[RISCV] Handle redundant SplitF64+BuildPairF64 pairs in a DAGCombine
r343712 performed this optimisation during instruction selection. As Eli
Friedman pointed out in post-commit review, implementing this as a DAGCombine
might allow opportunities for further optimisations.
llvm-svn: 343741
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.h b/llvm/lib/Target/RISCV/RISCVISelLowering.h
index e219511..47dbc1a 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.h
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.h
@@ -58,6 +58,8 @@
// Provide custom lowering hooks for some operations.
SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
+ SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
+
// This method returns the name of a target specific DAG node.
const char *getTargetNodeName(unsigned Opcode) const override;