[llvm-dev] Using store with operands in non-zero address space

Gleb Popov via llvm-dev
Fri, 21 Jun 2019 13:41:55 -0000

On Fri, Jun 21, 2019 at 3:14 PM Savonichev, Andrew via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Gleb Popov via llvm-dev writes:
> > I have the following IR:
>
> >   %x = alloca i32, align 4
> >   %p = alloca i32*, align 8
> >   store i32* %x, i32** %p, align 8
> >
> > Now I change module's data layout and run InferAddressSpacePass.
This
> turns that piece of code into
> >
> >   %x = alloca i32, align 4, addrspace(1)
> >   %p = alloca i32*, align 8, addrspace(1)
> >   store i32 addrspace(1)* %x, i32* addrspace(1)* %p, align 8
> >
> > But Verifier complains that the module is invalid, saying
> >
> > error: stored value and pointer type do not match
> > store i32 addrspace(1)* %x3, i32* addrspace(1)* %p4, align 8
> >
> > I didn't even manage to write correct IR manually in presence of
> addrspace().
> > Is it a bug, or I'm missing something?
>
> `i32* addrspace(1)*' is a pointer in addrspace(1) that points to a
pointer
> in
> addrspace(0) (zero address space is not printed). In other words, pointee
> type
> of `p' is `i32*', while you're trying to store `i32
addrspace(1)*'. You
> have to
> change the alloca to make it work:
>
>     %p = alloca i32 addrspace(1)*, align 8, addrspace(1)
>     store i32 addrspace(1)* %x, i32 addrspace(1)* addrspace(1)* %p, align 8
>

Ah, that's why stars are in different places! Thanks for clearing this up.


> --
> Andrew
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