summaryrefslogtreecommitdiffstats
path: root/lib/mpi/mpi-cmp.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/mpi/mpi-cmp.c')
-rw-r--r--lib/mpi/mpi-cmp.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c
new file mode 100644
index 000000000..0835b6213
--- /dev/null
+++ b/lib/mpi/mpi-cmp.c
@@ -0,0 +1,98 @@
+/* mpi-cmp.c - MPI functions
+ * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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.
+ *
+ * GnuPG 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "mpi-internal.h"
+
+int mpi_cmp_ui(MPI u, unsigned long v)
+{
+ mpi_limb_t limb = v;
+
+ mpi_normalize(u);
+ if (u->nlimbs == 0) {
+ if (v == 0)
+ return 0;
+ else
+ return -1;
+ }
+ if (u->sign)
+ return -1;
+ if (u->nlimbs > 1)
+ return 1;
+
+ if (u->d[0] == limb)
+ return 0;
+ else if (u->d[0] > limb)
+ return 1;
+ else
+ return -1;
+}
+EXPORT_SYMBOL_GPL(mpi_cmp_ui);
+
+static int do_mpi_cmp(MPI u, MPI v, int absmode)
+{
+ 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;
+ usign = absmode ? 0 : u->sign;
+ vsign = absmode ? 0 : v->sign;
+
+ /* Compare sign bits. */
+
+ if (!usign && vsign)
+ return 1;
+ if (usign && !vsign)
+ return -1;
+
+ /* U and V are either both positive or both negative. */
+
+ if (usize != vsize && !usign && !vsign)
+ return usize - vsize;
+ if (usize != vsize && usign && vsign)
+ return vsize + usize;
+ if (!usize)
+ return 0;
+ cmp = mpihelp_cmp(u->d, v->d, usize);
+ 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);