This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] diagnose unsupported uses of hardware register variables (PR 88000)
On Wed, 14 Nov 2018, Segher Boessenkool wrote:
> Yeah, using local register vars to access global registers only works
> by accident. It does work currently though, and people apparently use
> it, so we shouldn't break it :-/
In the proposed approach (copying from/to pseudos just before/after the
asm) we can emulate historic behavior by making uninitialized pseudos
take values of the corresponding hardregs. If we decide that doing that
just for must-uninit pseudos is enough, it's a simple extension to the
existing init-regs pass. Does this sound reasonable?
Alexander