Index: lib/Transforms/Scalar/SCCP.cpp
===================================================================
--- lib/Transforms/Scalar/SCCP.cpp
+++ lib/Transforms/Scalar/SCCP.cpp
@@ -1926,7 +1926,8 @@
         if (Inst->getType()->isVoidTy())
           continue;
         if (tryToReplaceWithConstant(Solver, Inst)) {
-          if (!isa<CallInst>(Inst) && !isa<TerminatorInst>(Inst))
+          if ((!isa<CallInst>(Inst) || !Inst->mayHaveSideEffects()) &&
+              !isa<TerminatorInst>(Inst))
             Inst->eraseFromParent();
           // Hey, we just changed something!
           MadeChanges = true;
Index: test/Transforms/IPConstantProp/remove-call-inst.ll
===================================================================
--- test/Transforms/IPConstantProp/remove-call-inst.ll
+++ test/Transforms/IPConstantProp/remove-call-inst.ll
@@ -6,7 +6,7 @@
 
 ; CHECK: define i32 @main() #0 {
 ; CHECK-NEXT: entry:
-; CHECK-NEXT: %call2 = tail call i32 @wwrite(i64 0) [[NUW:#[0-9]+]]
+; CHECK-NOT: call
 ; CHECK-NEXT: ret i32 123
 
 define i32 @main() noreturn nounwind {
@@ -31,4 +31,3 @@
 
 ; CHECK: attributes #0 = { noreturn nounwind }
 ; CHECK: attributes #1 = { nounwind readnone }
-; CHECK: attributes [[NUW]] = { nounwind }
Index: test/Transforms/IPConstantProp/user-with-multiple-uses.ll
===================================================================
--- test/Transforms/IPConstantProp/user-with-multiple-uses.ll
+++ test/Transforms/IPConstantProp/user-with-multiple-uses.ll
@@ -15,7 +15,7 @@
   ret i32 %call2
 }
 
-define internal i32 @wwrite(i64 %i) nounwind readnone {
+define internal i32 @wwrite(i64 %i) nounwind {
 entry:
   switch i64 %i, label %sw.default [
     i64 3, label %return
@@ -30,5 +30,4 @@
 }
 
 ; CHECK: attributes #0 = { noreturn nounwind }
-; CHECK: attributes #1 = { nounwind readnone }
-; CHECK: attributes [[NUW]] = { nounwind }
+; CHECK: attributes #1 = { nounwind }