tree c558834090ba95b750953a1ddbc9562969cc899e
parent dca02a66ee56e0e1ec46528087ebeb2037f3f5a9
author Craig Topper <craig.topper@sifive.com> 1616653396 -0700
committer Copybara-Service <copybara-worker@google.com> 1616712565 -0700

[RISCV] Teach targetShrinkDemandedConstant to preserve (and X, 0xffffffff).

We look for this pattern frequently in isel patterns so its a
good idea to try to preserve it.

This also let's us remove our special isel handling for srliw
and use a direct pattern match of (srl (and X, 0xffffffff), C)
since no bits will be removed from the and mask.

Differential Revision: https://reviews.llvm.org/D99042

GitOrigin-RevId: c40cea6f083a8a67ea950e058e16d37bb04e8c4b