Craig Topper ea87cf2acd [TargetLowering][RISCV] Don't transform (seteq/ne (sext_inreg X, VT), C1) -> (seteq/ne (zext_inreg X, VT), C1) if the sext_inreg is cheaper
RISCV has to use 2 shifts for (i64 (zext_inreg X, i32)), but we
can use addiw rd, rs1, x0 for sext_inreg. We already understood this
when type legalizing i32 seteq/ne on rv64. But this transform in
SimplifySetCC would sometimes undo it.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D95289
2021-01-25 16:37:21 -08:00
..
2020-04-08 13:44:31 -04:00
2020-12-09 11:36:51 +01:00