diff --git a/elfling_unpack.hpp b/elfling_unpack.hpp
new file mode 100644
index 0000000..4d623f3
--- /dev/null
+++ b/elfling_unpack.hpp
@@ -0,0 +1,83 @@
+#ifndef ELFLING_UNPACK_HPP
+#define ELFLING_UNPACK_HPP
+
+#include <stdint.h>
+
+#if !defined(MAX_CONTEXT_COUNT)
+#define MAX_CONTEXT_COUNT 16
+#endif
+
+#if !defined(MAX_CONTEXT_SIZE)
+#define MAX_CONTEXT_SIZE (4 << 20)
+#endif
+
+static void elfling_unpack(const uint8_t* weights, const uint8_t* contexts, unsigned contextCount, void* work,
+    const void* in, void* out, unsigned outLen)
+{
+  uint8_t* counters[MAX_CONTEXT_COUNT];  // Counter base offsets
+  uint8_t* cp[MAX_CONTEXT_COUNT];  // Current counters
+  const uint8_t* archive = static_cast<const uint8_t*>(in);
+  uint8_t* cout = static_cast<uint8_t*>(out);
+  uint8_t* base = static_cast<uint8_t*>(work);
+
+  for (uint8_t m = 0; m < contextCount; ++m) {
+    counters[m] = base;
+    cp[m] = base;
+    base += MAX_CONTEXT_SIZE;
+  }
+
+  *cout = 1;
+  uint32_t x1 = 0, x2 = 0xffffffff;                              
+  for (uint32_t j = outLen * 8; j > 0; --j) {
+    uint32_t n0 = 1, n1 = 1;
+    for (uint8_t m = 0; m < contextCount; ++m) {
+      n0 += cp[m][0] * weights[m];
+      n1 += cp[m][1] * weights[m];
+    }
+
+    uint32_t xmid = x1 + n0 * (uint64_t)(x2 - x1) / (n0 + n1);
+
+    uint8_t y;
+    cout[0] <<= 1;
+    if (*(uint32_t*)archive <= xmid) {
+      x2 = xmid;
+      y = 0;
+    } else {
+      cout[0] += 1;
+      x1 = xmid + 1;
+      y = 1;
+    }
+
+    if (((j - 1) & 7) == 0) {  // Start new byte
+      cout++;
+      *cout = 1;
+    }
+    
+    // Count y by context
+    for (uint8_t m = 0; m < contextCount; ++m) {
+      if (cp[m][y] < 255)
+        ++cp[m][y];
+      if (cp[m][1 - y] > 2)
+        cp[m][1 - y] = cp[m][1 - y] / 2 + 1;
+      uint32_t off = 0;
+      for (char i = 0; i < 8; ++i) {
+        if (contexts[m] & (1 << i)) {
+          off = (off << 8) + cout[-i];
+        }
+      }
+      uint32_t c = 0;
+      while (*(uint32_t*)&counters[m][c] != 0 && *(uint32_t*)&counters[m][c] != off) c += 6;
+      *(uint32_t*)&counters[m][c] = off;
+      cp[m] = &counters[m][c + 4];
+    }
+
+    while (((x1 ^ x2) >> 24) == 0) {
+      x1 <<= 8;
+      x2 = (x2 << 8) + 255;
+      --archive;
+    }
+  }
+}
+
+#endif
+
diff --git a/pack.cpp b/pack.cpp
index dc96e22..83365f5 100644
--- a/pack.cpp
+++ b/pack.cpp
@@ -124,7 +124,7 @@ bool Compressor::Compress(CompressionParameters* params, void* in, int inLen, vo
     CompressSingle(&c, in, inLen, out, &pats[pc].bs);
     ++pc;
   }
-  qsort(pats, pc, sizeof(Context), (__compar_fn_t)CompareContext);
+  qsort(pats, pc, sizeof(Context), (int (*)(const void*, const void*))CompareContext);
   if (verbose_) {
     for (int i = 0; i < pc; ++i) {
       printf("Pattern %2d [%2.2x] = %d bytes @ %d\n", i, pats[i].ctx, pats[i].bs, pats[i].bw);
@@ -154,7 +154,7 @@ bool Compressor::Compress(CompressionParameters* params, void* in, int inLen, vo
       g[j].fitness = *outLen;
       CompressSingle(&g[j].params, in, inLen, out, &g[j].fitness);
     }
-    qsort(g, GENOME_SIZE, sizeof(Genome), (__compar_fn_t)CompareGenome);
+    qsort(g, GENOME_SIZE, sizeof(Genome), (int (*)(const void*, const void*))CompareGenome);
     for (int j = 0; j < GENOME_SIZE; ++j) {
       if (j >= 3) break;
       printf("I[%3d,%d]: %d", i, j, g[j].fitness);
@@ -189,7 +189,7 @@ bool Compressor::Compress(CompressionParameters* params, void* in, int inLen, vo
         trg2[k >> 1] = src2[k >> 1];
       }
     }
-    qsort(g, GENOME_SIZE / 2, sizeof(Genome), (__compar_fn_t)CompareGenome);
+    qsort(g, GENOME_SIZE / 2, sizeof(Genome), (int (*)(const void*, const void*))CompareGenome);
     for (int j = 1; j < GENOME_SIZE / 2; ++j) {
       if (!memcmp(g[j].params.weights, g[j - 1].params.weights, CONTEXT_COUNT) && !memcmp(g[j].params.contexts, g[j - 1].params.contexts, CONTEXT_COUNT)) {
         int byte = rand() % (2 * CONTEXT_COUNT);
diff --git a/unpack.cpp b/unpack.cpp
index 1a29246..914d290 100644
--- a/unpack.cpp
+++ b/unpack.cpp
@@ -16,73 +16,12 @@
 
 #include "pack.h"
 
-#include <stdio.h>
+#include "elfling_unpack.hpp"
+
 #include <string.h>
 
 void Compressor::Decompress(CompressionParameters* params, void* in, void* out, int outLen) {
-  u8* counters[MAX_CONTEXT_COUNT];  // Counter base offsets
-  u8* cp[MAX_CONTEXT_COUNT];  // Current counters
-  u8* archive = (u8*)in;
-  u8* cout = (u8*)out;
-
   memset(modelCounters_, 0, MAX_CONTEXT_SIZE * params->contextCount);
-  u8* base = modelCounters_; 
-  for (int m = 0; m < params->contextCount; ++m) {
-    counters[m] = base;
-    cp[m] = base;
-    base += MAX_CONTEXT_SIZE;
-  }
-
-  *cout = 1;
-  u32 x1 = 0, x2 = 0xffffffff;                              
-  for (u32 j = outLen * 8; j > 0; --j) {
-    u32 n0 = 1, n1 = 1;
-    for (char m = 0; m < params->contextCount; ++m) {
-      n0 += cp[m][0] * params->weights[m];
-      n1 += cp[m][1] * params->weights[m];
-    }
-
-    u32 xmid = x1 + n0 * (u64)(x2 - x1) / (n0 + n1);
-
-    char y;
-    cout[0] <<= 1;
-    if (*(u32*)archive <= xmid) {
-      x2 = xmid;
-      y = 0;
-    } else {
-      cout[0] += 1;
-      x1 = xmid + 1;
-      y = 1;
-    }
-
-    if (((j - 1) & 7) == 0) {  // Start new byte
-      cout++;
-      *cout = 1;
-    }
-    
-    // Count y by context
-    for (char m = 0; m < params->contextCount; ++m) {
-      if (cp[m][y] < 255)
-        ++cp[m][y];
-      if (cp[m][1 - y] > 2)
-        cp[m][1 - y] = cp[m][1 - y] / 2 + 1;
-      u32 off = 0, cnt = 0;
-      for (char i = 0; i < 8; ++i) {
-        if (params->contexts[m] & (1 << i)) {
-          off = (off << 8) + cout[-i];
-        }
-      }
-      u32 c = 0;
-      while (*(u32*)&counters[m][c] != 0 && *(u32*)&counters[m][c] != off) c += 6;
-      *(u32*)&counters[m][c] = off;
-      cp[m] = &counters[m][c + 4];
-    }
-
-    while (((x1 ^ x2) >> 24) == 0) {
-      x1 <<= 8;
-      x2 = (x2 << 8) + 255;
-      --archive;
-    }
-  }
+  elfling_unpack(params->weights, params->contexts, params->contextCount, modelCounters_, in, out, outLen);
 }