Steve Ellcey <sell...@mips.com> writes:
> On Tue, 2012-12-11 at 21:52 +0000, Richard Sandiford wrote:
>
>> > + mips_dbx_regno[CPRESTORE_SLOT_REGNUM] = IGNORED_DWARF_REGNUM;
>
>
>> If even fake registers like these are going to be used, then I think
>> we should initialise to IGNORED_DWARF_REGNUM rather than INVALID_REGNUM in:
>>
>> for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
>> {
>> mips_dbx_regno[i] = INVALID_REGNUM;
>> ...
>> }
>>
>> and remove the ALL_COP_REG loop that was in the earlier patch.
>>
>> Richard
>
> So far, this is the only fake register that I have seen show up while
> building GCC, glibc, newlib, binutils, etc. I am not sure if we want to
> set all fake registers to IGNORED because of this one case. If more
> popped up then I could see us making that change.
I'm pretty sure we'll need more eventually though. A quick inspection
shows that we don't set mips_dbx_regno for DSP_ACC_REGS or ST_REGS.
DSP_ACC_REGS in paticular seems likely to hit, although you need to
test with an -mdsp option to get coverage. It's even conceivable
that we could end up with info for GOT_VERSION_REGNUM.
I don't think we really gain much by trying to distinguish in mips_dbx_regno
between INVALID_REGNUM (register isn't used at all by the compiler) and
IGNORED_DWARF_REGNUM. Especially since we don't distinguish between
registers that have been disabled through -msoft-float, -mips3 and below
(for ST_REGS other than $fcc0), -mno-dsp, etc.
Richard
