From 81ea7083453e84a028499c8fca28d5e653c2468c Mon Sep 17 00:00:00 2001
From: mike <michael@appmodel.nl>
Date: Sat, 17 Jan 2026 03:42:33 +0100
Subject: [PATCH] introduce bitloops

---
 src/main/java/puzzle/SwedishGenerator.java    | 45 +++----------------
 .../java/puzzle/SwedishGeneratorTest.java     |  2 +-
 2 files changed, 6 insertions(+), 41 deletions(-)

diff --git a/src/main/java/puzzle/SwedishGenerator.java b/src/main/java/puzzle/SwedishGenerator.java
index c6c478a..c7c35bc 100644
--- a/src/main/java/puzzle/SwedishGenerator.java
+++ b/src/main/java/puzzle/SwedishGenerator.java
@@ -10,7 +10,6 @@ import lombok.val;
 import precomp.Neighbors9x8;
 import precomp.Neighbors9x8.rci;
 import puzzle.Export.Bit1029;
-import puzzle.Export.ClueAt;
 import puzzle.Export.DictEntryDTO;
 import puzzle.Export.Gridded;
 import puzzle.Export.Strings;
@@ -732,7 +731,7 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
       }
       return best.grid;
    }
-   static long patternForSlot2(final long glo, final long ghi, final byte[] g, final int key, final long lo, final long hi) {
+   static long patternForSlot(final long glo, final long ghi, final byte[] g, final int key, final long lo, final long hi) {
       if (((lo & glo) | (hi & ghi)) == X) return 0;
       long p = 0;
       int  n = 0;
@@ -763,36 +762,6 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
       }
       return p;
    }
-   static long patternForSlot(final long glo, final long ghi, final byte[] g, final int key, final long lo, final long hi) {
-      if (((lo & glo) | (hi & ghi)) == X) return 0;
-      long p = 0;
-      if (Slot.increasing(key)) {
-         for (long b = lo & glo; b != X; b &= b - 1) {
-            int idx = numberOfTrailingZeros(b);
-            int i   = bitCount(lo & ((1L << idx) - 1));
-            p |= ((long) (i * 26 + g[idx])) << (i << 3);
-         }
-         int offset = bitCount(lo);
-         for (long b = hi & ghi; b != X; b &= b - 1) {
-            int idx = numberOfTrailingZeros(b);
-            int i   = offset + bitCount(hi & ((1L << idx) - 1));
-            p |= ((long) (i * 26 + g[64 | idx])) << (i << 3);
-         }
-      } else {
-         int offset = bitCount(hi);
-         for (long b = hi & ghi; b != X; b &= b - 1) {
-            int idx = numberOfTrailingZeros(b);
-            int i   = bitCount(hi & ~((1L << idx) | ((1L << idx) - 1)));
-            p |= ((long) (i * 26 + g[64 | idx])) << (i << 3);
-         }
-         for (long b = lo & glo; b != X; b &= b - 1) {
-            int idx = numberOfTrailingZeros(b);
-            int i   = offset + bitCount(lo & ~((1L << idx) | ((1L << idx) - 1)));
-            p |= ((long) (i * 26 + g[idx])) << (i << 3);
-         }
-      }
-      return p;
-   }
    static int slotScore(byte[] count, long lo, long hi) {
       int cross = 0;
       for (long b = lo; b != X; b &= b - 1) cross += (count[numberOfTrailingZeros(b)] - 1);
@@ -866,11 +835,7 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
       
       int[] indices = new int[count];
       for (int k = 0, ki = 0; k < numLongs; k++) {
-         long w = res[k];
-         while (w != X) {
-            indices[ki++] = (k << 6) | numberOfTrailingZeros(w);
-            w &= w - 1;
-         }
+         for (long w = res[k]; w != X; w &= w - 1) indices[ki++] = (k << 6) | numberOfTrailingZeros(w);
       }
       
       return indices;
@@ -977,7 +942,7 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
             for (int i = 0, count, count2 = -1, bestScore = -1, n = TOTAL; i < n; i++) {
                var s = slots[i];
                if (s.assign.w != X) continue;
-               var pattern = patternForSlot2(glo, ghi, g, s.key, s.lo, s.hi);
+               var pattern = patternForSlot(glo, ghi, g, s.key, s.lo, s.hi);
                var index   = s.entry;
                count = pattern == X ? index.length : candidateCountForPattern(bitset, pattern, index.posBitsets, index.numlong);
                
@@ -999,7 +964,7 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
                current = PICK_DONE;
                return;
             }
-            var pattern = patternForSlot2(glo, ghi, g, best.key, best.lo, best.hi);
+            var pattern = patternForSlot(glo, ghi, g, best.key, best.lo, best.hi);
             var index   = best.entry;
             current       = CARRIER;
             current.slot  = best;
@@ -1071,7 +1036,7 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
                low = glo;
                top = ghi;
                if (!placeWord(k, slo, shi, w)) continue;
-             
+               
                Bit1029.set(used, lemIdx);
                s.assign.w = w;
                if (backtrack(depth + 1)) return true;
diff --git a/src/test/java/puzzle/SwedishGeneratorTest.java b/src/test/java/puzzle/SwedishGeneratorTest.java
index 342bdf9..cdeefca 100644
--- a/src/test/java/puzzle/SwedishGeneratorTest.java
+++ b/src/test/java/puzzle/SwedishGeneratorTest.java
@@ -155,7 +155,7 @@ public class SwedishGeneratorTest {
       placeWord(grid, grid.g, Slot.packSlotKey(0, CLUE_RIGHT), 1L << OFF_2_0, 0, Lemma.from(0, "C"));
       var key     = Slot.packSlotKey(OFF_1_0, CLUE_RIGHT);
       var pattern = patternForSlot(grid.lo, grid.hi, grid.g, key, 7L, 0L);
-      assertEquals(1L | (55L << 16), pattern);
+      assertEquals(14081L, pattern);
    }
    
    @Test