Merge branch 'h48-corner-estimate'

2 files changed, 31 insertions, 26 deletions

diff --git a/benchmarks/results_h48.py b/benchmarks/results_h48.py
index a2db06c..9d8d19c 100644
--- a/benchmarks/results_h48.py
+++ b/benchmarks/results_h48.py
@@ -1,36 +1,36 @@
 h48_single_thread = {
-        6: {17: 52.7302, 18: 405.7879, 19: 2032.4602},
-        7: {17: 26.4977, 18: 212.7314, 19: 1074.2251},
-        8: {17: 19.8239, 18: 151.7597, 19: 639.6197},
-        9: {17: 9.0082, 18: 62.0400, 19: 293.2197},
-        10: {17: 6.2190, 18: 31.1395, 19: 158.3581, 20: 1118.7513, "superflip": 48.7016},
-        11: {17: 3.5879, 18: 19.5970, 19: 93.5762, 20: 651.2212, "superflip": 20.2721},
+        6: {17: 52.9727, 18: 407.1435, 19: 2055.8785},
+        7: {17: 26.8541, 18: 214.7064, 19: 1053.9732},
+        8: {17: 19.8408, 18: 152.2214, 19: 639.4834},
+        9: {17: 8.9053, 18: 61.6760, 19: 294.6517},
+        10: {17: 5.8445, 18: 30.0880, 19: 154.5389, 20: 1087.6552, "superflip": 48.8410},
+        11: {17: 3.2420, 18: 18.3482, 19: 85.6898, 20: 581.9588, "superflip": 19.2614},
 }
 
 h48_4_threads = {
-        6: {17: 15.2794, 18: 116.1387, 19: 577.3595},
-        7: {17: 7.7522, 18: 59.8914, 19: 293.4824},
-        8: {17: 5.8807, 18: 42.7619, 19: 180.4499},
-        9: {17: 2.7609, 18: 18.4867, 19: 84.1350, 20: 610.8914, "superflip": 25.3932},
-        10: {17: 1.9215, 18: 9.1287, 19: 43.7573, 20: 338.4877, "superflip": 14.2593},
-        11: {17: 1.1997, 18: 5.8332, 19: 26.6060, 20: 176.8453, "superflip": 6.1932},
+        6: {17: 15.2251, 18: 115.3688, 19: 605.5267},
+        7: {17: 7.8799, 18: 61.3355, 19: 303.0388},
+        8: {17: 5.8624, 18: 43.4193, 19: 179.8491},
+        9: {17: 2.7696, 18: 17.6190, 19: 87.1236, 20: 640.3405, "superflip": 25.3726},
+        10: {17: 1.8676, 18: 9.0543, 19: 44.7847, 20: 310.3914, "superflip": 14.0333},
+        11: {17: 1.1173, 18: 5.6240, 19: 24.1467, 20: 174.4689, "superflip": 5.9548},
 }
 
 h48_16_threads = {
-        6: {17: 5.3639, 18: 37.6695, 19: 191.8620},
-        7: {17: 2.8213, 18: 20.1045, 19: 96.7922},
-        8: {17: 2.0779, 18: 14.6013, 19: 60.4149},
-        9: {17: 1.0796, 18: 6.1831, 19: 27.5530, 20: 200.9519, "superflip": 10.7149},
-        10: {17: 0.7511, 18: 3.2061, 19: 15.0046, 20: 103.8125, "superflip": 5.6217},
-        11: {17: 0.5173, 18: 2.1196, 19: 8.6965, 20: 56.4344, "superflip": 2.4857},
+        6: {17: 5.3309, 18: 37.8142, 19: 193.5352},
+        7: {17: 2.8657, 18: 20.8215, 19: 99.9139},
+        8: {17: 2.0775, 18: 14.2672, 19: 60.0995},
+        9: {17: 1.0595, 18: 6.2074, 19: 27.5523, 20: 201.2200, "superflip": 10.7739},
+        10: {17: 0.7600, 18: 3.1980, 19: 14.5771, 20: 105.1686, "superflip": 5.5616},
+        11: {17: 0.4946, 18: 2.0381, 19: 8.3613, 20: 55.4269, "superflip": 2.4087},
 }
 
 h48_all_solutions = {
-        6: {17: 17.1940, 18: 203.6879, 19: 2286.7364},
-        7: {17: 9.0219, 18: 105.0559, 19: 1166.1059},
-        8: {17: 5.9919, 18: 68.8215, 19: 686.0935},
-        9: {17: 3.0192, 18: 31.9398, 19: 319.0297},
-        10: {17: 1.7972, 18: 17.8931, 19: 167.6695, 20: 1464.2636, "superflip": 48.9035},
-        11: {17: 1.1838, 18: 10.5628, 19: 96.0518, 20: 808.8516, "superflip": 22.6335},
+        6: {17: 17.1587, 18: 204.6182, 19: 2296.3135},
+        7: {17: 9.1380, 18: 106.0127, 19: 1177.4728},
+        8: {17: 6.1641, 18: 67.9895, 19: 685.6033},
+        9: {17: 3.0422, 18: 31.9821, 19: 323.2516},
+        10: {17: 1.7822, 18: 17.4947, 19: 168.2516, 20: 1465.2950, "superflip": 48.6248},
+        11: {17: 1.1364, 18: 10.2076, 19: 92.3419, 20: 791.1480, "superflip": 21.8014},
 }
 
diff --git a/src/solvers/h48/solve.h b/src/solvers/h48/solve.h
index 2920fa7..4aa3799 100644
--- a/src/solvers/h48/solve.h
+++ b/src/solvers/h48/solve.h
@@ -115,10 +115,15 @@ solve_h48_stop(dfsarg_solve_h48_t arg[static 1])
         arg->movemask_normal = arg->movemask_inverse = MM18_ALLMOVES;
         arg->nodes_visited++;
 
-        /* Preliminary probing using last computed bound, if possible */
-
         n = arg->solution_moves->nmoves + arg->solution_moves->npremoves;
         target = arg->target_depth - n;
+
+        /* We'll never get a bound higher than base + 3 */
+        if (arg->base + 3 <= target)
+                return false;
+
+        /* Preliminary probing using last computed bound, if possible */
+
         if ((arg->use_lb_normal && arg->lb_normal > target) ||
             (arg->use_lb_inverse && arg->lb_inverse > target))
                 return true;