diff --git a/bitutil.h b/bitutil.h
new file mode 100644
index 0000000..647f361
--- /dev/null
+++ b/bitutil.h
@@ -0,0 +1,82 @@
+/**
+    Copyright (C) powturbo 2013-2015
+    GPL v2 License
+  
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+    - homepage : https://sites.google.com/site/powturbo/
+    - github   : https://github.com/powturbo
+    - twitter  : https://twitter.com/powturbo
+    - email    : powturbo [_AT_] gmail [_DOT_] com
+**/
+//     bitutil.h - "Integer Compression" 
+  #ifdef __SSE2__
+#include <emmintrin.h>
+
+#define DELTAV(__v, __sv) _mm_sub_epi32(__v, _mm_or_si128(_mm_srli_si128(__sv, 12), _mm_slli_si128(__v, 4)))
+
+#define VSCAN( __v, __sv) __v = _mm_add_epi32(__v, _mm_slli_si128(__v, 4)); __sv = _mm_add_epi32(_mm_shuffle_epi32(__sv, _MM_SHUFFLE(3, 3, 3, 3)), _mm_add_epi32(_mm_slli_si128(__v, 8), __v) )
+#define VSCANI(__v, __sv, __vi) VSCAN(__v, __sv); __sv = _mm_add_epi32(__sv, __vi)
+
+// SIMD Horizontal OR
+//#define HOR(__v,__b) __b = (unsigned)_mm_cvtsi128_si32(__v) | (unsigned)_mm_extract_epi32(__v, 1) | (unsigned)_mm_extract_epi32(__v, 2) | (unsigned)_mm_extract_epi32(__v, 3)
+#define HOR(__v,__b) __v = _mm_or_si128(_mm_unpackhi_epi32(__v, __v), _mm_unpacklo_epi32(__v, __v));  /*a3|a1 a2|a0 a3|a1 a2|a0 = a3 a2 a3 a2 | a1 a0 a1 a0*/\
+                     __v = _mm_or_si128(_mm_unpackhi_epi32(__v, __v), _mm_unpacklo_epi32(__v, __v));  /* = a3|a2|a1|a0  a3|a2|a1|a0  a3|a2|a1|a0  a3|a2|a1|a0*/\
+                     __b = (unsigned)_mm_cvtsi128_si32(__v);
+
+#define BSRN(__in, __n, __b) { typeof(__in[0]) *_ip; __m128i v = _mm_setzero_si128();\
+  for(_ip = __in; _ip != __in+(__n&~(4-1)); _ip+=4) v = _mm_or_si128(v, _mm_loadu_si128((__m128i*)_ip));\
+  HOR(v,__b);\
+  while(_ip != __in+__n) __b |= *_ip++;\
+  __b = bsr32(__b);\
+}
+  #else																					
+#define BSRN(__in, __n, __b) { typeof(__in[0]) *_ip;\
+  for(__b=0,_ip = __in; _ip != __in+(__n&~(4-1)); )\
+    __b |= *_ip++ | *_ip++ | *_ip++ | *_ip++;\
+  while(_ip != __in+__n) __b |= *_ip++;\
+  __b = bsr32(__b);\
+}
+  #endif
+
+#define ZIGZAG( __in, __n, __mode,      __out) { unsigned _v; for(      __out[0]=__in[0],_v = __n-1; _v >   0; --_v) { int _z = ((int)__in[_v] - (int)__in[_v-1]) - __mode; __out[_v] = (_z << 1) ^ (_z >> 31); } }
+#define ZIGZAGB(__in, __n, __mode, __b, __out) { unsigned _v; for(__b=0,__out[0]=__in[0],_v = __n-1; _v >   0; --_v) { int _z = ((int)__in[_v] - (int)__in[_v-1]) - __mode; __out[_v] = (_z << 1) ^ (_z >> 31); __b |= __out[_v]; } __b = bsr32(__b); }
+
+#define UNZIGZAG(__out, __n, __mode) { unsigned _v,_x;\
+  for(_x = __out[0],_v = 1; _v <__n; _v++) { unsigned _z = __out[_v]; __out[_v] = (_x += (_z >> 1 ^ -(_z & 1)) + __mode); }\
+} 																						
+
+#define DELTR( __in, __n, __mode,      __out) { unsigned _v; for(      __out[0]=__in[0],_v = 1;     _v < __n; _v++) __out[_v] = (__in[_v] - __out[0]) -   _v*__mode; }
+#define DELTRB(__in, __n, __mode, __b, __out) { unsigned _v; for(__b=0,__out[0]=__in[0],_v = 1;     _v < __n; _v++) __out[_v] = (__in[_v] - __out[0]) -   _v*__mode, __b |= __out[_v]; __b = bsr32(__b); }
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// transform sorted integer array to delta array. inc = increment
+unsigned bitdelta32(unsigned *in, unsigned n, unsigned *out, unsigned start, unsigned inc);
+
+// get delta maximum bit length of the non decreasing integer array
+unsigned bitd32( unsigned *in, unsigned n, unsigned start);  
+
+// get delta maximum bit length of the non strictly decreasing integer array
+unsigned bitd132(unsigned *in, unsigned n, unsigned start);
+
+void bitundx32(unsigned *p, unsigned n, unsigned x, unsigned inc);
+void bitund32( unsigned *p, unsigned n, unsigned x);
+void bitund132(unsigned *p, unsigned n, unsigned x);
+#ifdef __cplusplus
+}
+#endif