On 04/30/14 09:15, Cesar Philippidis wrote:
I've been working on a patch to switch a few ppc targets to use softfp
in libgcc instead of fpbit and I noticed that ppc-none-eabispe fails to
bootstrap in both trunk and 4.9. The regression was introduced in
<http://gcc.gnu.org/ml/gcc-patches/2013-11/msg03588.html>. Essentially,
the assert for a hard register in dwf_regno () is not valid on ppc spe
targets. In rs6000_dwarf_register_span (), there is a note stating:
/* The duality of the SPE register size wreaks all kinds of havoc.
This is a way of distinguishing r0 in 32-bits from r0 in
64-bits. */
and the function adds 1200 to regno, which makes that register appear to
be a pseudo. This causes problems in dwf_regno (), which asserts that
reg is a hard register. Since the dwarf2 pass is executed after register
allocation it should, in theory, be ok for the rs6000 backend to be
using a pseudo register for this application.
Is this patch ok for trunk and 4.9? If so, please commit since I don't
have an svn account.
It seems to me the real problem here is the SPE port and this silly game
it plays with adding a large value to regno.
While it is currently safe to remove the assert, the assert is there to
help catch cases where a pseudo has leaked through to a point where it
shouldn't.
I'd rather look for another approach.
Jeff
