Exception thrown at 0x00007FF69997AA5C in HW04_Q01.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF. occurred

I wrote a procedure in a x64 assembly (masm) and when the execution of the code reaches the ret statment it gives this error : Exception thrown at 0x00007FF69997AA5C in HW04_Q01.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF. occurred

getSquareRoot proc
.data?
    temp2 complex <>
    a real8 ?
    b real8 ?
    x real8 ?
.data
    zero real8 0.0
    _two real8 2.0
    minusOne real8 -1.0
.code
    movsd xmm0, real8 ptr [rsi]
    movsd xmm1, real8 ptr [rsi + 8]
    movsd a, xmm0
    movsd b, xmm1
    mulsd xmm0, a
    mulsd xmm1, b
    movsd xmm2, xmm0
    addsd xmm2, xmm1
    movsd x, xmm2
    movsd xmm1, b
    _IF:
        ucomisd xmm1, zero
        jb _else 
            movsd xmm0,x
            call sqrt
            addsd xmm0, a
            divsd xmm0, _two
            call sqrt
            movsd temp2.real, xmm0

            movsd xmm0,x
            call sqrt
            movsd xmm1, minusOne
            mulsd xmm1, a
            addsd xmm0, xmm1
            divsd xmm0, _two
            call sqrt
            movsd temp2.imag, xmm0
        jmp _endIf
    _else:
            movsd xmm0,x
            call sqrt
            addsd xmm0, a
            divsd xmm0, _two
            call sqrt
            movsd temp2.real, xmm0

            movsd xmm0,x
            call sqrt
            movsd xmm1, minusOne
            mulsd xmm1, a
            addsd xmm0, xmm1
            divsd xmm0, _two
            call sqrt
            mulsd xmm0, minusOne
            movsd temp2.imag, xmm0
    _endIf:
    movsd xmm0, temp2.real
    movsd xmm1, temp2.imag
ret
getSquareRoot endp

actually i replaced each call to sqrt() C function with the mnemonic sqrtsd since the values i'm dealing with all stored in SSE registers(xmm0, xmm1, xmm2, ...) and it worked