-mcall-prologues
Functions prologues/epilogues are expanded as call to appropriate subroutines. Code size will be smaller.
-mno-interrupts
Change the stack pointer without disabling interrupts. Generated code is not compatible with hardware interrupts. Code size will be smaller.
-mno-tablejump
Do not generate table jump instructions (removed from GCC 4.5.1 coz same as -fno-jump-tables).
-msize
Output instruction sizes to the asm file (removed from avr-gcc coz same as using -dp switch which prints the instruction length).