v3.6.0

v3.6.0 — sqrt & cbrt handle the full uint256 domain

Two headline changes, plus cascading gas savings.

Highlights

• sqrt and cbrt now accept the full uint256 domain. No more upper-bound revert — any input in [0, uint256.max] returns a valid FP18 result. sqrt also drops 245 → 197 gas (−20%) and cbrt 368 → 340 (−8%) via a new CLZ-derived power-of-two seed + Newton refinement.
• pow overflow bugfix. The internal a · ln(x) inside unchecked could silently overflow int256 for adversarial exponents (|a| ≳ 3.25e56) and return plausible-looking garbage. Now bounded by MAX_POW_EXPONENT = 1e54 with a typed PowExponentOutOfBoundsError revert — ~18 orders of magnitude above any realistic exponent.

📖 Deep dive on the new sqrt: How I wrote a fixed-point Solidity sqrt that runs in 197 gas

⚠️ Breaking changes

• Removed errors SqrtUpperBoundError(), CbrtUpperBoundError().
• Removed constants SQRT_UPPER_BOUND, CBRT_UPPER_BOUND.
• Added PowExponentOutOfBoundsError() and MAX_POW_EXPONENT.

If you caught SqrtUpperBoundError / CbrtUpperBoundError, remove those handlers — the code paths no longer exist. Callers passing finite exponents to pow see no behavior change.

Gas changes

sqrtTime also picked up the new seed, so its savings cascade into every Black-Scholes function with an annualized time term (Greeks, IV, pricers). expm1/log1p shed a few gas each, flowing into Rates; the sqrt win compounds across Statistics. pow is the only function that went up — the new overflow check costs ~40 gas.

Function	v3.5.0	v3.6.0	Change
sqrt	245	197	−48 (−20%)
cbrt	368	340	−28 (−8%)
sqrtTime	184	163	−21 (−11%)
callOptionPrice	2,729	2,708	−21 (−0.8%)
binaryCallPrice	2,018	1,997	−21 (−1%)
pow	763	803	+40 (safety)
expm1	415	407	−8
log1p	487	476	−11
continuousToDiscrete	507	491	−16
discreteToContinuous	589	574	−15
geometricMean	330	284	−46
stdDev (N=100)	49,811	49,765	−46
historicalVolatility (N=100)	86,595	86,500	−95
sharpeRatio (N=100)	86,733	86,638	−95

Install

npm install defimath-lib@3.6.0

Foundry:

forge install defimath-lib=MerkleBlue/defimath

Links

• Docs: sqrt · cbrt · pow
• Full write-up: https://defimath.com/news/2026-07-19-defimath-v3-6-0-released/
• Benchmarks vs PRBMath / ABDK / Solady: https://github.com/MerkleBlue/defimath-compare

Full Changelog: v3.5.0...v3.6.0