Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2435,9 +2435,12 @@
   Instruction *LastInduction = VecInd;
   for (unsigned Part = 0; Part < UF; ++Part) {
     VectorLoopValueMap.setVectorValue(EntryVal, Part, LastInduction);
-    recordVectorLoopValueForInductionCast(II, LastInduction, Part);
+
     if (isa<TruncInst>(EntryVal))
       addMetadata(LastInduction, EntryVal);
+    else
+      recordVectorLoopValueForInductionCast(II, LastInduction, Part);
+
     LastInduction = cast<Instruction>(addFastMathFlag(
         Builder.CreateBinOp(AddOp, LastInduction, SplatVF, "step.add")));
   }
@@ -2559,15 +2562,17 @@
 
   // If we haven't yet vectorized the induction variable, splat the scalar
   // induction variable, and build the necessary step vectors.
+  // TODO: Don't do it unless the vectorized IV is really required.
   if (!VectorizedIV) {
     Value *Broadcasted = getBroadcastInstrs(ScalarIV);
     for (unsigned Part = 0; Part < UF; ++Part) {
       Value *EntryPart =
           getStepVector(Broadcasted, VF * Part, Step, ID.getInductionOpcode());
       VectorLoopValueMap.setVectorValue(EntryVal, Part, EntryPart);
-      recordVectorLoopValueForInductionCast(ID, EntryPart, Part);
       if (Trunc)
         addMetadata(EntryPart, Trunc);
+      else
+        recordVectorLoopValueForInductionCast(ID, EntryPart, Part);
     }
   }
 
Index: llvm/test/Transforms/LoopVectorize/pr35773.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopVectorize/pr35773.ll
@@ -0,0 +1,53 @@
+; RUN: opt -S -loop-vectorize -force-vector-width=4 -force-vector-interleave=1 < %s 2>&1 | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+@a = common local_unnamed_addr global i32 0, align 4
+@b = common local_unnamed_addr global i8 0, align 1
+
+; Function Attrs: norecurse nounwind uwtable
+define void @doit1() local_unnamed_addr{
+entry:
+  br label %for.body
+
+for.body:
+  %main.iv = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+
+  %i8.iv = phi i8 [ 0, %entry ], [ %i8.add, %for.body ]
+  %i32.iv = phi i32 [ 0, %entry ], [ %i32.add, %for.body ]
+
+  %trunc.to.be.converted.to.new.iv = trunc i32 %i32.iv to i8
+  %i8.add = add i8 %i8.iv, %trunc.to.be.converted.to.new.iv
+
+  %noop.conv.under.pse = and i32 %i32.iv, 255
+  %i32.add = add nuw nsw i32 %noop.conv.under.pse, 9
+
+  %inc = add i32 %main.iv, 1
+  %tobool = icmp eq i32 %inc, 16
+  br i1 %tobool, label %for.cond.for.end_crit_edge, label %for.body
+
+; CHECK-LABEL: @doit1(
+; CHECK:       vector.body:
+; CHECK-NEXT:    [[MAIN_IV:%.*]] = phi i32 [ 0, [[VECTOR_PH:%.*]] ], [ [[MAIN_IV_NEXT:%.*]], [[VECTOR_BODY:%.*]] ]
+; CHECK-NEXT:    [[I8_IV:%.*]] = phi <4 x i8> [ zeroinitializer, [[VECTOR_PH]] ], [ [[I8_IV_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[I32_IV:%.*]] = phi <4 x i32> [ <i32 0, i32 9, i32 18, i32 27>, [[VECTOR_PH]] ], [ [[I32_IV_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[IV_FROM_TRUNC:%.*]] = phi <4 x i8> [ <i8 0, i8 9, i8 18, i8 27>, [[VECTOR_PH]] ], [ [[IV_FROM_TRUNC_NEXT:%.*]], [[VECTOR_BODY]] ]
+
+; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i32> undef, i32 [[MAIN_IV]], i32 0
+; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[INDUCTION:%.*]] = add <4 x i32> [[BROADCAST_SPLAT]], <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[TMP7:%.*]] = add i32 [[MAIN_IV]], 0
+
+; CHECK-NEXT:    [[I8_IV_NEXT]] = add <4 x i8> [[I8_IV]], [[IV_FROM_TRUNC]]
+
+; CHECK-NEXT:    [[MAIN_IV_NEXT]] = add i32 [[MAIN_IV]], 4
+; CHECK-NEXT:    [[I32_IV_NEXT]] = add <4 x i32> [[I32_IV]], <i32 36, i32 36, i32 36, i32 36>
+; CHECK-NEXT:    [[IV_FROM_TRUNC_NEXT]] = add <4 x i8> [[IV_FROM_TRUNC]], <i8 36, i8 36, i8 36, i8 36>
+; CHECK-NEXT:    [[TMP9:%.*]] = icmp eq i32 [[MAIN_IV_NEXT]], 16
+; CHECK-NEXT:    br i1 [[TMP9]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop !0
+
+for.cond.for.end_crit_edge:
+  store i8 %i8.add, i8* @b, align 1
+  br label %for.end
+
+for.end:
+  ret void
+}