[PATCH] D37896: [DAGCombine] Resolving PR34474 by transforming mul(x, 2^c +/- 1) -> sub/add(shl(x, c) x) for any type including vector types

[Michael Haidl via Phabricator via llvm-commits]

pacxx planned changes to this revision.
pacxx marked an inline comment as done.
pacxx added a comment.

I will reevaluate enabling the patch for scalar types. At a first look with current llvm trunk the regression seemed to be gone and was possible not related to this patch.

When signs of the multiplier mismatch AllPow2 is not incremented and the test if all vector lanes match fails. Nothing will happen.


https://reviews.llvm.org/D37896