diff --git a/tiny_bvh.h b/tiny_bvh.h
index 42909fe..93de9b6 100644
--- a/tiny_bvh.h
+++ b/tiny_bvh.h
@@ -386,6 +386,8 @@ typedef bvhvec4 SIMDVEC4;
 #define SIMD_SETRVEC(a,b,c,d) bvhvec4( a, b, c, d )
 #endif
 
+#if defined BVH_USEAVX || defined BVH_USENEON
+
 static unsigned __bfind( unsigned x ) // https://github.com/mackron/refcode/blob/master/lzcnt.c
 {
 #if defined(_MSC_VER) && !defined(__clang__)
@@ -399,6 +401,8 @@ static unsigned __bfind( unsigned x ) // https://github.com/mackron/refcode/blob
 #endif
 }
 
+#endif
+
 // error handling
 #define FATAL_ERROR_IF(c,s) if (c) { fprintf( stderr, \
 	"Fatal error in tiny_bvh.h, line %i:\n%s\n", __LINE__, s ); exit( 1 ); }
@@ -814,6 +818,42 @@ class BVH
 
 namespace tinybvh {
 
+#if 0
+
+// Lookup tables for Fuetterling's traversal, under construction
+
+ALIGNED(64) static const unsigned long long int v_ = 0x1717171717171717, orderlut[8][17] = { { 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, { 0xe140e0e14111117, 0x60000060303090e, 0x60303090000, 0xa10111117000006, 
+	0x607070d0a0a100a, 0x7070d0000060000, 0x1617000006000006, 0x512121312121316, 0x10000010404, 0x1000001040405, 
+	0xb0a0a0b16161700, 0x10c0c0d0a0a, 0x10c0c0d000001, 0x1514141700000100, 0x202051212151212, 0x205000003000003, 
+	0x300000302 }, { 0x600030903000600, 0xe1117110e140e00, 0x309030006000e14, 0xd07000600000600, 0x110a100a00060007, 
+	0x6000a100a1117, 0x100000600070d07, 0x1200010004050400, 0x1213121617161213, 0x100040504000100, 0xc0d0c00010000, 
+	0x1617160a0b0a0001, 0xd0c0001000a0b0a, 0x20003000001000c, 0x1215120003000205, 0x300121512141714, 0x30002050200 }, 
+	{ 0x1414111717111717, 0x141117171117170e, 0x309090309090e14, 0x1717111717000606, 0x171117170a101011, 
+	0x70d0d0a10101117, 0x1717000606070d0d, 0x1712131316171716, 0x1213131617171617, 0x101040505040505, 0xb16171716171700, 
+	0x1617171617170a0b,0xd0d0c0d0d0a0b0b, 0x171417170001010c, 0x1417171215151417, 0x505121515141717, 0x30302050502 }, 
+	{ 0x303060000060000, 0x306000006000009, 0x140e0e140e0e0903, 0x60000171111, 0x600000d070706, 0x100a0a0d07070600, 
+	0x171111100a0a, 0x5040401000001, 0x504040100000100, 0x1616131212131212, 0xc01000001000017, 0x100000100000d0c, 
+	0xa0a0b0a0a0d0c0c, 0x300001716160b, 0x300000502020300, 0x1212050202030000, 0x17141415121215 }, 
+	{ 0x1117140e14171117, 0x906000609030917, 0x140e141711170903, 0xa10171117171117, 0x60d070d17111710, 
+	0x1711170d070d0600, 0x1617171117100a10, 0x517161713121317, 0x504050100010504, 0x1617131213171617, 0x170b0a0b17161717, 
+	0x100010d0c0d1716, 0xa0b1716170d0c0d, 0x151714171716170b, 0x502051714171512, 0x1417050205030003, 0x17141715121517 }, 
+	{ 0x903090903060600, 0x1117171114140e09, 0x17171114140e1717, 0xd07060600171711, 0x1110100a0d0d070d,
+	0x10100a1717111717, 0x100171711171711, 0x1205050405050401, 0x1717161717161313, 0x1716171716131312, 0xc0d0d0c01010017, 
+	0x1717160b0b0a0d0d, 0x17160b0b0a171716, 0x203030017171617, 0x1515120505020505, 0x1512171714171714, 0x17171417171415 }, 
+	{ v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_, v_ } }; // actually 8x136 uchars. 
+
+ALIGNED(64) static unsigned long long int compactlut[24][2] = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 }, 
+	{ 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0xe140e0e14111117 }, { 0x60000060303090e, 0x60303090000 }, 
+	{ 0xa10111117000006, 0x607070d0a0a100a }, { 0x7070d0000060000, 0x1617000006000006 }, { 0x512121312121316, 
+	0x10000010404 }, { 0x1000001040405, 0xb0a0a0b16161700 }, { 0x10c0c0d0a0a, 0x10c0c0d000001 }, 
+	{ 0x1514141700000100, 0x202051212151212 }, { 0x205000003000003, 0x300000302 }, { 0x600030903000600, 
+	0xe1117110e140e00 }, { 0x309030006000e14, 0xd07000600000600 }, { 0x110a100a00060007, 0x6000a100a1117 }, 
+	{ 0x100000600070d07, 0x1200010004050400 }, { 0x1213121617161213, 0x100040504000100 }, { 0xc0d0c00010000, 
+	0x1617160a0b0a0001 }, { 0xd0c0001000a0b0a, 0x20003000001000c } }; // actually 24x16 uchars in 6 cache lines.
+
+#endif
+
 void* BVH::AlignedAlloc( size_t size )
 {
 	return context.malloc ? context.malloc( size, context.userdata ) : nullptr;