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fix(core/vm): triple modexp cost post-cancun #32231 #2319

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Merged
gzliudan merged 1 commit into from
Apr 28, 2026
Merged

fix(core/vm): triple modexp cost post-cancun #32231 #2319

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4 changes: 3 additions & 1 deletion core/vm/contracts.go
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Original file line number Diff line number Diff line change
Expand Up @@ -438,7 +438,9 @@ func (c *bigModExp) RequiredGas(input []byte) uint64 {
gas.Mul(gas, adjExpLen)
}
// 2. Different divisor (`GQUADDIVISOR`) (3)
gas.Div(gas, big3)
if !c.eip7883 {
gas.Div(gas, big3)
}
Comment on lines 440 to +443
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Copilot AI Apr 20, 2026

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The inline comment says the divisor (GQUADDIVISOR) is 3, but with the new conditional the divisor becomes 1 when eip7883 is enabled (division is skipped). Please update the comment (and/or factor the divisor into a named variable) so the documented formula matches the implemented behavior for both modes.

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Comment on lines +441 to +443
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Copilot AI Apr 20, 2026

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This change only takes effect when c.eip7883 is true. In this repo, eip7883 is currently only enabled in PrecompiledContractsOsaka, while the network constants schedule Cancun but keep Osaka at math.MaxInt64 (unscheduled). If the intent is to fix modexp pricing post-Cancun (per PR title), this condition will never be hit on mainnet/testnet; consider wiring the eip7883 mode to the Cancun (or intended) fork rules instead of Osaka-only.

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Comment on lines +441 to +443
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Copilot AI Apr 20, 2026

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The PR changes modexp gas accounting, but the existing precompile tests don't assert RequiredGas (they only run with whatever gas RequiredGas returns). Please add/extend unit tests to assert the expected RequiredGas for at least a few representative vectors (e.g., reuse the Gas field already present in core/vm/testdata/precompiles/modexp_eip7883.json) so this repricing can’t regress silently.

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if gas.BitLen() > 64 {
return math.MaxUint64
}
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