[llvm-dev] relation between address spaces and physical memory locations

James Molloy via llvm-dev
2016-03-23T09:43:38Z

Hi,

Address spaces in LLVM are an abstract concept and LLVM attaches no
internal meaning to address spaces, apart from:

- Location 0 in address space 0 is 'nullptr' and a pointer to this
cannot
be dereferenced in a well formed program.

- pointers in different address spaces cannot alias.

Different backends attach different meanings. So for example an OpenCL
backend might interpret address space 1 as local memory, 2 as private
memory etc (in fact for OpenCL, these mappings are defined in the Clang
frontend, if I recall correctly)

Cheers,

James

On Wed, 23 Mar 2016 at 09:31, Mohammad Norouzi via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Hi,
>
> Do address spaces in llvm corespond to different memory locations? For
> example, Shared and Global refer to RAM while Local refers to registers?
>
> I guess that this may be true in GPU programming. So, I would like to know
> about CPUs.
>
> Thanks.
>
> Best,
> Mohammad
>
>
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