2x interleave non-FP loop

diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs
index 7763cac9e0cfd692a4181488bcf3292bf11fa9fa..c5c875f4acbf0b512b26730328473200199ba735 100644 (file)
--- a/lightning/src/routing/scoring.rs
+++ b/lightning/src/routing/scoring.rs
@@ -1934,19 +1934,33 @@ mod bucketed_history {
 
                        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];
+                               let max_max_idx = 31 - min_idx;
                                if payment_pos < min_bucket_start_pos {
-                                       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 {
+                                       for (idx, chunk) in max_liquidity_offset_history_buckets.chunks(2).enumerate().take(16 - min_idx/2) {
+                                               let max_idx_a = idx * 2;
+                                               let max_idx_b = idx * 2 + 1;
+
+                                               let max_bucket_a = chunk[0];
+                                               let mut max_bucket_b = chunk[1];
+
+                                               let max_bucket_end_pos_a = BUCKET_START_POS[32 - max_idx_a] - 1;
+                                               if payment_pos >= max_bucket_end_pos_a {
                                                        // Success probability 0, the payment amount may be above the max liquidity
                                                        break;
                                                }
+                                               let max_bucket_end_pos_b = BUCKET_START_POS[32 - max_idx_b] - 1;
+                                               if max_idx_b > max_max_idx || payment_pos >= max_bucket_end_pos_b { max_bucket_b = 0 }
+
                                                // Note that this multiply can only barely not overflow - two 16 bit ints plus
                                                // 30 bits is 62 bits.
-                                               let bucket_prob_times_billion = ((*min_bucket as u32) * (*max_bucket as u32)) as u64
+                                               let bucket_prob_times_billion_a = ((*min_bucket as u32) * (max_bucket_a as u32)) as u64
+                                                       * 1024 * 1024 * 1024 / total_valid_points_tracked;
+                                               let bucket_prob_times_billion_b = ((*min_bucket as u32) * (max_bucket_b as u32)) as u64
                                                        * 1024 * 1024 * 1024 / total_valid_points_tracked;
-                                               debug_assert!(bucket_prob_times_billion < u32::max_value() as u64);
-                                               cumulative_success_prob_times_billion += bucket_prob_times_billion;
+                                               debug_assert!(bucket_prob_times_billion_a < u32::max_value() as u64);
+                                               debug_assert!(bucket_prob_times_billion_b < u32::max_value() as u64);
+                                               cumulative_success_prob_times_billion += bucket_prob_times_billion_a;
+                                               cumulative_success_prob_times_billion += bucket_prob_times_billion_b;
                                        }
                                } else {
                        macro_rules! main_liq_loop { ($prob: ident, $accum: ident) => { {