On 27.07.2022 02:10, Stefano Stabellini wrote: > On Tue, 26 Jul 2022, Jan Beulich wrote: >> You forgot the imo better intermediate option of using the "X" constraint. > > I couldn't get "X" to compile in any way (not even for arm64). Do you > have a concrete example that you think should work using "X" as > constraint?
Perhaps you tried to use the respective input then as an operand to the insn? That won't work afaik - as Xenia says, it can be used only as a "fake" operand (i.e. one that tells the compiler something, but having no direct meaning for the insn). Actually I thought we had uses of "X" already somewhere in Xen and/or XTF, but now that I looked I can't find any. (Anymore?) Jan
