[llvm] [DAG] Add generic m_TernaryOp() / m_c_TernaryOp() matchers (PR #165520)

[Simon Pilgrim via llvm-commits]

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@@ -18369,11 +18369,14 @@ template <class MatchContextClass> SDValue DAGCombiner::visitFMA(SDNode *N) {
     }
   }
 
-  // FIXME: Support splat of constant.
-  if (N0CFP && N0CFP->isExactlyValue(1.0))
-    return matcher.getNode(ISD::FADD, DL, VT, N1, N2);
-  if (N1CFP && N1CFP->isExactlyValue(1.0))
-    return matcher.getNode(ISD::FADD, DL, VT, N0, N2);
+  using namespace SDPatternMatch;
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RKSimon wrote:

unnecessary - we already have this at file scope near the top

https://github.com/llvm/llvm-project/pull/165520