.. py:module:: ethereum.gray_glacier.vm.precompiled_contracts.modexp

Ethereum Virtual Machine (EVM) MODEXP PRECOMPILED CONTRACT
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. contents:: Table of Contents
    :backlinks: none
    :local:

Introduction
------------

Implementation of the `MODEXP` precompiled contract.


.. only:: stage1

Module Contents
---------------


Functions
~~~~~~~~~

.. autoapisummary::
   :nosignatures:

   ethereum.gray_glacier.vm.precompiled_contracts.modexp.modexp
   ethereum.gray_glacier.vm.precompiled_contracts.modexp.complexity
   ethereum.gray_glacier.vm.precompiled_contracts.modexp.iterations
   ethereum.gray_glacier.vm.precompiled_contracts.modexp.gas_cost



Attributes
~~~~~~~~~~

.. autoapisummary::

   ethereum.gray_glacier.vm.precompiled_contracts.modexp.GQUADDIVISOR


Module Details
---------------

GQUADDIVISOR
~~~~~~~~~~~~



.. py:data:: GQUADDIVISOR
   
   

.. undocinclude:: /../src/ethereum/gray_glacier/vm/precompiled_contracts/modexp.py
   :language: python
   :lines: 20-20


modexp
~~~~~~


.. function:: modexp(evm: ethereum.gray_glacier.vm.Evm) -> None
   :noindexentry:

   Calculates `(base**exp) % modulus` for arbitary sized `base`, `exp` and.
   `modulus`. The return value is the same length as the modulus.




.. undocinclude:: /../src/ethereum/gray_glacier/vm/precompiled_contracts/modexp.py
   :language: python
   :pyobject: modexp

complexity
~~~~~~~~~~


.. function:: complexity(base_length: ethereum.base_types.U256, modulus_length: ethereum.base_types.U256) -> ethereum.base_types.Uint
   :noindexentry:

   Estimate the complexity of performing a modular exponentiation.

   :param base_length: Length of the array representing the base integer.
   :param modulus_length: Length of the array representing the modulus integer.

   :returns: **complexity** -- Complexity of performing the operation.
   :rtype: `Uint`




.. undocinclude:: /../src/ethereum/gray_glacier/vm/precompiled_contracts/modexp.py
   :language: python
   :pyobject: complexity

iterations
~~~~~~~~~~


.. function:: iterations(exponent_length: ethereum.base_types.U256, exponent_head: ethereum.base_types.Uint) -> ethereum.base_types.Uint
   :noindexentry:

   Calculate the number of iterations required to perform a modular
   exponentiation.

   :param exponent_length: Length of the array representing the exponent integer.
   :param exponent_head: First 32 bytes of the exponent (with leading zero padding if it is
                         shorter than 32 bytes), as an unsigned integer.

   :returns: **iterations** -- Number of iterations.
   :rtype: `Uint`




.. undocinclude:: /../src/ethereum/gray_glacier/vm/precompiled_contracts/modexp.py
   :language: python
   :pyobject: iterations

gas_cost
~~~~~~~~


.. function:: gas_cost(base_length: ethereum.base_types.U256, modulus_length: ethereum.base_types.U256, exponent_length: ethereum.base_types.U256, exponent_head: ethereum.base_types.Uint) -> ethereum.base_types.Uint
   :noindexentry:

   Calculate the gas cost of performing a modular exponentiation.

   :param base_length: Length of the array representing the base integer.
   :param modulus_length: Length of the array representing the modulus integer.
   :param exponent_length: Length of the array representing the exponent integer.
   :param exponent_head: First 32 bytes of the exponent (with leading zero padding if it is
                         shorter than 32 bytes), as an unsigned integer.

   :returns: **gas_cost** -- Gas required for performing the operation.
   :rtype: `Uint`




.. undocinclude:: /../src/ethereum/gray_glacier/vm/precompiled_contracts/modexp.py
   :language: python
   :pyobject: gas_cost