brine-fp

brine-fp is a 192-bit fixed-point math library built for high-precision, deterministic computation in constrained environments like the Solana SVM. It provides arithmetic, exponentiation, logarithms, and powers using u192-based representations, and is optimized for low compute unit (CU) usage on-chain.

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⚡ Performance

Operation	CU (Approx.)
log(2)	~18,500
exp(0.5)	~15,000
pow(2, ½)	~100
frexp(2)	~150

These values are measured inside the Solana SVM (via test programs).

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✨ Features

• 192-bit unsigned & signed fixed-point types with 18 decimal places.
• Supports log, exp, pow, floor, ceil, almost_eq, etc.
• Remez polynomial approximations based on FreeBSD msun.
• Designed for deterministic and overflow-aware computation.
• Suitable for smart contract environments and financial logic.

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🚀 Quick Start

use brine_fp::UnsignedNumeric;

// Construct a fixed-point number: 5.0
let five = UnsignedNumeric::new(5).unwrap();

// Compute its exponential
let result = five.signed().exp().unwrap();

println!("e^5 ≈ {}", result.to_string());

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🧠 Internal Representation

Each UnsignedNumeric wraps a InnerUint([lo, mid, hi]), representing a 192-bit unsigned integer:

InnerUint([lo, mid, hi])

// Equivalent to:
// value = lo + (mid << 64) + (hi << 128)

All values are scaled by 10^18, enabling 18-digit decimal precision.

This format ensures:

• Extreme range: from 1e-18 up to ~6.3 × 10³⁹ real-world units
• High precision: 18 decimals
• Fully deterministic integer math (no f64, no float)

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🧱 Use Cases

• On-chain bonding curves
• DeFi math & simulations
• Deterministic pricing formulas
• Token economics
• Time-value calculations
• Anywhere you want exp() or log() without f64

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🛠 no_std Compatibility

This crate is designed for no_std environments like the Solana SVM.

If you're building in a no_std context, disable the default std feature:

[dependencies.brine-fp]
version = "0.1"
default-features = false

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Why “brine-fp”?

“Brine” evokes salt water — a precise solution. The name reflects a design focused on precision, fluidity, and minimal bloat — ideal for constrained environments.

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Upstream Acknowledgements

brine-fp is heavily based on prior work and stands on the shoulders of giants. The core math and algorithms are derived from:

• Solana Labs math-spl (Apache 2.0)
• Strata Foundation bonding curves (AGPL v3)

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🙌 Contributing

Contributions are welcome! Please open issues or PRs on the GitHub repo.