OvmfPkg/XenBusDxe/X64/TestAndClearBit.S

   1 # INT32
   2 # EFIAPI
   3 # TestAndClearBit (
   4 #   IN  INT32 Bit,                // rcx
   5 #   IN  volatile VOID* Address    // rdx
   6 #   );
   7 ASM_GLOBAL ASM_PFX(TestAndClearBit)
   8 ASM_PFX(TestAndClearBit):
   9   lock
  10   btrl %ecx, (%rdx)
  11   sbbl %eax, %eax
  12   ret