[flang-commits] [flang] [flang][OpenMP] Fix alias analysis for omp.private copy region block arguments to help inline hlfir.assign to improve time taken in LTO. (PR #209539)

[Pranav Bhandarkar via flang-commits]

bhandarkar-pranav wrote:

> This also fixes #203890, which is filed separately: a `firstprivate` fixed-size array in a `target` region fails to link for `amdgcn-amd-amdhsa` because the copy falls back to `_FortranAAssign`, which does not exist on the device.
> 
> Verified on gfx90a at `d1d3891077f6`, same flags, using the reproducer from #203890:
> 
> offload link
> baseline	`ld.lld: error: undefined symbol: _FortranAAssign`
> this PR	links, 1241304 bytes
> So the compile-time regression in #200922 and the device link failure in #203890 are the same root cause, and this closes both.
> 
> This is approved and green. Do you plan to land it? I ask because #211543 is a narrower fix for the same thing at the `InlineHLFIRAssign` call site, and @tblah prefers this design. Mine produces a byte-identical binary on the same reproducer, so it is redundant with yours. I will close it once this lands, and would rather not leave two open PRs for one bug.

I think I hit merge just as your comment came :). 

https://github.com/llvm/llvm-project/pull/209539