Steven Scholz wrote:

How about

a = b / 5; ?

Will that result in

a = (b >> 2) - b;

, i.e. still no division but only shift operations?

Short answer:

${CROSS_COMPILE}gcc a.c -O2 -c -g -o a.o ${CROSS_COMPILE}objdump -S a.o

In other words, YMMV (arch, flags, gcc version, etc.). Some arch pipelines may be faster at division (with divisor on 8 bits), than shift and subtract which must serialize.

Feel free to ask/contribute to the GCC project :-)