Hi @Artem-B, I believe that these patterns are not correct. Doing the comparison, without first ensuring that the value only uses the lower 8 bits, can lead to incorrect results. For example, when `%a := Ox100` and `%b := Ox1`, `setugt (i16 (and (trunc Int32Regs:$a), 255)), (i16 (and (trunc Int32Regs:$b), 255)))` produces a false predicate. Whereas `SETP_u32rr Int32Regs:$a, Int32Regs:$b, CmpHI` will produce a true predicate. (I'm not super familiar with the pattern syntax through, so please correct me if I'm misunderstanding something.)

When we extract v4i8 values we must truncate them to 8 bits. They are carried in i16, so for negative values we end up with the unwanted extra 8 sign bits.

is it expected that the script checks for the hardcoded variable name?

It looks like we are missing some actions for v4i8 types like from line 639 to line 658. ``` setI16x2OperationAction(ISD::ABS, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::SMIN, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::SMAX, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::UMIN, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::UMAX, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::CTPOP, MVT::v2i16, Legal, Expand); setI16x2OperationAction(ISD::CTLZ, MVT::v2i16, Legal, Expand); setI16x2OperationAction(ISD::ADD, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::SUB, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::MUL, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::SHL, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::SREM, MVT::v2i16, Legal, Custom); setI16x2OperationAction(ISD::UREM, MVT::v2i16, Legal, Custom); // Other arithmetic and logic ops are unsupported. setOperationAction({ISD::SDIV, ISD::UDIV, ISD::SRA, ISD::SRL, ISD::MULHS, ISD::MULHU, ISD::FP_TO_SINT, ISD::FP_TO_UINT, ISD::SINT_TO_FP, ISD::UINT_TO_FP}, MVT::v2i16, Expand); ```

This still needs tests.

this generates ptx like this: ``` mov.b32 %r10, {%rs2, %rs1, %rs4, %rs3}; ``` which cause ptxas to emit this error: ``` error : Arguments mismatch for instruction 'mov' ```