Schedule tweak for more locality
Schedule tweak for more locality

cascades the sliding window pyramid collapse instead of computing them
all at (output,y). Reduces runtime from 27ms to 21ms on my machine.


Former-commit-id: a1d821fc4202e368fff0a15512423f1efab6e964
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide