[cfe-dev] [LLVMdev] Named register variables GNU-style

[Renato Golin]

On 7 April 2014 12:16, Richard Sandiford <rsandifo at linux.vnet.ibm.com> wrote:
> It might not matter, but MIPS linux is one case where a non-allocatable
> register is used as a true global variable, rather than as a convienent
> way of getting the value of a fixed-purpose register.  The register used
> there is $gp, which on bare-metal is usually reserved for small-data and
> (in theory) GOT accesses.  Since linux knows it doesn't use either,
> it instead uses $gp to hold information about the current thread.

Hi Richard,

I think all cases for named registers are unusual, and that's the
point. I think this is a perfectly valid case for using named
registers, since there is no way in C to represent this logic and bare
metal code might have a heavy use of that register's value.

cheers,
--renato