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-rw-r--r--lib/ffts/src/ffts_real.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/lib/ffts/src/ffts_real.c b/lib/ffts/src/ffts_real.c
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+++ b/lib/ffts/src/ffts_real.c
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+/*
+
+ This file is part of FFTS -- The Fastest Fourier Transform in the South
+
+ Copyright (c) 2012, Anthony M. Blake <amb@anthonix.com>
+ Copyright (c) 2012, The University of Waikato
+
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * Neither the name of the organization nor the
+ names of its contributors may be used to endorse or promote products
+ derived from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL ANTHONY M. BLAKE BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include "ffts_real.h"
+
+void ffts_free_1d_real(ffts_plan_t *p) {
+ ffts_free(p->plans[0]);
+ free(p->A);
+ free(p->B);
+ free(p->plans);
+ free(p->buf);
+ free(p);
+}
+
+void ffts_execute_1d_real(ffts_plan_t *p, const void *vin, void *vout) {
+ float *out = (float *)vout;
+ float *buf = (float *)p->buf;
+ float *A = p->A;
+ float *B = p->B;
+
+ p->plans[0]->transform(p->plans[0], vin, buf);
+
+ size_t N = p->N;
+ buf[N] = buf[0];
+ buf[N+1] = buf[1];
+
+ float *p_buf0 = buf;
+ float *p_buf1 = buf + N - 2;
+ float *p_out = out;
+
+ size_t i;
+#ifdef __ARM_NEON__
+ for(i=0;i<N/2;i+=2) {
+ __asm__ __volatile__ ("vld1.32 {q8}, [%[pa], :128]!\n\t"
+ "vld1.32 {q9}, [%[pb], :128]!\n\t"
+ "vld1.32 {q10}, [%[buf0], :128]!\n\t"
+ "vld1.32 {q11}, [%[buf1], :64]\n\t"
+ "sub %[buf1], %[buf1], #16\n\t"
+
+ "vdup.32 d26, d16[1]\n\t"
+ "vdup.32 d27, d17[1]\n\t"
+ "vdup.32 d24, d16[0]\n\t"
+ "vdup.32 d25, d17[0]\n\t"
+
+ "vdup.32 d30, d23[1]\n\t"
+ "vdup.32 d31, d22[1]\n\t"
+ "vdup.32 d28, d23[0]\n\t"
+ "vdup.32 d29, d22[0]\n\t"
+
+ "vmul.f32 q13, q13, q10\n\t"
+ "vmul.f32 q15, q15, q9\n\t"
+ "vmul.f32 q12, q12, q10\n\t"
+ "vmul.f32 q14, q14, q9\n\t"
+ "vrev64.f32 q13, q13\n\t"
+ "vrev64.f32 q15, q15\n\t"
+
+ "vtrn.32 d26, d27\n\t"
+ "vtrn.32 d30, d31\n\t"
+ "vneg.f32 d26, d26\n\t"
+ "vneg.f32 d31, d31\n\t"
+ "vtrn.32 d26, d27\n\t"
+ "vtrn.32 d30, d31\n\t"
+
+ "vadd.f32 q12, q12, q14\n\t"
+ "vadd.f32 q13, q13, q15\n\t"
+ "vadd.f32 q12, q12, q13\n\t"
+ "vst1.32 {q12}, [%[pout], :128]!\n\t"
+ : [pa] "+r" (A), [pb] "+r" (B), [buf0] "+r" (p_buf0), [buf1] "+r" (p_buf1),
+ [pout] "+r" (p_out)
+ :
+ : "memory", "q8", "q9", "q10", "q11", "q12", "q13", "q14", "q15"
+ );
+#else
+ for(i=0;i<N/2;i++) {
+ out[2*i] = buf[2*i]*A[2*i] - buf[2*i+1]*A[2*i+1] + buf[N-2*i]*B[2*i] + buf[N-2*i+1]*B[2*i+1];
+ out[2*i+1] = buf[2*i+1]*A[2*i] + buf[2*i]*A[2*i+1] + buf[N-2*i]*B[2*i+1] - buf[N-2*i+1]*B[2*i];
+
+// out[2*N-2*i] = out[2*i];
+// out[2*N-2*i+1] = -out[2*i+1];
+
+#endif
+ }
+
+ out[N] = buf[0] - buf[1];
+ out[N+1] = 0.0f;
+
+}
+
+void ffts_execute_1d_real_inv(ffts_plan_t *p, const void *vin, void *vout) {
+ float *out = (float *)vout;
+ float *in = (float *)vin;
+ float *buf = (float *)p->buf;
+ float *A = p->A;
+ float *B = p->B;
+ size_t N = p->N;
+
+ float *p_buf0 = in;
+ float *p_buf1 = in + N - 2;
+
+ float *p_out = buf;
+
+ size_t i;
+#ifdef __ARM_NEON__
+ for(i=0;i<N/2;i+=2) {
+ __asm__ __volatile__ ("vld1.32 {q8}, [%[pa], :128]!\n\t"
+ "vld1.32 {q9}, [%[pb], :128]!\n\t"
+ "vld1.32 {q10}, [%[buf0], :128]!\n\t"
+ "vld1.32 {q11}, [%[buf1], :64]\n\t"
+ "sub %[buf1], %[buf1], #16\n\t"
+
+ "vdup.32 d26, d16[1]\n\t"
+ "vdup.32 d27, d17[1]\n\t"
+ "vdup.32 d24, d16[0]\n\t"
+ "vdup.32 d25, d17[0]\n\t"
+
+ "vdup.32 d30, d23[1]\n\t"
+ "vdup.32 d31, d22[1]\n\t"
+ "vdup.32 d28, d23[0]\n\t"
+ "vdup.32 d29, d22[0]\n\t"
+
+ "vmul.f32 q13, q13, q10\n\t"
+ "vmul.f32 q15, q15, q9\n\t"
+ "vmul.f32 q12, q12, q10\n\t"
+ "vmul.f32 q14, q14, q9\n\t"
+ "vrev64.f32 q13, q13\n\t"
+ "vrev64.f32 q15, q15\n\t"
+
+ "vtrn.32 d26, d27\n\t"
+ "vtrn.32 d28, d29\n\t"
+ "vneg.f32 d27, d27\n\t"
+ "vneg.f32 d29, d29\n\t"
+ "vtrn.32 d26, d27\n\t"
+ "vtrn.32 d28, d29\n\t"
+
+ "vadd.f32 q12, q12, q14\n\t"
+ "vsub.f32 q13, q13, q15\n\t"
+ "vadd.f32 q12, q12, q13\n\t"
+ "vst1.32 {q12}, [%[pout], :128]!\n\t"
+ : [pa] "+r" (A), [pb] "+r" (B), [buf0] "+r" (p_buf0), [buf1] "+r" (p_buf1),
+ [pout] "+r" (p_out)
+ :
+ : "memory", "q8", "q9", "q10", "q11", "q12", "q13", "q14", "q15"
+ );
+
+
+#else
+ for(i=0;i<N/2;i++) {
+ buf[2*i] = in[2*i]*A[2*i] + in[2*i+1]*A[2*i+1] + in[N-2*i]*B[2*i] - in[N-2*i+1]*B[2*i+1];
+ buf[2*i+1] = in[2*i+1]*A[2*i] - in[2*i]*A[2*i+1] - in[N-2*i]*B[2*i+1] - in[N-2*i+1]*B[2*i];
+#endif
+}
+
+ p->plans[0]->transform(p->plans[0], buf, out);
+
+}
+
+ffts_plan_t *ffts_init_1d_real(size_t N, int sign) {
+ ffts_plan_t *p = malloc(sizeof(ffts_plan_t));
+
+ if(sign < 0) p->transform = &ffts_execute_1d_real;
+ else p->transform = &ffts_execute_1d_real_inv;
+
+ p->destroy = &ffts_free_1d_real;
+ p->N = N;
+ p->rank = 1;
+ p->plans = malloc(sizeof(ffts_plan_t **) * 1);
+
+ p->plans[0] = ffts_init_1d(N/2, sign);
+
+ p->buf = valloc(sizeof(float) * 2 * ((N/2) + 1));
+
+ p->A = valloc(sizeof(float) * N);
+ p->B = valloc(sizeof(float) * N);
+
+ if(sign < 0) {
+ int i;
+ for (i = 0; i < N/2; i++) {
+ p->A[2 * i] = 0.5 * (1.0 - sin (2.0f * PI / (double) (N) * (double) i));
+ p->A[2 * i + 1] = 0.5 * (-1.0 * cos (2.0f * PI / (double) (N) * (double) i));
+ p->B[2 * i] = 0.5 * (1.0 + sin (2.0f * PI / (double) (N) * (double) i));
+ p->B[2 * i + 1] = 0.5 * (1.0 * cos (2.0f * PI / (double) (N) * (double) i));
+ }
+ }else{
+ int i;
+ for (i = 0; i < N/2; i++) {
+ p->A[2 * i] = 1.0 * (1.0 - sin (2.0f * PI / (double) (N) * (double) i));
+ p->A[2 * i + 1] = 1.0 * (-1.0 * cos (2.0f * PI / (double) (N) * (double) i));
+ p->B[2 * i] = 1.0 * (1.0 + sin (2.0f * PI / (double) (N) * (double) i));
+ p->B[2 * i + 1] = 1.0 * (1.0 * cos (2.0f * PI / (double) (N) * (double) i));
+ }
+ }
+
+ return p;
+}
+
+
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