http://gcc.gnu.org/viewcvs?view=revision&revision=183151
As explained in its comment, the test case works only if BRANCH_COST > 1.
This is done by the patch.
* gcc.dg/pr46309.c: Set branch cost to greater 1 for avr.
--- trunk/gcc/testsuite/gcc.dg/pr46309.c 2012/01/13 05:11:45 183150
+++ trunk/gcc/testsuite/gcc.dg/pr46309.c 2012/01/13 10:32:16 183151
@@ -4,6 +4,7 @@
/* The transformation depends on BRANCH_COST being greater than 1
(see the notes in the PR), so try to force that. */
/* { dg-additional-options "-mtune=octeon2" { target mips*-*-* } } */
+/* { dg-additional-options "-mbranch-cost=2" { target avr*-*-* } } */
int
f1 (int a)
