[PATCH] D13417: [MachineCombiner] remove "slack" from critical path cost calculation (PR25016)

[Haicheng Wu via llvm-commits]

haicheng added a comment.

I added another test case in https://llvm.org/bugs/show_bug.cgi?id=25016 which reassociates i32 mul and spill registers at last.  This test case basically calculates a0*b0*c0*d0+a1*b1*c1*d1, but reassociates it into (((b0*c0)*d0)*a0)+(((b1*c1)*d1)*a1).


http://reviews.llvm.org/D13417