Check for full words on boundaries

ConflictSet.cpp

@@ -116,6 +116,11 @@ struct BitSet {
     // Check begin partial word
     if (begin & 63) {
       uint64_t word = words[begin >> 6] & (uint64_t(-1) << (begin & 63));
+      if (std::popcount(word) + (begin & 63) == 64) {
+        while (begin & 63) {
+          f(begin++);
+        }
+      } else {
         while (word) {
           uint64_t temp = word & -word;
           int index = (begin & ~63) + std::countr_zero(word);
@@ -125,6 +130,7 @@ struct BitSet {
         begin &= ~63;
         begin += 64;
       }
+    }
 
     // Check inner, full words
     while (begin != (end & ~63)) {
@@ -147,6 +153,11 @@ struct BitSet {
     if (end & 63) {
       // Check end partial word
       uint64_t word = words[end >> 6] & ~(uint64_t(-1) << (end & 63));
+      if (std::popcount(word) == (end & 63)) {
+        while (begin < end) {
+          f(begin++);
+        }
+      } else {
         while (word) {
           uint64_t temp = word & -word;
           int index = begin + std::countr_zero(word);
@@ -155,6 +166,7 @@ struct BitSet {
         }
       }
     }
+  }
 
 private:
   uint64_t words[4] = {};