As reported by feqin fan on sdcc-devel on 2012-12-31 (found a magic number 0x102----sdcc PIC14 PORT) and confirmed by Gál Zsolt, the following code lacks code for the "+ 0x102" part when compiled with the current svn head:
int i, temp = 0x100;
for (i=0 ;i<10; i++)
temp = temp + 0x102; // this will be disappear magically.
// I mean the number 0x102 will NOT be added to the temp.
// if the number is other besides 0x102, everything is all right
PORTA = temp; // I konwn only the low 8 bit will be used.