# python "yield" can be iterated. use this to make it clear how
# the indices are generated by using natural-looking nested loops
-def iterate_dct_inner_butterfly_indices(SVSHAPE):
+def iterate_dct_butterfly_indices(SVSHAPE):
# get indices to iterate over, in the required order
n = SVSHAPE.lims[0]
# createing lists of indices to iterate over in each dimension
x_r.append(size)
size *= 2
# invert order if requested
- if SVSHAPE.invxyz[0]: x_r.reverse()
+ if SVSHAPE.invxyz[0]:
+ x_r.reverse()
if len(x_r) == 0:
return
# reference (read/write) the in-place data in *reverse-bit-order*
ri = list(range(n))
- ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+ if SVSHAPE.mode == 0b01:
+ levels = n.bit_length() - 1
+ ri = [ri[reverse_bits(i, levels)] for i in range(n)]
# reference list for not needing to do data-swaps, just swap what
# *indices* are referenced (two levels of indirection at the moment)
# pre-reverse the data-swap list so that it *ends up* in the order 0123..
ji = list(range(n))
- inplace_mode = SVSHAPE.skip not in [0b10, 0b11]
+ inplace_mode = SVSHAPE.mode == 0b01 and SVSHAPE.skip not in [0b10, 0b11]
if inplace_mode:
ji = halfrev2(ji, True)
hz2 = halfsize // 2 # zero stops reversing 1-item lists
# if you *really* want to do the in-place swapping manually,
# this allows you to do it. good luck...
- if not inplace_mode:
+ if SVSHAPE.mode == 0b01 and not inplace_mode:
jr = j_r[:hz2]
for j in j_r: # loop over 1st order dimension
z_end = j == j_r[-1]
yield result + SVSHAPE.offset, loopends
# now in-place swap
- if inplace_mode:
- for ci, (jl, jh) in enumerate(zip(j[:hz2], jr[:hz2])):
+ if SVSHAPE.mode == 0b01 and inplace_mode:
+ for ci, jl in enumerate(j_r[:hz2]):
+ jh = size-jl-1 # upper half, reverse order
jlh = jl+halfsize
tmp1, tmp2 = ji[jlh], ji[jh]
ji[jlh], ji[jh] = tmp2, tmp1
-# totally cool *in-place* DCT algorithm
-def transform2(vec):
+def pprint_schedule(schedule, n):
+ size = 2
+ idx = 0
+ while size <= n:
+ halfsize = size // 2
+ tablestep = n // size
+ print ("size %d halfsize %d tablestep %d" % \
+ (size, halfsize, tablestep))
+ for i in range(0, n, size):
+ prefix = "i %d\t" % i
+ for j in range(i, i + halfsize):
+ (jl, je), (jh, he) = schedule[idx]
+ print (" %-3d\t%s j=%-2d jh=%-2d "
+ "j[jl=%-2d] j[jh=%-2d]" % \
+ (idx, prefix, j, j+halfsize,
+ jl, jh,
+ ),
+ "end", bin(je)[2:], bin(je)[2:])
+ idx += 1
+ size *= 2
- # Initialization
- n = len(vec)
- levels = n.bit_length() - 1
- # and pretend we LDed data in half-swapped *and* bit-reversed order as well
- # TODO: merge these two
- vec = halfrev2(vec, False)
- vec = [vec[ri[i]] for i in range(n)]
+def demo():
+ # set the dimension sizes here
+ xdim = 8
+ ydim = 0 # not needed
+ zdim = 0 # again, not needed
- # start the inner butterfly
- size = n
- while size >= 2:
+ # set total. err don't know how to calculate how many there are...
+ # do it manually for now
+ VL = 0
+ size = 2
+ n = xdim
+ while size <= n:
halfsize = size // 2
tablestep = n // size
- ir = list(range(0, n, size))
- for i in ir:
- # two lists of half-range indices, e.g. j 0123, jr 7654
- j = list(range(i, i + halfsize))
- jr = list(range(i+halfsize, i + size))
- jr.reverse()
- for ci, (jl, jh) in enumerate(zip(j, jr)):
- vec[ri[ji[jl]]] = t1 + t2
- vec[ri[ji[jh]]] = (t1 - t2) * (1/coeff)
- hz2 = halfsize // 2 # can be zero which stops reversing 1-item lists
- for ci, (jl, jh) in enumerate(zip(j[:hz2], jr[:hz2])):
- jlh = jl+halfsize
- tmp1, tmp2 = ji[jlh], ji[jh]
- ji[jlh], ji[jh] = tmp2, tmp1
- size //= 2
-
-def dct_outer_butterfly(SVSHAPE):
- n = len(vec)
- size = n // 2
- while size >= 2:
- halfsize = size // 2
- ir = list(range(0, halfsize))
- print ("itersum", halfsize, size, ir)
- for i in ir:
- jr = list(range(i+halfsize, i+n-halfsize, size))
- print ("itersum jr", i+halfsize, i+size, jr)
- for jh in jr:
- vec[jh] += vec[jh+size]
- print (" itersum", size, i, jh, jh+size)
- size //= 2
-
- return vec
+ for i in range(0, n, size):
+ for j in range(i, i + halfsize):
+ VL += 1
+ size *= 2
+ ################
+ # INNER butterfly
+ ################
+
+ # set up an SVSHAPE
+ class SVSHAPE:
+ pass
+ # j schedule
+ SVSHAPE0 = SVSHAPE()
+ SVSHAPE0.lims = [xdim, ydim, zdim]
+ SVSHAPE0.order = [0,1,2] # experiment with different permutations, here
+ SVSHAPE0.mode = 0b01
+ SVSHAPE0.skip = 0b00
+ SVSHAPE0.offset = 0 # experiment with different offset, here
+ SVSHAPE0.invxyz = [0,0,0] # inversion if desired
+ # j+halfstep schedule
+ SVSHAPE1 = SVSHAPE()
+ SVSHAPE1.lims = [xdim, ydim, zdim]
+ SVSHAPE1.order = [0,1,2] # experiment with different permutations, here
+ SVSHAPE1.mode = 0b01
+ SVSHAPE1.skip = 0b01
+ SVSHAPE1.offset = 0 # experiment with different offset, here
+ SVSHAPE1.invxyz = [0,0,0] # inversion if desired
+
+ # enumerate over the iterator function, getting new indices
+ schedule = []
+ i0 = iterate_dct_butterfly_indices(SVSHAPE0)
+ i1 = iterate_dct_butterfly_indices(SVSHAPE1)
+ for idx, (jl, jh) in enumerate(zip(i0, i1)):
+ if idx >= VL:
+ break
+ schedule.append((jl, jh))
+
+ # ok now pretty-print the results, with some debug output
+ print ("inner butterfly")
+ pprint_schedule(schedule, n)
+ print ("")
+
+ ################
+ # outer butterfly
+ ################
+
+ # j schedule
+ SVSHAPE0 = SVSHAPE()
+ SVSHAPE0.lims = [xdim, ydim, zdim]
+ SVSHAPE0.order = [0,1,2] # experiment with different permutations, here
+ SVSHAPE0.mode = 0b10
+ SVSHAPE0.skip = 0b00
+ SVSHAPE0.offset = 0 # experiment with different offset, here
+ SVSHAPE0.invxyz = [1,0,0] # inversion if desired
+ # j+halfstep schedule
+ SVSHAPE1 = SVSHAPE()
+ SVSHAPE1.lims = [xdim, ydim, zdim]
+ SVSHAPE1.order = [0,1,2] # experiment with different permutations, here
+ SVSHAPE1.mode = 0b10
+ SVSHAPE1.skip = 0b01
+ SVSHAPE1.offset = 0 # experiment with different offset, here
+ SVSHAPE1.invxyz = [1,0,0] # inversion if desired
+
+ # enumerate over the iterator function, getting new indices
+ schedule = []
+ i0 = iterate_dct_butterfly_indices(SVSHAPE0)
+ i1 = iterate_dct_butterfly_indices(SVSHAPE1)
+ for idx, (jl, jh) in enumerate(zip(i0, i1)):
+ if idx >= VL:
+ break
+ schedule.append((jl, jh))
+
+ # ok now pretty-print the results, with some debug output
+ print ("outer butterfly")
+ pprint_schedule(schedule, n)
+
+# run the demo
+if __name__ == '__main__':
+ demo()
projects / openpower-isa.git / commitdiff