feat: reduce computations in backprop of lfilter
#4796
| Job | Run time |
|---|---|
| 6s | |
| 5m 13s | |
| 9m 20s | |
| 9m 8s | |
| 8m 26s | |
| 15m 25s | |
| 17m 8s | |
| 7m 35s | |
| 40s | |
| 43s | |
| 34s | |
| 30s | |
| 34s | |
| 37s | |
| 34s | |
| 1h 16m 33s |
lfilter
#4796
| Job | Run time |
|---|---|
| 6s | |
| 5m 13s | |
| 9m 20s | |
| 9m 8s | |
| 8m 26s | |
| 15m 25s | |
| 17m 8s | |
| 7m 35s | |
| 40s | |
| 43s | |
| 34s | |
| 30s | |
| 34s | |
| 37s | |
| 34s | |
| 1h 16m 33s |