## cvtsi2sd - convert integer to double (64 bit floating point)

    dest = source

The cvtsi2sd instruction adds the source value (second operand) to the destination (an XMM register). The source can be a 32 or 64 bit general purpose register or a 64 bit memory location.

If the integer can't be stored exactly as a double, it will be rounded according to the MXCSR register. For example the number 123456789123456789 fits in a quadword integer but a double is only accurate for about 16 decimal digits. It will probably be rounded up to about 1234567891234568xx though the final 8 may be a 7 and the last 2 digits will vary depending on the specific number.

            cvtsi2sd   xmm0, edx         ; convert edx to double in xmm0
                                         ; leave the rest of xmm0 as is
            cvtsi2sd   xmm0, r8          ; convert r8 to double in xmm0
                                         ; leave the rest of xmm0 as is
            cvtsi2sd   xmm0, qword [x]   ; convert 64 bit variable x to xmm0
                                         ; leave the rest of xmm0 as is
            cvtsi2sd   xmm0, dword [rsi] ; convert 32 bit value [rsi] to xmm0
                                         ; rsi holds the address of an int
                                         ; leave the rest of xmm0 as is

### flags: none