Kris Kross Funeral -- Daddy Mac Breaks Down ... 'I Know Chris Is in H

Kris Kross rapper Chris "Daddy Mac" Smith broke down in tears today during the funeral for his former KK partner Chris Kelly -- telling the congregation, "It's been like a struggle for me every day ... I know Chris is in heaven."

During the service, which took place at a Baptist church in Atlanta, Smith said, "He was a true friend ... I just wanna say I love you man ... and I'm gonna miss you dearly."

He added, "My life ... it ain't ever gonna be the same, but I just hope our legacy for hip-hop is never forgotten. I'm gonna do my part to make sure Chris' legacy will live on."

The funeral was filled with Chris Kelly's famous friends -- including R&B singer Keke Wyatt and the members of Xscape, all of whom performed songs.

Jermaine Dupri and rapper Da Brat were also present. Da Brat was wearing her pants backwards as a tribute to the dead rapper.

As we reported, Chris was pronounced dead last Wednesday after his body was found unresponsive in his Georgia home. His mother told police he'd been doing a mixture of cocaine and heroin the night before, and had an "extensive history of drug use."

Chris -- AKA "Mac Daddy" -- was 34.