!Fixup Add getUniqueIndex

llvm/lib/Target/AIE/AIECombinerHelper.cpp

@@ -1832,6 +1832,27 @@ bool llvm::matchShuffleToVSel(
   return true;
 }
 
+/// This function returns the unique index in the shuffle mask \p Mask if the
+/// unique index exists.
+static std::optional<int> getUniqueIndex(ArrayRef<int> Mask) {
+  int UniqOpIdx = -1;
+  for (unsigned I = 0; I < Mask.size(); I++) {
+    int Idx = Mask[I];
+    if (Idx < 0)
+      continue;
+
+    if (UniqOpIdx < 0) {
+      UniqOpIdx = Idx;
+      continue;
+    }
+
+    if (UniqOpIdx != Idx) {
+      return std::nullopt;
+    }
+  }
+  return UniqOpIdx;
+}
+
 /// \returns true if it is possible to combine the shuffle vector with a mask
 /// that extracts the only element from the first source vector and broadcasts
 /// it. E.g.:
@@ -1846,31 +1867,19 @@ bool llvm::matchShuffleToExtractBroadcast(MachineInstr &MI,
                                           BuildFnTy &MatchInfo) {
   assert(MI.getOpcode() == TargetOpcode::G_SHUFFLE_VECTOR);
   ArrayRef<int> Mask = MI.getOperand(3).getShuffleMask();
-  const unsigned NumElems = Mask.size();
 
-  int UniqOpIdx = -1;
-  for (unsigned I = 0; I < NumElems; I++) {
-    int Idx = Mask[I];
-    if (Idx < 0)
-      continue;
-
-    if (UniqOpIdx < 0) {
-      UniqOpIdx = Idx;
-      continue;
-    }
+  std::optional<int> UniqOpIdx = getUniqueIndex(Mask);
+  if (!UniqOpIdx)
+    return false;
 
-    if (UniqOpIdx != Idx) {
-      return false;
-    }
-  }
   assert(UniqOpIdx >= 0 && "Couldn't find a unique operand to extract!");
 
   const unsigned ExtractOpc = TII.getGenericExtractVectorEltOpcode(true);
 
   MatchInfo = [=, &MI, &MRI](MachineIRBuilder &B) {
     const Register DstReg = MI.getOperand(0).getReg();
     const Register SrcVecReg = MI.getOperand(1).getReg();
-    auto Cst = B.buildConstant(LLT::scalar(32), UniqOpIdx);
+    auto Cst = B.buildConstant(LLT::scalar(32), UniqOpIdx.value());
     auto Extr = B.buildInstr(ExtractOpc, {LLT::scalar(32)}, {SrcVecReg, Cst});
     buildBroadcastVector(B, MRI, Extr.getReg(0), DstReg);
   };