[CodeGenPrepare] Replace `undef` use with `poison` [NFC] (#123111)

When generating a constant vector, if `UseSplat` is false, the indices
different from the index of the extract can be filled with `poison`
instead of `undef`.

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index a3392b7..7106e53 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -7983,8 +7983,8 @@ class VectorPromoteHelper {
   /// \p UseSplat defines whether or not \p Val should be replicated
   /// across the whole vector.
   /// In other words, if UseSplat == true, we generate <Val, Val, ..., Val>,
-  /// otherwise we generate a vector with as many undef as possible:
-  /// <undef, ..., undef, Val, undef, ..., undef> where \p Val is only
+  /// otherwise we generate a vector with as many poison as possible:
+  /// <poison, ..., poison, Val, poison, ..., poison> where \p Val is only
   /// used at the index of the extract.
   Value *getConstantVector(Constant *Val, bool UseSplat) const {
     unsigned ExtractIdx = std::numeric_limits<unsigned>::max();
@@ -8004,12 +8004,12 @@ class VectorPromoteHelper {
 
     if (!EC.isScalable()) {
       SmallVector<Constant *, 4> ConstVec;
-      UndefValue *UndefVal = UndefValue::get(Val->getType());
+      PoisonValue *PoisonVal = PoisonValue::get(Val->getType());
       for (unsigned Idx = 0; Idx != EC.getKnownMinValue(); ++Idx) {
         if (Idx == ExtractIdx)
           ConstVec.push_back(Val);
         else
-          ConstVec.push_back(UndefVal);
+          ConstVec.push_back(PoisonVal);
       }
       return ConstantVector::get(ConstVec);
     } else