Index: lib/Transforms/Scalar/GVN.cpp
===================================================================
--- lib/Transforms/Scalar/GVN.cpp
+++ lib/Transforms/Scalar/GVN.cpp
@@ -638,6 +638,13 @@
     DominatorTree &getDominatorTree() const { return *DT; }
     AliasAnalysis *getAliasAnalysis() const { return VN.getAliasAnalysis(); }
     MemoryDependenceAnalysis &getMemDep() const { return *MD; }
+    void addGVN(Instruction *I) {
+      uint32_t NextNum = VN.getNextUnusedValueNumber();
+      unsigned Num = VN.lookup_or_add(I);
+      if (Num >= NextNum)
+        addToLeaderTable(Num, I, I->getParent());
+    }
+
   private:
     /// Push a new Value to the LeaderTable onto the list for its value number.
     void addToLeaderTable(uint32_t N, Value *V, const BasicBlock *BB) {
@@ -1195,6 +1202,7 @@
     LoadInst *NewLoad = Builder.CreateLoad(PtrVal);
     NewLoad->takeName(SrcVal);
     NewLoad->setAlignment(SrcVal->getAlignment());
+    gvn.addGVN(static_cast<Instruction*>(PtrVal));
 
     DEBUG(dbgs() << "GVN WIDENED LOAD: " << *SrcVal << "\n");
     DEBUG(dbgs() << "TO: " << *NewLoad << "\n");
@@ -1206,6 +1214,7 @@
       RV = Builder.CreateLShr(RV,
                     NewLoadSize*8-SrcVal->getType()->getPrimitiveSizeInBits());
     RV = Builder.CreateTrunc(RV, SrcVal->getType());
+    gvn.addGVN(static_cast<Instruction*>(RV));
     SrcVal->replaceAllUsesWith(RV);
 
     // We would like to use gvn.markInstructionForDeletion here, but we can't
Index: test/Transforms/GVN/pr25440.ll
===================================================================
--- /dev/null
+++ test/Transforms/GVN/pr25440.ll
@@ -0,0 +1,66 @@
+;RUN: opt -gvn -S < %s | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n8:16:32-S64"
+target triple = "thumbv7--linux-gnueabi"
+
+%struct.a = type { i16, i16, [1 x %union.a] }
+%union.a = type { i32 }
+
+@length = external global [0 x i32], align 4
+
+; Function Attrs: nounwind
+define fastcc void @foo(%struct.a* nocapture readonly %x) {
+;CHECK-LABEL: foo
+entry:
+  br label %bb0
+
+bb0:                                      ; preds = %land.lhs.true, %entry
+;CHECK: bb0:
+  %x.tr = phi %struct.a* [ %x, %entry ], [ null, %land.lhs.true ]
+  %code1 = getelementptr inbounds %struct.a, %struct.a* %x.tr, i32 0, i32 0
+  %0 = load i16, i16* %code1, align 4
+; CHECK: load i32, i32*
+  %conv = zext i16 %0 to i32
+  switch i32 %conv, label %if.end.50 [
+    i32 43, label %cleanup
+    i32 52, label %if.then.5
+  ]
+
+if.then.5:                                        ; preds = %bb0
+  br i1 undef, label %land.lhs.true, label %if.then.26
+
+land.lhs.true:                                    ; preds = %if.then.5
+  br i1 undef, label %cleanup, label %bb0
+
+if.then.26:                                       ; preds = %if.then.5
+  %x.tr.lcssa163 = phi %struct.a* [ %x.tr, %if.then.5 ]
+  br i1 undef, label %cond.end, label %cond.false
+
+cond.false:                                       ; preds = %if.then.26
+; CHECK: cond.false:
+; CHECK-NOT: load
+  %mode = getelementptr inbounds %struct.a, %struct.a* %x.tr.lcssa163, i32 0, i32 1
+  %bf.load = load i16, i16* %mode, align 2
+  %bf.shl = shl i16 %bf.load, 8
+  br label %cond.end
+
+cond.end:                                         ; preds = %cond.false, %if.then.26
+  br i1 undef, label %if.then.44, label %cleanup
+
+if.then.44:                                       ; preds = %cond.end
+  unreachable
+
+if.end.50:                                        ; preds = %bb0
+;%CHECK: if.end.50:
+  %conv.lcssa = phi i32 [ %conv, %bb0 ]
+  %arrayidx52 = getelementptr inbounds [0 x i32], [0 x i32]* @length, i32 0, i32 %conv.lcssa
+  %1 = load i32, i32* %arrayidx52, align 4
+  br i1 undef, label %for.body.57, label %cleanup
+
+for.body.57:                                      ; preds = %if.end.50
+  %i.2157 = add nsw i32 %1, -1
+  unreachable
+
+cleanup:                                          ; preds = %if.end.50, %cond.end, %land.lhs.true, %bb0
+  ret void
+}