+    Printf.sprintf
+      "static const hc2c_desc desc = {%d, \"%s\", twinstr, &GENUS, %s};\n\n"
+      n name (flops_of tree)
+  and register = "X(khc2c_register)"
+
+  in
+  let init =
+    "\n" ^
+    twinstr ^ 
+    desc ^
+    (declare_register_fcn name) ^
+    (Printf.sprintf "{\n%s(p, %s, &desc, HC2C_VIA_RDFT);\n}" register name)
+  in
+
+  (unparse tree) ^ "\n" ^ init
+
+
+let main () =
+  begin 
+    parse (speclist @ Twiddle.speclist) usage;
+    print_string (generate (check_size ()));
+  end
+
+let _ = main()