mov eax, xmm2
fld eax
psrldq 4, xmm2
mov eax, xmm2
fld eax
fadd st(0), st(1)

psrldq 4, xmm2
mov eax, xmm2
fld eax
psrldq 4, xmm2
mov eax, xmm2
fld eax
fadd st(0), st(1)

mov eax, xmm1
fld eax
psrldq 4, xmm1
mov eax, xmm1
fld eax
fadd st(0), st(1)

psrldq 4, xmm1
mov eax, xmm1
fld eax
psrldq 4, xmm1
mov eax, xmm1
fld eax
fadd st(0), st(1)

//fpu stack artithmetic after this: 
//1:2 (2) 3:4 (1) 5:6 (4) 7:8 (3)