[PATCH] D117006: [PowerPC] Add custom lowering for SELECT_CC fp128 using xsmaxcqp

[ChenZheng via Phabricator via llvm-commits]

shchenz added inline comments.


================
Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:1345
+    if (Subtarget.hasP10Vector()) {
+      setOperationAction(ISD::SELECT_CC, MVT::f128, Custom);
+    }
----------------
tingwang wrote:
> qiucf wrote:
> > We already have a `setOperationAction(ISD::SELECT_CC, MVT::f128, Custom);` under `Subtarget.hasVSX()`, so don't need this.
> That setOperationAction is located under the else part of Subtarget.hasP9Vector(), since P9Vector is part of P9InheritableFeatures, P10 test Subtarget.hasP9Vector() as true, so not hit that setOperationAction. Since this is supported by P10, and do not see Subtarget.hasP10Vector() predicate in this file, so added one under the Subtarget.hasAltivec() big block.
What if we set `Custom` for `SELECT_CC` for all targets `hasVSX()`? I don't see a reason why we can not set ` setOperationAction(ISD::SELECT_CC, MVT::f128, Custom);` on Power9. If so, we can just set `SELECT_CC` for type `f128` under `hasVSX()` instead of setting it two times for P10 and hasVSX()?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D117006/new/

https://reviews.llvm.org/D117006