Created attachment 24892 [details]
test for loop unrolling
I see exactly the case that was mentioned here - http://gcc.gnu.org/ml/gcc/2010-01/msg00057.html:
exp_gcc/gcc -c -O3 test_unroll.c -fno-tree-dominator-opts performs complete unroll and
exp_gcc/gcc -c -O3 test_unroll.c does not do the unroll
Thread model: posix
gcc version 4.7.0 20110802 (experimental) (GCC)
cunrolli does not handle the loop in the testcase because of the condition "ul == UL_NO_GROWTH && unr_insns > ninsns" in try_unroll_loop_completely. Meanwhile may_increase_size is true in tree_unroll_loops_completely.