Index: lib/Transforms/Scalar/GVN.cpp
===================================================================
--- lib/Transforms/Scalar/GVN.cpp
+++ lib/Transforms/Scalar/GVN.cpp
@@ -765,6 +765,16 @@
     if (SSAUpdate.HasValueForBlock(BB))
       continue;
 
+    // We must clear nuw/nsw for original value. Otherwise we
+    // can see the poison value where it was not originally.
+    Value *V = AV.AV.Val.getPointer();
+    if (V)
+      if (auto *I = dyn_cast<Instruction>(V))
+        if (isa<OverflowingBinaryOperator>(I)) {
+          I->setHasNoSignedWrap(false);
+          I->setHasNoUnsignedWrap(false);
+        }
+
     SSAUpdate.AddAvailableValue(BB, AV.MaterializeAdjustedValue(LI, gvn));
   }
 
Index: test/Transforms/GVN/PRE/pre-jt-load.ll
===================================================================
--- /dev/null
+++ test/Transforms/GVN/PRE/pre-jt-load.ll
@@ -0,0 +1,39 @@
+; RUN: opt < %s -gvn -enable-pre -jump-threading -S | FileCheck %s
+
+@H = common global i32 0
+@G = common global i32 0
+
+define i32 @test(i1 %cond, i32 %v) nounwind {
+; CHECK-LABEL: @test
+entry:
+  br i1 %cond, label %bb, label %bb1
+
+bb:
+; CHECK: store
+; CHECK-NOT: br label %return
+  %add.1 = add nuw nsw i32 %v, -1
+  store i32 %add.1, i32* @G, align 4
+  br label %merge
+
+bb1:
+; CHECK: store
+; CHECK-NOT: br label %return
+  %add.2 = add i32 %v, -1
+  store i32 %add.2, i32* @G, align 4
+  br label %merge
+
+merge:
+  %foo = load i32, i32* @G, align 4
+  %cmp = icmp sgt i32 %foo, 0
+  br i1 %cmp, label %action, label %return
+
+action:
+; CHECK: store
+; CHECK-NEXT: br label %return
+  store i32 %foo, i32* @H, align 4
+  br label %return
+
+return:
+  %p = phi i32 [0, %merge], [1, %action]
+  ret i32 %p
+}