On 1/2/25 12:04 PM, Harald Anlauf wrote:
Dear all,
this patch addresses overeager optimization of Cray pointers when
used in comparisons. Cray pointers are non-standard, and odd in a
sense that they were introduced before modern Fortran pointers.
Comparisons with e.g. a "NULL" pointer are actually comparisons
with integer zero etc., which means that while they are references
they can actually be "NULL" to mimic a disassociated pointer.
The only solution I could find was treating them locally as volatile
when used in a comparison. If someone has a better solution, please
share!
As this is a local solution, and a real-world legacy code using Cray
pointers would likely never use such a test in a vectorizable loop,
I expect negligible (performance and code-size) impact.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
This PR is marked as a regression (since gcc-7), is this OK for
a (limited?) backport?
Thanks,
Harald
The hack is fairly isolated and simple. The problem is a quirk from the
past. The only way to expose an issue is to get it into the real world
and see if anyone notices a problem.
OK for trunk and maybe 14. If you think farther back, up to you.
Jerry
