/
medium-fft.lisp
165 lines (159 loc) · 7.21 KB
/
medium-fft.lisp
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(defconstant +blocking-factor+ 1)
(defun gen-simple-fft/medium (size
&key (dst 'dst)
(src 'src)
(tmp 'tmp)
(startd 'startd)
(starts 'starts)
(startt 'startt)
(strides 1)
(strided 1)
(twiddle 'twiddle)
(cooley-tukey 'cooley-tukey))
(assert (evenp (integer-length (1- size))))
(assert (= 1 strided))
(let ((half-size (ash 1 (truncate (integer-length (1- size))
2))))
`(flet ((sub-fft (dst src twiddle
startd starts)
(declare (type complex-sample-array dst src twiddle)
(type index startd starts))
,(gen-fft/small half-size)))
(loop for i of-type index below ,half-size
for j of-type index from 0 by ,half-size
do (loop for count of-type index from ,half-size above 0
for j from ,startt
for k of-type index from (+ i ,starts) by ,half-size
do (setf (ref ,tmp j) (ref ,src (* k ,strides))))
(sub-fft ,dst ,tmp ,twiddle (+ j ,startd) ,startt)
(loop for i of-type index from (+ j ,startd)
for idx of-type index from j
for count below ,half-size
do (setf (ref ,dst i)
(* (ref ,dst i)
(ref ,cooley-tukey idx)))))
(loop for i of-type index below ,half-size do
(loop for count from ,half-size above 0
for j of-type index from ,startt
for k of-type index from (+ i ,startd) by ,half-size
do (setf (ref ,tmp j) (ref ,dst k)))
(sub-fft ,tmp ,tmp ,twiddle
(+ ,startt ,half-size) ,startt)
(loop for count from ,half-size above 0
for j of-type index from (+ ,startt ,half-size)
for k of-type index from (+ i ,startd) by ,half-size
do (setf (ref ,dst k) (ref ,tmp j))))
dst)))
(defun gen-generic-fft/medium (size
&key (dst 'dst)
(src 'src)
(tmp 'tmp)
(startd 'startd)
(starts 'starts)
(startt 'startt)
(strides 1)
(strided 1)
(twiddle 'twiddle)
(cooley-tukey 'cooley-tukey))
(let* ((size1 (ash 1 (truncate (integer-length (1- size))
2)))
(size2 (/ size size1)))
(assert (integerp size2))
`(progn
(loop for i of-type index below ,size1
for j of-type index from 0 by ,size2
do (loop for count of-type index from ,size2 above 0
for j from ,startt
for k of-type index from (+ i ,starts) by ,size1
do (setf (ref ,tmp j) (ref ,src (* k ,strides))))
(let ((startd (+ j ,startd)))
,(gen-fft/small size2
:dst dst :src tmp :twiddle twiddle
:startd 'startd
:starts startt
:strided strided))
(loop for i of-type index from (+ j ,startd) by ,strided
for idx of-type index from j
for count below ,size2
do (setf (ref ,dst i)
(* (ref ,dst i)
(ref ,cooley-tukey idx)))))
(loop for i of-type index below ,size2 do
(loop for count from ,size1 above 0
for j of-type index from ,startt
for k of-type index from (+ i ,startd) by (* ,size2 ,strided)
do (setf (ref ,tmp j) (ref ,dst k)))
(let ((startd (+ ,startt ,size1)))
,(gen-fft/small size1
:dst tmp :src tmp :twiddle twiddle
:startd 'startd
:starts startt))
(loop for count from ,size1 above 0
for j of-type index from (+ ,startt ,size1)
for k of-type index from (+ i ,startd) by (* ,size2 ,strided)
do (setf (ref ,dst k) (ref ,tmp j))))
dst)))
(defun gen-fft/medium (size &rest args
&key (dst 'dst)
(src 'src)
(tmp 'tmp)
(startd 'startd)
(starts 'starts)
(startt 'startt)
(strides 1)
(strided 1)
(twiddle 'twiddle)
(cooley-tukey 'cooley-tukey))
(declare (ignore dst src tmp
startd starts startt
strides
twiddle cooley-tukey))
(if (and (evenp (integer-length (1- size)))
(eql strided 1))
(apply 'gen-square-fft/medium size args)
(apply 'gen-generic-fft/medium size args)))
#+nil
(let ((fun (compile nil `(lambda (dst src twiddle startd starts)
,(gen-fft/small 16))))
(twiddle (bordeaux-fft::make-twiddle-factors 16 1))
(ck-factors (bordeaux-fft::make-cooley-tuckey-factors 16 16 1))
(src *vec*)
(dst (make-array 256 :element-type 'complex-sample))
(tmp (make-array 256 :element-type 'complex-sample)))
(medium-fft fun twiddle 256
src dst tmp ck-factors))
#+nil
(defun medium-fft (small-fft twiddle size
vec dst tmp ck-factors)
(declare (type function small-fft)
(type size size)
(type complex-sample-array vec dst tmp
twiddle ck-factors)
(optimize speed (safety 0)))
(let ((half-size (ash 1 (truncate (integer-length (1- size))
2))))
(loop for i of-type index below half-size
for dsts of-type index by half-size
do (loop for j of-type index below half-size
for k of-type index from i by half-size
do (setf (ref tmp j) (ref vec k)))
(funcall small-fft
dst tmp twiddle
dsts 0)
(loop for i from dsts
for count from half-size above 0
do (setf (ref dst i)
(* (ref dst i)
(ref ck-factors i)))))
(loop for i of-type index below half-size do
(loop for j of-type index below half-size
for k of-type index from i by half-size
do (setf (ref tmp j) (ref dst k)))
(funcall small-fft
tmp tmp twiddle
half-size 0)
(loop for j of-type index from half-size
for k of-type index from i by half-size
below size
do (setf (ref dst k) (ref tmp j))))
dst))