Commit c9131cf1 authored by Steven J. Plimpton's avatar Steven J. Plimpton
Browse files

drop FFTW2 support, and change doc pages

parent 023c8e5d

doc/src/Build_settings.txt

+9 −23
Original line number Diff line number Diff line
@@ -33,27 +33,25 @@ LAMMPS can use them if they are available on your system. 


[CMake variables]:



-D FFT=value              # KISS or FFTW3 or FFTW2 or MKL, default is FFTW3 if found, else KISS

-D FFT=value              # FFTW3 or MKL or KISS, default is FFTW3 if found, else KISS

-D FFT_SINGLE=value       # yes or no (default), no = double precision

-D FFT_PACK=value         # array (default) or pointer or memcpy :pre



NOTE: The values for the FFT variable must be in upper-case.

This is an exception to the rule that all CMake variables can

be specified with lower-case values.

NOTE: The values for the FFT variable must be in upper-case.  This is

an exception to the rule that all CMake variables can be specified

with lower-case values.



Usually these settings are all that is needed.  If CMake cannot find

the FFT library, you can set these variables:



-D FFTW3_INCLUDE_DIRS=path  # path to FFTW3 include files

-D FFTW3_LIBRARIES=path     # path to FFTW3 libraries

-D FFTW2_INCLUDE_DIRS=path  # ditto for FFTW2

-D FFTW2_LIBRARIES=path

-D MKL_INCLUDE_DIRS=path    # ditto for Intel MKL library

-D MKL_LIBRARIES=path :pre



[Makefile.machine settings]:



FFT_INC = -DFFT_FFTW3         # -DFFT_FFTW3, -DFFT_FFTW2, -DFFT_FFTW (same as -DFFT_FFTW3), -DFFT_MKL, or -DFFT_KISS

FFT_INC = -DFFT_FFTW3         # -DFFT_FFTW3, -DFFT_FFTW (same as -DFFT_FFTW3), -DFFT_MKL, or -DFFT_KISS

                              # default is KISS if not specified

FFT_INC = -DFFT_SINGLE        # do not specify for double precision

FFT_INC = -DFFT_PACK_ARRAY    # or -DFFT_PACK_POINTER or -DFFT_PACK_MEMCPY :pre
@@ -63,8 +61,6 @@ FFT_INC = -I/usr/local/include 
FFT_PATH =      -L/usr/local/lib

FFT_LIB =	-lfftw3             # FFTW3 double precision

FFT_LIB =	-lfftw3 -lfftw3f    # FFTW3 single precision

FFT_LIB =	-lfftw              # FFTW2 double precision, or -ldfftw

FFT_LIB =	-lsfftw             # FFTW2 single precision

FFT_LIB =       -lmkl_intel_lp64 -lmkl_sequential -lmkl_core  # MKL with Intel compiler

FFT_LIB =       -lmkl_gf_lp64 -lmkl_sequential -lmkl_core     # MKL with GNU compier :pre
@@ -89,12 +85,8 @@ details. 


FFTW is a fast, portable FFT library that should also work on any

platform and can be faster than the KISS FFT library.  You can

download it from "www.fftw.org"_http://www.fftw.org.  Both the

(obsolete) legacy version 2.1.X and the newer 3.X versions are

supported.



NOTE: FFTW2 has not been updated since 1999 and has been declared

obsolete by its developers.

download it from "www.fftw.org"_http://www.fftw.org.  LAMMPS requires

version 3.X; the legacy version 2.1.X is no longer supported.



Building FFTW for your box should be as simple as ./configure; make;

make install.  The install command typically requires root privileges
@@ -116,8 +108,8 @@ error is less than the difference in precision. Using the -DFFT_SINGLE 
setting trades off a little accuracy for reduced memory use and

parallel communication costs for transposing 3d FFT data.



When using -DFFT_SINGLE with FFTW3 or FFTW2, you may need to build the

FFTW library a second time with support for single-precision.

When using -DFFT_SINGLE with FFTW3 you may need to build the FFTW

library a second time with support for single-precision.



For FFTW3, do the following, which should produce the additional

library libfftw3f.a
@@ -125,12 +117,6 @@ library libfftw3f.a 
make clean

./configure --enable-single; make; make install :pre



For FFTW2, do the following, which should produce the additional

library libsfftw.a



make clean

./configure --enable-float --enable-type-prefix; make; make install :pre



Performing 3d FFTs requires communication to transpose the 3d FFT

grid.  The data packing/unpacking for this can be done in one of 3

modes (ARRAY, POINTER, MEMCPY) as set by the FFT_PACK syntax above.

src/KSPACE/fft3d.cpp

+13 −1
Original line number Diff line number Diff line
@@ -104,11 +104,13 @@ void fft_3d(FFT_DATA *in, FFT_DATA *out, int flag, struct fft_plan_3d *plan) 
    DftiComputeForward(plan->handle_fast,data);

  else

    DftiComputeBackward(plan->handle_fast,data);

  /*

#elif defined(FFT_FFTW2)

  if (flag == -1)

    fftw(plan->plan_fast_forward,total/length,data,1,length,NULL,0,0);

  else

   fftw(plan->plan_fast_backward,total/length,data,1,length,NULL,0,0);

  */

#elif defined(FFT_FFTW3)

  if (flag == -1)

    theplan=plan->plan_fast_forward;
@@ -143,11 +145,13 @@ void fft_3d(FFT_DATA *in, FFT_DATA *out, int flag, struct fft_plan_3d *plan) 
    DftiComputeForward(plan->handle_mid,data);

  else

    DftiComputeBackward(plan->handle_mid,data);

  /*

#elif defined(FFT_FFTW2)

  if (flag == -1)

    fftw(plan->plan_mid_forward,total/length,data,1,length,NULL,0,0);

  else

    fftw(plan->plan_mid_backward,total/length,data,1,length,NULL,0,0);

  */

#elif defined(FFT_FFTW3)

  if (flag == -1)

    theplan=plan->plan_mid_forward;
@@ -182,11 +186,13 @@ void fft_3d(FFT_DATA *in, FFT_DATA *out, int flag, struct fft_plan_3d *plan) 
    DftiComputeForward(plan->handle_slow,data);

  else

    DftiComputeBackward(plan->handle_slow,data);

  /*

#elif defined(FFT_FFTW2)

  if (flag == -1)

    fftw(plan->plan_slow_forward,total/length,data,1,length,NULL,0,0);

  else

    fftw(plan->plan_slow_backward,total/length,data,1,length,NULL,0,0);

  */

#elif defined(FFT_FFTW3)

  if (flag == -1)

    theplan=plan->plan_slow_forward;
@@ -520,6 +526,7 @@ struct fft_plan_3d *fft_3d_create_plan( 
      (out_khi-out_klo+1);

  }



  /*

#elif defined(FFT_FFTW2)



  plan->plan_fast_forward =
@@ -561,6 +568,7 @@ struct fft_plan_3d *fft_3d_create_plan( 
    plan->normnum = (out_ihi-out_ilo+1) * (out_jhi-out_jlo+1) *

      (out_khi-out_klo+1);

  }

  */



#elif defined(FFT_FFTW3)

  plan->plan_fast_forward =
@@ -660,6 +668,7 @@ void fft_3d_destroy_plan(struct fft_plan_3d *plan) 
  DftiFreeDescriptor(&(plan->handle_fast));

  DftiFreeDescriptor(&(plan->handle_mid));

  DftiFreeDescriptor(&(plan->handle_slow));

  /*

#elif defined(FFT_FFTW2)

  if (plan->plan_slow_forward != plan->plan_fast_forward &&

      plan->plan_slow_forward != plan->plan_mid_forward) {
@@ -672,6 +681,7 @@ void fft_3d_destroy_plan(struct fft_plan_3d *plan) 
  }

  fftw_destroy_plan(plan->plan_fast_forward);

  fftw_destroy_plan(plan->plan_fast_backward);

  */

#elif defined(FFT_FFTW3)

  FFTW_API(destroy_plan)(plan->plan_slow_forward);

  FFTW_API(destroy_plan)(plan->plan_slow_backward);
@@ -809,6 +819,7 @@ void fft_1d_only(FFT_DATA *data, int nsize, int flag, struct fft_plan_3d *plan) 
    DftiComputeBackward(plan->handle_mid,data);

    DftiComputeBackward(plan->handle_slow,data);

  }

  /*

#elif defined(FFT_FFTW2)

  if (flag == -1) {

    fftw(plan->plan_fast_forward,total1/length1,data,1,0,NULL,0,0);
@@ -819,6 +830,7 @@ void fft_1d_only(FFT_DATA *data, int nsize, int flag, struct fft_plan_3d *plan) 
    fftw(plan->plan_mid_backward,total2/length2,data,1,0,NULL,0,0);

    fftw(plan->plan_slow_backward,total3/length3,data,1,0,NULL,0,0);

  }

  */

#elif defined(FFT_FFTW3)

  FFTW_API(plan) theplan;

  if (flag == -1)

src/KSPACE/fft3d.h

+22 −22
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ typedef float FFT_SCALAR; 
typedef double FFT_SCALAR;

#endif



// set default fftw library. switch to FFT_FFTW3 when convenient.

// if user set FFTW, it means FFTW3



#ifdef FFT_FFTW

#define FFT_FFTW3
@@ -41,13 +41,13 @@ typedef double FFT_SCALAR; 
typedef float _Complex FFT_DATA;

#define FFT_MKL_PREC DFTI_SINGLE



#elif defined(FFT_FFTW2)

#if defined(FFTW_SIZE)

#include "sfftw.h"

#else

#include "fftw.h"

#endif

typedef FFTW_COMPLEX FFT_DATA;

//#elif defined(FFT_FFTW2)

//#if defined(FFTW_SIZE)

//#include "sfftw.h"

//#else

//#include "fftw.h"

//#endif

//typedef FFTW_COMPLEX FFT_DATA;



#elif defined(FFT_FFTW3)

#include "fftw3.h"
@@ -82,13 +82,13 @@ typedef struct kiss_fft_state* kiss_fft_cfg; 
typedef double _Complex FFT_DATA;

#define FFT_MKL_PREC DFTI_DOUBLE



#elif defined(FFT_FFTW2)

#if defined(FFTW_SIZE)

#include "dfftw.h"

#else

#include "fftw.h"

#endif

typedef FFTW_COMPLEX FFT_DATA;

//#elif defined(FFT_FFTW2)

//#if defined(FFTW_SIZE)

//#include "dfftw.h"

//#else

//#include "fftw.h"

//#endif

//typedef FFTW_COMPLEX FFT_DATA;



#elif defined(FFT_FFTW3)

#include "fftw3.h"
@@ -139,13 +139,13 @@ struct fft_plan_3d { 
  DFTI_DESCRIPTOR *handle_fast;

  DFTI_DESCRIPTOR *handle_mid;

  DFTI_DESCRIPTOR *handle_slow;

#elif defined(FFT_FFTW2)

  fftw_plan plan_fast_forward;

  fftw_plan plan_fast_backward;

  fftw_plan plan_mid_forward;

  fftw_plan plan_mid_backward;

  fftw_plan plan_slow_forward;

  fftw_plan plan_slow_backward;

//#elif defined(FFT_FFTW2)

//  fftw_plan plan_fast_forward;

//  fftw_plan plan_fast_backward;

//  fftw_plan plan_mid_forward;

//  fftw_plan plan_mid_backward;

//fftw_plan plan_slow_forward;

//fftw_plan plan_slow_backward;

#elif defined(FFT_FFTW3)

  FFTW_API(plan) plan_fast_forward;

  FFTW_API(plan) plan_fast_backward;

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