ENH: uarray based backend support for scipy.fft

LICENSES_bundled.txt

@@ -163,3 +163,8 @@ Name: pypocketfft
 Files: scipy/fft/_pocketfft/[pocketfft.h, pypocketfft.cxx]
 License: 3-Clause BSD
   For details, see scipy/fft/_pocketfft/LICENSE.md
+
+Name: uarray
+Files: scipy/_lib/uarray/*
+License: 3-Clause BSD
+  For details, see scipy/_lib/uarray/LICENSE

benchmarks/benchmarks/fft_basic.py

@@ -115,3 +115,85 @@ def setup(self, size, cmplx, module):
 
     def time_fftn(self, size, cmplx, module):
         self.fftn(self.x)
+
+
+class FftBackends(Benchmark):
+    params = [
+        [100, 256, 313, 512, 1000, 1024, 2048, 2048*2, 2048*4],
+        ['real', 'cmplx'],
+        ['pocketfft', 'pyfftw', 'numpy', 'direct']
+    ]
+    param_names = ['size', 'type', 'backend']
+
+    def setup(self, size, cmplx, backend):
+        import scipy.fft
+        if cmplx == 'cmplx':
+            self.x = random([size]).astype(cdouble)+random([size]).astype(cdouble)*1j
+        else:
+            self.x = random([size]).astype(double)
+
+        self.fft = scipy.fft.fft
+        self.ifft = scipy.fft.ifft
+
+        if backend == 'pocketfft':
+            scipy.fft.set_global_backend('scipy')
+        elif backend == 'pyfftw':
+            from scipy.fft._debug_backends import PyfftwBackend
+            import pyfftw
+            pyfftw.interfaces.cache.enable()
+            scipy.fft.set_global_backend(PyfftwBackend)
+        elif backend == 'numpy':
+            from scipy.fft._debug_backends import NumPyBackend
+            scipy.fft.set_global_backend(NumPyBackend)
+        elif backend == 'direct':
+            import scipy.fft._pocketfft
+            self.fft = scipy.fft._pocketfft.fft
+            self.ifft = scipy.fft._pocketfft.ifft
+
+    def time_fft(self, size, cmplx, module):
+        self.fft(self.x)
+
+    def time_ifft(self, size, cmplx, module):
+        self.ifft(self.x)
+
+
+class FftnBackends(Benchmark):
+    params = [
+        ["100x100", "313x100", "1000x100", "256x256", "512x512"],
+        ['real', 'cmplx'],
+        ['pocketfft', 'pyfftw', 'numpy', 'direct']
+    ]
+    param_names = ['size', 'type', 'backend']
+
+    def setup(self, size, cmplx, backend):
+        import scipy.fft
+        size = list(map(int, size.split("x")))
+
+        if cmplx == 'cmplx':
+            self.x = random(size).astype(double)+random(size).astype(double)*1j
+        else:
+            self.x = random(size).astype(double)
+
+        self.fftn = scipy.fft.fftn
+        self.ifftn = scipy.fft.ifftn
+
+        if backend == 'pocketfft':
+            scipy.fft.set_global_backend('scipy')
+        elif backend == 'pyfftw':
+            from scipy.fft._debug_backends import PyfftwBackend
+            import pyfftw
+            pyfftw.interfaces.cache.enable()
+            scipy.fft.set_global_backend(PyfftwBackend)
+        elif backend == 'numpy':
+            from scipy.fft._debug_backends import NumPyBackend
+            scipy.fft.set_global_backend(NumPyBackend)
+        elif backend == 'direct':
+            import scipy.fft._pocketfft
+            self.fftn = scipy.fft._pocketfft.fftn
+            self.ifftn = scipy.fft._pocketfft.ifftn
+
+    def time_fft(self, size, cmplx, module):
+        self.fftn(self.x)
+
+    def time_ifft(self, size, cmplx, module):
+        self.ifftn(self.x)

doc/source/conf.py

@@ -17,6 +17,14 @@
 
 needs_sphinx = '1.6'
 
+# Workaround for sphinx-doc/sphinx#6573
+# ua._Function should not be treated as an attribute
+from sphinx.util import inspect
+import scipy._lib.uarray as ua
+old_isattrdesc = inspect.isattributedescriptor
+inspect.isattributedescriptor = (lambda obj: old_isattrdesc(obj)
+                                 and not isinstance(obj, ua._Function))
+
 # -----------------------------------------------------------------------------
 # General configuration
 # -----------------------------------------------------------------------------

scipy/_build_utils/compiler_helper.py

@@ -0,0 +1,55 @@
+"""
+Helpers for detection of compiler features
+"""
+import tempfile
+import os
+
+def try_compile(compiler, code=None, flags=[], ext=None):
+    """Returns True if the compiler is able to compile the given code"""
+    from distutils.errors import CompileError
+
+    code = code or 'int main (int argc, char **argv) { return 0; }'
+    ext = ext or compiler.src_extensions[0]
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        fname = os.path.join(temp_dir, 'main'+ext)
+        with open(fname, 'w') as f:
+            f.write(code)
+
+        try:
+            compiler.compile([fname], output_dir=temp_dir, extra_postargs=flags)
+        except CompileError:
+            return False
+    return True
+
+
+def has_flag(compiler, flag, ext=None):
+    """Returns True if the compiler supports the given flag"""
+    return try_compile(compiler, flags=[flag], ext=ext)
+
+
+def get_cxx_std_flag(compiler):
+    """Detects compiler flag for c++14, c++11 or None if not detected"""
+    gnu_flags = ['--std=c++14', '--std=c++11']
+    flags_by_cc = {
+        'msvc': ['/std:c++14', None],
+        'intelw': ['/Qstd=c++14', '/Qstd=c++11']
+    }
+    flags = flags_by_cc.get(compiler.compiler_type, gnu_flags)
+
+    for flag in flags:
+        if flag is None:
+            return None
+
+        if has_flag(compiler, flag):
+            return flag
+
+    from numpy.distutils import log
+    log.warn('Could not detect c++ standard flag')
+    return None
+
+
+def try_add_flag(args, compiler, flag, ext=None):
+    """Appends flag to the list of arguments if supported by the compiler"""
+    if try_compile(compiler, flags=args+[flag], ext=ext):
+        args.append(flag)

scipy/_build_utils/tests/test_circular_imports.py

@@ -9,6 +9,7 @@
     'cluster.hierarchy',
     'cluster.vq',
     'constants',
+    'fft'
     'fftpack',
     'fftpack.convolve',
     'integrate',
@@ -44,4 +45,3 @@ def test_importing_submodules():
             subprocess.check_output(cmd)
         except subprocess.CalledProcessError:
             raise AssertionError('Importing scipy.{0} failed'.format(name))
-