http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56484
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-03-01
CC| |jakub at gcc dot gnu.org,
| |uros at gcc dot gnu.org
Target Milestone|--- |4.8.0
Summary|ICE in assign_by_spills, at |[4.8 Regression] ICE in
|lra-assigns.c:1268 |assign_by_spills, at
| |lra-assigns.c:1268
Ever Confirmed|0 |1
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-01
08:30:31 UTC ---
Started with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=188526
but it was merely latent before that, so it isn't LRA bug, because it fails
with reload equally.
I think the problem is in combine, where we have:
ax = call ...
flags = r59 != 0
r60 = flags >= 0 ? ax : r59
r65 = buf
r68 = 768
rep stosd [r65 .. r65 + r68 - 4] = 0
r59 = r60
and the combiner combines the r60 = flags >= 0 ? ax : r59 instruction with
r59 = r60 into r59 = flags >= 0 ? ax : r59 instruction in the last spot, thus
extending the lifetime of the ax and flags hard registers across various other
instructions.
