Totally confused by O2 code (perdrix)

This is a sample of a small section of O2 code output (dsPIC33FJ12MC201) 1038: SPI_Received = SPI1BUF; // Read SPI input into buffer
0004F4 801240 MOV SPI1BUF, W0
00059C 780080 MOV W0, W1
00060E 780080 MOV W0, W1
000686 780080 MOV W0, ..