Warren Beatty must already be dreading next April 15. His paycheck for "Dick Tracy" is almost surely a new Hollywood record. As the Los Angeles Herald Examiner recently reported, Beatty is said to be getting about $6.5 million to star in the Martin Scorsese-directed film -- plus another half-million to produce, plus a minimum of 20 percent of the gross (not the profits). It's enough to give a guy a real headache come tax time . . .

But maybe Paramount Pictures, which is releasing "Dick Tracy," can afford the expense. After all, it doesn't have Barry Diller on the payroll any more. Diller is the former Paramount executive who left in October to become chairman of 20th Century-Fox, where he signed a top-secret contract that was, insiders muttered, one of the largest in the industry. A week ago the details of that contract surfaced at the Securities and Exchange Commission in Washington, and it is a record deal: Diller's salary is $3 million a year; over the next five years he receives 25 percent of any increase in the value of TCF Holdings, Fox's parent company (excluding increases due to the TV series "M*A*S*H*," a proven moneymaker established long before Diller came to Fox); and he has such complete control over the entertainment side of Fox that owner Marvin Davis can't even talk to anybody about movie deals without Diller's participation.

20th Century-Fox, you might remember, canceled last year's Christmas party and all planned raises and bonuses after spending most of 1984 mired in a serious box office slump -- which the studio is now counting on Ron Howard's "Cocoon" to end . . .

Last weekend's box office totals were resolutely unspectacular, with "Police Academy II" retaining the No. 1 position even as it slipped to $5.4 million from the $8.6 million it made two weekends ago . . . "King David," meanwhile, has shown there's not much market for a period epic in which Richard Gere doesn't strip down (although he does do a free-form dance in the biblical equivalent of Jockey shorts), while Disney's "Baby" hasn't found many moviegoers excited about mechanical dinosaurs, no matter how cute. The $17 million "King David" has made less than $5 million after three weeks. "Baby," which cost $18 million, is around the $12 million mark . . . Of last weekend's newcomers, "Ladyhawke" and "Cat's Eye" both had respectable $3.5 million openings . . .

When "The Breakfast Club" director John Hughes cast Molly Ringwald as a prom queen type and Ally Sheedy as a painfully withdrawn recluse, some thought that likelier casting would have been to reverse the two young actresses' roles. Now Ringwald has a chance to play a part that sounds similar to Sheedy's "Breakfast Club" character. In "Pretty in Pink," the 17-year-old Ringwald will portray Andie Walsh, described by Paramount as "a free-thinking 'zoid' whose unconventional whim is to join the rich kids at the sacrosanct high school prom." Directing is Howie Deutch, a veteran of music videos making his feature film debut. Producing is Ringwald's old boss John Hughes, who also cast her in "Sixteen Candles" . . .

Ready for another new rating? The Motion Picture Association of America probably isn't, either, but the MPAA says it's considering a proposed "SA" rating. The proposal has been endorsed by the Caucus of Producers, Writers and Directors and by the Entertainment Industries Council. SA, which stands for Substance Abuse, would be used when a film shows alcohol or drug abuse without negative consequences . . .