Merge iPhone contacts on different accounts to iCloud

New contacts on my iPhone are not syncing to my other apple devices (MacBook/iMac). I figured out that my Default Account on my iPhone in Setting > Contacts > Default Account was set to my gmail, not my iCloud. Now that it's set to iCloud, any new contacts I add are synced to my iMac/Macbook. However, there are hundreds of contacts on my iPhone which are associated to my gmail account, not iCloud. How do I do one of the two things?

1. Sync all contacts on my iPhone to the iCloud Account (preferred method)
2. Add gmail contact account to my iMac/Macbook