diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index f49d12748f3d4..b9ffb8a8318fb 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -6122,6 +6122,7 @@ bool CodeGenPrepare::optimizePhiType(
   SmallVector<Instruction *, 4> Worklist;
   Worklist.push_back(cast<Instruction>(I));
   SmallPtrSet<PHINode *, 4> PhiNodes;
+  SmallPtrSet<ConstantData *, 4> Constants;
   PhiNodes.insert(I);
   Visited.insert(I);
   SmallPtrSet<Instruction *, 4> Defs;
@@ -6164,9 +6165,10 @@ bool CodeGenPrepare::optimizePhiType(
             AnyAnchored |= !isa<LoadInst>(OpBC->getOperand(0)) &&
                            !isa<ExtractElementInst>(OpBC->getOperand(0));
           }
-        } else if (!isa<UndefValue>(V)) {
+        } else if (auto *OpC = dyn_cast<ConstantData>(V))
+          Constants.insert(OpC);
+        else
           return false;
-        }
       }
     }
 
@@ -6208,7 +6210,8 @@ bool CodeGenPrepare::optimizePhiType(
   // Create all the new phi nodes of the new type, and bitcast any loads to the
   // correct type.
   ValueToValueMap ValMap;
-  ValMap[UndefValue::get(PhiTy)] = UndefValue::get(ConvertTy);
+  for (ConstantData *C : Constants)
+    ValMap[C] = ConstantExpr::getCast(Instruction::BitCast, C, ConvertTy);
   for (Instruction *D : Defs) {
     if (isa<BitCastInst>(D)) {
       ValMap[D] = D->getOperand(0);
diff --git a/llvm/test/CodeGen/AArch64/convertphitype.ll b/llvm/test/CodeGen/AArch64/convertphitype.ll
index f6bfb69e510bb..22d130d4000a1 100644
--- a/llvm/test/CodeGen/AArch64/convertphitype.ll
+++ b/llvm/test/CodeGen/AArch64/convertphitype.ll
@@ -881,11 +881,11 @@ define float @convphi2_zero(i32 *%s, i32 *%d, i32 %n) {
 ; CHECK-NEXT:    br i1 [[CMP15]], label [[THEN:%.*]], label [[END:%.*]]
 ; CHECK:       then:
 ; CHECK-NEXT:    [[LS:%.*]] = load i32, i32* [[S:%.*]], align 4
+; CHECK-NEXT:    [[LS_BC:%.*]] = bitcast i32 [[LS]] to float
 ; CHECK-NEXT:    br label [[END]]
 ; CHECK:       end:
-; CHECK-NEXT:    [[PHI:%.*]] = phi i32 [ [[LS]], [[THEN]] ], [ 0, [[ENTRY:%.*]] ]
-; CHECK-NEXT:    [[B:%.*]] = bitcast i32 [[PHI]] to float
-; CHECK-NEXT:    ret float [[B]]
+; CHECK-NEXT:    [[PHI_TC:%.*]] = phi float [ [[LS_BC]], [[THEN]] ], [ 0.000000e+00, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    ret float [[PHI_TC]]
 ;
 entry:
   %cmp15 = icmp sgt i32 %n, 0
@@ -908,11 +908,11 @@ define i32 @convphi2f_zero(float *%s, float *%d, i32 %n) {
 ; CHECK-NEXT:    br i1 [[CMP15]], label [[THEN:%.*]], label [[END:%.*]]
 ; CHECK:       then:
 ; CHECK-NEXT:    [[LS:%.*]] = load float, float* [[S:%.*]], align 4
+; CHECK-NEXT:    [[LS_BC:%.*]] = bitcast float [[LS]] to i32
 ; CHECK-NEXT:    br label [[END]]
 ; CHECK:       end:
-; CHECK-NEXT:    [[PHI:%.*]] = phi float [ [[LS]], [[THEN]] ], [ 0.000000e+00, [[ENTRY:%.*]] ]
-; CHECK-NEXT:    [[B:%.*]] = bitcast float [[PHI]] to i32
-; CHECK-NEXT:    ret i32 [[B]]
+; CHECK-NEXT:    [[PHI_TC:%.*]] = phi i32 [ [[LS_BC]], [[THEN]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    ret i32 [[PHI_TC]]
 ;
 entry:
   %cmp15 = icmp sgt i32 %n, 0
@@ -935,11 +935,11 @@ define float @convphi2_ten(i32 *%s, i32 *%d, i32 %n) {
 ; CHECK-NEXT:    br i1 [[CMP15]], label [[THEN:%.*]], label [[END:%.*]]
 ; CHECK:       then:
 ; CHECK-NEXT:    [[LS:%.*]] = load i32, i32* [[S:%.*]], align 4
+; CHECK-NEXT:    [[LS_BC:%.*]] = bitcast i32 [[LS]] to float
 ; CHECK-NEXT:    br label [[END]]
 ; CHECK:       end:
-; CHECK-NEXT:    [[PHI:%.*]] = phi i32 [ [[LS]], [[THEN]] ], [ 10, [[ENTRY:%.*]] ]
-; CHECK-NEXT:    [[B:%.*]] = bitcast i32 [[PHI]] to float
-; CHECK-NEXT:    ret float [[B]]
+; CHECK-NEXT:    [[PHI_TC:%.*]] = phi float [ [[LS_BC]], [[THEN]] ], [ 0x36D4000000000000, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    ret float [[PHI_TC]]
 ;
 entry:
   %cmp15 = icmp sgt i32 %n, 0
@@ -962,11 +962,11 @@ define i32 @convphi2f_ten(float *%s, float *%d, i32 %n) {
 ; CHECK-NEXT:    br i1 [[CMP15]], label [[THEN:%.*]], label [[END:%.*]]
 ; CHECK:       then:
 ; CHECK-NEXT:    [[LS:%.*]] = load float, float* [[S:%.*]], align 4
+; CHECK-NEXT:    [[LS_BC:%.*]] = bitcast float [[LS]] to i32
 ; CHECK-NEXT:    br label [[END]]
 ; CHECK:       end:
-; CHECK-NEXT:    [[PHI:%.*]] = phi float [ [[LS]], [[THEN]] ], [ 1.000000e+01, [[ENTRY:%.*]] ]
-; CHECK-NEXT:    [[B:%.*]] = bitcast float [[PHI]] to i32
-; CHECK-NEXT:    ret i32 [[B]]
+; CHECK-NEXT:    [[PHI_TC:%.*]] = phi i32 [ [[LS_BC]], [[THEN]] ], [ 1092616192, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    ret i32 [[PHI_TC]]
 ;
 entry:
   %cmp15 = icmp sgt i32 %n, 0