add a word in the middle

I have a file where in I need to add gctunit1/gtdivcompebb1/ after the = sign

for example:

gtfix31/gctunit_gtdivcompebb1/csclkswcompbypassstepgnnnh[4] = gctunit1/gtdivcompebb1/csclkswcompbypassstepgnnnh

You have provided the sample output. What is your input?

if your input is
gtfix31/gctunit_gtdivcompebb1/csclkswcompbypassstepgnnnh= csclkswcompbypassstepgnnnh

echo "gtfix31/gctunit_gtdivcompebb1/csclkswcompbypassstepgnnnh= csclkswcompbypassstepgnnnh"|sed 's/\(.*\)\(=\)\(.*\)/\1\2gctunit1\/gtdivcompebb1\/\3/g'

output will be

gtfix31/gctunit_gtdivcompebb1/csclkswcompbypassstepgnnnh[4] = gctunit1/gtdivcompebb1/csclkswcompbypassstepgnnnh

thanks