[PATCH] D71499: Add builtins for aligning and checking alignment of pointers and integers

[Roman Lebedev via Phabricator via cfe-commits]

lebedev.ri requested changes to this revision.
lebedev.ri added a comment.
This revision now requires changes to proceed.

(temporarily undoing my review since it looks like things may change)

In D71499#1801302 <https://reviews.llvm.org/D71499#1801302>, @arichardson wrote:

> ...


Aha! :)

In D71499#1801302 <https://reviews.llvm.org/D71499#1801302>, @arichardson wrote:

> However, I think this means that for the downstream CHERI codegen
>  there is one more case where we need to be careful
>  (but that shouldn't matter for upstream).
>  For us `uintptr_t` is represented as `i8 addrspace(200)*`.
>  As `uintptr_t` can hold values that are plain integers and not pointers,
>  we would need to add the inbounds only if the AST type is a pointer,
>  and use a non-inbounds GEP for `(u)intptr_t`.


I may be missing some details, but won't we get that for free,
since we only do `gep` for pointers already?

In D71499#1801302 <https://reviews.llvm.org/D71499#1801302>, @arichardson wrote:

> Does that sound correct or did I misunderstand something?


To //me// this all sounds great.
Since we get to dictate^W define semantics, i'd think we can require

In D71499#1801302 <https://reviews.llvm.org/D71499#1801302>, @arichardson wrote:

> both input and output should be a `Logical pointer`.
>  If you want random values, you should be aligning uintptr_t instead.



Repository:
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  https://reviews.llvm.org/D71499/new/

https://reviews.llvm.org/D71499