On Mon, Nov 12, 2018 at 11:54:58AM -0700, Jeff Law wrote: > On 11/12/18 10:52 AM, Andrew Stubbs wrote: > > If there are two instructions that both have an UNSPEC_VOLATILE, will > > combine coalesce them into one in the combined pattern? > I think you can put a different constant on each.
combine (like everything else) will not remove an unspec_volatile. Two identical ones can be merged, in theory anyway, but the resulting program will always still execute the same number of them, in the same order. unspec_volatile's have unknown side effects, and those have to happen. If you really need to prevent merging them, then sure, using different unspec numbers will work, sure. Segher
