Improve transforms for (icmp uPred X * Z, Y * Z) -> (icmp uPred X, Y)

Several cases where missing.

1. `(icmp eq/ne X*Z, Y*Z) [if Z % 2 != 0] -> (icmp eq/ne X, Y)`
    EQ: https://alive2.llvm.org/ce/z/6_HPZ5
    NE: https://alive2.llvm.org/ce/z/c34qSU

    There was previously an implementation of this that work of `Y`
    was non-constant, but it was missing if `Y*Z` evaluated to a
    constant and/or `nsw`/`nuw` where both false. As well it only
    worked if `Z` was a constant but we can check 1s bit of
    `KnownBits` to cover more cases.

2. `(icmp eq/ne X*Z, Y*Z) [if Z != 0 and nsw(X*Y) and nsw(Y*Z)] -> (icmp eq/ne X, Y)`
    EQ: https://alive2.llvm.org/ce/z/6SdAG6
    NE: https://alive2.llvm.org/ce/z/fjsq_b

    This was previously implemented only to work if `Z` was constant,
    but we can use `isKnownNonZero` to cover more cases.

3. `(icmp uPred X*Y, Y*Z) [if Z != 0 and nuw(X*Y) and nuw(X*Y)] -> (icmp uPred X, Y)`
    EQ:  https://alive2.llvm.org/ce/z/FqWQLX
    NE:  https://alive2.llvm.org/ce/z/2gHrd2
    ULT: https://alive2.llvm.org/ce/z/MUAWgZ
    ULE: https://alive2.llvm.org/ce/z/szQQ2L
    UGT: https://alive2.llvm.org/ce/z/McVUdu
    UGE: https://alive2.llvm.org/ce/z/95uyC8

    This was previously implemented only for `eq/ne` cases. As well
    only if `Z` was constant, but again we can use `isKnownNonZero` to
    cover more cases.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D142786

0 files changed, 0 insertions, 0 deletions