split loops on linear success

diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs
index defffaf1ae164b113505a01b0c853d6fe4934a28..7763cac9e0cfd692a4181488bcf3292bf11fa9fa 100644 (file)
--- a/lightning/src/routing/scoring.rs
+++ b/lightning/src/routing/scoring.rs
@@ -1099,8 +1099,12 @@ fn linear_success_probability(
 #[inline(always)]
 fn nonlinear_success_probability_f(
        amount_msat: u16, min_liquidity_msat: u16, max_liquidity_msat: u16, capacity_msat: u16,
-       value_numerator: u64, value_denominator: u64, times_16_on_21: bool,
+       min_zero_implies_no_successes: bool, value_numerator: u64, value_denominator: u64,
 ) -> f32 {
+       debug_assert!(min_liquidity_msat <= amount_msat);
+       debug_assert!(amount_msat < max_liquidity_msat);
+       debug_assert!(max_liquidity_msat <= capacity_msat);
+
        let min_max_amt_max_msat = FourF32::from_ints(
                min_liquidity_msat,
                max_liquidity_msat,
@@ -1122,7 +1126,7 @@ fn nonlinear_success_probability_f(
        let zero_zero_maxmin_maxamt = min_max_amt_max_pow.hsub();
 
        let mut zero_zero_den_num = zero_zero_maxmin_maxamt;
-       if times_16_on_21 {
+       if min_zero_implies_no_successes && min_liquidity_msat == 0 {
                let zero_zero_twentyone_sixteen = FourF32::new(0.0f32, 0.0f32, 21.0f32, 16.0f32);
                zero_zero_den_num = zero_zero_den_num * zero_zero_twentyone_sixteen;
        }
@@ -1210,30 +1214,19 @@ fn success_probability(
 /// min_zero_implies_no_successes signals that a `min_liquidity_msat` of 0 means we've not
 /// (recently) seen an HTLC successfully complete over this channel.
 #[inline(always)]
-fn success_probability_times_value_times_billion(
+fn linear_success_probability_times_value_times_billion(
        amount_msat: u16, min_liquidity_msat: u16, max_liquidity_msat: u16, capacity_msat: u16,
-       params: &ProbabilisticScoringFeeParameters, min_zero_implies_no_successes: bool,
-       value_numerator: u64, value_denominator: u64,
+       min_zero_implies_no_successes: bool, value_numerator: u64, value_denominator: u64,
 ) -> u64 {
        debug_assert!(min_liquidity_msat <= amount_msat);
        debug_assert!(amount_msat < max_liquidity_msat);
        debug_assert!(max_liquidity_msat <= capacity_msat);
 
-       if params.linear_success_probability {
-               let (numerator, denominator) = linear_success_probability(
-                       amount_msat as u64, min_liquidity_msat as u64, max_liquidity_msat as u64, min_zero_implies_no_successes
-               );
-               const BILLIONISH: u64 = 1024 * 1024 * 1024;
-               return (value_numerator * BILLIONISH / value_denominator) * numerator / denominator;
-       }
-
-       let res = nonlinear_success_probability_f(
-               amount_msat, min_liquidity_msat, max_liquidity_msat, capacity_msat,
-               value_numerator, value_denominator, min_zero_implies_no_successes && min_liquidity_msat == 0
+       let (numerator, denominator) = linear_success_probability(
+               amount_msat as u64, min_liquidity_msat as u64, max_liquidity_msat as u64, min_zero_implies_no_successes
        );
-
-       const BILLIONISH: f32 = 1024.0 * 1024.0 * 1024.0;
-       (res * BILLIONISH) as u64
+       const BILLIONISH: u64 = 1024 * 1024 * 1024;
+       return (value_numerator * BILLIONISH / value_denominator) * numerator / denominator;
 }
 
 impl<L: Deref<Target = u64>, HT: Deref<Target = HistoricalLiquidityTracker>, T: Deref<Target = Duration>>
@@ -1904,6 +1897,8 @@ mod bucketed_history {
                        }
 
                        let mut cumulative_success_prob_times_billion = 0;
+                       let mut cumulative_float_success_prob = 0.0;
+                       macro_rules! zero_min_bucket { ($prob: ident, $accum: ident) => { {
                        // Special-case the 0th min bucket - it generally means we failed a payment, so only
                        // consider the highest (i.e. largest-offset-from-max-capacity) max bucket for all
                        // points against the 0th min bucket. This avoids the case where we fail to route
@@ -1923,13 +1918,19 @@ mod bucketed_history {
                                let max_bucket_end_pos = BUCKET_START_POS[32 - highest_max_bucket_with_points] - 1;
                                if payment_pos < max_bucket_end_pos {
                                        let bucket_points = (min_liquidity_offset_history_buckets[0] as u64) * total_max_points;
-                                       cumulative_success_prob_times_billion += success_probability_times_value_times_billion(
+                                       $accum += $prob(
                                                payment_pos, 0, max_bucket_end_pos,
-                                               POSITION_TICKS - 1, params, true,
+                                               POSITION_TICKS - 1, true,
                                                bucket_points, total_valid_points_tracked
                                        );
                                }
                        }
+                       } } }
+                       if params.linear_success_probability {
+                               zero_min_bucket!(linear_success_probability_times_value_times_billion, cumulative_success_prob_times_billion);
+                       } else {
+                               zero_min_bucket!(nonlinear_success_probability_f, cumulative_float_success_prob);
+                       }
 
                        for (min_idx, min_bucket) in min_liquidity_offset_history_buckets.iter().enumerate().skip(1) {
                                let min_bucket_start_pos = BUCKET_START_POS[min_idx];
@@ -1948,6 +1949,7 @@ mod bucketed_history {
                                                cumulative_success_prob_times_billion += bucket_prob_times_billion;
                                        }
                                } else {
+                       macro_rules! main_liq_loop { ($prob: ident, $accum: ident) => { {
                                        for (max_idx, max_bucket) in max_liquidity_offset_history_buckets.iter().enumerate().take(32 - min_idx) {
                                                let max_bucket_end_pos = BUCKET_START_POS[32 - max_idx] - 1;
                                                if payment_pos >= max_bucket_end_pos {
@@ -1957,14 +1959,23 @@ mod bucketed_history {
                                                // Note that this multiply can only barely not overflow - two 16 bit ints plus
                                                // 30 bits is 62 bits.
                                                let bucket_points = ((*min_bucket as u32) * (*max_bucket as u32)) as u64;
-                                               cumulative_success_prob_times_billion += success_probability_times_value_times_billion(
+                                               $accum += $prob(
                                                        payment_pos, min_bucket_start_pos,
-                                                       max_bucket_end_pos, POSITION_TICKS - 1, params, true,
+                                                       max_bucket_end_pos, POSITION_TICKS - 1, true,
                                                        bucket_points, total_valid_points_tracked);
                                        }
+                       } } }
+                       if params.linear_success_probability {
+                               main_liq_loop!(linear_success_probability_times_value_times_billion, cumulative_success_prob_times_billion);
+                       } else {
+                               main_liq_loop!(nonlinear_success_probability_f, cumulative_float_success_prob);
+                       }
                                }
                        }
 
+                       const BILLIONISH: f32 = 1024.0 * 1024.0 * 1024.0;
+                       cumulative_success_prob_times_billion += (cumulative_float_success_prob * BILLIONISH) as u64;
+
                        Some(cumulative_success_prob_times_billion)
                }
        }