[PATCH] D130146: [RISCV] Add isel pattern for (mul (and X, 0xffffffff), 3<<C) with Zba.

[Craig Topper via Phabricator via llvm-commits]

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We can use slli.uw by C followed by sh1add. Similar can be done
for multiples of 5 and 9. We need to make sure that C is less than
32 to stay in bounds of the 5-bit immediate for slli.uw.

We have existing patterns for (mul X, 3<<C) that use sh1add
followed by slli. That order doesn't allow the and to be folded.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D130146

Files:
  llvm/lib/Target/RISCV/RISCVInstrInfoZb.td
  llvm/test/CodeGen/RISCV/rv64zba.ll

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