On Mon, 2020-01-27 at 04:53 +0000, Feng Xue OS wrote:
> Current IPA does not propagate aggregate constant for by-ref argument
> if it is simple pass-through of caller parameter. Here is an example,
>
> f1 (int *p)
> {
> ... = *p;
> ...
> }
>
> f2 (int *p)
> {
> *p = 2;
> f1 (p);
> }
>
> It is easy to know that in f1(), *p should be 2 after a simple propagation
> from f2() to f1(). But this is missed due to some bug, which is targeted
> by this patch.
>
> Bootstrapped/regtested on x86_64-linux and aarch64-linux.
>
> Feng
> ---
> 2020-01-27 Feng Xue <f...@os.amperecomputing.com>
>
> PR ipa/93429
> * ipa-cp.c (propagate_aggs_across_jump_function): Further
> check aggregate jump functions if by-ref argument is simple
> pass through.
> (intersect_aggregates_with_edge): Likewise.
I'm deferring this to gcc-11 as it's a missed-optimization and we're in
stage4.
jeff
