On Tue, Apr 28, 2020 at 3:48 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > On 26/04/20 13:52, Uros Bizjak wrote: > > Improve handle_external_interrupt_irqoff inline assembly in several ways: > > - use "n" operand constraint instead of "i" and remove > > unneeded %c operand modifiers and "$" prefixes > > - use %rsp instead of _ASM_SP, since we are in CONFIG_X86_64 part > > - use $-16 immediate to align %rsp > > - remove unneeded use of __ASM_SIZE macro > > - define "ss" named operand only for X86_64 > > > > The patch introduces no functional changes. > > I think I agree with all of these, so the patch is okay! Thanks, Actually, after some more thinking, neither "i", and neither "n" is correct for x86_64 as far as push is concerned. The correct constraint is "e", but in case the value doesn't fit this constraint, we have to allow "r" and eventually "m". Let's use "rme", which allows everything the insn is able to handle, and leave to the compiler to use the optimal one. GCC uses this constraint internally, and it also fits 32bit targets. V3 patch is in the works. Uros.
