From 5a422aba704c375a307a902bafe658342e209906 Mon Sep 17 00:00:00 2001 From: scuri Date: Fri, 17 Oct 2008 06:10:15 +0000 Subject: First commit - moving from LuaForge to SourceForge --- src/fftw3/reodft/reodft11e-r2hc-odd.c | 304 ++++++++++++++++++++++++++++++++++ 1 file changed, 304 insertions(+) create mode 100644 src/fftw3/reodft/reodft11e-r2hc-odd.c (limited to 'src/fftw3/reodft/reodft11e-r2hc-odd.c') diff --git a/src/fftw3/reodft/reodft11e-r2hc-odd.c b/src/fftw3/reodft/reodft11e-r2hc-odd.c new file mode 100644 index 0000000..471f7ca --- /dev/null +++ b/src/fftw3/reodft/reodft11e-r2hc-odd.c @@ -0,0 +1,304 @@ +/* + * Copyright (c) 2003 Matteo Frigo + * Copyright (c) 2003 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 + * + */ + +/* $Id: reodft11e-r2hc-odd.c,v 1.1 2008/10/17 06:13:18 scuri Exp $ */ + +/* Do an R{E,O}DFT11 problem via an R2HC problem of the same *odd* size, + with some permutations and post-processing, as described in: + + S. C. Chan and K. L. Ho, "Fast algorithms for computing the + discrete cosine transform," IEEE Trans. Circuits Systems II: + Analog & Digital Sig. Proc. 39 (3), 185--190 (1992). + + (For even sizes, see reodft11e-radix2.c.) + + This algorithm is related to the 8 x n prime-factor-algorithm (PFA) + decomposition of the size 8n "logical" DFT corresponding to the + R{EO}DFT11. + + Aside from very confusing notation (several symbols are redefined + from one line to the next), be aware that this paper has some + errors. In particular, the signs are wrong in Eqs. (34-35). Also, + Eqs. (36-37) should be simply C(k) = C(2k + 1 mod N), and similarly + for S (or, equivalently, the second cases should have 2*N - 2*k - 1 + instead of N - k - 1). Note also that in their definition of the + DFT, similarly to FFTW's, the exponent's sign is -1, but they + forgot to correspondingly multiply S (the sine terms) by -1. +*/ + +#include "reodft.h" + +typedef struct { + solver super; +} S; + +typedef struct { + plan_rdft super; + plan *cld; + int is, os; + int n; + int vl; + int ivs, ovs; + rdft_kind kind; +} P; + +static DK(SQRT2, +1.4142135623730950488016887242096980785696718753769); + +#define SGN_SET(x, i) ((i) % 2 ? -(x) : (x)) + +static void apply_re11(const plan *ego_, R *I, R *O) +{ + const P *ego = (const P *) ego_; + int is = ego->is, os = ego->os; + int i, n = ego->n, n2 = n/2; + int iv, vl = ego->vl; + int ivs = ego->ivs, ovs = ego->ovs; + R *buf; + + buf = (R *) MALLOC(sizeof(R) * n, BUFFERS); + + for (iv = 0; iv < vl; ++iv, I += ivs, O += ovs) { + { + int m; + for (i = 0, m = n2; m < n; ++i, m += 4) + buf[i] = I[is * m]; + for (; m < 2 * n; ++i, m += 4) + buf[i] = -I[is * (2*n - m - 1)]; + for (; m < 3 * n; ++i, m += 4) + buf[i] = -I[is * (m - 2*n)]; + for (; m < 4 * n; ++i, m += 4) + buf[i] = I[is * (4*n - m - 1)]; + m -= 4 * n; + for (; i < n; ++i, m += 4) + buf[i] = I[is * m]; + } + + { /* child plan: R2HC of size n */ + plan_rdft *cld = (plan_rdft *) ego->cld; + cld->apply((plan *) cld, buf, buf); + } + + /* FIXME: strength-reduce loop by 4 to eliminate ugly sgn_set? */ + for (i = 0; i + i + 1 < n2; ++i) { + int k = i + i + 1; + E c1, s1; + E c2, s2; + c1 = buf[k]; + c2 = buf[k + 1]; + s2 = buf[n - (k + 1)]; + s1 = buf[n - k]; + + O[os * i] = SQRT2 * (SGN_SET(c1, (i+1)/2) + + SGN_SET(s1, i/2)); + O[os * (n - (i+1))] = SQRT2 * (SGN_SET(c1, (n-i)/2) - + SGN_SET(s1, (n-(i+1))/2)); + + O[os * (n2 - (i+1))] = SQRT2 * (SGN_SET(c2, (n2-i)/2) - + SGN_SET(s2, (n2-(i+1))/2)); + O[os * (n2 + (i+1))] = SQRT2 * (SGN_SET(c2, (n2+i+2)/2) + + SGN_SET(s2, (n2+(i+1))/2)); + } + if (i + i + 1 == n2) { + E c, s; + c = buf[n2]; + s = buf[n - n2]; + O[os * i] = SQRT2 * (SGN_SET(c, (i+1)/2) + + SGN_SET(s, i/2)); + O[os * (n - (i+1))] = SQRT2 * (SGN_SET(c, (i+2)/2) + + SGN_SET(s, (i+1)/2)); + } + O[os * n2] = SQRT2 * SGN_SET(buf[0], (n2+1)/2); + } + + X(ifree)(buf); +} + +/* like for rodft01, rodft11 is obtained from redft11 by + reversing the input and flipping the sign of every other output. */ +static void apply_ro11(const plan *ego_, R *I, R *O) +{ + const P *ego = (const P *) ego_; + int is = ego->is, os = ego->os; + int i, n = ego->n, n2 = n/2; + int iv, vl = ego->vl; + int ivs = ego->ivs, ovs = ego->ovs; + R *buf; + + buf = (R *) MALLOC(sizeof(R) * n, BUFFERS); + + for (iv = 0; iv < vl; ++iv, I += ivs, O += ovs) { + { + int m; + for (i = 0, m = n2; m < n; ++i, m += 4) + buf[i] = I[is * (n - 1 - m)]; + for (; m < 2 * n; ++i, m += 4) + buf[i] = -I[is * (m - n)]; + for (; m < 3 * n; ++i, m += 4) + buf[i] = -I[is * (3*n - 1 - m)]; + for (; m < 4 * n; ++i, m += 4) + buf[i] = I[is * (m - 3*n)]; + m -= 4 * n; + for (; i < n; ++i, m += 4) + buf[i] = I[is * (n - 1 - m)]; + } + + { /* child plan: R2HC of size n */ + plan_rdft *cld = (plan_rdft *) ego->cld; + cld->apply((plan *) cld, buf, buf); + } + + /* FIXME: strength-reduce loop by 4 to eliminate ugly sgn_set? */ + for (i = 0; i + i + 1 < n2; ++i) { + int k = i + i + 1; + int j; + E c1, s1; + E c2, s2; + c1 = buf[k]; + c2 = buf[k + 1]; + s2 = buf[n - (k + 1)]; + s1 = buf[n - k]; + + O[os * i] = SQRT2 * (SGN_SET(c1, (i+1)/2 + i) + + SGN_SET(s1, i/2 + i)); + O[os * (n - (i+1))] = SQRT2 * (SGN_SET(c1, (n-i)/2 + i) - + SGN_SET(s1, (n-(i+1))/2 + i)); + + j = n2 - (i+1); + O[os * j] = SQRT2 * (SGN_SET(c2, (n2-i)/2 + j) - + SGN_SET(s2, (n2-(i+1))/2 + j)); + O[os * (n2 + (i+1))] = SQRT2 * (SGN_SET(c2, (n2+i+2)/2 + j) + + SGN_SET(s2, (n2+(i+1))/2 + j)); + } + if (i + i + 1 == n2) { + E c, s; + c = buf[n2]; + s = buf[n - n2]; + O[os * i] = SQRT2 * (SGN_SET(c, (i+1)/2 + i) + + SGN_SET(s, i/2 + i)); + O[os * (n - (i+1))] = SQRT2 * (SGN_SET(c, (i+2)/2 + i) + + SGN_SET(s, (i+1)/2 + i)); + } + O[os * n2] = SQRT2 * SGN_SET(buf[0], (n2+1)/2 + n2); + } + + X(ifree)(buf); +} + +static void awake(plan *ego_, int flg) +{ + P *ego = (P *) ego_; + AWAKE(ego->cld, flg); +} + +static void destroy(plan *ego_) +{ + P *ego = (P *) ego_; + X(plan_destroy_internal)(ego->cld); +} + +static void print(const plan *ego_, printer *p) +{ + const P *ego = (const P *) ego_; + p->print(p, "(%se-r2hc-odd-%d%v%(%p%))", + X(rdft_kind_str)(ego->kind), ego->n, ego->vl, ego->cld); +} + +static int applicable0(const solver *ego_, const problem *p_) +{ + UNUSED(ego_); + if (RDFTP(p_)) { + const problem_rdft *p = (const problem_rdft *) p_; + return (1 + && p->sz->rnk == 1 + && p->vecsz->rnk <= 1 + && p->sz->dims[0].n % 2 == 1 + && (p->kind[0] == REDFT11 || p->kind[0] == RODFT11) + ); + } + + return 0; +} + +static int applicable(const solver *ego, const problem *p, const planner *plnr) +{ + return (!NO_UGLYP(plnr) && applicable0(ego, p)); +} + +static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr) +{ + P *pln; + const problem_rdft *p; + plan *cld; + R *buf; + int n; + opcnt ops; + + static const plan_adt padt = { + X(rdft_solve), awake, print, destroy + }; + + if (!applicable(ego_, p_, plnr)) + return (plan *)0; + + p = (const problem_rdft *) p_; + + n = p->sz->dims[0].n; + buf = (R *) MALLOC(sizeof(R) * n, BUFFERS); + + cld = X(mkplan_d)(plnr, X(mkproblem_rdft_1_d)(X(mktensor_1d)(n, 1, 1), + X(mktensor_0d)(), + buf, buf, R2HC)); + X(ifree)(buf); + if (!cld) + return (plan *)0; + + pln = MKPLAN_RDFT(P, &padt, p->kind[0]==REDFT11 ? apply_re11:apply_ro11); + pln->n = n; + pln->is = p->sz->dims[0].is; + pln->os = p->sz->dims[0].os; + pln->cld = cld; + pln->kind = p->kind[0]; + + X(tensor_tornk1)(p->vecsz, &pln->vl, &pln->ivs, &pln->ovs); + + X(ops_zero)(&ops); + ops.add = n - 1; + ops.mul = n; + ops.other = 4*n; + + X(ops_zero)(&pln->super.super.ops); + X(ops_madd2)(pln->vl, &ops, &pln->super.super.ops); + X(ops_madd2)(pln->vl, &cld->ops, &pln->super.super.ops); + + return &(pln->super.super); +} + +/* constructor */ +static solver *mksolver(void) +{ + static const solver_adt sadt = { mkplan }; + S *slv = MKSOLVER(S, &sadt); + return &(slv->super); +} + +void X(reodft11e_r2hc_odd_register)(planner *p) +{ + REGISTER_SOLVER(p, mksolver()); +} -- cgit v1.2.3