http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47614
--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-02-09 21:10:23 UTC --- Please move the side_effects_p check in reload_cse_simplify_operands right before the cselib_lookup call, there is no point calling cselib_lookup if it has side effects. BTW, on powerpc64-linux Alex's incdec patch apparently broke profiledbootstrap, cc1 built with -fprofile-use keeps segfaulting on most of libgcc compilations. A patch similar to #c13 (just with if (side_effects_p (op)) continue; moved in front of v = cselib_lookup (...);) fixed the profiledbootstrap apparently (but guess a patch using check_for_inc_dec + the *_operands change will do the same). I agree that in this case it can generate better code to delete the redundant insn and just keep the side effects.
