[llvm] [InstCombine] Combine trunc (lshr X, BW-1) to i1 --> icmp slt X, 0 (#142593) (PR #143846)

[via llvm-commits]

mayanksolanki393 wrote:

The transformation is kicking for the following lines in the already present `llvm/test/Transforms/InstCombine/logical-select.ll` 

In `bitcast_vec_cond_commute3()` for `%s = ashr <4 x i8> %cond, <i8 7, i8 7, i8 7, i8 7>`
In `not_d_allSignBits()` for `%bitmask = ashr i32 %cond, 31`




https://github.com/llvm/llvm-project/pull/143846