9c0c7f0975ae3b25aca17067ec2e14a3e9192e76 - llvm-project/llvm

commit: 9c0c7f0975ae3b25aca17067ec2e14a3e9192e76
[log]
author: Craig Topper <craig.topper@sifive.com>
Wed Mar 24 23:23:16 2021 -0700
committer: Copybara-Service <copybara-worker@google.com>
Thu Mar 25 15:49:25 2021 -0700
tree: c558834090ba95b750953a1ddbc9562969cc899e
parent: dca02a66ee56e0e1ec46528087ebeb2037f3f5a9 [diff]

[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

lib/Target/RISCV/RISCVISelDAGToDAG.cpp[diff]
lib/Target/RISCV/RISCVISelDAGToDAG.h[diff]
lib/Target/RISCV/RISCVISelLowering.cpp[diff]
lib/Target/RISCV/RISCVInstrInfo.td[diff]
lib/Target/RISCV/RISCVInstrInfoB.td[diff]
test/CodeGen/RISCV/alu32.ll[diff]
test/CodeGen/RISCV/rv64zba.ll[diff]

7 files changed

tree: c558834090ba95b750953a1ddbc9562969cc899e