Update EIP-8141: align SIGPARAM copy operand order with CALLDATACOPY - #8
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Update EIP-8141: align SIGPARAM copy operand order with CALLDATACOPY#8Marchhill wants to merge 1 commit into
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SIGPARAM's copy form (param == 0x04) lists itsmemOffset/dataOffset/lengthoperands in the reverse of theCALLDATACOPY/CODECOPY/RETURNDATACOPYconvention, and the reverse of the siblingFRAMEDATACOPY— which was aligned to that convention in ethereum#11938. This alignsSIGPARAM's copy operands withFRAMEDATACOPY/CALLDATACOPY(memOffset,dataOffset,length, top to bottom), removing the internal inconsistency.The two orders differ observably for asymmetric operands (wrong pop order gives the wrong source/destination, hence wrong memory and state root), so aligning them removes a correctness footgun.
This is a normative change: an implementation following the current reversed order must flip its
SIGPARAMcopy handling. If instead the reversed order is intended, an explicit stack table documenting it would resolve the inconsistency the other way — but matching the established convention and the already-fixedFRAMEDATACOPYis the safer default.