text: # Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
  # Spack Project Developers. See the top-level COPYRIGHT file for details.
  #
  # SPDX-License-Identifier: (Apache-2.0 OR MIT)
  
  import os
  import os.path
  
  import llnl.util.lang
  
  from spack import *
  
  
  class Fftw(AutotoolsPackage):
      """FFTW is a C subroutine library for computing the discrete Fourier
         transform (DFT) in one or more dimensions, of arbitrary input
         size, and of both real and complex data (as well as of even/odd
         data, i.e. the discrete cosine/sine transforms or DCT/DST). We
         believe that FFTW, which is free software, should become the FFT
         library of choice for most applications."""
  
      homepage = "http://www.fftw.org"
      url = "http://www.fftw.org/fftw-3.3.4.tar.gz"
      list_url = "http://www.fftw.org/download.html"
  
      version('3.3.8', sha256='6113262f6e92c5bd474f2875fa1b01054c4ad5040f6b0da7c03c98821d9ae303')
      version('3.3.7', sha256='3b609b7feba5230e8f6dd8d245ddbefac324c5a6ae4186947670d9ac2cd25573')
      version('3.3.6-pl2', sha256='a5de35c5c824a78a058ca54278c706cdf3d4abba1c56b63531c2cb05f5d57da2')
      version('3.3.5', sha256='8ecfe1b04732ec3f5b7d279fdb8efcad536d555f9d1e8fabd027037d45ea8bcf')
      version('3.3.4', sha256='8f0cde90929bc05587c3368d2f15cd0530a60b8a9912a8e2979a72dbe5af0982')
      version('2.1.5', sha256='f8057fae1c7df8b99116783ef3e94a6a44518d49c72e2e630c24b689c6022630')
  
      patch('pfft-3.3.5.patch', when="@3.3.5:+pfft_patches", level=0)
      patch('pfft-3.3.4.patch', when="@3.3.4+pfft_patches", level=0)
      patch('pgi-3.3.6-pl2.patch', when="@3.3.6-pl2%pgi", level=0)
  
      variant(
          'precision', values=any_combination_of(
              'float', 'double', 'long_double', 'quad'
          ).prohibit_empty_set().with_default('float,double'),
          description='Build the selected floating-point precision libraries'
      )
      variant('openmp', default=False, description="Enable OpenMP support.")
      variant('mpi', default=True, description='Activate MPI support')
      variant(
          'pfft_patches', default=False,
          description='Add extra transpose functions for PFFT compatibility')
  
      depends_on('mpi', when='+mpi')
      depends_on('automake', type='build', when='+pfft_patches')
      depends_on('autoconf', type='build', when='+pfft_patches')
      depends_on('libtool', type='build', when='+pfft_patches')
  
      # https://github.com/FFTW/fftw3/commit/902d0982522cdf6f0acd60f01f59203824e8e6f3
      conflicts('%gcc@8:8.9999', when="@3.3.7")
      conflicts('precision=long_double', when='@2.1.5',
                msg='Long double precision is not supported in FFTW 2')
      conflicts('precision=quad', when='@2.1.5',
                msg='Quad precision is not supported in FFTW 2')
  
      provides('fftw-api@2', when='@2.1.5')
      provides('fftw-api@3', when='@3:')
  
      @property
      def libs(self):
  
          # Reduce repetitions of entries
          query_parameters = list(llnl.util.lang.dedupe(
              self.spec.last_query.extra_parameters
          ))
  
          # List of all the suffixes associated with float precisions
          precisions = [
              ('float', 'f'),
              ('double', ''),
              ('long_double', 'l'),
              ('quad', 'q')
          ]
  
          # Retrieve the correct suffixes, or use double as a default
          suffixes = [v for k, v in precisions if k in query_parameters] or ['']
  
          # Construct the list of libraries that needs to be found
          libraries = []
          for sfx in suffixes:
              if 'mpi' in query_parameters and '+mpi' in self.spec:
                  libraries.append('libfftw3' + sfx + '_mpi')
  
              if 'openmp' in query_parameters and '+openmp' in self.spec:
                  libraries.append('libfftw3' + sfx + '_omp')
  
              libraries.append('libfftw3' + sfx)
  
          return find_libraries(libraries, root=self.prefix, recursive=True)
  
      def patch(self):
          # If fftw/config.h exists in the source tree, it will take precedence
          # over the copy in build dir.  As only the latter has proper config
          # for our build, this is a problem.  See e.g. issue #7372 on github
          if os.path.isfile('fftw/config.h'):
              os.rename('fftw/config.h', 'fftw/config.h.SPACK_RENAMED')
  
      def autoreconf(self, spec, prefix):
          if '+pfft_patches' in spec:
              autoreconf = which('autoreconf')
              autoreconf('-ifv')
  
      @property
      def selected_precisions(self):
          """Precisions that have been selected in this build"""
          return self.spec.variants['precision'].value
  
      def configure(self, spec, prefix):
          # Base options
          options = [
              '--prefix={0}'.format(prefix),
              '--enable-shared',
              '--enable-threads'
          ]
          if not self.compiler.f77 or not self.compiler.fc:
              options.append("--disable-fortran")
          if spec.satisfies('@:2'):
              options.append('--enable-type-prefix')
  
          # Variants that affect every precision
          if '+openmp' in spec:
              # Note: Apple's Clang does not support OpenMP.
              if spec.satisfies('%clang'):
                  ver = str(self.compiler.version)
                  if ver.endswith('-apple'):
                      raise InstallError("Apple's clang does not support OpenMP")
              options.append('--enable-openmp')
              if spec.satisfies('@:2'):
                  # TODO: libtool strips CFLAGS, so 2.x libxfftw_threads
                  #       isn't linked to the openmp library. Patch Makefile?
                  options.insert(0, 'CFLAGS=' + self.compiler.openmp_flag)
          if '+mpi' in spec:
              options.append('--enable-mpi')
  
          # Specific SIMD support.
          # all precisions
          simd_features = ['sse2', 'avx', 'avx2', 'avx512', 'avx-128-fma',
                           'kcvi', 'vsx', 'neon']
          # float only
          float_simd_features = ['altivec', 'sse']
  
          simd_options = []
          for feature in simd_features:
              msg = '--enable-{0}' if feature in spec.target else '--disable-{0}'
              simd_options.append(msg.format(feature))
  
          # If no features are found, enable the generic ones
          if not any(f in spec.target for f in
                     simd_features + float_simd_features):
              simd_options += [
                  '--enable-generic-simd128',
                  '--enable-generic-simd256'
              ]
  
          simd_options += [
              '--enable-fma' if 'fma' in spec.target else '--disable-fma'
          ]
  
          # Double is the default precision, for all the others we need
          # to enable the corresponding option.
          enable_precision = {
              'float': ['--enable-float'],
              'double': None,
              'long_double': ['--enable-long-double'],
              'quad': ['--enable-quad-precision']
          }
  
          # Different precisions must be configured and compiled one at a time
          configure = Executable('../configure')
          for precision in self.selected_precisions:
              opts = (enable_precision[precision] or []) + options[:]
  
              # SIMD optimizations are available only for float and double
              # starting from FFTW 3
              if precision in ('float', 'double') and spec.satisfies('@3:'):
                  opts += simd_options
  
              # float-only acceleration
              if precision == 'float':
                  for feature in float_simd_features:
                      if feature in spec.target:
                          msg = '--enable-{0}'
                      else:
                          msg = '--disable-{0}'
                      opts.append(msg.format(feature))
  
              with working_dir(precision, create=True):
                  configure(*opts)
  
      def for_each_precision_make(self, *targets):
          for precision in self.selected_precisions:
              with working_dir(precision):
                  make(*targets)
  
      def build(self, spec, prefix):
          self.for_each_precision_make()
  
      def check(self):
          self.for_each_precision_make('check')
  
      def install(self, spec, prefix):
          self.for_each_precision_make('install')
  