Simon Pilgrim aef0e77c76
[DAG] visitAND - Fold (and (srl X, C), 1) -> (srl X, BW-1) for signbit extraction (#114992)
If we're masking the LSB of a SRL node result and that is shifting down an extended sign bit, see if we can change the SRL to shift down the MSB directly.

These patterns can occur during legalisation when we've sign extended to a wider type but the SRL is still shifting from the subreg.

Alternative to #114967

Fixes the remaining regression in #112588
2024-11-05 14:42:15 +00:00
..
2023-06-14 22:27:15 +00:00