[PATCH] D108916: [RISCV] Optimize (add (shl x, c0), (shl y, c1)) with SH*ADD

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:5784
+  // Check c0 and c1.
+  auto *NC0 = dyn_cast<ConstantSDNode>(N0->getOperand(1));
+  auto *NC1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
----------------
NC0 -> N0C as I think that's the style DAGCombiner.cpp uses.


================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:5917
+  //      (SLLI (SH*ADD x, y), c0), if c1-c0 equals to [1|2|3].
+  SDValue N0 = transformAddShlImm(N, DAG, Subtarget);
+  if (N0)
----------------
Don't N0 for the name here. N0 usually means N->getOperand(0)

Use

```
if (SDValue V = transformAddShlImm(N, DAG, Subtarget))
  return V;
```

V is pretty generic and putting it in the if limits the scope.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D108916/new/

https://reviews.llvm.org/D108916