[Bug rtl-optimization/46585] [4.6 Regression] ICE: SIGSEGV in vinsn_create (sel-sched-ir.c:1189) with -fno-dce -fschedule-insns -fselective-scheduling

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46585

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amonakov at gcc dot
                   |                            |gnu.org, jakub at gcc dot
                   |                            |gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-22 
10:43:01 UTC ---
This is a bug in sel-sched, which is upset about a nop insn:
(insn 8 3 9 2 (const_int 0 [0]) pr46585.c:7 638 {nop}
     (nil))

(nops exist in -O0 code mainly to carry through location information; of course
scheduling of -O0 code doesn't make any sense, but unfortunately we allow it).

I'm not familiar enough with sel-sched to find out whether it would be best not
to mark nops as SETs (and thus clonable), or just vinsn_init shouldn't instead
of
if (VINSN_SEPARABLE_P (vi))
use
if (VINSN_SEPARABLE_P (vi) && VINSN_RHS (vi))
but I guess the former.