comparison src/fftw-3.3.3/mpi/dft-rank1.c @ 10:37bf6b4a2645

Add FFTW3

+/*
+ * Copyright (c) 2003, 2007-11 Matteo Frigo
+ * Copyright (c) 2003, 2007-11 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
+ *
+ */
+
+/* Complex DFTs of rank == 1 via six-step algorithm. */
+
+#include "mpi-dft.h"
+#include "mpi-transpose.h"
+#include "dft.h"
+
+typedef struct {
+     solver super;
+     rdftapply apply; /* apply_ddft_first or apply_ddft_last */
+     int preserve_input; /* preserve input even if DESTROY_INPUT was passed */
+} S;
+
+typedef struct {
+     plan_mpi_dft super;
+
+     triggen *t;
+     plan *cldt, *cld_ddft, *cld_dft;
+     INT roff, ioff;
+     int preserve_input;
+     INT vn, xmin, xmax, xs, m, r;
+} P;
+
+static void do_twiddle(triggen *t, INT ir, INT m, INT vn, R *xr, R *xi)
+{
+     void (*rotate)(triggen *, INT, R, R, R *) = t->rotate;
+     INT im, iv;
+     for (im = 0; im < m; ++im)
+	  for (iv = 0; iv < vn; ++iv) {
+	       /* TODO: modify/inline rotate function
+		  so that it can do whole vn vector at once? */
+	       R c[2];
+	       rotate(t, ir * im, *xr, *xi, c);
+	       *xr = c[0]; *xi = c[1];
+	       xr += 2; xi += 2;
+	  }
+}
+
+/* radix-r DFT of size r*m.  This is equivalent to an m x r 2d DFT,
+   plus twiddle factors between the size-m and size-r 1d DFTs, where
+   the m dimension is initially distributed.  The output is transposed
+   to r x m where the r dimension is distributed. 
+
+   This algorithm follows the general sequence:
+        global transpose (m x r -> r x m)
+        DFTs of size m
+	multiply by twiddles + global transpose (r x m -> m x r)
+	DFTs of size r
+	global transpose (m x r -> r x m)
+   where the multiplication by twiddles can come before or after
+   the middle transpose.  The first/last transposes are omitted
+   for SCRAMBLED_IN/OUT formats, respectively.
+
+   However, we wish to exploit our dft-rank1-bigvec solver, which
+   solves a vector of distributed DFTs via transpose+dft+transpose.
+   Therefore, we can group *either* the DFTs of size m *or* the
+   DFTs of size r with their surrounding transposes as a single
+   distributed-DFT (ddft) plan.  These two variations correspond to
+   apply_ddft_first or apply_ddft_last, respectively.
+*/
+
+static void apply_ddft_first(const plan *ego_, R *I, R *O)
+{
+     const P *ego = (const P *) ego_;
+     plan_dft *cld_dft;
+     plan_rdft *cldt, *cld_ddft;
+     INT roff, ioff, im, mmax, ms, r, vn;
+     triggen *t;
+     R *dI, *dO;
+
+     /* distributed size-m DFTs, with output in m x r format */
+     cld_ddft = (plan_rdft *) ego->cld_ddft;
+     cld_ddft->apply(ego->cld_ddft, I, O);
+
+     cldt = (plan_rdft *) ego->cldt;
+     if (ego->preserve_input || !cldt) I = O;
+
+     /* twiddle multiplications, followed by 1d DFTs of size-r */
+     cld_dft = (plan_dft *) ego->cld_dft;
+     roff = ego->roff; ioff = ego->ioff;
+     mmax = ego->xmax; ms = ego->xs;
+     t = ego->t; r = ego->r; vn = ego->vn;
+     dI = O; dO = I;
+     for (im = ego->xmin; im <= mmax; ++im) {
+	  do_twiddle(t, im, r, vn, dI+roff, dI+ioff);
+	  cld_dft->apply((plan *) cld_dft, dI+roff, dI+ioff, dO+roff, dO+ioff);
+	  dI += ms; dO += ms;
+     }
+
+     /* final global transpose (m x r -> r x m), if not SCRAMBLED_OUT */
+     if (cldt) 
+	  cldt->apply((plan *) cldt, I, O);
+}
+
+static void apply_ddft_last(const plan *ego_, R *I, R *O)
+{
+     const P *ego = (const P *) ego_;
+     plan_dft *cld_dft;
+     plan_rdft *cldt, *cld_ddft;
+     INT roff, ioff, ir, rmax, rs, m, vn;
+     triggen *t;
+     R *dI, *dO0, *dO;
+
+     /* initial global transpose (m x r -> r x m), if not SCRAMBLED_IN */
+     cldt = (plan_rdft *) ego->cldt;
+     if (cldt) {
+	  cldt->apply((plan *) cldt, I, O);
+	  dI = O;
+     }
+     else 
+	  dI = I;
+     if (ego->preserve_input) dO = O; else dO = I;
+     dO0 = dO;
+
+     /* 1d DFTs of size m, followed by twiddle multiplications */
+     cld_dft = (plan_dft *) ego->cld_dft;
+     roff = ego->roff; ioff = ego->ioff;
+     rmax = ego->xmax; rs = ego->xs;
+     t = ego->t; m = ego->m; vn = ego->vn;
+     for (ir = ego->xmin; ir <= rmax; ++ir) {
+	  cld_dft->apply((plan *) cld_dft, dI+roff, dI+ioff, dO+roff, dO+ioff);
+	  do_twiddle(t, ir, m, vn, dO+roff, dO+ioff);
+	  dI += rs; dO += rs;
+     }
+
+     /* distributed size-r DFTs, with output in r x m format */
+     cld_ddft = (plan_rdft *) ego->cld_ddft;
+     cld_ddft->apply(ego->cld_ddft, dO0, O);
+}
+
+static int applicable(const S *ego, const problem *p_,
+		      const planner *plnr,
+		      INT *r, INT rblock[2], INT mblock[2])
+{
+     const problem_mpi_dft *p = (const problem_mpi_dft *) p_;
+     int n_pes;
+     MPI_Comm_size(p->comm, &n_pes);
+     return (1
+	     && p->sz->rnk == 1
+
+	     && ONLY_SCRAMBLEDP(p->flags)
+
+	     && (!ego->preserve_input || (!NO_DESTROY_INPUTP(plnr)
+                                          && p->I != p->O))
+
+	     && (!(p->flags & SCRAMBLED_IN) || ego->apply == apply_ddft_last)
+	     && (!(p->flags & SCRAMBLED_OUT) || ego->apply == apply_ddft_first)
+
+	     && (!NO_SLOWP(plnr) /* slow if dft-serial is applicable */
+                 || !XM(dft_serial_applicable)(p))
+
+	     /* disallow if dft-rank1-bigvec is applicable since the
+		data distribution may be slightly different (ugh!) */
+	     && (p->vn < n_pes || p->flags)
+
+	     && (*r = XM(choose_radix)(p->sz->dims[0], n_pes,
+				       p->flags, p->sign,
+				       rblock, mblock))
+
+	     /* ddft_first or last has substantial advantages in the
+		bigvec transpositions for the common case where
+		n_pes == n/r or r, respectively */
+	     && (!NO_UGLYP(plnr)
+		 || !(*r == n_pes && ego->apply == apply_ddft_first)
+		 || !(p->sz->dims[0].n / *r == n_pes 
+		      && ego->apply == apply_ddft_last))
+	  );
+}
+
+static void awake(plan *ego_, enum wakefulness wakefulness)
+{
+     P *ego = (P *) ego_;
+     X(plan_awake)(ego->cldt, wakefulness);
+     X(plan_awake)(ego->cld_dft, wakefulness);
+     X(plan_awake)(ego->cld_ddft, wakefulness);
+
+     switch (wakefulness) {
+         case SLEEPY:
+              X(triggen_destroy)(ego->t); ego->t = 0;
+              break;
+         default:
+              ego->t = X(mktriggen)(AWAKE_SQRTN_TABLE, ego->r * ego->m);
+              break;
+     }
+}
+
+static void destroy(plan *ego_)
+{
+     P *ego = (P *) ego_;
+     X(plan_destroy_internal)(ego->cldt);
+     X(plan_destroy_internal)(ego->cld_dft);
+     X(plan_destroy_internal)(ego->cld_ddft);
+}
+
+static void print(const plan *ego_, printer *p)
+{
+     const P *ego = (const P *) ego_;
+     p->print(p, "(mpi-dft-rank1/%D%s%s%(%p%)%(%p%)%(%p%))",
+	      ego->r,
+	      ego->super.apply == apply_ddft_first ? "/first" : "/last",
+	      ego->preserve_input==2 ?"/p":"",
+	      ego->cld_ddft, ego->cld_dft, ego->cldt);
+}
+
+static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)
+{
+     const S *ego = (const S *) ego_;
+     const problem_mpi_dft *p;
+     P *pln;
+     plan *cld_dft = 0, *cld_ddft = 0, *cldt = 0;
+     R *ri, *ii, *ro, *io, *I, *O;
+     INT r, rblock[2], m, mblock[2], rp, mp, mpblock[2], mpb;
+     int my_pe, n_pes, preserve_input, ddft_first;
+     dtensor *sz;
+     static const plan_adt padt = {
+          XM(dft_solve), awake, print, destroy
+     };
+
+     UNUSED(ego);
+
+     if (!applicable(ego, p_, plnr, &r, rblock, mblock))
+          return (plan *) 0;
+
+     p = (const problem_mpi_dft *) p_;
+
+     MPI_Comm_rank(p->comm, &my_pe);
+     MPI_Comm_size(p->comm, &n_pes);
+
+     m = p->sz->dims[0].n / r;
+
+     /* some hackery so that we can plan both ddft_first and ddft_last
+	as if they were ddft_first */
+     if ((ddft_first = (ego->apply == apply_ddft_first))) {
+	  rp = r; mp = m;
+	  mpblock[IB] = mblock[IB]; mpblock[OB] = mblock[OB];
+	  mpb = XM(block)(mp, mpblock[OB], my_pe);
+     }
+     else {
+	  rp = m; mp = r;
+	  mpblock[IB] = rblock[IB]; mpblock[OB] = rblock[OB];
+	  mpb = XM(block)(mp, mpblock[IB], my_pe);
+     }
+
+     preserve_input = ego->preserve_input ? 2 : NO_DESTROY_INPUTP(plnr);
+
+     sz = XM(mkdtensor)(1);
+     sz->dims[0].n = mp;
+     sz->dims[0].b[IB] = mpblock[IB];
+     sz->dims[0].b[OB] = mpblock[OB];
+     I = (ddft_first || !preserve_input) ? p->I : p->O;
+     O = p->O;
+     cld_ddft = X(mkplan_d)(plnr, XM(mkproblem_dft_d)(sz, rp * p->vn,
+						      I, O, p->comm, p->sign,
+						      RANK1_BIGVEC_ONLY));
+     if (XM(any_true)(!cld_ddft, p->comm)) goto nada;
+
+     I = TAINT((ddft_first || !p->flags) ? p->O : p->I, rp * p->vn * 2);
+     O = TAINT((preserve_input || (ddft_first && p->flags)) ? p->O : p->I, 
+	       rp * p->vn * 2);
+     X(extract_reim)(p->sign, I, &ri, &ii);
+     X(extract_reim)(p->sign, O, &ro, &io);
+     cld_dft = X(mkplan_d)(plnr,
+			X(mkproblem_dft_d)(X(mktensor_1d)(rp, p->vn*2,p->vn*2),
+					   X(mktensor_1d)(p->vn, 2, 2),
+					   ri, ii, ro, io));
+     if (XM(any_true)(!cld_dft, p->comm)) goto nada;
+     
+     if (!p->flags) { /* !(SCRAMBLED_IN or SCRAMBLED_OUT) */
+	  I = (ddft_first && preserve_input) ? p->O : p->I;
+	  O = p->O;
+	  cldt = X(mkplan_d)(plnr,
+			     XM(mkproblem_transpose)(
+				  m, r, p->vn * 2,
+				  I, O,
+				  ddft_first ? mblock[OB] : mblock[IB],
+				  ddft_first ? rblock[OB] : rblock[IB],
+				  p->comm, 0));
+	  if (XM(any_true)(!cldt, p->comm)) goto nada;	  
+     }
+
+     pln = MKPLAN_MPI_DFT(P, &padt, ego->apply);
+
+     pln->cld_ddft = cld_ddft;
+     pln->cld_dft = cld_dft;
+     pln->cldt = cldt;
+     pln->preserve_input = preserve_input;
+     X(extract_reim)(p->sign, p->O, &ro, &io);
+     pln->roff = ro - p->O;
+     pln->ioff = io - p->O;
+     pln->vn = p->vn;
+     pln->m = m;
+     pln->r = r;
+     pln->xmin = (ddft_first ? mblock[OB] : rblock[IB]) * my_pe;
+     pln->xmax = pln->xmin + mpb - 1;
+     pln->xs = rp * p->vn * 2;
+     pln->t = 0;
+
+     X(ops_add)(&cld_ddft->ops, &cld_dft->ops, &pln->super.super.ops);
+     if (cldt) X(ops_add2)(&cldt->ops, &pln->super.super.ops);
+     {
+          double n0 = (1 + pln->xmax - pln->xmin) * (mp - 1) * pln->vn;
+          pln->super.super.ops.mul += 8 * n0;
+          pln->super.super.ops.add += 4 * n0;
+          pln->super.super.ops.other += 8 * n0;
+     }
+
+     return &(pln->super.super);
+
+ nada:
+     X(plan_destroy_internal)(cldt);
+     X(plan_destroy_internal)(cld_dft);
+     X(plan_destroy_internal)(cld_ddft);
+     return (plan *) 0;
+}
+
+static solver *mksolver(rdftapply apply, int preserve_input)
+{
+     static const solver_adt sadt = { PROBLEM_MPI_DFT, mkplan, 0 };
+     S *slv = MKSOLVER(S, &sadt);
+     slv->apply = apply;
+     slv->preserve_input = preserve_input;
+     return &(slv->super);
+}
+
+void XM(dft_rank1_register)(planner *p)
+{
+     rdftapply apply[] = { apply_ddft_first, apply_ddft_last };
+     unsigned int iapply;
+     int preserve_input;
+     for (iapply = 0; iapply < sizeof(apply) / sizeof(apply[0]); ++iapply)
+	  for (preserve_input = 0; preserve_input <= 1; ++preserve_input)
+	       REGISTER_SOLVER(p, mksolver(apply[iapply], preserve_input));
+}