diff --git a/source/build/include/build.h b/source/build/include/build.h
index 3810042e7..8e37a42e2 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -1157,9 +1157,6 @@ static FORCE_INLINE void rotatesprite_win(int32_t sx, int32_t sy, int32_t z, int
     rotatesprite_(sx, sy, z, a, picnum, dashade, dapalnum, dastat, 0, 0, windowxy1.x,windowxy1.y,windowxy2.x,windowxy2.y);
 }
 
-void bfirst_search_init(int16_t * const list, uint8_t * const bitmap, int32_t * const eltnumptr, int const maxelts, int const firstelt);
-void bfirst_search_try(int16_t * const list, uint8_t * const bitmap, int32_t * const eltnumptr, int const elt);
-
 void   getzrange(const vec3_t *pos, int16_t sectnum, int32_t *ceilz, int32_t *ceilhit, int32_t *florz,
                  int32_t *florhit, int32_t walldist, uint32_t cliptype) ATTRIBUTE((nonnull(1,3,4,5,6)));
 int32_t   hitscan(const vec3_t *sv, int16_t sectnum, int32_t vx, int32_t vy, int32_t vz,
diff --git a/source/build/include/compat.h b/source/build/include/compat.h
index a45d3160f..b5186304d 100644
--- a/source/build/include/compat.h
+++ b/source/build/include/compat.h
@@ -1138,9 +1138,35 @@ CONSTEXPR size_t logbasenegative(T n)
 
 #endif
 
+////////// Bitfield manipulation //////////
+
+static FORCE_INLINE void bitmap_set(uint8_t *const ptr, int const n) { ptr[n >> 3] |= 1 << (n & 7); }
+static FORCE_INLINE void bitmap_clear(uint8_t *const ptr, int const n) { ptr[n >> 3] &= ~(1 << (n & 7)); }
+static FORCE_INLINE CONSTEXPR char bitmap_test(uint8_t const *const ptr, int const n) { return ptr[n >> 3] & (1 << (n & 7)); }
 
 ////////// Utility functions //////////
 
+// breadth-first search helpers
+template <typename T>
+void bfirst_search_init(T *const list, uint8_t *const bitmap, T *const eltnumptr, int const maxelts, int const firstelt)
+{
+    Bmemset(bitmap, 0, (maxelts+7)>>3);
+
+    list[0] = firstelt;
+    bitmap_set(bitmap, firstelt);
+    *eltnumptr = 1;
+}
+
+template <typename T>
+void bfirst_search_try(T *const list, uint8_t *const bitmap, T *const eltnumptr, int const elt)
+{
+    if (!bitmap_test(bitmap, elt))
+    {
+        bitmap_set(bitmap, elt);
+        list[(*eltnumptr)++] = elt;
+    }
+}
+
 #if RAND_MAX == 32767
 static FORCE_INLINE uint16_t system_15bit_rand(void) { return (uint16_t)rand(); }
 #else  // RAND_MAX > 32767, assumed to be of the form 2^k - 1
@@ -1168,12 +1194,6 @@ static inline void append_ext_UNSAFE(char *outbuf, const char *ext)
         Bstrcpy(p, ext);
 }
 
-////////// Bitfield manipulation //////////
-
-static FORCE_INLINE void bitmap_set(uint8_t *const ptr, int const n) { ptr[n >> 3] |= 1 << (n & 7); }
-static FORCE_INLINE void bitmap_clear(uint8_t *const ptr, int const n) { ptr[n >> 3] &= ~(1 << (n & 7)); }
-static FORCE_INLINE CONSTEXPR char bitmap_test(uint8_t const *const ptr, int const n) { return ptr[n >> 3] & (1 << (n & 7)); }
-
 /* Begin dependence on compat.o object. */
 
 
diff --git a/source/build/src/clip.cpp b/source/build/src/clip.cpp
index 0b469dcff..cdce22535 100644
--- a/source/build/src/clip.cpp
+++ b/source/build/src/clip.cpp
@@ -933,7 +933,7 @@ static void clipupdatesector(vec2_t const &pos, int16_t * const sectnum, int con
 
     static int16_t sectlist[MAXSECTORS];
     static uint8_t sectbitmap[(MAXSECTORS+7)>>3];
-    int32_t        nsecs;
+    int16_t        nsecs;
 
     bfirst_search_init(sectlist, sectbitmap, &nsecs, MAXCLIPSECTORS, *sectnum);
 
diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index 9d1261b80..9e24d6eaa 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -11007,25 +11007,6 @@ int32_t lastwall(int16_t point)
     return point;
 }
 
-// breadth-first search helpers
-void bfirst_search_init(int16_t * const list, uint8_t * const bitmap, int32_t * const eltnumptr, int const maxelts, int const firstelt)
-{
-    Bmemset(bitmap, 0, (maxelts+7)>>3);
-
-    list[0] = firstelt;
-    bitmap_set(bitmap, firstelt);
-    *eltnumptr = 1;
-}
-
-void bfirst_search_try(int16_t * const list, uint8_t * const bitmap, int32_t * const eltnumptr, int const elt)
-{
-    if (elt >= 0 && bitmap_test(bitmap, elt)==0)
-    {
-        bitmap_set(bitmap, elt);
-        list[(*eltnumptr)++] = elt;
-    }
-}
-
 ////////// UPDATESECTOR* FAMILY OF FUNCTIONS //////////
 
 /* Different "is inside" predicates.
@@ -11121,7 +11102,7 @@ void updatesector(int32_t const x, int32_t const y, int16_t * const sectnum)
 
         static int16_t sectlist[MAXSECTORS];
         static uint8_t sectbitmap[(MAXSECTORS+7)>>3];
-        int32_t nsecs;
+        int16_t nsecs;
 
         bfirst_search_init(sectlist, sectbitmap, &nsecs, MAXSECTORS, initialsectnum);
 
@@ -11220,7 +11201,7 @@ void updatesectorz(int32_t const x, int32_t const y, int32_t const z, int16_t *
 
         static int16_t sectlist[MAXSECTORS];
         static uint8_t sectbitmap[(MAXSECTORS+7)>>3];
-        int32_t nsecs;
+        int16_t nsecs;
 
         bfirst_search_init(sectlist, sectbitmap, &nsecs, MAXSECTORS, correctedsectnum);
 
diff --git a/source/duke3d/src/astub.cpp b/source/duke3d/src/astub.cpp
index d901d248d..687b1e2d6 100644
--- a/source/duke3d/src/astub.cpp
+++ b/source/duke3d/src/astub.cpp
@@ -6718,7 +6718,7 @@ static void Keys3d(void)
 
             static int16_t sectlist[MAXSECTORS];
             static uint8_t sectbitmap[(MAXSECTORS+7)>>3];
-            int32_t sectcnt, sectnum;
+            int16_t sectcnt, sectnum;
 
             i = searchsector;
             if (CEILINGFLOOR(i, stat)&1)
diff --git a/source/duke3d/src/m32exec.cpp b/source/duke3d/src/m32exec.cpp
index fc2797cc0..7b56e1aab 100644
--- a/source/duke3d/src/m32exec.cpp
+++ b/source/duke3d/src/m32exec.cpp
@@ -1235,7 +1235,7 @@ skip_check:
 
                 const int32_t o_g_st=vm.g_st, arsize = gar->size;
                 instype *const end=insptr;
-                int32_t sectcnt, numsects=0;
+                int16_t sectcnt, numsects=0;
 
                 // XXX: relies on -fno-strict-aliasing
                 int16_t *const sectlist = (int16_t *)gar->vals;  // actually an int32_t array