EIP-2046: Reduced gas cost for static calls made to precompiles


  Ethereum Improvement Proposals
        
        
          
            
              
            
          
        

        AllCoreNetworkingInterfaceERCMetaInformational

      



      
        
  
    

  
    
      🚧 Stagnant
    
    
    
    
    
      Standards Track: Core
    
  
  
    
      EIP-2046: Reduced gas cost for static calls made to precompiles
    
    
      
        
      
    
    
      
        
      
    
  

  

  	Authors	Alex Beregszaszi (@axic)
	Created	2019-05-17
	Discussion Link	https://ethereum-magicians.org/t/eip-2046-reduced-gas-cost-for-static-calls-made-to-precompiles/3291
	Requires	

  EIP-214, 

  EIP-1352




  


  

  
    Table of Contents

    	Simple Summary
	Abstract
	Motivation
	Specification
	Rationale
	Backwards Compatibility
	Test Cases
	Implementation
	References
	Acknowledgements
	Copyright



  


  
      
      
         Simple Summary
      
      
    


This change reduces the gas cost of using precompiled contracts.

  
    
      
      
         Abstract
      
      
    


Reduce the base gas cost of calling precompiles using STATICCALL from 700 to 40. This should allow more efficient use of precompiles as well as precompiles with a total cost below 700.

  
    
      
      
         Motivation
      
      
    


The Spurious Dragon hard fork increased the cost of calls significantly to account for loading contract code from the state without making an exception for precompiles, whose “code” is always loaded.


This made use of certain precompiles impractical.


FIXME: extend this with recent reasoning about ECC repricings.

  
    
      
      
         Specification
      
      
    


After block HF the STATICCALL (0xfa) instruction charges different basic gas cost (Gcall in Yellow Paper’s notation) depending on the destination address provided:

	for precompiles (address range as per EIP-1352) the cost is 40
	for every other address the cost remains unchanged (700)


  
    
      
      
         Rationale
      
      
    


Only the STATICCALL instruction was changed to reduce the impact of the change. This should not be a limiting factor, given precompiles (currently) do not have a state and cannot change the state.
However, contracts created and deployed before Byzantium likely will not use STATICCALL and as a result this change will not reduce their costs.


Contrary to EIP-1109 gas reduction to 0 is not proposed. The cost 40 is kept as a cost representing the context switching needed.

  
    
      
      
         Backwards Compatibility
      
      
    


This EIP should be backwards compatible. The only effect is that the cost is reduced. Since the cost is not reduced to zero, it should not be possible for a malicious proxy contract, when deployed before
the HF, to do any state changing operation.

  
    
      
      
         Test Cases
      
      
    


TBA

  
    
      
      
         Implementation
      
      
    


TBA

  
    
      
      
         References
      
      
    


This has been previously suggested as part of EIP-1109 and EIP-1231.
However EIP-1109 was later changed to a very different approach. The author has suggested to change EIP-1109.

  
    
      
      
         Acknowledgements
      
      
    


Jordi Baylina (@jbaylina) and Matthew Di Ferrante (@mattdf) who have proposed this before.

  
    
      
      
         Copyright
      
      
    


Copyright and related rights waived via CC0.


  Citation

  Please cite this document as:

  
  Alex Beregszaszi (@axic), "EIP-2046: Reduced gas cost for static calls made to precompiles [DRAFT]," Ethereum Improvement Proposals, no. 2046, May 2019. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-2046.






      
    
  

  

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        Ethereum Improvement Proposals (EIPs) describe standards for the Ethereum platform, including core protocol specifications, client APIs, and contract standards.