text: from __future__ import division, absolute_import
  
  __copyright__ = """
  Copyright (C) 2017 Andreas Kloeckner
  """
  
  __license__ = """
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  """
  
  import sys
  import numpy as np
  
  from warnings import warn
  import pyopencl._cl as _cl
  from pytools.persistent_dict import WriteOncePersistentDict
  from pyopencl.tools import _NumpyTypesKeyBuilder
  
  _PYPY = '__pypy__' in sys.builtin_module_names
  _CPY2 = not _PYPY and sys.version_info < (3,)
  _CPY26 = _CPY2 and sys.version_info < (2, 7)
  
  
  # {{{ arg packing helpers
  
  _size_t_char = ({
      8: 'Q',
      4: 'L',
      2: 'H',
      1: 'B',
  })[_cl._sizeof_size_t()]
  _type_char_map = {
      'n': _size_t_char.lower(),
      'N': _size_t_char
  }
  del _size_t_char
  
  # }}}
  
  
  # {{{ individual arg handling
  
  def generate_buffer_arg_setter(gen, arg_idx, buf_var):
      from pytools.py_codegen import Indentation
  
      if _CPY2 or _PYPY:
          # https://github.com/numpy/numpy/issues/5381
          gen("if isinstance({buf_var}, np.generic):".format(buf_var=buf_var))
          with Indentation(gen):
              if _PYPY:
                  gen("{buf_var} = np.asarray({buf_var})".format(buf_var=buf_var))
              else:
                  gen("{buf_var} = np.getbuffer({buf_var})".format(buf_var=buf_var))
  
      gen("""
          self._set_arg_buf({arg_idx}, {buf_var})
          """
          .format(arg_idx=arg_idx, buf_var=buf_var))
  
  
  def generate_bytes_arg_setter(gen, arg_idx, buf_var):
      gen("""
          self._set_arg_buf({arg_idx}, {buf_var})
          """
          .format(arg_idx=arg_idx, buf_var=buf_var))
  
  
  def generate_generic_arg_handler(gen, arg_idx, arg_var):
      from pytools.py_codegen import Indentation
  
      gen("""
          if {arg_var} is None:
              self._set_arg_null({arg_idx})
          elif isinstance({arg_var}, _KERNEL_ARG_CLASSES):
              self.set_arg({arg_idx}, {arg_var})
          """
          .format(arg_idx=arg_idx, arg_var=arg_var))
  
      gen("else:")
      with Indentation(gen):
          generate_buffer_arg_setter(gen, arg_idx, arg_var)
  
  # }}}
  
  
  # {{{ generic arg handling body
  
  def generate_generic_arg_handling_body(num_args):
      from pytools.py_codegen import PythonCodeGenerator
      gen = PythonCodeGenerator()
  
      if num_args == 0:
          gen("pass")
  
      for i in range(num_args):
          gen("# process argument {arg_idx}".format(arg_idx=i))
          gen("")
          gen("current_arg = {arg_idx}".format(arg_idx=i))
          generate_generic_arg_handler(gen, i, "arg%d" % i)
          gen("")
  
      return gen
  
  # }}}
  
  
  # {{{ specific arg handling body
  
  def generate_specific_arg_handling_body(function_name,
          num_cl_args, scalar_arg_dtypes,
          work_around_arg_count_bug, warn_about_arg_count_bug):
  
      assert work_around_arg_count_bug is not None
      assert warn_about_arg_count_bug is not None
  
      fp_arg_count = 0
      cl_arg_idx = 0
  
      from pytools.py_codegen import PythonCodeGenerator
      gen = PythonCodeGenerator()
  
      if not scalar_arg_dtypes:
          gen("pass")
  
      for arg_idx, arg_dtype in enumerate(scalar_arg_dtypes):
          gen("# process argument {arg_idx}".format(arg_idx=arg_idx))
          gen("")
          gen("current_arg = {arg_idx}".format(arg_idx=arg_idx))
          arg_var = "arg%d" % arg_idx
  
          if arg_dtype is None:
              generate_generic_arg_handler(gen, cl_arg_idx, arg_var)
              cl_arg_idx += 1
              gen("")
              continue
  
          arg_dtype = np.dtype(arg_dtype)
  
          if arg_dtype.char == "V":
              generate_generic_arg_handler(gen, cl_arg_idx, arg_var)
              cl_arg_idx += 1
  
          elif arg_dtype.kind == "c":
              if warn_about_arg_count_bug:
                  warn("{knl_name}: arguments include complex numbers, and "
                          "some (but not all) of the target devices mishandle "
                          "struct kernel arguments (hence the workaround is "
                          "disabled".format(
                              knl_name=function_name), stacklevel=2)
  
              if arg_dtype == np.complex64:
                  arg_char = "f"
              elif arg_dtype == np.complex128:
                  arg_char = "d"
              else:
                  raise TypeError("unexpected complex type: %s" % arg_dtype)
  
              if (work_around_arg_count_bug == "pocl"
                      and arg_dtype == np.complex128
                      and fp_arg_count + 2 <= 8):
                  gen(
                          "buf = pack('{arg_char}', {arg_var}.real)"
                          .format(arg_char=arg_char, arg_var=arg_var))
                  generate_bytes_arg_setter(gen, cl_arg_idx, "buf")
                  cl_arg_idx += 1
                  gen("current_arg = current_arg + 1000")
                  gen(
                          "buf = pack('{arg_char}', {arg_var}.imag)"
                          .format(arg_char=arg_char, arg_var=arg_var))
                  generate_bytes_arg_setter(gen, cl_arg_idx, "buf")
                  cl_arg_idx += 1
  
              elif (work_around_arg_count_bug == "apple"
                      and arg_dtype == np.complex128
                      and fp_arg_count + 2 <= 8):
                  raise NotImplementedError("No work-around to "
                          "Apple's broken structs-as-kernel arg "
                          "handling has been found. "
                          "Cannot pass complex numbers to kernels.")
  
              else:
                  gen(
                          "buf = pack('{arg_char}{arg_char}', "
                          "{arg_var}.real, {arg_var}.imag)"
                          .format(arg_char=arg_char, arg_var=arg_var))
                  generate_bytes_arg_setter(gen, cl_arg_idx, "buf")
                  cl_arg_idx += 1
  
              fp_arg_count += 2
  
          elif arg_dtype.char in "IL" and _CPY26:
              # Prevent SystemError: ../Objects/longobject.c:336: bad
              # argument to internal function
  
              gen(
                      "buf = pack('{arg_char}', long({arg_var}))"
                      .format(arg_char=arg_dtype.char, arg_var=arg_var))
              generate_bytes_arg_setter(gen, cl_arg_idx, "buf")
              cl_arg_idx += 1
  
          else:
              if arg_dtype.kind == "f":
                  fp_arg_count += 1
  
              arg_char = arg_dtype.char
              arg_char = _type_char_map.get(arg_char, arg_char)
              gen(
                      "buf = pack('{arg_char}', {arg_var})"
                      .format(
                          arg_char=arg_char,
                          arg_var=arg_var))
              generate_bytes_arg_setter(gen, cl_arg_idx, "buf")
              cl_arg_idx += 1
  
          gen("")
  
      if cl_arg_idx != num_cl_args:
          raise TypeError(
              "length of argument list (%d) and "
              "CL-generated number of arguments (%d) do not agree"
              % (cl_arg_idx, num_cl_args))
  
      return gen
  
  # }}}
  
  
  # {{{ error handler
  
  def wrap_in_error_handler(body, arg_names):
      from pytools.py_codegen import PythonCodeGenerator, Indentation
  
      err_gen = PythonCodeGenerator()
  
      def gen_error_handler():
          err_gen("""
              if current_arg is not None:
                  args = [{args}]
                  advice = ""
                  from pyopencl.array import Array
                  if isinstance(args[current_arg], Array):
                      advice = " (perhaps you meant to pass 'array.data' " \
                          "instead of the array itself?)"
  
                  raise _cl.LogicError(
                          "when processing argument #%d (1-based): %s%s"
                          % (current_arg+1, str(e), advice))
              else:
                  raise
              """
              .format(args=", ".join(arg_names)))
          err_gen("")
  
      err_gen("try:")
      with Indentation(err_gen):
          err_gen.extend(body)
      err_gen("except TypeError as e:")
      with Indentation(err_gen):
          gen_error_handler()
      err_gen("except _cl.LogicError as e:")
      with Indentation(err_gen):
          gen_error_handler()
  
      return err_gen
  
  # }}}
  
  
  def add_local_imports(gen):
      gen("import numpy as np")
      gen("import pyopencl._cl as _cl")
      gen("from pyopencl import _KERNEL_ARG_CLASSES")
      gen("")
  
  
  def _generate_enqueue_and_set_args_module(function_name,
          num_passed_args, num_cl_args,
          scalar_arg_dtypes,
          work_around_arg_count_bug, warn_about_arg_count_bug):
  
      from pytools.py_codegen import PythonCodeGenerator, Indentation
  
      arg_names = ["arg%d" % i for i in range(num_passed_args)]
  
      if scalar_arg_dtypes is None:
          body = generate_generic_arg_handling_body(num_passed_args)
      else:
          body = generate_specific_arg_handling_body(
                  function_name, num_cl_args, scalar_arg_dtypes,
                  warn_about_arg_count_bug=warn_about_arg_count_bug,
                  work_around_arg_count_bug=work_around_arg_count_bug)
  
      err_handler = wrap_in_error_handler(body, arg_names)
  
      gen = PythonCodeGenerator()
  
      gen("from struct import pack")
      gen("from pyopencl import status_code")
      gen("")
  
      # {{{ generate _enqueue
  
      enqueue_name = "enqueue_knl_%s" % function_name
      gen("def %s(%s):"
              % (enqueue_name,
                  ", ".join(
                      ["self", "queue", "global_size", "local_size"]
                      + arg_names
                      + ["global_offset=None",
                          "g_times_l=None",
                          "allow_empty_ndrange=False",
                          "wait_for=None"])))
  
      with Indentation(gen):
          add_local_imports(gen)
          gen.extend(err_handler)
  
          gen("""
              return _cl.enqueue_nd_range_kernel(queue, self, global_size, local_size,
                      global_offset, wait_for, g_times_l=g_times_l,
                      allow_empty_ndrange=allow_empty_ndrange)
              """)
  
      # }}}
  
      # {{{ generate set_args
  
      gen("")
      gen("def set_args(%s):"
              % (", ".join(["self"] + arg_names)))
  
      with Indentation(gen):
          add_local_imports(gen)
          gen.extend(err_handler)
  
      # }}}
  
      return gen.get_picklable_module(), enqueue_name
  
  
  invoker_cache = WriteOncePersistentDict(
          "pyopencl-invoker-cache-v7",
          key_builder=_NumpyTypesKeyBuilder())
  
  
  def generate_enqueue_and_set_args(function_name,
          num_passed_args, num_cl_args,
          scalar_arg_dtypes,
          work_around_arg_count_bug, warn_about_arg_count_bug):
  
      cache_key = (function_name, num_passed_args, num_cl_args,
              scalar_arg_dtypes,
              work_around_arg_count_bug, warn_about_arg_count_bug)
  
      from_cache = False
  
      try:
          result = invoker_cache[cache_key]
          from_cache = True
      except KeyError:
          pass
  
      if not from_cache:
          result = _generate_enqueue_and_set_args_module(*cache_key)
          invoker_cache.store_if_not_present(cache_key, result)
  
      pmod, enqueue_name = result
  
      return (
              pmod.mod_globals[enqueue_name],
              pmod.mod_globals["set_args"])
  
  # }}}
  
  
  # vim: foldmethod=marker
  