On Thu, Aug 24 2023 at 00:27, huangshaobo3@xxxxxxxxxx wrote: > On Wed, 23 Aug 2023 16:15:27 +0200, Thomas Gleixner wrote: >> I'm not seeing what this solves: > >> > - if (control & PCI_MSI_FLAGS_64BIT) >> > + if (desc.pci.msi_attrib.is_64) > >> Both variants resolve to a test of a bit and a conditional instruction >> on the result. It's exactly zero difference in terms of "calculation". > >> So all this does is change the memory location to test. Not more not >> less. It does not generate better code and does not save anything. > > It may not be appropriate to write to eliminate duplicate calculations, > can it be proposed again with clean code? What's wrong with the existing code?
