diff --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -38,9 +38,7 @@
 using namespace PatternMatch;
 
 /// ReuseOrCreateCast - Arrange for there to be a cast of V to Ty at IP,
-/// reusing an existing cast if a suitable one exists, moving an existing
-/// cast if a suitable one exists but isn't in the right place, or
-/// creating a new one.
+/// reusing an existing cast if a suitable one exists, or creating a new one.
 Value *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty,
                                        Instruction::CastOps Op,
                                        BasicBlock::iterator IP) {
@@ -66,11 +64,8 @@
           // Likewise, do not reuse a cast at BIP because it must dominate
           // instructions that might be inserted before BIP.
           if (BasicBlock::iterator(CI) != IP || BIP == IP) {
-            // Create a new cast, and leave the old cast in place in case
-            // it is being used as an insert point.
             Ret = CastInst::Create(Op, V, Ty, "", &*IP);
-            Ret->takeName(CI);
-            CI->replaceAllUsesWith(Ret);
+            rememberInstruction(Ret);
             break;
           }
           Ret = CI;
@@ -78,15 +73,16 @@
         }
 
   // Create a new cast.
-  if (!Ret)
+  if (!Ret) {
     Ret = CastInst::Create(Op, V, Ty, V->getName(), &*IP);
+    rememberInstruction(Ret);
+  }
 
   // We assert at the end of the function since IP might point to an
   // instruction with different dominance properties than a cast
   // (an invoke for example) and not dominate BIP (but the cast does).
   assert(SE.DT.dominates(Ret, &*BIP));
 
-  rememberInstruction(Ret);
   return Ret;
 }
 
diff --git a/llvm/test/Transforms/LoopDistribute/bounds-expansion-bug.ll b/llvm/test/Transforms/LoopDistribute/bounds-expansion-bug.ll
--- a/llvm/test/Transforms/LoopDistribute/bounds-expansion-bug.ll
+++ b/llvm/test/Transforms/LoopDistribute/bounds-expansion-bug.ll
@@ -1,5 +1,12 @@
 ; RUN: opt -basic-aa -loop-distribute -enable-loop-distribute -S < %s | FileCheck %s
 
+; XFAIL: *
+
+; SCEVExpander now less aggressively re-uses existing casts, in order to avoid
+; touching IR outside of the expanded instructions. Re-using existing casts
+; should only be a small optimization and can be re-introduced once we can
+; properly clean up expansion results, if they are unused.
+
 ; When emitting the memchecks for:
 ;
 ;   for (i = 0; i < n; i++) {
diff --git a/llvm/test/Transforms/LoopIdiom/reuse-cast.ll b/llvm/test/Transforms/LoopIdiom/reuse-cast.ll
--- a/llvm/test/Transforms/LoopIdiom/reuse-cast.ll
+++ b/llvm/test/Transforms/LoopIdiom/reuse-cast.ll
@@ -84,9 +84,8 @@
 ; CHECK-LABEL: @reuse_cast_2(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[STACK:%.*]] = alloca [2 x i32], align 4
-; CHECK-NEXT:    [[CAST_TO_REUSE:%.*]] = bitcast [2 x i32]* [[STACK]] to i8*
 ; CHECK-NEXT:    [[C_0:%.*]] = icmp sgt i32 [[X:%.*]], 0
-; CHECK-NEXT:    [[TMP0:%.*]] = bitcast [2 x i32]* [[STACK]] to i8*
+; CHECK-NEXT:    [[CAST_TO_REUSE:%.*]] = bitcast [2 x i32]* [[STACK]] to i8*
 ; CHECK-NEXT:    [[PTR_2_START:%.*]] = getelementptr inbounds [2 x i32], [2 x i32]* [[STACK]], i64 0, i64 0
 ; CHECK-NEXT:    call void @use.i8(i8* [[CAST_TO_REUSE]])
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
diff --git a/llvm/test/Transforms/LoopStrengthReduce/pr27056.ll b/llvm/test/Transforms/LoopStrengthReduce/pr27056.ll
--- a/llvm/test/Transforms/LoopStrengthReduce/pr27056.ll
+++ b/llvm/test/Transforms/LoopStrengthReduce/pr27056.ll
@@ -37,7 +37,7 @@
 ; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
 ; CHECK:       for.body:
 ; CHECK-NEXT:    [[TMP5:%.*]] = inttoptr i64 [[LSR_IV]] to %struct.L*
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq %struct.L* [[UGLYGEP1]], [[TMP]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq %struct.L* [[UGLYGEP1]], [[TMP5]]
 ; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_END_LOOPEXIT:%.*]], label [[FOR_BODY]]
 ; CHECK:       for.end.loopexit:
 ; CHECK-NEXT:    br label [[FOR_END]]