[llvm] PPC: Custom lower ppcf128 is_fpclass if is_fpclass is custom (PR #105540)

[Matt Arsenault via llvm-commits]

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@@ -11479,6 +11480,12 @@ SDValue PPCTargetLowering::LowerIS_FPCLASS(SDValue Op,
   uint64_t RHSC = Op.getConstantOperandVal(1);
   SDLoc Dl(Op);
   FPClassTest Category = static_cast<FPClassTest>(RHSC);
+  if (LHS.getValueType() == MVT::ppcf128) {
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arsenm wrote:

It is still needed. PPC only custom lowers this for Subtarget.useCRBits, otherwise it still hits the default expansion 

https://github.com/llvm/llvm-project/pull/105540