1 files changed, 33 insertions, 0 deletions
diff --git a/src/libbiguint/bu_gcd.c b/src/libbiguint/bu_gcd.c
new file mode 100644
index 0000000..d6c5791
--- /dev/null
+++ b/src/libbiguint/bu_gcd.c
@@ -0,0 +1,33 @@
+/* ISC license. */
+
+#include <skalibs/uint32.h>
+#include <skalibs/biguint.h>
+
+int bu_gcd (uint32 *r, unsigned int rn, uint32 const *a, unsigned int an, uint32 const *b, unsigned int bn)
+{
+  if (bu_cmp(a, an, b, bn) < 0)
+  {
+    register uint32 const *t = a ;
+    register unsigned int tn = an ;
+    a = b ; an = bn ;
+    b = t ; bn = tn ;
+  }
+  {
+    uint32 trash[an] ;
+    uint32 aa[an] ;
+    uint32 bb[an] ;
+    uint32 *aaa = aa, *bbb = bb ;
+    bu_copy_internal(aa, a, an) ;
+    bu_copy_internal(bb, b, bn) ;
+    bu_zero(bb+bn, an-bn) ;
+
+    while (bu_len(bbb, an))
+    {
+      register uint32 *ttt = aaa ;
+      bu_div_internal(aaa, an, bbb, an, trash, an) ;
+      aaa = bbb ;
+      bbb = ttt ;
+    }
+    return bu_copy(r, rn, aaa, an) ;
+  }
+}