On Wed, Nov 30, 2016 at 01:52:51PM +0100, Richard Biener wrote: > On Wed, Nov 30, 2016 at 1:46 PM, Segher Boessenkool > <seg...@kernel.crashing.org> wrote: > > In the testcase, IRA propagates a constant into a TRAP_IF insn, which > > then becomes an unconditional trap. Unconditional traps are control > > flow insns so doing this requires surgery on the cfg. > > Huh, that's an odd choice ;) I'd say TRAP_IF should be a control-flow insn > as well, but well...
It doesn't really matter here, converting a conditional TRAP_IF to an unconditional one requires changing the cfg in any case (and we cannot do that here). Making every TRAP_IF a control flow insn means they will end their BB; that will make some things simpler, sure. It will also limit some of the RTL optimizations a bit. Segher
