gnu /
gcc /
80f13430350276a8c932d068c971cc00d5e43b78 range-cache: Fix ranger ICE if number of bbs increases [PR116899]
Ranger cache during initialization reserves number of basic block slots
in the m_workback vector (in an inefficient way by doing create (0)
and safe_grow_cleared (n) and truncate (0) rather than say create (n)
or reserve (n) after create). The problem is that some passes split bbs and/or
create new basic blocks and so when one is unlucky, the quick_push into that
vector can ICE.
The following patch replaces those 4 quick_push calls with safe_push.
I've also gathered some statistics from compiling 63 gcc sources (picked those
that dependent on gimple-range-cache.h just because I had to rebuild them once
for the instrumentation), and that showed that in 81% of cases nothing has
been pushed into the vector at all (and note, not everything was small, there
were even cases with 10000+ basic blocks), another 18.5% of cases had just 1-4
elements in the vector at most, 0.08% had 5-8 and 19 out of 305386 cases
had at most 9-11 elements, nothing more. So, IMHO reserving number of basic
block in the vector is a waste of compile time memory and with the safe_push
calls, the patch just initializes the vector to vNULL.
2024-10-01 Jakub Jelinek <jakub@redhat.com>
PR middle-end/116899
* gimple-range-cache.cc (ranger_cache::ranger_cache): Set m_workback
to vNULL instead of creating it, growing and then truncating.
(ranger_cache::fill_block_cache): Use safe_push rather than quick_push
on m_workback.
(ranger_cache::range_from_dom): Likewise.
* gcc.dg/bitint-111.c: New test.
(cherry picked from commit de25f1729d212c11d6e2955130f4eb1d272b5ce7)
2 files changed
