mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-18 10:01:57 -05:00
3962a3514a
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6274 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
142 lines
4.3 KiB
Fortran
142 lines
4.3 KiB
Fortran
program timefft
|
|
|
|
! Tests and times one-dimensional FFTs computed by FFTW3
|
|
|
|
use, intrinsic :: iso_c_binding
|
|
use FFTW3
|
|
|
|
complex(C_FLOAT_COMPLEX),pointer :: a(:),b(:),c(:)
|
|
real(C_FLOAT),pointer :: ar(:),br(:)
|
|
type(C_PTR) :: plan1,plan2 !Pointers to FFTW plans
|
|
type(C_PTR) :: pa,pb,pc
|
|
integer(C_INT) iret
|
|
integer*8 count0,count1,clkfreq
|
|
character problem*9
|
|
logical linplace,lcomplex,lthreading
|
|
|
|
! Get command-line parameters
|
|
call timefft_opts(npatience,maxthreads,linplace,lcomplex,nfft,problem,nflags)
|
|
lthreading=maxthreads.ge.1
|
|
maxthreads=max(1,maxthreads)
|
|
|
|
call sgran() ! see C rand generator (used in gran)
|
|
|
|
! Allocate data arrays
|
|
pa=fftwf_alloc_complex(int(nfft,C_SIZE_T))
|
|
call c_f_pointer(pa,a,[nfft])
|
|
call c_f_pointer(pa,ar,[nfft])
|
|
|
|
pb=fftwf_alloc_complex(int(nfft,C_SIZE_T))
|
|
call c_f_pointer(pb,b,[nfft])
|
|
call c_f_pointer(pb,br,[nfft])
|
|
|
|
pc=fftwf_alloc_complex(int(nfft,C_SIZE_T))
|
|
call c_f_pointer(pc,c,[nfft])
|
|
|
|
! Initialize FFTW threading
|
|
if(lthreading) iret=fftwf_init_threads()
|
|
|
|
! Import FFTW wisdom, if available
|
|
iret=fftwf_import_wisdom_from_filename(C_CHAR_'wis.dat' // C_NULL_CHAR)
|
|
|
|
do i=1,nfft !Generate random data
|
|
x=gran()
|
|
y=gran()
|
|
b(i)=cmplx(x,y)
|
|
enddo
|
|
iters=100
|
|
|
|
write(*,1000)
|
|
1000 format(/'Problem Threads Plan Time Gflops RMS iters'/ &
|
|
'--------------------------------------------------------')
|
|
|
|
! Try nthreads = 1,maxthreads
|
|
do nthreads=1,maxthreads
|
|
a(1:nfft)=b(1:nfft) !Copy test data into a()
|
|
call system_clock(count0,clkfreq)
|
|
! Make the plans
|
|
if(lthreading) call fftwf_plan_with_nthreads(nthreads)
|
|
if(lcomplex) then
|
|
if(linplace) then
|
|
plan1=fftwf_plan_dft_1d(nfft,a,a,-1,nflags)
|
|
plan2=fftwf_plan_dft_1d(nfft,a,a,+1,nflags)
|
|
else
|
|
plan1=fftwf_plan_dft_1d(nfft,a,c,-1,nflags)
|
|
plan2=fftwf_plan_dft_1d(nfft,c,a,+1,nflags)
|
|
endif
|
|
else
|
|
if(linplace) then
|
|
plan1=fftwf_plan_dft_r2c_1d(nfft,ar,a,nflags)
|
|
plan2=fftwf_plan_dft_c2r_1d(nfft,a,ar,nflags)
|
|
else
|
|
plan1=fftwf_plan_dft_r2c_1d(nfft,ar,c,nflags)
|
|
plan2=fftwf_plan_dft_c2r_1d(nfft,c,ar,nflags)
|
|
endif
|
|
endif
|
|
call system_clock(count1,clkfreq)
|
|
tplan=0.5*float(count1-count0)/float(clkfreq) !Plan time for one transform
|
|
|
|
total=0.
|
|
do iter=1,iters !Do many iterations
|
|
a=b !Copy test data into a()
|
|
call system_clock(count0,clkfreq)
|
|
! Compute the transforms
|
|
if(lcomplex) then
|
|
if(linplace) then
|
|
call fftwf_execute_dft(plan1,a,a)
|
|
call fftwf_execute_dft(plan2,a,a)
|
|
else
|
|
call fftwf_execute_dft(plan1,a,c)
|
|
call fftwf_execute_dft(plan2,c,a)
|
|
endif
|
|
else
|
|
if(linplace) then
|
|
call fftwf_execute_dft_r2c(plan1,ar,a)
|
|
call fftwf_execute_dft_c2r(plan2,a,ar)
|
|
else
|
|
call fftwf_execute_dft_r2c(plan1,ar,c)
|
|
call fftwf_execute_dft_c2r(plan2,c,ar)
|
|
endif
|
|
endif
|
|
call system_clock(count1,clkfreq)
|
|
total=total + float(count1-count0)/float(clkfreq)
|
|
if(total>=1.0 .and. iter>=10) go to 40 !Cut iterations short ?
|
|
enddo
|
|
iter=iters
|
|
|
|
40 time=0.5*total/iter !Time for one FFT
|
|
gflops=5.0/(1.e9*time/(nfft*log(float(nfft))/log(2.0)))
|
|
a(1:nfft)=a(1:nfft)/nfft !Normalize the back-transformed data
|
|
|
|
! Compute RMS difference between original data and back-transformed data.
|
|
sq=0.
|
|
if(lcomplex) then
|
|
do i=1,nfft
|
|
sq=sq + real(a(i)-b(i))**2 + aimag(a(i)-b(i))**2
|
|
enddo
|
|
else
|
|
do i=1,nfft
|
|
sq=sq + (ar(i)-br(i))**2
|
|
enddo
|
|
endif
|
|
rms=sqrt(sq/nfft)
|
|
|
|
! Display results
|
|
write(*,1050) problem,nthreads,tplan,time,gflops,rms,iter
|
|
1050 format(a9,i4,f8.3,f10.6,f7.2,f11.7,i5)
|
|
enddo
|
|
|
|
! Export accumulated FFTW wisdom
|
|
iret=fftwf_export_wisdom_to_filename(C_CHAR_'wis.dat' // C_NULL_CHAR)
|
|
|
|
! Clean up
|
|
call fftwf_destroy_plan(plan1)
|
|
call fftwf_destroy_plan(plan2)
|
|
call fftwf_free(pa)
|
|
call fftwf_free(pb)
|
|
call fftwf_free(pc)
|
|
call fftwf_cleanup_threads()
|
|
call fftwf_cleanup()
|
|
|
|
end program timefft
|