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#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#
#     https://www.apache.org/licenses/LICENSE-2.0
#
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# Helpers for building MHLO operators

from typing import Optional, Sequence, Union
import jaxlib.mlir.ir as ir
import jaxlib.mlir.dialects.mhlo as mhlo
import numpy as np

def custom_call(call_target_name: str, out_types: Sequence[ir.Type],
                operands: Sequence[ir.Value],
                operand_layouts: Sequence[Sequence[int]],
                result_layouts: Sequence[Sequence[int]],
                backend_config: Optional[str] = None,
                has_side_effect: bool = False,
                api_version: int = 2,
                ) -> Union[ir.Value, Sequence[ir.Value]]:
  """Less-verbose helper for building an MHLO custom call op.

  Once https://github.com/llvm/llvm-project/issues/54932 is fixed, this helper
  may be able to go away.
  """
  i32_type = ir.IntegerType.get_signless(32)
  out = mhlo.CustomCallOp(
      (out_types if len(out_types) == 1 else
       [ir.TupleType.get_tuple(out_types)]),
      operands,
      call_target_name=ir.StringAttr.get(call_target_name),
      has_side_effect=ir.BoolAttr.get(has_side_effect),
      backend_config=ir.StringAttr.get(
          "" if backend_config is None else backend_config),
      api_version=ir.IntegerAttr.get(i32_type, api_version),
      called_computations=ir.ArrayAttr.get([]),
      operand_layouts=ir.ArrayAttr.get(
        [ir.DenseIntElementsAttr.get(
              np.atleast_1d(np.asarray(l, dtype=np.int64)),
              type=ir.IndexType.get())
         for l in operand_layouts]),
      result_layouts=ir.ArrayAttr.get(
        [ir.DenseIntElementsAttr.get(
              np.atleast_1d(np.asarray(l, dtype=np.int64)),
              type=ir.IndexType.get())
         for l in result_layouts]))
  if len(out_types) == 1:
    return out.result
  else:
    return [mhlo.GetTupleElementOp(out, ir.IntegerAttr.get(i32_type, i)).result
            for i in range(len(out_types))]