[PATCH] D47895: llvm: Add support for "-fno-delete-null-pointer-checks"

[Manoj Gupta via Phabricator via llvm-commits]

manojgupta added a comment.

In https://reviews.llvm.org/D47895#1131374, @efriedma wrote:

> Tests look good, at first glance.
>
> For LangRef, I was referring to https://llvm.org/docs/LangRef.html#function-attributes, yes.  (There might be some gaps in the documentation, but ideally that should cover all the function attributes recognized by LLVM transforms and code generation.)


Thanks, Will add it there.

> It looks like you still didn't look at all the files I mentioned earlier?

I went through those files but many of these addressSpace() ==  0 (and != 0) checks are not for null pointers but for disabling/skipping some memory optimizations. And it is not clear to me if moving all of those checks to the new NullPointerIsDefined function makes sense there.



================
Comment at: lib/Transforms/IPO/GlobalOpt.cpp:1931
       GV->getValueType()->isSingleValueType() &&
       GV->getType()->getAddressSpace() == 0 &&
       !GV->isExternallyInitialized() &&
----------------
This pass already skips non-zero address space values. I didn't want to bail out here since all of the accesses to a GV might be in functions without null-pointer-is-valid attribute.


Repository:
  rL LLVM

https://reviews.llvm.org/D47895