Index: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -2393,6 +2393,17 @@
     if (UsePostInc)
       IVLimit = SE->getAddExpr(IVLimit, SE->getOne(IVLimit->getType()));
 
+    // If computed limit is equal to old limit then do not use SCEV expander
+    // because it can lost NUW/NSW flags and create extra instructions.
+    BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
+    if (ICmpInst *Cmp = dyn_cast<ICmpInst>(BI->getOperand(0))) {
+      Value *Limit = Cmp->getOperand(0);
+      if (!L->isLoopInvariant(Limit))
+        Limit = Cmp->getOperand(1);
+      if (SE->getSCEV(Limit) == IVLimit)
+        return Limit;
+    }
+
     // Expand the code for the iteration count.
     assert(SE->isLoopInvariant(IVLimit, L) &&
            "Computed iteration count is not loop invariant!");
@@ -2401,7 +2412,6 @@
     // SCEV expression (IVInit) for a pointer type IV value (IndVar).
     Type *LimitTy = ExitCount->getType()->isPointerTy() ?
       IndVar->getType() : ExitCount->getType();
-    BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
     return Rewriter.expandCodeFor(IVLimit, LimitTy, BI);
   }
 }
Index: llvm/test/Transforms/IndVarSimplify/add_nsw.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/IndVarSimplify/add_nsw.ll
@@ -0,0 +1,23 @@
+; RUN: opt -indvars -S %s | FileCheck %s
+
+target datalayout = "e-p:32:32-i64:64-n8:16:32"
+
+; CHECK: for.body.preheader:
+; CHECK-NOT: add
+; CHECK: for.body:
+
+define void @foo(i32 %a1, i32 %a2) {
+entry:
+  %maxval = add nuw nsw i32 %a1, %a2
+  %cmp = icmp slt i32 %maxval, 1
+  br i1 %cmp, label %for.end, label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %j.02 = phi i32 [ 0, %entry ], [ %add31, %for.body ]
+  %add31 = add nuw nsw i32 %j.02, 1
+  %cmp22 = icmp slt i32 %add31, %maxval
+  br i1 %cmp22, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body
+  ret void
+}
Index: llvm/test/Transforms/IndVarSimplify/lftr-reuse.ll
===================================================================
--- llvm/test/Transforms/IndVarSimplify/lftr-reuse.ll
+++ llvm/test/Transforms/IndVarSimplify/lftr-reuse.ll
@@ -67,11 +67,9 @@
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 0, [[SUB1]]
 ; CHECK-NEXT:    br i1 [[CMP1]], label [[OUTER_PREHEADER:%.*]], label [[EXIT:%.*]]
 ; CHECK:       outer.preheader:
-; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[ARG]], -1
 ; CHECK-NEXT:    br label [[OUTER:%.*]]
 ; CHECK:       outer:
-; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i32 [ [[TMP0]], [[OUTER_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[OUTER_INC:%.*]] ]
-; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[I_INC:%.*]], [[OUTER_INC]] ], [ 0, [[OUTER_PREHEADER]] ]
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[I_INC:%.*]], [[OUTER_INC:%.*]] ], [ 0, [[OUTER_PREHEADER]] ]
 ; CHECK-NEXT:    [[SUB2:%.*]] = sub nsw i32 [[ARG]], [[I]]
 ; CHECK-NEXT:    [[SUB3:%.*]] = sub nsw i32 [[SUB2]], 1
 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 0, [[SUB3]]
@@ -81,14 +79,13 @@
 ; CHECK:       inner:
 ; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[INNER_PH]] ], [ [[J_INC:%.*]], [[INNER]] ]
 ; CHECK-NEXT:    [[J_INC]] = add nuw nsw i32 [[J]], 1
-; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i32 [[J_INC]], [[INDVARS_IV]]
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i32 [[J_INC]], [[SUB3]]
 ; CHECK-NEXT:    br i1 [[EXITCOND]], label [[INNER]], label [[OUTER_INC_LOOPEXIT:%.*]]
 ; CHECK:       outer.inc.loopexit:
 ; CHECK-NEXT:    br label [[OUTER_INC]]
 ; CHECK:       outer.inc:
 ; CHECK-NEXT:    [[I_INC]] = add nuw nsw i32 [[I]], 1
-; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add i32 [[INDVARS_IV]], -1
-; CHECK-NEXT:    [[EXITCOND1:%.*]] = icmp ne i32 [[I_INC]], [[TMP0]]
+; CHECK-NEXT:    [[EXITCOND1:%.*]] = icmp ne i32 [[I_INC]], [[SUB1]]
 ; CHECK-NEXT:    br i1 [[EXITCOND1]], label [[OUTER]], label [[EXIT_LOOPEXIT:%.*]]
 ; CHECK:       exit.loopexit:
 ; CHECK-NEXT:    br label [[EXIT]]
Index: llvm/test/Transforms/IndVarSimplify/udiv.ll
===================================================================
--- llvm/test/Transforms/IndVarSimplify/udiv.ll
+++ llvm/test/Transforms/IndVarSimplify/udiv.ll
@@ -133,6 +133,7 @@
 ; CHECK-LABEL: @foo(
 ; CHECK: for.body.preheader:
 ; CHECK-NOT: udiv
+; CHECK: for.body:
 
 define void @foo(double* %p, i64 %n) nounwind {
 entry: