From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Date: Wed, 14 Jan 2015 15:15:57 +0000 (+0000)
Subject: MPILIB: Deobfuscate mpi_cmp
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7fe21291bad93458100fbbf0078d40cdb529a646;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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>
---

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);