Does the Olympics count as an extra tournament on the slot?
Right now he's got a zero for one of the ATP tour 1000, and two zeros, for his last two countable tournaments, one 500 and one 250.
only one zero for his optional results, which would be gone after Tokyo if he played one more ATP500 tournament or Monte-Carlo, but I really don't think he will, then this zeropointer will stay in his ranking.
Davis cup 25 points will replace Monte-Carlo after Monte-Carlo is gone, then if he plays Halle (which he's supposed to do), his points in Halle will replace his Davis cup 25 points.
Then the Olympics will replace the worst of Halle and Doha 90 points.
Honestly if he does well in RG, I would prefer him to skip Halle (after all Nadal and Djokovic will be there then the tournament won't miss Roger too much) because last year he was not fit enough for the end of Wimbledon imo. And Halle is nearly useless as far as the rankings are concerned.