Mercurial > hg > peckfft
annotate peck_fftr.c @ 13:3e85a9101f02 default tip
readme
| author | Peter Meerwald <p.meerwald@bct-electronic.com> |
|---|---|
| date | Thu, 09 Feb 2012 09:44:39 +0100 |
| parents | 655dc5c14169 |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 Copyright (c) 2003-2004, Mark Borgerding | |
| 3 | |
| 4 All rights reserved. | |
| 5 | |
| 6 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: | |
| 7 | |
| 8 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. | |
| 9 * 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. | |
| 10 * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission. | |
| 11 | |
| 12 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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. | |
| 13 */ | |
| 14 | |
| 15 #include "peck_fftr.h" | |
| 16 #include "_peck_fft_guts.h" | |
| 17 | |
| 18 struct peck_fftr_state{ | |
| 19 peck_fft_cfg substate; | |
| 20 peck_fft_cpx *tmpbuf; | |
| 21 peck_fft_cpx *super_twiddles; | |
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parents:
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22 void *pad; |
| 0 | 23 }; |
| 24 | |
| 25 peck_fftr_cfg peck_fftr_alloc(int nfft, int inverse_fft, void *mem, size_t *lenmem) { | |
| 26 int i; | |
| 27 peck_fftr_cfg st = NULL; | |
| 28 size_t subsize, memneeded; | |
| 29 | |
| 30 if (nfft & 1) { | |
| 31 fprintf(stderr, "Real FFT must be even.\n"); | |
| 32 return NULL; | |
| 33 } | |
| 34 nfft >>= 1; | |
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parents:
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35 peck_fft_alloc(nfft, inverse_fft, NULL, &subsize); |
| 0 | 36 |
| 37 memneeded = sizeof(struct peck_fftr_state) + subsize + sizeof(peck_fft_cpx) * (nfft * 3 / 2); | |
| 38 if (lenmem == NULL) { | |
| 39 st = (peck_fftr_cfg) PECK_FFT_MALLOC(memneeded); | |
| 40 } else { | |
| 41 if (*lenmem >= memneeded) | |
| 42 st = (peck_fftr_cfg) mem; | |
| 43 *lenmem = memneeded; | |
| 44 } | |
| 45 if (!st) | |
| 46 return NULL; | |
| 47 | |
| 48 st->substate = (peck_fft_cfg) (st + 1); /* just beyond peck_fftr_state struct */ | |
| 49 st->tmpbuf = (peck_fft_cpx *) (((char *) st->substate) + subsize); | |
| 50 st->super_twiddles = st->tmpbuf + nfft; | |
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neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
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51 |
| 0 | 52 peck_fft_alloc(nfft, inverse_fft, st->substate, &subsize); |
| 53 | |
| 54 for (i = 0; i < nfft/2; ++i) { | |
| 55 float phase = | |
| 56 -3.14159265359f * ((float) (i+1) / nfft + 0.5f); | |
| 57 if (inverse_fft) | |
| 58 phase *= -1; | |
| 3 | 59 kf_cexp(st->super_twiddles+i, phase); |
| 0 | 60 } |
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neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
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diff
changeset
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61 |
| 0 | 62 return st; |
| 63 } | |
| 64 | |
| 65 void peck_fftr(peck_fftr_cfg st, const peck_fft_scalar *timedata, peck_fft_cpx *freqdata) { | |
| 66 /* Input buffer timedata is stored row-wise */ | |
| 67 int k, ncfft; | |
| 68 peck_fft_cpx fpnk, fpk, f1k, f2k, tw, tdc; | |
| 69 | |
| 70 if (st->substate->inverse) { | |
| 71 fprintf(stderr, "peck_fft usage error: improper alloc\n"); | |
| 72 exit(EXIT_FAILURE); | |
| 73 } | |
| 74 | |
| 75 ncfft = st->substate->nfft; | |
| 76 | |
| 77 /* Perform the parallel FFT of two real signals packed in real,imag */ | |
| 78 peck_fft(st->substate, (const peck_fft_cpx*)timedata, st->tmpbuf); | |
| 79 /* The real part of the DC element of the frequency spectrum in st->tmpbuf | |
| 80 * contains the sum of the even-numbered elements of the input time sequence. | |
| 81 * The imag part is the sum of the odd-numbered elements. | |
| 82 * | |
| 83 * The sum of tdc.r and tdc.i is the sum of the input time sequence, | |
| 84 * yielding DC of the input time sequence. | |
| 85 * The difference of tdc.r - tdc.i is the sum of the input (dot product) [1,-1,1,-1,... | |
| 86 * yielding the Nyquist bin of input time sequence. | |
| 87 */ | |
| 88 | |
| 89 tdc.r = st->tmpbuf[0].r; | |
| 90 tdc.i = st->tmpbuf[0].i; | |
| 91 freqdata[0].r = tdc.r + tdc.i; | |
| 92 freqdata[ncfft].r = tdc.r - tdc.i; | |
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neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
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93 #if USE_SIMD == SIMD_SSE2 |
| 0 | 94 freqdata[ncfft].i = freqdata[0].i = _mm_set1_ps(0); |
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neon2 and neon4 support
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parents:
3
diff
changeset
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95 #elif USE_SIMD == SIMD_NEON4 |
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neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
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96 freqdata[ncfft].i = freqdata[0].i = vdupq_n_f32(0.0f); |
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2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
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97 #elif USE_SIMD == SIMD_NEON2 |
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2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
98 freqdata[ncfft].i = freqdata[0].i = vdup_n_f32(0.0f); |
| 0 | 99 #else |
| 100 freqdata[ncfft].i = freqdata[0].i = 0; | |
| 101 #endif | |
| 102 | |
| 103 for (k = 1; k <= ncfft/2; ++k) { | |
| 104 fpk = st->tmpbuf[k]; | |
| 105 fpnk.r = st->tmpbuf[ncfft-k].r; | |
| 106 fpnk.i = - st->tmpbuf[ncfft-k].i; | |
| 107 | |
| 108 C_ADD(f1k, fpk, fpnk); | |
| 109 C_SUB(f2k, fpk, fpnk); | |
| 110 C_MUL(tw, f2k, st->super_twiddles[k-1]); | |
| 111 | |
| 112 freqdata[k].r = HALF_OF(f1k.r + tw.r); | |
| 113 freqdata[k].i = HALF_OF(f1k.i + tw.i); | |
| 114 freqdata[ncfft-k].r = HALF_OF(f1k.r - tw.r); | |
| 115 freqdata[ncfft-k].i = HALF_OF(tw.i - f1k.i); | |
| 116 } | |
| 117 } | |
| 118 | |
| 119 void peck_fftri(peck_fftr_cfg st,const peck_fft_cpx *freqdata,peck_fft_scalar *timedata) { | |
| 120 /* input buffer timedata is stored row-wise */ | |
| 121 int k, ncfft; | |
| 122 | |
| 123 if (st->substate->inverse == 0) { | |
| 124 fprintf (stderr, "peck_fft usage error: improper alloc\n"); | |
| 125 exit(EXIT_FAILURE); | |
| 126 } | |
| 127 | |
| 128 ncfft = st->substate->nfft; | |
| 129 | |
| 130 st->tmpbuf[0].r = freqdata[0].r + freqdata[ncfft].r; | |
| 131 st->tmpbuf[0].i = freqdata[0].r - freqdata[ncfft].r; | |
| 132 | |
| 133 for (k = 1; k <= ncfft / 2; ++k) { | |
| 134 peck_fft_cpx fk, fnkc, fek, fok, tmp; | |
| 135 fk = freqdata[k]; | |
| 136 fnkc.r = freqdata[ncfft - k].r; | |
| 137 fnkc.i = -freqdata[ncfft - k].i; | |
| 138 | |
| 139 C_ADD(fek, fk, fnkc); | |
| 140 C_SUB(tmp, fk, fnkc); | |
| 141 C_MUL(fok, tmp, st->super_twiddles[k-1]); | |
| 142 C_ADD(st->tmpbuf[k], fek, fok); | |
| 143 C_SUB(st->tmpbuf[ncfft - k], fek, fok); | |
|
4
2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
144 #if USE_SIMD == SIMD_SSE2 |
|
2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
145 st->tmpbuf[ncfft - k].i *= _mm_set1_ps(-1.0f); |
|
2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
146 #elif USE_SIMD == SIMD_NEON4 |
|
2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
147 st->tmpbuf[ncfft - k].i *= vdupq_n_f32(-1.0f); |
|
2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
148 #elif USE_SIMD == SIMD_NEON2 |
|
2d6c49fcafcb
neon2 and neon4 support
Peter Meerwald <p.meerwald@bct-electronic.com>
parents:
3
diff
changeset
|
149 st->tmpbuf[ncfft - k].i *= vdup_n_f32(-1.0f); |
| 0 | 150 #else |
| 151 st->tmpbuf[ncfft - k].i *= -1; | |
| 152 #endif | |
| 153 } | |
| 154 peck_fft(st->substate, st->tmpbuf, (peck_fft_cpx *) timedata); | |
| 155 } |