[PATCH] D90173: [PowerPC] Exploit splat instruction xxsplti32dx in Power10

[Albion Fung via Phabricator via cfe-commits]

Conanap added a comment.

Replied to a comment



================
Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:9213
+
+      if (bot) {
+        SplatNode = DAG.getNode(
----------------
NeHuang wrote:
> I do not quite understand the `if` and `else` logic here, current logic seems we can overwrite `SplatNode` after we execute `SplatNode = DAG.getTargetConstant(0, dl, MVT::v2i64);` 
> Is that as expected? 
Thanks for bringing this up. `SplatNode` is reused in `if (Lo)` and `if (Hi)`; it just saves a variable and a ternary statement (`if (Hi)` will also have to check if `Lo` created a `SDNode` before deciding between `SplatNode` or the `SDNode` created by `Lo`), but can understandably be confusing. I could separate them in to different variables and if statements to make it easier to understand if that's preferred. 


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D90173/new/

https://reviews.llvm.org/D90173