[clang] [llvm] [PowerPC] Add Support for BCDSHIFT, BCDSHIFTR, BCDTRUNC, BCDUTRUNC, and BCDUSHIFT instruction support (PR #154715)

[Kai Nacke via llvm-commits]

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@@ -11151,6 +11161,20 @@ SDValue PPCTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
 
   SDLoc dl(Op);
 
+  // Lowers BCD intrinsics with rounding operand
+  auto MapNodeWithSplatVector = [&](unsigned Opcode) -> SDValue {
+    SDValue SplatVal =
+        DAG.getNode(ISD::SPLAT_VECTOR, dl, MVT::v4i32, Op.getOperand(2));
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redstar wrote:

You cannot generate a SPLAT_VECTOR with a pattern. You either have to create patterns for all the PPC opcodes SPLAT_VECTOR maps to, or introducing a pseudo instruction which is resolved later. Both seems more work than the simple function here. 

https://github.com/llvm/llvm-project/pull/154715