# Pre-RFC: Conditionally-supported volatile access to address 0

**URL:** <https://internals.rust-lang.org/t/pre-rfc-conditionally-supported-volatile-access-to-address-0/12881>\
**Category:** libs\
**Created:** [August 13, 2020, 3:50am UTC](https://internals.rust-lang.org/t/pre-rfc-conditionally-supported-volatile-access-to-address-0/12881 "2020-08-13T03:50:17Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![InfernoDeity](https://sea2.discourse-cdn.com/flex002/user_avatar/internals.rust-lang.org/infernodeity/32/7588_2.png) [@InfernoDeity](https://internals.rust-lang.org/u/InfernoDeity)\
**Post date:** [August 13, 2020, 12:02pm UTC](https://internals.rust-lang.org/t/pre-rfc-conditionally-supported-volatile-access-to-address-0/12881/7 "2020-08-13T12:02:38Z")

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> [@scottmcm](#):
>
> don't see how this one would be true. If you don't know that it's at address zero, how would you know that you need to use the \_volatile methods to access that particular object

I said it does not solve such issues, which, at least for my purposes, I can live with (in my case, if it happens I'm about to overflow the stack anyways).

> [@RalfJung](#):
>
> Is this even implementable with LLVM

To my knowledge, no, though if it is possible that may be useful. This is why I said its _conditionally-supported_. If it is possible, then it could be enabled for architectures where it makes sense, rather than leaving it on always, so as to preserve certain optimizations. I could look into it specifically, and respond on the viability of supporting it on rustc's llvm backend at all.

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