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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-03-23 08:06:43 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-03-23 08:06:43 -0300
commit7483d45f0aee3afc0646d185cabd4af9f6cab58c (patch)
treea312f7d77c34748bec62f0431df33007b10e4e7f /lib/mpi/mpi-gcd.c
parent3e85fc1b9fc1c7e20b9a01f2314bb633bb10501a (diff)
parentf92c97c8bd77992ff8bd6ef29a23dc82dca799cb (diff)
downloadolio-linux-3.10-7483d45f0aee3afc0646d185cabd4af9f6cab58c.tar.xz
olio-linux-3.10-7483d45f0aee3afc0646d185cabd4af9f6cab58c.zip
Merge branch 'staging/for_v3.4' into v4l_for_linus
* staging/for_v3.4: (10117 commits) [media] update CARDLIST.em28xx [media] partially reverts changeset fa5527c [media] stb0899: fix the limits for signal strength values [media] em28xx: support for 2304:0242 PCTV QuatroStick (510e) [media] em28xx: support for 2013:0251 PCTV QuatroStick nano (520e) [media] -EINVAL -> -ENOTTY [media] gspca - sn9c20x: Cleanup source [media] gspca - sn9c20x: Simplify register write for capture start/stop [media] gspca - sn9c20x: Add automatic JPEG compression mechanism [media] gspca - sn9c20x: Greater delay in case of sensor no response [media] gspca - sn9c20x: Optimize the code of write sequences [media] gspca - sn9c20x: Add the JPEG compression quality control [media] gspca - sn9c20x: Add a delay after Omnivision sensor reset [media] gspca - sn9c20x: Propagate USB errors to higher level [media] gspca - sn9c20x: Use the new video control mechanism [media] gspca - sn9c20x: Fix loss of frame start [media] gspca - zc3xx: Lack of register 08 value for sensor cs2102k [media] gspca - ov534_9: Add brightness to OmniVision 5621 sensor [media] gspca - zc3xx: Add V4L2_CID_JPEG_COMPRESSION_QUALITY control support [media] pvrusb2: fix 7MHz & 8MHz DVB-T tuner support for HVR1900 rev D1F5 ...
Diffstat (limited to 'lib/mpi/mpi-gcd.c')
-rw-r--r--lib/mpi/mpi-gcd.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/mpi/mpi-gcd.c b/lib/mpi/mpi-gcd.c
new file mode 100644
index 00000000000..13c48aef9c4
--- /dev/null
+++ b/lib/mpi/mpi-gcd.c
@@ -0,0 +1,59 @@
+/* mpi-gcd.c - MPI functions
+ * Copyright (C) 1998, 1999, 2000, 2001 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"
+
+/****************
+ * Find the greatest common divisor G of A and B.
+ * Return: true if this 1, false in all other cases
+ */
+int mpi_gcd(MPI g, const MPI xa, const MPI xb)
+{
+ MPI a = NULL, b = NULL;
+
+ if (mpi_copy(&a, xa) < 0)
+ goto nomem;
+
+ if (mpi_copy(&b, xb) < 0)
+ goto nomem;
+
+ /* TAOCP Vol II, 4.5.2, Algorithm A */
+ a->sign = 0;
+ b->sign = 0;
+ while (mpi_cmp_ui(b, 0)) {
+ if (mpi_fdiv_r(g, a, b) < 0) /* g used as temorary variable */
+ goto nomem;
+ if (mpi_set(a, b) < 0)
+ goto nomem;
+ if (mpi_set(b, g) < 0)
+ goto nomem;
+ }
+ if (mpi_set(g, a) < 0)
+ goto nomem;
+
+ mpi_free(a);
+ mpi_free(b);
+ return !mpi_cmp_ui(g, 1);
+
+nomem:
+ mpi_free(a);
+ mpi_free(b);
+ return -ENOMEM;
+}