mirror of
https://gitlab.com/pulsechaincom/erigon-pulse.git
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8b57c49490
Reworked the EVM gas instructions to use 64bit integers rather than arbitrary size big ints. All gas operations, be it additions, multiplications or divisions, are checked and guarded against 64 bit integer overflows. In additon, most of the protocol paramaters in the params package have been converted to uint64 and are now constants rather than variables. * common/math: added overflow check ops * core: vmenv, env renamed to evm * eth, internal/ethapi, les: unmetered eth_call and cancel methods * core/vm: implemented big.Int pool for evm instructions * core/vm: unexported intPool methods & verification methods * core/vm: added memoryGasCost overflow check and test
26 lines
616 B
Go
26 lines
616 B
Go
package math
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import gmath "math"
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/*
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* NOTE: The following methods need to be optimised using either bit checking or asm
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*/
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// SafeSub returns subtraction result and whether overflow occurred.
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func SafeSub(x, y uint64) (uint64, bool) {
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return x - y, x < y
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}
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// SafeAdd returns the result and whether overflow occurred.
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func SafeAdd(x, y uint64) (uint64, bool) {
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return x + y, y > gmath.MaxUint64-x
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}
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// SafeMul returns multiplication result and whether overflow occurred.
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func SafeMul(x, y uint64) (uint64, bool) {
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if x == 0 {
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return 0, false
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}
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return x * y, x != 0 && y != 0 && y > gmath.MaxUint64/x
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}
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