This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: Can't use SImode as Pmode for x32
- From: Richard Henderson <rth at redhat dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Jakub Jelinek <jakub at redhat dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 18 Mar 2011 14:03:15 -0700
- Subject: Re: Can't use SImode as Pmode for x32
- References: <AANLkTik07Srb++fzXg1ag-Y5pZ6Mp42z+Vcy2MjvrVDM@mail.gmail.com>
On 03/17/2011 03:28 PM, H.J. Lu wrote:
> It will require very extensive changes to x86 backend since stack pointer
> and frame pointer are really in DImode for x32 as x32 process runs in
> 64bit mode. If you can make it to work, please let me know.
Yes, the stack pointer uses all 64 bits for e.g. push/pop/call. But so
what? Given that our 32-bit move insns also implicitly zero-extend, I
don't see that we need to actually expose the fact of the 64-bit RSP to
the rest of the compiler.
r~