On 11/11/15 12:00, Jakub Jelinek wrote:
On Wed, Nov 11, 2015 at 11:51:02AM +0100, Richard Biener wrote:
The option -foffload-alias=pointer instructs the compiler to assume that
objects references in an offload region do not alias.
The option -foffload-alias=all instructs the compiler to make no
assumptions about aliasing in offload regions.
The default value is -foffload-alias=none.
I think global options for this is nonsense. Please follow what
we do for #pragma GCC ivdep for example, thus allow the alias
behavior to be specified per "region" (whatever makes sense here
in the context of offloading).
Yeah, completely agreed. I don't see why the offloaded region would be in
any way special, they are C/C++/Fortran code as any other.
What we can and should improve is teach IPA aliasing/points to analysis
about the way we lower the host vs. offloading region boundary, so that
if alias analysis on the caller of GOMP_target_ext/GOACC_parallel_keyed
determines something it can be used on the offloaded function side and vice
versa, but a switch like the above is just wrong.
Filed the GOMP_target_ext bit as PR 68675 - Handle GOMP_target_ext
optimally in ipa-pta.
Thanks,
- Tom
