On 11/25/2014 08:06 PM, Yury Gribov wrote:
> This patch improves current optimization of ASAN_CHECKS performed by
> sanopt pass.  In addition to searching the sanitized pointer in
> asan_check_map, it also tries to search for definition of this pointer.
>   This allows more checks to be dropped when definition is not a gimple
> value (e.g. load from struct field) and thus cannot be propagated by
> forwprop.
>
> In my experiments this rarely managed to remove more than 0.5% of
> ASAN_CHECKs but some files got as much as 1% improvement e.g.
> * gimple.c: 49 (out of 5293)
> * varasm.c: 42 (out of 3678)
>
> For a total it was able to remove 2657 checks in Asan-bootstrapped GCC
> (out of ~500K).

Hi all,

Here is the updated version of the patch.

Asan-bootstrapped, bootstrapped and regtested on x64.

Marek, do you think similar optimization may be useful for UBSan?

-Y