[PATCH] D82660: [RISCV] Optimize multiplication by specific immediates

[Sam Elliott via Phabricator via llvm-commits]

lenary added a comment.

One issue, then I'm happy.



================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:2990
+    if (auto *ConstNode = dyn_cast<ConstantSDNode>(C.getNode())) {
+      int64_t Imm = ConstNode->getSExtValue();
+      if (isPowerOf2_64(Imm + 1) || isPowerOf2_64(Imm - 1) ||
----------------
getSExtValue will assert if the value does not fit into 64 bits - you need to do a check before you get there.

I think this hook can be called before legalisation, so you may not get only legal types in this call.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82660/new/

https://reviews.llvm.org/D82660