Add a Pythran backend for Numpy operation

When the user asked for it (thanks to the --np-pythran flag), use
Pythran's Numpy implementation as a backend for numpy operation. This
flag forces the C++ mode, as the Pythran implementation is written in
C++. Distutils integration through the 'np_pythran' flag of the
cythonize API is also provided.

This commit also adds a Pythran mode for the tests, that can enable the
pythran mode for the C++ tests, and allows the reuse of Cython tests to
test for the Pythran integration.

Cython/Build/Dependencies.py

@@ -16,6 +16,7 @@ except ImportError:
     gzip_ext = ''
 import shutil
 import subprocess
+import os
 
 try:
     import hashlib
@@ -42,6 +43,11 @@ except ImportError:
             return os.path.curdir
         return os.path.join(*rel_list)
 
+try:
+    import pythran
+    PythranAvailable = True
+except:
+    PythranAvailable = False
 
 from distutils.extension import Extension
 
@@ -775,7 +781,7 @@ def create_extension_list(patterns, exclude=None, ctx=None, aliases=None, quiet=
 
 # This is the user-exposed entry point.
 def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False, force=False, language=None,
-              exclude_failures=False, **options):
+              exclude_failures=False, np_pythran=False, **options):
     """
     Compile a set of source modules into C/C++ files and return a list of distutils
     Extension objects for them.
@@ -800,6 +806,8 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
     that this only really makes sense for compiling .py files which can also
     be used without compilation.
 
+    To use the Pythran backend for numpy operations, set np_pythran to True.
+
     Additional compilation options can be passed as keyword arguments.
     """
     if exclude is None:
@@ -810,6 +818,13 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
         if options.get('cache'):
             raise NotImplementedError("common_utility_include_dir does not yet work with caching")
         safe_makedirs(options['common_utility_include_dir'])
+    if np_pythran:
+        if not PythranAvailable:
+            raise RuntimeError("You first need to install Pythran to use the np_pythran flag.")
+        pythran_options = CompilationOptions(**options);
+        pythran_options.cplus = True
+        pythran_options.np_pythran = True
+        pythran_include_dir = os.path.dirname(pythran.__file__)
     c_options = CompilationOptions(**options)
     cpp_options = CompilationOptions(**options); cpp_options.cplus = True
     ctx = c_options.create_context()
@@ -845,7 +860,13 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
         for source in m.sources:
             base, ext = os.path.splitext(source)
             if ext in ('.pyx', '.py'):
-                if m.language == 'c++':
+                if np_pythran:
+                    c_file = base + '.cpp'
+                    options = pythran_options
+                    m.include_dirs.append(pythran_include_dir)
+                    m.extra_compile_args.extend(('-std=c++11','-DENABLE_PYTHON_MODULE','-D__PYTHRAN__'))
+                    m.language = 'c++'
+                elif m.language == 'c++':
                     c_file = base + '.cpp'
                     options = cpp_options
                 else:

Cython/Compiler/Buffer.py

@@ -12,7 +12,6 @@ from . import PyrexTypes
 from . import Naming
 from . import Symtab
 
-
 def dedent(text, reindent=0):
     from textwrap import dedent
     text = dedent(text)

Cython/Compiler/FusedNode.py

@@ -315,19 +315,22 @@ class FusedCFuncDefNode(StatListNode):
 
     match = "dest_sig[{{dest_sig_idx}}] = '{{specialized_type_name}}'"
     no_match = "dest_sig[{{dest_sig_idx}}] = None"
-    def _buffer_check_numpy_dtype(self, pyx_code, specialized_buffer_types):
+    def _buffer_check_numpy_dtype(self, pyx_code, specialized_buffer_types, pythran_types):
         """
         Match a numpy dtype object to the individual specializations.
         """
         self._buffer_check_numpy_dtype_setup_cases(pyx_code)
 
-        for specialized_type in specialized_buffer_types:
+        for specialized_type in pythran_types+specialized_buffer_types:
+            final_type = specialized_type
+            if specialized_type.is_pythran_expr:
+                specialized_type = specialized_type.org_buffer
             dtype = specialized_type.dtype
             pyx_code.context.update(
                 itemsize_match=self._sizeof_dtype(dtype) + " == itemsize",
                 signed_match="not (%s_is_signed ^ dtype_signed)" % self._dtype_name(dtype),
                 dtype=dtype,
-                specialized_type_name=specialized_type.specialization_string)
+                specialized_type_name=final_type.specialization_string)
 
             dtypes = [
                 (dtype.is_int, pyx_code.dtype_int),
@@ -342,8 +345,11 @@ class FusedCFuncDefNode(StatListNode):
                     if dtype.is_int:
                         cond += ' and {{signed_match}}'
 
+                    if final_type.is_pythran_expr:
+                        cond += ' and arg_is_pythran_compatible'
+
                     if codewriter.indenter("if %s:" % cond):
-                        # codewriter.putln("print 'buffer match found based on numpy dtype'")
+                        #codewriter.putln("print 'buffer match found based on numpy dtype'")
                         codewriter.putln(self.match)
                         codewriter.putln("break")
                         codewriter.dedent()
@@ -388,7 +394,7 @@ class FusedCFuncDefNode(StatListNode):
                         __pyx_PyErr_Clear()
             """ % self.match)
 
-    def _buffer_checks(self, buffer_types, pyx_code, decl_code, env):
+    def _buffer_checks(self, buffer_types, pythran_types, pyx_code, decl_code, env):
         """
         Generate Cython code to match objects to buffer specializations.
         First try to get a numpy dtype object and match it against the individual
@@ -402,6 +408,7 @@ class FusedCFuncDefNode(StatListNode):
                 if ndarray is not None:
                     if isinstance(arg, ndarray):
                         dtype = arg.dtype
+                        arg_is_pythran_compatible = True
                     elif __pyx_memoryview_check(arg):
                         arg_base = arg.base
                         if isinstance(arg_base, ndarray):
@@ -415,11 +422,26 @@ class FusedCFuncDefNode(StatListNode):
                     if dtype is not None:
                         itemsize = dtype.itemsize
                         kind = ord(dtype.kind)
+                        # We only support the endianess of the current compiler
+                        byteorder = dtype.byteorder
+                        if byteorder == "<" and not __Pyx_Is_Little_Endian():
+                            arg_is_pythran_compatible = False
+                        if byteorder == ">" and __Pyx_Is_Little_Endian():
+                            arg_is_pythran_compatible = False
                         dtype_signed = kind == 'i'
+                        if arg_is_pythran_compatible:
+                            cur_stride = itemsize
+                            for dim,stride in zip(reversed(arg.shape),reversed(arg.strides)):
+                                if stride != cur_stride:
+                                    arg_is_pythran_compatible = False
+                                    break
+                                cur_stride *= dim
+                            else:
+                                arg_is_pythran_compatible = not (arg.flags.f_contiguous and arg.ndim > 1)
             """)
         pyx_code.indent(2)
         pyx_code.named_insertion_point("numpy_dtype_checks")
-        self._buffer_check_numpy_dtype(pyx_code, buffer_types)
+        self._buffer_check_numpy_dtype(pyx_code, buffer_types, pythran_types)
         pyx_code.dedent(2)
 
         for specialized_type in buffer_types:
@@ -446,8 +468,10 @@ class FusedCFuncDefNode(StatListNode):
                 cdef Py_ssize_t itemsize
                 cdef bint dtype_signed
                 cdef char kind
+                cdef bint arg_is_pythran_compatible
 
                 itemsize = -1
+                arg_is_pythran_compatible = False
             """)
 
         pyx_code.imports.put_chunk(
@@ -491,7 +515,7 @@ class FusedCFuncDefNode(StatListNode):
         specialized_types.sort()
 
         seen_py_type_names = set()
-        normal_types, buffer_types = [], []
+        normal_types, buffer_types, pythran_types = [], [], []
         has_object_fallback = False
         for specialized_type in specialized_types:
             py_type_name = specialized_type.py_type_name()
@@ -503,10 +527,12 @@ class FusedCFuncDefNode(StatListNode):
                     has_object_fallback = True
                 else:
                     normal_types.append(specialized_type)
+            elif specialized_type.is_pythran_expr:
+                pythran_types.append(specialized_type)
             elif specialized_type.is_buffer or specialized_type.is_memoryviewslice:
                 buffer_types.append(specialized_type)
 
-        return normal_types, buffer_types, has_object_fallback
+        return normal_types, buffer_types, pythran_types, has_object_fallback
 
     def _unpack_argument(self, pyx_code):
         pyx_code.put_chunk(
@@ -533,6 +559,8 @@ class FusedCFuncDefNode(StatListNode):
         """
         from . import TreeFragment, Code, UtilityCode
 
+        env.use_utility_code(Code.UtilityCode.load_cached("IsLittleEndian","ModuleSetupCode.c"))
+
         fused_types = self._get_fused_base_types([
             arg.type for arg in self.node.args if arg.type.is_fused])
 
@@ -549,6 +577,7 @@ class FusedCFuncDefNode(StatListNode):
             u"""
                 cdef extern from *:
                     void __pyx_PyErr_Clear "PyErr_Clear" ()
+                    int __Pyx_Is_Little_Endian()
             """)
         decl_code.indent()
 
@@ -571,8 +600,10 @@ class FusedCFuncDefNode(StatListNode):
 
                     # instance check body
             """)
+
         pyx_code.indent() # indent following code to function body
         pyx_code.named_insertion_point("imports")
+        pyx_code.named_insertion_point("func_defs")
         pyx_code.named_insertion_point("local_variable_declarations")
 
         fused_index = 0
@@ -597,15 +628,15 @@ class FusedCFuncDefNode(StatListNode):
                     default_idx=default_idx,
                 )
 
-                normal_types, buffer_types, has_object_fallback = self._split_fused_types(arg)
+                normal_types, buffer_types, pythran_types, has_object_fallback = self._split_fused_types(arg)
                 self._unpack_argument(pyx_code)
 
                 # 'unrolled' loop, first match breaks out of it
                 if pyx_code.indenter("while 1:"):
                     if normal_types:
                         self._fused_instance_checks(normal_types, pyx_code, env)
-                    if buffer_types:
-                        self._buffer_checks(buffer_types, pyx_code, decl_code, env)
+                    if buffer_types or pythran_types:
+                        self._buffer_checks(buffer_types, pythran_types, pyx_code, decl_code, env)
                     if has_object_fallback:
                         pyx_code.context.update(specialized_type_name='object')
                         pyx_code.putln(self.match)
@@ -616,6 +647,7 @@ class FusedCFuncDefNode(StatListNode):
 
                 fused_index += 1
                 all_buffer_types.update(buffer_types)
+                all_buffer_types.update(ty.org_buffer for ty in pythran_types)
 
             if arg.default:
                 default_idx += 1

Cython/Compiler/Main.py

@@ -561,6 +561,10 @@ class CompilationOptions(object):
             warnings.warn(message)
 
         directives = dict(options['compiler_directives'])  # copy mutable field
+        if directives.get('np_pythran', False) and not options['cplus']:
+            import warnings
+            warnings.warn("C++ mode forced when in Pythran mode!")
+            options['cplus'] = True
         options['compiler_directives'] = directives
         if 'language_level' in directives and 'language_level' not in kw:
             options['language_level'] = int(directives['language_level'])
@@ -754,4 +758,5 @@ default_options = dict(
     build_dir=None,
     cache=None,
     create_extension=None,
+    np_pythran=False
 )

Cython/Compiler/ModuleNode.py

@@ -22,13 +22,14 @@ from . import Nodes
 from . import Options
 from . import TypeSlots
 from . import PyrexTypes
+from . import Pythran
 
 from .Errors import error, warning
 from .PyrexTypes import py_object_type
 from ..Utils import open_new_file, replace_suffix, decode_filename
 from .Code import UtilityCode
 from .StringEncoding import EncodedString
-
+from .Pythran import has_np_pythran
 
 def check_c_declarations_pxd(module_node):
     module_node.scope.check_c_classes_pxd()
@@ -103,6 +104,8 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             self.scope.merge_in(scope)
 
     def analyse_declarations(self, env):
+        if has_np_pythran(env):
+            Pythran.include_pythran_generic(env)
         if self.directives:
             env.old_style_globals = self.directives['old_style_globals']
         if not Options.docstrings:
@@ -115,6 +118,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         else:
             env.doc = self.doc
         env.directives = self.directives
+
         self.body.analyse_declarations(env)
 
     def prepare_utility_code(self):
@@ -713,6 +717,9 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         code.putln('static const char * %s= %s;' % (Naming.cfilenm_cname, Naming.file_c_macro))
         code.putln('static const char *%s;' % Naming.filename_cname)
 
+        if has_np_pythran(env):
+            env.use_utility_code(UtilityCode.load_cached("PythranConversion", "CppSupport.cpp"))
+
     def generate_extern_c_macro_definition(self, code):
         name = Naming.extern_c_macro
         code.putln("#ifndef %s" % name)

Cython/Compiler/Nodes.py

@@ -28,6 +28,7 @@ from .StringEncoding import EncodedString
 from . import Future
 from . import Options
 from . import DebugFlags
+from .Pythran import has_np_pythran, pythran_type, is_pythran_buffer
 from ..Utils import add_metaclass
 
 
@@ -1127,6 +1128,8 @@ class TemplatedTypeNode(CBaseTypeNode):
                                 for name, value in options.items()])
 
             self.type = PyrexTypes.BufferType(base_type, **options)
+            if has_np_pythran(env) and is_pythran_buffer(self.type):
+                self.type = PyrexTypes.PythranExpr(pythran_type(self.type), self.type)
 
         else:
             # Array
@@ -2298,7 +2301,7 @@ class CFuncDefNode(FuncDefNode):
             if type_arg.type.is_buffer and 'inline' in self.modifiers:
                 warning(formal_arg.pos, "Buffer unpacking not optimized away.", 1)
 
-            if type_arg.type.is_buffer:
+            if type_arg.type.is_buffer or type_arg.type.is_pythran_expr:
                 if self.type.nogil:
                     error(formal_arg.pos,
                           "Buffer may not be acquired without the GIL. Consider using memoryview slices instead.")
@@ -2815,6 +2818,13 @@ class DefNode(FuncDefNode):
                 name_declarator = None
             else:
                 base_type = arg.base_type.analyse(env)
+                # If we hare in pythran mode and we got a buffer supported by
+                # Pythran, we change this node to a fused type
+                if has_np_pythran(env) and base_type.is_pythran_expr:
+                    base_type = PyrexTypes.FusedType([
+                        base_type,
+                        #PyrexTypes.PythranExpr(pythran_type(self.type, "numpy_texpr")),
+                        base_type.org_buffer])
                 name_declarator, type = \
                     arg.declarator.analyse(base_type, env)
                 arg.name = name_declarator.name
@@ -2855,6 +2865,11 @@ class DefNode(FuncDefNode):
                     error(arg.pos, "Only Python type arguments can have 'or None'")
         env.fused_to_specific = f2s
 
+        if has_np_pythran(env):
+            self.np_args_idx = [i for i,a in enumerate(self.args) if a.type.is_numpy_buffer]
+        else:
+            self.np_args_idx = []
+
     def analyse_signature(self, env):
         if self.entry.is_special:
             if self.decorators:
@@ -3144,6 +3159,8 @@ class DefNodeWrapper(FuncDefNode):
 
         self.signature = target_entry.signature
 
+        self.np_args_idx = self.target.np_args_idx
+
     def prepare_argument_coercion(self, env):
         # This is only really required for Cython utility code at this time,
         # everything else can be done during code generation.  But we expand

Cython/Compiler/Options.py

@@ -175,6 +175,7 @@ _directive_defaults = {
     'type_version_tag': True,   # enables Py_TPFLAGS_HAVE_VERSION_TAG on extension types
     'unraisable_tracebacks': True,
     'old_style_globals': False,
+    'np_pythran': False,
 
     # set __file__ and/or __path__ to known source/target path at import time (instead of not having them available)
     'set_initial_path' : None,  # SOURCEFILE or "/full/path/to/module"
@@ -311,6 +312,7 @@ directive_scopes = { # defaults to available everywhere
     # globals() could conceivably be controlled at a finer granularity,
     # but that would complicate the implementation
     'old_style_globals': ('module',),
+    'np_pythran': ('module',)
 }
 
 

Cython/Compiler/ParseTreeTransforms.py

@@ -24,7 +24,6 @@ from .StringEncoding import EncodedString, _unicode
 from .Errors import error, warning, CompileError, InternalError
 from .Code import UtilityCode
 
-
 class NameNodeCollector(TreeVisitor):
     """Collect all NameNodes of a (sub-)tree in the ``name_nodes``
     attribute.
@@ -601,6 +600,22 @@ class PxdPostParse(CythonTransform, SkipDeclarations):
         else:
             return node
 
+class TrackNumpyAttributes(CythonTransform, SkipDeclarations):
+    def __init__(self, context):
+        super(TrackNumpyAttributes, self).__init__(context)
+        self.numpy_module_names = set()
+
+    def visit_CImportStatNode(self, node):
+        if node.module_name == u"numpy":
+            self.numpy_module_names.add(node.as_name or u"numpy")
+        return node
+
+    def visit_AttributeNode(self, node):
+        self.visitchildren(node)
+        if node.obj.is_name and node.obj.name in self.numpy_module_names:
+            node.is_numpy_attribute = True
+        return node
+
 class InterpretCompilerDirectives(CythonTransform, SkipDeclarations):
     """
     After parsing, directives can be stored in a number of places:
@@ -859,7 +874,8 @@ class InterpretCompilerDirectives(CythonTransform, SkipDeclarations):
             if optname:
                 directivetype = Options.directive_types.get(optname)
                 if directivetype is bool:
-                    return [(optname, True)]
+                    arg = ExprNodes.BoolNode(node.pos, value=True)
+                    return [self.try_to_parse_directive(optname, [arg], None, node.pos)]
                 elif directivetype is None:
                     return [(optname, None)]
                 else:
@@ -869,6 +885,8 @@ class InterpretCompilerDirectives(CythonTransform, SkipDeclarations):
 
     def try_to_parse_directive(self, optname, args, kwds, pos):
         directivetype = Options.directive_types.get(optname)
+        if optname == 'np_pythran' and not self.context.cpp:
+            raise PostParseError(pos, 'The %s directive can only be used in C++ mode.' % optname)
         if len(args) == 1 and isinstance(args[0], ExprNodes.NoneNode):
             return optname, Options.get_directive_defaults()[optname]
         elif directivetype is bool:

Cython/Compiler/Pipeline.py

@@ -145,7 +145,7 @@ def create_pipeline(context, mode, exclude_classes=()):
     from .ParseTreeTransforms import ForwardDeclareTypes, AnalyseDeclarationsTransform
     from .ParseTreeTransforms import AnalyseExpressionsTransform, FindInvalidUseOfFusedTypes
     from .ParseTreeTransforms import CreateClosureClasses, MarkClosureVisitor, DecoratorTransform
-    from .ParseTreeTransforms import InterpretCompilerDirectives, TransformBuiltinMethods
+    from .ParseTreeTransforms import TrackNumpyAttributes, InterpretCompilerDirectives, TransformBuiltinMethods
     from .ParseTreeTransforms import ExpandInplaceOperators, ParallelRangeTransform
     from .ParseTreeTransforms import CalculateQualifiedNamesTransform
     from .TypeInference import MarkParallelAssignments, MarkOverflowingArithmetic
@@ -183,6 +183,7 @@ def create_pipeline(context, mode, exclude_classes=()):
         NormalizeTree(context),
         PostParse(context),
         _specific_post_parse,
+        TrackNumpyAttributes(context),
         InterpretCompilerDirectives(context, context.compiler_directives),
         ParallelRangeTransform(context),
         AdjustDefByDirectives(context),

Cython/Compiler/PyrexTypes.py

@@ -186,6 +186,8 @@ class PyrexType(BaseType):
     #  is_returncode         boolean     Is used only to signal exceptions
     #  is_error              boolean     Is the dummy error type
     #  is_buffer             boolean     Is buffer access type
+    #  is_pythran_expr       boolean     Is Pythran expr
+    #  is_numpy_buffer       boolean     Is Numpy array buffer
     #  has_attributes        boolean     Has C dot-selectable attributes
     #  default_value         string      Initial value
     #  entry                 Entry       The Entry for this type
@@ -245,6 +247,8 @@ class PyrexType(BaseType):
     is_buffer = 0
     is_ctuple = 0
     is_memoryviewslice = 0
+    is_pythran_expr = 0
+    is_numpy_buffer = 0
     has_attributes = 0
     default_value = ""
 
@@ -1008,6 +1012,7 @@ class BufferType(BaseType):
         self.mode = mode
         self.negative_indices = negative_indices
         self.cast = cast
+        self.is_numpy_buffer = self.base.name == "ndarray"
 
     def can_coerce_to_pyobject(self,env):
         return True
@@ -1451,6 +1456,40 @@ class CType(PyrexType):
             source_code,
             code.error_goto_if(error_condition or self.error_condition(result_code), error_pos))
 
+class PythranExpr(CType):
+    # Pythran object of a given type
+
+    to_py_function = "to_python_from_expr"
+    is_pythran_expr = True
+    writable = True
+    has_attributes = 1
+
+    def __init__(self, pythran_type, org_buffer=None):
+        self.org_buffer = org_buffer
+        self.pythran_type = pythran_type
+        self.name = self.pythran_type
+        self.cname = self.pythran_type
+        self.from_py_function = "from_python<%s>" % (self.pythran_type)
+        self.scope = None
+
+    def declaration_code(self, entity_code, for_display = 0, dll_linkage = None, pyrex = 0):
+        assert pyrex == 0
+        return "%s %s" % (self.name, entity_code)
+
+    def attributes_known(self):
+        if self.scope is None:
+            from . import Symtab
+            self.scope = scope = Symtab.CClassScope(
+                    '',
+                    None,
+                    visibility="extern")
+            scope.parent_type = self
+            scope.directives = {}
+            # rank 3 == long
+            scope.declare_var("shape", CPtrType(CIntType(3)), None, cname="_shape", is_cdef=True)
+            scope.declare_var("ndim", CIntType(3), None, cname="value", is_cdef=True)
+
+        return True
 
 class CConstType(BaseType):
 
@@ -4120,13 +4159,17 @@ def best_match(arg_types, functions, pos=None, env=None, args=None):
             # function that takes a char *, the coercion will mean that the
             # type will simply become bytes. We need to do this coercion
             # manually for overloaded and fused functions
-            if not assignable and src_type.is_pyobject:
+            if not assignable:
+                c_src_type = None
+                if src_type.is_pyobject:
                     if src_type.is_builtin_type and src_type.name == 'str' and dst_type.resolve().is_string:
                         c_src_type = dst_type.resolve()
                     else:
                         c_src_type = src_type.default_coerced_ctype()
+                elif src_type.is_pythran_expr:
+                        c_src_type = src_type.org_buffer
 
-                if c_src_type:
+                if c_src_type is not None:
                     assignable = dst_type.assignable_from(c_src_type)
                     if assignable:
                         src_type = c_src_type

Cython/Compiler/Pythran.py

+from .PyrexTypes import BufferType, CType, CTypedefType, CStructOrUnionType
+
+_pythran_var_prefix = "__pythran__"
+# Pythran/Numpy specific operations
+def has_np_pythran(env):
+    while not env is None:
+        if hasattr(env, "directives") and env.directives.get('np_pythran', False):
+            return True
+        env = env.outer_scope
+
+def is_pythran_supported_dtype(type_):
+    if isinstance(type_, CTypedefType):
+        return is_pythran_supported_type(type_.typedef_base_type)
+    return type_.is_numeric
+
+def pythran_type(Ty,ptype="ndarray"):
+    if Ty.is_buffer:
+        ndim,dtype = Ty.ndim, Ty.dtype
+        if isinstance(dtype, CStructOrUnionType):
+            ctype = dtype.cname
+        elif isinstance(dtype, CType):
+            ctype = dtype.sign_and_name()
+        elif isinstance(dtype, CTypedefType):
+            ctype = dtype.typedef_cname
+        else:
+            raise ValueError("unsupported type %s!" % str(dtype))
+        return "pythonic::types::%s<%s,%d>" % (ptype,ctype, ndim)
+    from .PyrexTypes import PythranExpr
+    if Ty.is_pythran_expr:
+        return Ty.pythran_type
+    #if Ty.is_none:
+    #    return "decltype(pythonic::__builtin__::None)"
+    if Ty.is_numeric:
+        return Ty.sign_and_name()
+    raise ValueError("unsupported pythran type %s (%s)" % (str(Ty), str(type(Ty))))
+    return None
+
+def type_remove_ref(ty):
+    return "typename std::remove_reference<%s>::type" % ty
+
+def pythran_binop_type(op, tA, tB):
+    return "decltype(std::declval<%s>() %s std::declval<%s>())" % \
+        (pythran_type(tA), op, pythran_type(tB))
+
+def pythran_unaryop_type(op, type_):
+    return "decltype(%sstd::declval<%s>())" % (
+        op, pythran_type(type_))
+
+def pythran_indexing_type(type_, indices):
+    def index_code(idx):
+        if idx.is_slice:
+            if idx.step.is_none:
+                func = "contiguous_slice"
+                n = 2
+            else:
+                func = "slice"
+                n = 3
+            return "pythonic::types::%s(%s)" % (func,",".join(["0"]*n))
+        elif idx.type.is_int:
+            return "std::declval<long>()"
+        elif idx.type.is_pythran_expr:
+            return "std::declval<%s>()" % idx.type.pythran_type
+        raise ValueError("unsupported indice type %s!" % idx.type)
+    indexing = ",".join(index_code(idx) for idx in indices)
+    return type_remove_ref("decltype(std::declval<%s>()(%s))" % (pythran_type(type_), indexing))
+
+def pythran_indexing_code(indices):
+    def index_code(idx):
+        if idx.is_slice:
+            values = idx.start, idx.stop, idx.step
+            if idx.step.is_none:
+                func = "contiguous_slice"
+                values = values[:2]
+            else:
+                func = "slice"
+            return "pythonic::types::%s(%s)" % (func,",".join((v.pythran_result() for v in values)))
+        elif idx.type.is_int:
+            return idx.result()
+        elif idx.type.is_pythran_expr:
+            return idx.pythran_result()
+        raise ValueError("unsupported indice type %s!" % str(idx.type))
+    return ",".join(index_code(idx) for idx in indices)
+
+def pythran_func_type(func, args):
+    args = ",".join(("std::declval<%s>()" % pythran_type(a.type) for a in args))
+    return "decltype(pythonic::numpy::functor::%s{}(%s))" % (func, args)
+
+def to_pythran(op,ptype=None):
+    op_type = op.type
+    if is_type(op_type,["is_pythran_expr", "is_int", "is_numeric", "is_float",
+        "is_complex"]):
+        return op.result()
+    if op.is_none:
+        return "pythonic::__builtin__::None"
+    if ptype is None:
+        ptype = pythran_type(op_type)
+    assert(op.type.is_pyobject)
+    return "from_python<%s>(%s)" % (ptype, op.py_result())
+
+def from_pythran():
+    return "to_python"
+
+def is_type(type_, types):
+    for attr in types:
+        if getattr(type_, attr, False):
+            return True
+    return False
+
+def is_pythran_supported_node_or_none(node):
+    return node.is_none or is_pythran_supported_type(node.type)
+
+def is_pythran_supported_type(type_):
+    pythran_supported = (
+        "is_pythran_expr", "is_int", "is_numeric", "is_float", "is_none",
+        "is_complex")
+    return is_type(type_, pythran_supported) or is_pythran_expr(type_)
+
+def is_pythran_supported_operation_type(type_):
+    pythran_supported = (
+        "is_pythran_expr", "is_int", "is_numeric", "is_float", "is_complex")
+    return is_type(type_,pythran_supported) or is_pythran_expr(type_)
+
+def is_pythran_expr(type_):
+    return type_.is_pythran_expr
+
+def is_pythran_buffer(type_):
+    return type_.is_numpy_buffer and is_pythran_supported_dtype(type_.dtype) and \
+           type_.mode in ("c","strided") and not type_.cast
+
+def include_pythran_generic(env):
+    # Generic files
+    env.add_include_file("pythonic/core.hpp")
+    env.add_include_file("pythonic/python/core.hpp")
+    env.add_include_file("pythonic/types/bool.hpp")
+    env.add_include_file("pythonic/types/ndarray.hpp")
+    env.add_include_file("<new>") # for placement new
+
+    for i in (8,16,32,64):
+        env.add_include_file("pythonic/types/uint%d.hpp" % i)
+        env.add_include_file("pythonic/types/int%d.hpp" % i)
+    for t in ("float", "float32", "float64", "set", "slice", "tuple", "int",
+            "long", "complex", "complex64", "complex128"):
+        env.add_include_file("pythonic/types/%s.hpp" % t)
+
+def include_pythran_type(env, type_):
+    pass
+
+def type_is_numpy(type_):
+    if not hasattr(type_, "is_numpy"):
+        return False
+    return type_.is_numpy

Cython/Compiler/Symtab.py

@@ -1205,6 +1205,10 @@ class ModuleScope(Scope):
             scope = scope.find_submodule(submodule)
         return scope
 
+    def generate_library_function_declarations(self, code):
+        if self.directives['np_pythran']:
+            code.putln("import_array();")
+
     def lookup_submodule(self, name):
         # Return scope for submodule of this module, or None.
         if '.' in name:

Cython/Includes/numpy/__init__.pxd

@@ -342,28 +342,28 @@ cdef extern from "numpy/arrayobject.h":
         double imag
 
     ctypedef struct npy_clongdouble:
-        double real
-        double imag
+        long double real
+        long double imag
 
     ctypedef struct npy_complex64:
-        double real
-        double imag
+        float real
+        float imag
 
     ctypedef struct npy_complex128:
         double real
         double imag
 
     ctypedef struct npy_complex160:
-        double real
-        double imag
+        long double real
+        long double imag
 
     ctypedef struct npy_complex192:
-        double real
-        double imag
+        long double real
+        long double imag
 
     ctypedef struct npy_complex256:
-        double real
-        double imag
+        long double real
+        long double imag
 
     ctypedef struct PyArray_Dims:
         npy_intp *ptr

Cython/Utility/CppSupport.cpp

@@ -46,3 +46,13 @@ static void __Pyx_CppExn2PyErr() {
   }
 }
 #endif
+
+/////////////// PythranConversion.proto ///////////////
+
+template <class T>
+auto to_python_from_expr(T &&value) -> decltype(to_python(
+      typename pythonic::returnable<typename std::remove_cv<typename std::remove_reference<T>::type>::type>::type{std::forward<T>(value)}))
+{
+  using returnable_type = typename pythonic::returnable<typename std::remove_cv<typename std::remove_reference<T>::type>::type>::type;
+  return to_python(returnable_type{std::forward<T>(value)});
+}

Cython/Utility/ModuleSetupCode.c

@@ -420,6 +420,19 @@
 
 #define __Pyx_void_to_None(void_result) ((void)(void_result), Py_INCREF(Py_None), Py_None)
 
+#ifdef _MSC_VER
+    #ifndef _MSC_STDINT_H_
+        #if _MSC_VER < 1300
+           typedef unsigned char     uint8_t;
+           typedef unsigned int      uint32_t;
+        #else
+           typedef unsigned __int8   uint8_t;
+           typedef unsigned __int32  uint32_t;
+        #endif
+    #endif
+#else
+   #include <stdint.h>
+#endif
 
 /////////////// CInitCode ///////////////
 
@@ -662,6 +675,22 @@ static int __Pyx_check_binary_version(void) {
     return 0;
 }
 
+/////////////// IsLittleEndian.proto ///////////////
+
+static int __Pyx_Is_Little_Endian(void);
+
+/////////////// IsLittleEndian ///////////////
+
+static int __Pyx_Is_Little_Endian(void)
+{
+  union {
+    uint32_t u32;
+    uint8_t u8[4];
+  } S;
+  S.u32 = 0x01020304;
+  return S.u8[0] == 4;
+}
+
 /////////////// Refnanny.proto ///////////////
 
 #ifndef CYTHON_REFNANNY

docs/src/userguide/index.rst

@@ -23,6 +23,7 @@ Contents:
    parallelism
    debugging
    numpy_tutorial
+   numpy_pythran
 
 Indices and tables
 ------------------

docs/src/userguide/numpy_pythran.rst

+.. highlight:: python
+
+.. _numpy-pythran:
+
+**************************
+Pythran as a Numpy backend
+**************************
+
+Using the flag ``--np-pythran``, it is possible to use the `Pythran`_ numpy
+implementation for numpy related operations. One advantage to use this backend
+is that the Pythran implementation uses C++ expression templates to save memory
+transfers and can benefit from SIMD instructions of modern CPU.
+
+This can lead to really interesting speedup in some cases, going from 2 up to
+16, depending on the targeted CPU architecture and the original algorithm.
+
+Please note that this feature is experimental.
+
+Usage example with distutils
+----------------------------
+
+You first need to install Pythran. See its `documentation
+<https://pythonhosted.org/pythran/MANUAL.html>`_ for more information.
+
+Then, simply add ``np_pythran=True`` to the ``cythonize`` call in the related
+setup.py.
+
+Here is an example:
+
+.. code::
+
+  from distutils.core import setup
+  from Cython.Build import cythonize
+  
+  setup(
+      name = "My hello app",
+      ext_modules = cythonize('hello_pythran.pyx', np_pythran=True)
+  )
+
+
+.. _Pythran: https://github.com/serge-sans-paille/pythran

runtests.py

@@ -487,7 +487,7 @@ class TestBuilder(object):
                  cleanup_workdir, cleanup_sharedlibs, cleanup_failures,
                  with_pyregr, cython_only, languages, test_bugs, fork, language_level,
                  test_determinism,
-                 common_utility_dir):
+                 common_utility_dir, pythran_dir=None):
         self.rootdir = rootdir
         self.workdir = workdir
         self.selectors = selectors
@@ -504,6 +504,7 @@ class TestBuilder(object):
         self.language_level = language_level
         self.test_determinism = test_determinism
         self.common_utility_dir = common_utility_dir
+        self.pythran_dir = pythran_dir
 
     def build_suite(self):
         suite = unittest.TestSuite()
@@ -607,13 +608,14 @@ class TestBuilder(object):
 
         preparse_list = tags.get('preparse', ['id'])
         tests = [ self.build_test(test_class, path, workdir, module, tags, language,
-                                  expect_errors, expect_warnings, warning_errors, preparse)
+                                  expect_errors, expect_warnings, warning_errors, preparse,
+                                  self.pythran_dir if language == "cpp" else None)
                   for language in languages
                   for preparse in preparse_list ]
         return tests
 
     def build_test(self, test_class, path, workdir, module, tags, language,
-                   expect_errors, expect_warnings, warning_errors, preparse):
+                   expect_errors, expect_warnings, warning_errors, preparse, pythran_dir):
         language_workdir = os.path.join(workdir, language)
         if not os.path.exists(language_workdir):
             os.makedirs(language_workdir)
@@ -634,7 +636,8 @@ class TestBuilder(object):
                           language_level=self.language_level,
                           warning_errors=warning_errors,
                           test_determinism=self.test_determinism,
-                          common_utility_dir=self.common_utility_dir)
+                          common_utility_dir=self.common_utility_dir,
+                          pythran_dir=pythran_dir)
 
 
 class CythonCompileTestCase(unittest.TestCase):
@@ -643,7 +646,7 @@ class CythonCompileTestCase(unittest.TestCase):
                  cleanup_sharedlibs=True, cleanup_failures=True, cython_only=False,
                  fork=True, language_level=2, warning_errors=False,
                  test_determinism=False,
-                 common_utility_dir=None):
+                 common_utility_dir=None, pythran_dir=None):
         self.test_directory = test_directory
         self.tags = tags
         self.workdir = workdir
@@ -663,10 +666,11 @@ class CythonCompileTestCase(unittest.TestCase):
         self.warning_errors = warning_errors
         self.test_determinism = test_determinism
         self.common_utility_dir = common_utility_dir
+        self.pythran_dir = pythran_dir
         unittest.TestCase.__init__(self)
 
     def shortDescription(self):
-        return "compiling (%s) %s" % (self.language, self.name)
+        return "compiling (%s%s) %s" % (self.language, "/pythran" if self.pythran_dir is not None else "", self.name)
 
     def setUp(self):
         from Cython.Compiler import Options
@@ -846,6 +850,7 @@ class CythonCompileTestCase(unittest.TestCase):
             annotate = annotate,
             use_listing_file = False,
             cplus = self.language == 'cpp',
+            np_pythran = self.pythran_dir is not None,
             language_level = self.language_level,
             generate_pxi = False,
             evaluate_tree_assertions = True,
@@ -875,6 +880,9 @@ class CythonCompileTestCase(unittest.TestCase):
             if extra_extension_args is None:
                 extra_extension_args = {}
 
+            if self.pythran_dir is not None:
+                ext_compile_flags.extend(['-I',self.pythran_dir,'-DENABLE_PYTHON_MODULE','-std=c++11','-D__PYTHRAN__=2','-Wno-cpp'])
+
             related_files = self.related_files(test_directory, module)
             self.copy_files(test_directory, workdir, related_files)
 
@@ -1044,7 +1052,7 @@ class CythonRunTestCase(CythonCompileTestCase):
         if self.cython_only:
             return CythonCompileTestCase.shortDescription(self)
         else:
-            return "compiling (%s) and running %s" % (self.language, self.name)
+            return "compiling (%s%s) and running %s" % (self.language, "/pythran" if self.pythran_dir is not None else "", self.name)
 
     def run(self, result=None):
         if result is None:
@@ -1839,6 +1847,8 @@ def main():
     parser.add_option("--use_formal_grammar", default=False, action="store_true")
     parser.add_option("--test_determinism", default=False, action="store_true",
                       help="test whether Cython's output is deterministic")
+    parser.add_option("--pythran-dir", dest="pythran_dir", default=None,
+                      help="specify Pythran include directory. This will run the C++ tests using Pythran backend for Numpy")
 
     options, cmd_args = parser.parse_args(args)
 
@@ -2095,7 +2105,7 @@ def runtests(options, cmd_args, coverage=None):
                                 options.cython_only, languages, test_bugs,
                                 options.fork, options.language_level,
                                 options.test_determinism,
-                                common_utility_dir)
+                                common_utility_dir, options.pythran_dir)
         test_suite.addTest(filetests.build_suite())
 
     if options.system_pyregr and languages:
@@ -2110,7 +2120,7 @@ def runtests(options, cmd_args, coverage=None):
                                     options.cython_only, languages, test_bugs,
                                     options.fork, sys.version_info[0],
                                     options.test_determinism,
-                                    common_utility_dir)
+                                    common_utility_dir, options.pythran_dir)
             sys.stderr.write("Including CPython regression tests in %s\n" % sys_pyregr_dir)
             test_suite.addTest(filetests.handle_directory(sys_pyregr_dir, 'pyregr'))