lib/mpi: Extend the MPI library

[linux-2.6-block.git] / lib / mpi / mpi-cmp.c

diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c
index d25e9e96c310fc8aeeaff05213ac74b9f6280a96..c4cfa3ff058189c41eb7b7a5e84bb8e2ec92fa7d 100644 (file)
--- a/lib/mpi/mpi-cmp.c
+++ b/lib/mpi/mpi-cmp.c
@@ -41,28 +41,54 @@ int mpi_cmp_ui(MPI u, unsigned long v)
 }
 EXPORT_SYMBOL_GPL(mpi_cmp_ui);
 
-int mpi_cmp(MPI u, MPI v)
+static int do_mpi_cmp(MPI u, MPI v, int absmode)
 {
-       mpi_size_t usize, vsize;
+       mpi_size_t usize;
+       mpi_size_t vsize;
+       int usign;
+       int vsign;
        int cmp;
 
        mpi_normalize(u);
        mpi_normalize(v);
+
        usize = u->nlimbs;
        vsize = v->nlimbs;
-       if (!u->sign && v->sign)
+       usign = absmode ? 0 : u->sign;
+       vsign = absmode ? 0 : v->sign;
+
+       /* Compare sign bits.  */
+
+       if (!usign && vsign)
                return 1;
-       if (u->sign && !v->sign)
+       if (usign && !vsign)
                return -1;
-       if (usize != vsize && !u->sign && !v->sign)
+
+       /* U and V are either both positive or both negative.  */
+
+       if (usize != vsize && !usign && !vsign)
                return usize - vsize;
-       if (usize != vsize && u->sign && v->sign)
-               return vsize - usize;
+       if (usize != vsize && usign && vsign)
+               return vsize + usize;
        if (!usize)
                return 0;
        cmp = mpihelp_cmp(u->d, v->d, usize);
-       if (u->sign)
-               return -cmp;
-       return cmp;
+       if (!cmp)
+               return 0;
+       if ((cmp < 0?1:0) == (usign?1:0))
+               return 1;
+
+       return -1;
+}
+
+int mpi_cmp(MPI u, MPI v)
+{
+       return do_mpi_cmp(u, v, 0);
 }
 EXPORT_SYMBOL_GPL(mpi_cmp);
+
+int mpi_cmpabs(MPI u, MPI v)
+{
+       return do_mpi_cmp(u, v, 1);
+}
+EXPORT_SYMBOL_GPL(mpi_cmpabs);