diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -22,6 +22,7 @@
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/InstVisitor.h"
 #include "llvm/IR/PatternMatch.h"
+#include "llvm/IR/Value.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/KnownBits.h"
 #include "llvm/Transforms/InstCombine/InstCombineWorklist.h"
@@ -623,6 +624,7 @@
   Instruction *foldPHIArgGEPIntoPHI(PHINode &PN);
   Instruction *foldPHIArgLoadIntoPHI(PHINode &PN);
   Instruction *foldPHIArgZextsIntoPHI(PHINode &PN);
+  Instruction *foldPHIArgIntToPtrToPHI(PHINode &PN);
 
   /// If an integer typed PHI has only one use which is an IntToPtr operation,
   /// replace the PHI with an existing pointer typed PHI if it exists. Otherwise
diff --git a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
@@ -299,6 +299,29 @@
                                           IntToPtr->getOperand(0)->getType());
 }
 
+// Remove RoundTrip IntToPtr/PtrToInt Cast on PHI-Operand and
+// fold Phi-operand to bitcast.
+Instruction *InstCombinerImpl::foldPHIArgIntToPtrToPHI(PHINode &PN) {
+  // convert ptr2int ( phi[ int2ptr(ptr2int(x))] ) --> ptr2int ( phi [ x ] )
+  // Make sure all uses of phi are ptr2int.
+  if (!all_of(PN.users(), [](User *U) { return isa<PtrToIntInst>(U); }))
+    return nullptr;
+
+  // Iterating over all operands to check presence of target pointers for
+  // optimization.
+  bool OperandWithRoundTripCast = false;
+  for (unsigned OpNum = 0; OpNum != PN.getNumIncomingValues(); ++OpNum) {
+    if (auto *NewOp =
+            simplifyIntToPtrRoundTripCast(PN.getIncomingValue(OpNum))) {
+      PN.setIncomingValue(OpNum, NewOp);
+      OperandWithRoundTripCast = true;
+    }
+  }
+  if (!OperandWithRoundTripCast)
+    return nullptr;
+  return &PN;
+}
+
 /// If we have something like phi [insertvalue(a,b,0), insertvalue(c,d,0)],
 /// turn this into a phi[a,c] and phi[b,d] and a single insertvalue.
 Instruction *
@@ -1306,6 +1329,9 @@
   if (Instruction *Result = foldPHIArgZextsIntoPHI(PN))
     return Result;
 
+  if (Instruction *Result = foldPHIArgIntToPtrToPHI(PN))
+    return Result;
+
   // If all PHI operands are the same operation, pull them through the PHI,
   // reducing code size.
   if (isa<Instruction>(PN.getIncomingValue(0)) &&
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
@@ -359,7 +359,8 @@
             PtrToInt->getSrcTy()->getPointerAddressSpace() &&
         DL.getPointerTypeSizeInBits(PtrToInt->getSrcTy()) ==
             DL.getTypeSizeInBits(PtrToInt->getDestTy())) {
-      return Builder.CreateBitCast(PtrToInt->getOperand(0), CastTy);
+      return CastInst::CreateBitOrPointerCast(PtrToInt->getOperand(0), CastTy,
+                                              "", PtrToInt);
     }
   }
   return nullptr;
diff --git a/llvm/test/Transforms/InstCombine/phi-int2ptr-fold.ll b/llvm/test/Transforms/InstCombine/phi-int2ptr-fold.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/phi-int2ptr-fold.ll
@@ -0,0 +1,175 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -instcombine -S -disable-i2p-p2i-opt < %s | FileCheck %s
+
+target datalayout = "e-p:64:64-p1:16:16-p2:32:32:32-p3:64:64:64"
+target triple = "x86_64-unknown-linux-gnu"
+
+; convert ptrtoint [ phi[ inttoptr (ptrtoint (x) ) ] ---> ptrtoint (phi[x])
+
+define i64 @func(i32** %X, i32** %Y, i1 %cond) {
+; CHECK-LABEL: @func(
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[BB2:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       bb2:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[PHI_IN_IN:%.*]] = phi i32** [ [[X:%.*]], [[BB1]] ], [ [[Y:%.*]], [[BB2]] ]
+; CHECK-NEXT:    [[PHI_IN:%.*]] = ptrtoint i32** [[PHI_IN_IN]] to i64
+; CHECK-NEXT:    ret i64 [[PHI_IN]]
+;
+  br i1 %cond, label %bb1, label %bb2
+
+bb1:
+  %X.i = ptrtoint i32** %X to i64
+  %X.p = inttoptr i64 %X.i to i32*
+  br label %exit
+
+bb2:
+  %Y.i = ptrtoint i32** %Y to i64
+  %Y.p = inttoptr i64 %Y.i to i32*
+  br label %exit
+
+exit:
+  %phi = phi i32* [%X.p, %bb1], [%Y.p, %bb2]
+  %X.p.i = ptrtoint i32* %phi to i64
+  ret i64 %X.p.i
+}
+
+define i64 @func_single_operand(i32** %X, i32** %Y, i1 %cond) {
+; CHECK-LABEL: @func_single_operand(
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[EXIT:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[PHI_IN:%.*]] = phi i32** [ [[X:%.*]], [[BB1]] ], [ [[Y:%.*]], [[TMP0:%.*]] ]
+; CHECK-NEXT:    [[X_P_I:%.*]] = ptrtoint i32** [[PHI_IN]] to i64
+; CHECK-NEXT:    ret i64 [[X_P_I]]
+;
+  %Y.p = bitcast i32** %Y to i32*
+  br i1 %cond, label %bb1, label %exit
+
+bb1:
+  %X.i = ptrtoint i32** %X to i64
+  %X.p = inttoptr i64 %X.i to i32*
+  br label %exit
+
+exit:
+  %phi = phi i32* [%X.p, %bb1], [%Y.p, %0]
+  %X.p.i = ptrtoint i32* %phi to i64
+  ret i64 %X.p.i
+}
+
+define i64 @func_pointer_different_types(i16** %X, i32** %Y, i1 %cond) {
+; CHECK-LABEL: @func_pointer_different_types(
+; CHECK-NEXT:    [[Y_P:%.*]] = bitcast i32** [[Y:%.*]] to i32*
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[EXIT:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast i16** [[X:%.*]] to i32*
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[PHI:%.*]] = phi i32* [ [[TMP1]], [[BB1]] ], [ [[Y_P]], [[TMP0:%.*]] ]
+; CHECK-NEXT:    [[X_P_I:%.*]] = ptrtoint i32* [[PHI]] to i64
+; CHECK-NEXT:    ret i64 [[X_P_I]]
+;
+  %Y.p = bitcast i32** %Y to i32*
+  br i1 %cond, label %bb1, label %exit
+
+bb1:
+  %X.i = ptrtoint i16** %X to i64
+  %X.p = inttoptr i64 %X.i to i32*
+  br label %exit
+
+exit:
+  %phi = phi i32* [%X.p, %bb1], [%Y.p, %0]
+  %X.p.i = ptrtoint i32* %phi to i64
+  ret i64 %X.p.i
+}
+
+; Negative test - Wrong Integer type
+
+define i64 @func_integer_type_too_small(i32** %X, i32** %Y, i1 %cond) {
+; CHECK-LABEL: @func_integer_type_too_small(
+; CHECK-NEXT:    [[Y_P:%.*]] = bitcast i32** [[Y:%.*]] to i32*
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[EXIT:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint i32** [[X:%.*]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP1]], 4294967295
+; CHECK-NEXT:    [[X_P:%.*]] = inttoptr i64 [[TMP2]] to i32*
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[PHI:%.*]] = phi i32* [ [[X_P]], [[BB1]] ], [ [[Y_P]], [[TMP0:%.*]] ]
+; CHECK-NEXT:    [[X_P_I:%.*]] = ptrtoint i32* [[PHI]] to i64
+; CHECK-NEXT:    ret i64 [[X_P_I]]
+;
+  %Y.p = bitcast i32** %Y to i32*
+  br i1 %cond, label %bb1, label %exit
+
+bb1:
+  %X.i = ptrtoint i32** %X to i32
+  %X.p = inttoptr i32 %X.i to i32*
+  br label %exit
+
+exit:
+  %phi = phi i32* [%X.p, %bb1], [%Y.p, %0]
+  %X.p.i = ptrtoint i32* %phi to i64
+  ret i64 %X.p.i
+}
+
+; Negative test - phi not used in ptrtoint
+
+define i32* @func_phi_not_use_in_ptr2int(i32** %X, i32** %Y, i1 %cond) {
+; CHECK-LABEL: @func_phi_not_use_in_ptr2int(
+; CHECK-NEXT:    [[Y_P:%.*]] = bitcast i32** [[Y:%.*]] to i32*
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[EXIT:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint i32** [[X:%.*]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP1]], 4294967295
+; CHECK-NEXT:    [[X_P:%.*]] = inttoptr i64 [[TMP2]] to i32*
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[PHI:%.*]] = phi i32* [ [[X_P]], [[BB1]] ], [ [[Y_P]], [[TMP0:%.*]] ]
+; CHECK-NEXT:    ret i32* [[PHI]]
+;
+  %Y.p = bitcast i32** %Y to i32*
+  br i1 %cond, label %bb1, label %exit
+
+bb1:
+  %X.i = ptrtoint i32** %X to i32
+  %X.p = inttoptr i32 %X.i to i32*
+  br label %exit
+
+exit:
+  %phi = phi i32* [%X.p, %bb1], [%Y.p, %0]
+  ret i32* %phi
+}
+
+; Negative test - Pointers in different address spaces
+
+define i64 @func_ptr_different_addrspace(i16 addrspace(2)* %X, i32** %Y, i1 %cond) {
+; CHECK-LABEL: @func_ptr_different_addrspace(
+; CHECK-NEXT:    [[Y_P:%.*]] = bitcast i32** [[Y:%.*]] to i32*
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[BB1:%.*]], label [[EXIT:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint i16 addrspace(2)* [[X:%.*]] to i32
+; CHECK-NEXT:    [[X_I:%.*]] = zext i32 [[TMP1]] to i64
+; CHECK-NEXT:    [[X_P:%.*]] = inttoptr i64 [[X_I]] to i32*
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[PHI:%.*]] = phi i32* [ [[X_P]], [[BB1]] ], [ [[Y_P]], [[TMP0:%.*]] ]
+; CHECK-NEXT:    [[X_P_I:%.*]] = ptrtoint i32* [[PHI]] to i64
+; CHECK-NEXT:    ret i64 [[X_P_I]]
+;
+  %Y.p = bitcast i32** %Y to i32*
+  br i1 %cond, label %bb1, label %exit
+
+bb1:
+  %X.i = ptrtoint i16 addrspace(2)* %X to i64
+  %X.p = inttoptr i64 %X.i to i32*
+  br label %exit
+
+exit:
+  %phi = phi i32* [%X.p, %bb1], [%Y.p, %0]
+  %X.p.i = ptrtoint i32* %phi to i64
+  ret i64 %X.p.i
+}