[Bug rtl-optimization/55158] ICE: [4.8 Regreesion] [IA64] segv in schedule_region

[gary at intrepid dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55158

--- Comment #1 from Gary Funck <gary at intrepid dot com> 2012-11-01 00:15:54 UTC ---
Some additional debugging information.

In sched_rgn_init(), the bb_state array is initialized.

3049        {
3050          bb_state_array = (char *) xmalloc (last_basic_block *
dfa_state_size);
3051          bb_state = XNEWVEC (state_t, last_basic_block);
3052          for (i = 0; i < last_basic_block; i++)
3053            {
3054              bb_state[i] = (state_t) (bb_state_array + i *
dfa_state_size);
3055          
3056              state_reset (bb_state[i]);
3057            }
3058        }

For the given test case.

(gdb) p last_basic_block
$3 = 23

Yet, it is the access of bb_state[23] that leads to the segfault.

The last basic block is 23, and the array bb_state[] is initialized only for
entries 0..22.  Perhaps the number entries allocated should be
(last_basic_block +  1) with the initialization loop adjusted accordingly?