[llvm] [PowerPC] Forbid f128 SELECT_CC optimized into fsel (PR #71497)

[Qiu Chaofan via llvm-commits]

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@@ -8080,7 +8080,8 @@ SDValue PPCTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
   // For more information, see section F.3 of the 2.06 ISA specification.
   // With ISA 3.0
   if ((!DAG.getTarget().Options.NoInfsFPMath && !Flags.hasNoInfs()) ||
-      (!DAG.getTarget().Options.NoNaNsFPMath && !Flags.hasNoNaNs()))
+      (!DAG.getTarget().Options.NoNaNsFPMath && !Flags.hasNoNaNs()) ||
+      ResVT == MVT::f128)
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ecnelises wrote:

No. `PPCISD::FSEL` is only generated in `LowerSELECT_CC`, while `SELECT_CC ppc_fp128` is expand.

https://github.com/llvm/llvm-project/pull/71497