On Thu, Nov 10, 2011 at 02:29:04PM +0100, Bernd Schmidt wrote: > On 11/10/11 13:14, Richard Guenther wrote: > > Fair enough. You can count me as "one" then, and I'll defer to Bernd > > to either provide a fix or ack the revert. > > I'm trying to track it down. > > In 189r.outof_cfglayout, we have > > (insn 31 33 35 3 (use (reg/i:SI 0 r0)) > ../../../../baseline-trunk/libstdc++-v3/libsupc++/new_opv.cc:34 -1 > (nil)) > > ;; Successors: EXIT [100.0%] (fallthru) > ;; lr out 0 [r0] 11 [fp] 13 [sp] 14 [lr] 25 [sfp] 26 [afp] > ;; live out 0 [r0] 11 [fp] 13 [sp] 25 [sfp] 26 [afp] > > followed by a number of other basic blocks, so that looks wrong to me. > outof_cfglayout seems to assume that fallthrough edges to the exit block > are OK and don't need fixing up, and changing that seems nontrivial at > first glance. > > The situation is first created during cfgcleanup in into_cfglayout. The > following patch makes the testcase compile by stopping the compiler from > moving the exit fallthru block around, but I've not checked whether it > has a negative effect on code quality. HP, can you run full tests?
FWIW, I did bootstrap and make check with/without this patch, and it introduces no regressions in the PowerPC, but I haven't look at the code generated. -- Michael Meissner, IBM 5 Technology Place Drive, M/S 2757, Westford, MA 01886-3141, USA meiss...@linux.vnet.ibm.com fax +1 (978) 399-6899
