From 1cd02ff3fb5e12a8b52bfd9aaf98543ecd9ce2fd Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Tue, 12 Dec 2023 23:24:06 +0000 Subject: [PATCH] use f32s --- lightning/src/routing/scoring.rs | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs index 3493dea86..ed1daa066 100644 --- a/lightning/src/routing/scoring.rs +++ b/lightning/src/routing/scoring.rs @@ -1070,9 +1070,9 @@ const PRECISION_LOWER_BOUND_DENOMINATOR: u64 = log_approx::LOWER_BITS_BOUND; const AMOUNT_PENALTY_DIVISOR: u64 = 1 << 20; const BASE_AMOUNT_PENALTY_DIVISOR: u64 = 1 << 30; -/// Raises three `f64`s to the 3rd power, without `powi` because it requires `std` (dunno why). +/// Raises three `f32`s to the 3rd power, without `powi` because it requires `std` (dunno why). #[inline(always)] -fn three_f64_pow_3(a: f64, b: f64, c: f64) -> (f64, f64, f64) { +fn three_f32_pow_3(a: f32, b: f32, c: f32) -> (f32, f32, f32) { (a * a * a, b * b * b, c * c * c) } @@ -1101,11 +1101,11 @@ fn linear_success_probability( #[inline(always)] fn nonlinear_success_probability( amount_msat: u64, min_liquidity_msat: u64, max_liquidity_msat: u64, capacity_msat: u64, -) -> (f64, f64) { - let capacity = capacity_msat as f64; - let min = (min_liquidity_msat as f64) / capacity; - let max = (max_liquidity_msat as f64) / capacity; - let amount = (amount_msat as f64) / capacity; +) -> (f32, f32) { + let capacity = capacity_msat as f32; + let min = (min_liquidity_msat as f32) / capacity; + let max = (max_liquidity_msat as f32) / capacity; + let amount = (amount_msat as f32) / capacity; // Assume the channel has a probability density function of (x - 0.5)^2 for values from // 0 to 1 (where 1 is the channel's full capacity). The success probability given some @@ -1117,7 +1117,7 @@ fn nonlinear_success_probability( // calculate the cumulative density function between the min/max bounds trivially. Note // that we don't bother to normalize the CDF to total to 1, as it will come out in the // division of num / den. - let (max_pow, amt_pow, min_pow) = three_f64_pow_3(max - 0.5, amount - 0.5, min - 0.5); + let (max_pow, amt_pow, min_pow) = three_f32_pow_3(max - 0.5, amount - 0.5, min - 0.5); (max_pow - amt_pow, max_pow - min_pow) } @@ -1148,7 +1148,7 @@ fn success_probability( // Because our numerator and denominator max out at 0.5^3 we need to multiply them by // quite a large factor to get something useful (ideally in the 2^30 range). - const BILLIONISH: f64 = 1024.0 * 1024.0 * 1024.0; + const BILLIONISH: f32 = 1024.0 * 1024.0 * 1024.0; let numerator = (num * BILLIONISH) as u64 + 1; let mut denominator = (den * BILLIONISH) as u64 + 1; debug_assert!(numerator <= 1 << 30, "Got large numerator ({}) from float {}.", numerator, num); @@ -1194,7 +1194,7 @@ fn success_probability_times_value_times_billion( amount_msat, min_liquidity_msat, max_liquidity_msat, capacity_msat ); - let value = (value_numerator as f64) / (value_denominator as f64); + let value = (value_numerator as f32) / (value_denominator as f32); if min_zero_implies_no_successes && min_liquidity_msat == 0 { // If we have no knowledge of the channel, scale probability down by ~75% @@ -1204,7 +1204,7 @@ fn success_probability_times_value_times_billion( den = den * 21.0 / 16.0 } - const BILLIONISH: f64 = 1024.0 * 1024.0 * 1024.0; + const BILLIONISH: f32 = 1024.0 * 1024.0 * 1024.0; let res = (value * num / den) * BILLIONISH; res as u64 -- 2.39.5