diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2024,24 +2024,13 @@
     }
   }
 
-  // Handle malformed GEP of GEP in PR13621, where Src and GEP mutually use each
-  // other. This is normally not allowed, so just bail out.
-  if (llvm::any_of(GEP.users(), [&](User *U) {
-        if (Instruction *SrcI = dyn_cast<Instruction>(Src)) {
-          return U == SrcI || DT.dominates(U, SrcI);
-        }
-        return false;
-      }))
-    return nullptr;
-
   // Canonicalize swapping. Swap GEP with constant index suffix to the back if
   // it doesn't violate def-use relations or contradict with loop invariant
   // swap above. This allows more potential applications of constant-indexed GEP
   // optimizations below.
   if (shouldCanonicalizeSwap && Src->hasOneUse() &&
-      (Src->getType()->getScalarType()->isOpaquePointerTy() ||
-       Src->getPointerOperand()->getType() ==
-           GEP.getPointerOperand()->getType())) {
+      Src->getPointerOperand()->getType() ==
+          GEP.getPointerOperand()->getType()) {
     // When swapping, GEP with all constant indices are more prioritized than
     // GEP with only the last few indices (but not all) being constant because
     // it may be merged with GEP with all constant indices.
@@ -2051,9 +2040,7 @@
       bool InBounds = isMergedGEPInBounds(*Src, *cast<GEPOperator>(&GEP));
       Value *NewSrc = Builder.CreateGEP(
           GEP.getSourceElementType(), Src->getOperand(0),
-          SmallVector<Value *>(GEP.indices()), Src->getName());
-      if (GetElementPtrInst *NewGEP = dyn_cast<GetElementPtrInst>(NewSrc))
-        NewGEP->setIsInBounds(InBounds);
+          SmallVector<Value *>(GEP.indices()), Src->getName(), InBounds);
       GetElementPtrInst *NewGEP = GetElementPtrInst::Create(
           Src->getSourceElementType(), NewSrc,
           SmallVector<Value *>(Src->indices()), GEP.getName());
@@ -2100,23 +2087,11 @@
     if (!GEP.accumulateConstantOffset(DL, Offset))
       return nullptr;
 
-    APInt OffsetOld = Offset;
     // Convert the total offset back into indices.
     SmallVector<APInt> ConstIndices =
         DL.getGEPIndicesForOffset(BaseType, Offset);
-    if (!Offset.isZero() || (!IsFirstType && !ConstIndices[0].isZero())) {
-      // If both GEP are constant-indexed, and cannot be merged in either way,
-      // convert them to a GEP of i8.
-      if (Src->hasAllConstantIndices())
-        return isMergedGEPInBounds(*Src, *cast<GEPOperator>(&GEP))
-            ? GetElementPtrInst::CreateInBounds(
-                Builder.getInt8Ty(), Src->getOperand(0),
-                Builder.getInt(OffsetOld), GEP.getName())
-            : GetElementPtrInst::Create(
-                Builder.getInt8Ty(), Src->getOperand(0),
-                Builder.getInt(OffsetOld), GEP.getName());
+    if (!Offset.isZero() || (!IsFirstType && !ConstIndices[0].isZero()))
       return nullptr;
-    }
 
     SmallVector<Value *> Indices;
     append_range(Indices, drop_end(Src->indices(),
diff --git a/llvm/test/Transforms/InstCombine/gep-merge-constant-indices.ll b/llvm/test/Transforms/InstCombine/gep-merge-constant-indices.ll
--- a/llvm/test/Transforms/InstCombine/gep-merge-constant-indices.ll
+++ b/llvm/test/Transforms/InstCombine/gep-merge-constant-indices.ll
@@ -56,8 +56,9 @@
 ; result = (i8*) p + 14
 define ptr @array2(ptr %p, i64 %a) {
 ; CHECK-LABEL: @array2(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[P:%.*]], i64 14
-; CHECK-NEXT:    ret ptr [[TMP1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds [7 x i32], ptr [[P:%.*]], i64 0, i64 3
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds i8, ptr [[TMP1]], i64 2
+; CHECK-NEXT:    ret ptr [[TMP2]]
 ;
   %1 = getelementptr inbounds [7 x i32], ptr %p, i64 0, i64 3
   %2 = getelementptr inbounds i8, ptr %1, i64 2
@@ -67,8 +68,9 @@
 ; result = (i8*) p + 20
 define ptr @array3(ptr %p) {
 ; CHECK-LABEL: @array3(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[P:%.*]], i64 20
-; CHECK-NEXT:    ret ptr [[TMP1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i64, ptr [[P:%.*]], i64 2
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds [3 x i8], ptr [[TMP1]], i64 1, i64 1
+; CHECK-NEXT:    ret ptr [[TMP2]]
 ;
   %1 = getelementptr inbounds i64, ptr %p, i64 2
   %2 = getelementptr inbounds [3 x i8], ptr %1, i64 1, i64 1
@@ -78,8 +80,9 @@
 ; result = (i8*) p + 36
 define ptr @struct1(ptr %p) {
 ; CHECK-LABEL: @struct1(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[P:%.*]], i64 36
-; CHECK-NEXT:    ret ptr [[TMP1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i64, ptr [[P:%.*]], i64 3
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds [[STRUCT_C:%.*]], ptr [[TMP1]], i64 1
+; CHECK-NEXT:    ret ptr [[TMP2]]
 ;
   %1 = getelementptr inbounds i64, ptr %p, i64 3
   %2 = getelementptr inbounds %struct.C, ptr %1, i64 1
@@ -138,8 +141,9 @@
 ; result = &((struct.C*) p + 2).member1
 define ptr @structMemberAliasing(ptr %p, i64 %a) {
 ; CHECK-LABEL: @structMemberAliasing(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[P:%.*]], i64 28
-; CHECK-NEXT:    ret ptr [[TMP1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i64, ptr [[P:%.*]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds [[STRUCT_C:%.*]], ptr [[TMP1]], i64 1, i32 2
+; CHECK-NEXT:    ret ptr [[TMP2]]
 ;
   %1 = getelementptr inbounds i64, ptr %p, i64 1
   %2 = getelementptr inbounds %struct.C, ptr %1, i64 1, i32 2
@@ -150,8 +154,9 @@
 ; 8-bit aligned.
 define ptr @notDivisible(ptr %p) {
 ; CHECK-LABEL: @notDivisible(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[P:%.*]], i64 7
-; CHECK-NEXT:    ret ptr [[TMP1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i24, ptr [[P:%.*]], i64 1
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds i32, ptr [[TMP1]], i64 1
+; CHECK-NEXT:    ret ptr [[TMP2]]
 ;
   %1 = getelementptr inbounds i24, ptr %p, i64 1
   %2 = getelementptr inbounds i32, ptr %1, i64 1
diff --git a/llvm/test/Transforms/InstCombine/opaque-ptr.ll b/llvm/test/Transforms/InstCombine/opaque-ptr.ll
--- a/llvm/test/Transforms/InstCombine/opaque-ptr.ll
+++ b/llvm/test/Transforms/InstCombine/opaque-ptr.ll
@@ -211,7 +211,8 @@
 
 define ptr @geps_combinable_different_elem_type4(ptr %a) {
 ; CHECK-LABEL: @geps_combinable_different_elem_type4(
-; CHECK-NEXT:    [[A3:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 14
+; CHECK-NEXT:    [[A2:%.*]] = getelementptr { i32, i32 }, ptr [[A:%.*]], i64 0, i32 1
+; CHECK-NEXT:    [[A3:%.*]] = getelementptr i8, ptr [[A2]], i64 10
 ; CHECK-NEXT:    ret ptr [[A3]]
 ;
   %a2 = getelementptr { i32, i32 }, ptr %a, i32 0, i32 1