https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68920
--- Comment #6 from James Greenhalgh <jgreenhalgh at gcc dot gnu.org> --- Rather than a target macro, I think I'd rather implement this as a parameter along the lines of "max-rtl-ifcvt-insns" - i386 backend could then set this to 1 and avoid the issue. I'll try to get to that in the next day - but I'll be out of office starting from Friday, so I might not get to it until 2016. If someone else wanted to pick it up, there's nothing too smart to the patch I'd propose. Just add the parameter and wire it up so that the call to BRANCH_COST in RTL if-convert takes MIN of the param and the returned value.
