As we have seen/established in D84108, the cut-off thresholds for Memory Dependence Analysis may need tuning.
In particular, currently they are:
- scan up to 100 instructions per block. IMO this may be a bit low. (rL179713, changed from 500)
- Scan up to 1000 (*sic*) blocks. That seems to be somewhat high.. (D16123)
- There is no cumulative limit on scanned instructions, so one query can end up scanning up to 100 instructions/block * 1k blocks = 100k instructions. Just as @nikic noted in https://reviews.llvm.org/D84108#2174113, that is indeed kinda just insane.
For now, this patch simply adds said cut-off option, but the limit is presently unset.
D84609 will be lowering the limits.