Provide refmpn_gcd_22.

2 files changed, 41 insertions, 0 deletions

diff --git a/tests/refmpn.c b/tests/refmpn.c
index 7d2348ed9..42bb41122 100644
--- a/tests/refmpn.c
+++ b/tests/refmpn.c
@@ -2001,6 +2001,46 @@ refmpn_gcd_11 (mp_limb_t x, mp_limb_t y)
   return y;
 }
 
+mp_double_limb_t
+refmpn_gcd_22 (mp_limb_t x1, mp_limb_t x0, mp_limb_t y1, mp_limb_t y0)
+{
+  ASSERT ((x0 & 1) != 0);
+  ASSERT ((y0 & 1) != 0);
+  mp_double_limb_t g;
+  mp_limb_t cy;
+
+  do
+    {
+      while ((x0 & 1) == 0)
+	{
+	  x0 = (x1 << (GMP_NUMB_BITS - 1)) | (x0 >> 1);
+	  x1 >>= 1;
+	}
+      while ((y0 & 1) == 0)
+	{
+	  y0 = (y1 << (GMP_NUMB_BITS - 1)) | (y0 >> 1);
+	  y1 >>= 1;
+	}
+
+
+      if (x1 < y1 || (x1 == y1 && x0 < y0))
+	{
+	  mp_limb_t t;
+	  t = x1; x1 = y1; y1 = t;
+	  t = x0; x0 = y0; y0 = t;
+	}
+
+      cy = (x0 < y0);
+      x0 -= y0;
+      x1 -= y1 + cy;
+    }
+  while ((x1 | x0) != 0);
+
+  g.d1 = y1;
+  g.d0 = y0;
+  return g;
+}
+
 mp_limb_t
 refmpn_gcd_1 (mp_srcptr xp, mp_size_t xsize, mp_limb_t y)
 {
diff --git a/tests/tests.h b/tests/tests.h
index a44d39950..882c63477 100644
--- a/tests/tests.h
+++ b/tests/tests.h
@@ -232,6 +232,7 @@ void refmpn_fill (mp_ptr, mp_size_t, mp_limb_t);
 
 mp_limb_t refmpn_gcd_11 (mp_limb_t, mp_limb_t);
 mp_limb_t refmpn_gcd_1 (mp_srcptr, mp_size_t, mp_limb_t);
+mp_double_limb_t refmpn_gcd_22 (mp_limb_t, mp_limb_t, mp_limb_t, mp_limb_t);
 mp_limb_t refmpn_gcd (mp_ptr, mp_ptr, mp_size_t, mp_ptr, mp_size_t);
 
 size_t refmpn_get_str (unsigned char *, int, mp_ptr, mp_size_t);