Bothered to have a look, you certainly have some strange code for 64 bit. Looks suspiciously like hybrid STDCALL 32 bit code embedded in 64 bit.
0x140001248:
stosq qword ptr [rdi], rax ; no REP
0x14000119b:
push rsi
push rdi
push rbx
push rdx
mov rsi, rcx
mov rdi, rdx
xor rbx, rbx
pop rdx
pop rbx
pop rdi
pop rsi
ret
jdebP:
mov qword ptr [0x140002700], rsp
lea rsp, [0x140002790]
push r15
push r14
push r13
push r12
push r11
push r10
push r9
push r8
push rdi
push rsi
push rbp
push rsp
push rbx
push rdx
push rcx
push rax
lea rdx, [0x140002700]
mov rax, qword ptr [rsp-0x10]
mov rdx, qword ptr [rax]
sub rdx, 5
mov qword ptr [rsp-8], rdx
mov qword ptr [rsp+0x20], rax
add qword ptr [rsp+0x20], 8
xchg rax, rsp ; antique junk
or eax, 0xffffffff
cdq ; more antique junk
lea rcx, [0x140002790]
fxsave ptr [rcx]
ret
