[SOLVED] shifting of negative number in PIC MCU's

[ashugtiwari]

Hi all,
in one of my project, im doing some division operation on negative numbers, which is division by 2 and 4 mostly, so when i use right shift for division or left shift for multiplication, will the sign persist? or do i have to chk sign before and after operation and make adjustments?

Im using PIC16F1937 8 bit MCU and MPLAB X, plz reply

thanks
Ashutosh

 

[PRABAKARDEVA]

Zip and post your Project files.

 

[thylacine1975]

In general: yes, the sign is preserved. It's worth checking the documentation (once) for the particular compiler/assembler/device instruction set you're using, but don't add code to test at run time

 

[ashugtiwari]

Hi thylacine1975,
thanks for the answer. you r right, it preserves the sign, the compiler uses arithmetic shift instruction for signed numbers.