.xmm
option casemap:none
option dotname
option frame:auto
option win64:8
option stackbase:rsp
.code
TestProc proc Arg1:QWORD, Arg2:VARARG
mov r8, Arg1
mov r9, Arg2
ret
TestProc endp
; VARARG immediates that don't fit in a signed dword should be promoted to qwords.
start proc
invoke TestProc, 0123456789ABCDEFh, QWORD ptr 0123456789ABCDEFh, 0123456789ABCDEFh, 0123456789ABCDEFh, 0123456789ABCDEFh
invoke TestProc, 0A23456789ABCDEFh, rax, rbx, rcx, rdx
ret
start endp
end start