!fixup add missing ternary VPInstruction matcher, update test.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h

@@ -216,6 +216,16 @@ using BinaryVPInstruction_match =
     BinaryRecipe_match<Op0_t, Op1_t, Opcode, /*Commutative*/ false,
                        VPInstruction>;
 
+template <typename Op0_t, typename Op1_t, typename Op2_t, unsigned Opcode,
+          bool Commutative, typename... RecipeTys>
+using TernaryRecipe_match = Recipe_match<std::tuple<Op0_t, Op1_t, Op2_t>,
+                                         Opcode, Commutative, RecipeTys...>;
+
+template <typename Op0_t, typename Op1_t, typename Op2_t, unsigned Opcode>
+using TernaryVPInstruction_match =
+    TernaryRecipe_match<Op0_t, Op1_t, Op2_t, Opcode, /*Commutative*/ false,
+                        VPInstruction>;
+
 template <typename Op0_t, typename Op1_t, unsigned Opcode,
           bool Commutative = false>
 using AllBinaryRecipe_match =
@@ -234,6 +244,13 @@ m_VPInstruction(const Op0_t &Op0, const Op1_t &Op1) {
   return BinaryVPInstruction_match<Op0_t, Op1_t, Opcode>(Op0, Op1);
 }
 
+template <unsigned Opcode, typename Op0_t, typename Op1_t, typename Op2_t>
+inline TernaryVPInstruction_match<Op0_t, Op1_t, Op2_t, Opcode>
+m_VPInstruction(const Op0_t &Op0, const Op1_t &Op1, const Op2_t &Op2) {
+  return TernaryVPInstruction_match<Op0_t, Op1_t, Op2_t, Opcode>(
+      {Op0, Op1, Op2});
+}
+
 template <typename Op0_t>
 inline UnaryVPInstruction_match<Op0_t, VPInstruction::Not>
 m_Not(const Op0_t &Op0) {

llvm/test/Transforms/LoopVectorize/vplan-printing-reductions.ll

@@ -234,7 +234,7 @@ define i64 @find_last_iv(ptr %a, i64 %n, i64 %start) {
 ; CHECK-NEXT: Successor(s): middle.block
 ; CHECK-EMPTY:
 ; CHECK-NEXT: middle.block:
-; CHECK-NEXT:   EMIT vp<[[RDX_RES:%.+]]> = compute-find-last-iv-result ir<%rdx>, ir<%cond>
+; CHECK-NEXT:   EMIT vp<[[RDX_RES:%.+]]> = compute-find-last-iv-result ir<%rdx>, ir<%start>, ir<%cond>
 ; CHECK-NEXT:   EMIT vp<[[EXT:%.+]]> = extract-from-end vp<[[RDX_RES]]>, ir<1>
 ; CHECK-NEXT:   EMIT vp<%cmp.n> = icmp eq ir<%n>, vp<{{.+}}>
 ; CHECK-NEXT:   EMIT branch-on-cond vp<%cmp.n>