MPILIB: Deobfuscate mpi_cmp

The condition preceding 'return 1;' makes my head hurt. At this point,
we know that u and v have the same sign; if they are negative, they
compare opposite to how their absolute values compare (which
mpihelp_cmp found for us), otherwise cmp itself is the
answer. Negating cmp is ok since mpihelp_cmp returns {-1,0,1};
-INT_MIN==INT_MIN won't bite us.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c
index 1871e7b61ca0..8ed36b8cbe02 100644
--- a/lib/mpi/mpi-cmp.c
+++ b/lib/mpi/mpi-cmp.c
@@ -61,10 +61,8 @@ int mpi_cmp(MPI u, MPI v)
         if (!usize)
                 return 0;
         cmp = mpihelp_cmp(u->d, v->d, usize);
-        if (!cmp)
-                return 0;
-        if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
-                return 1;
-        return -1;
+        if (u->sign)
+                return -cmp;
+        return cmp;
 }
 EXPORT_SYMBOL_GPL(mpi_cmp);