add globalptr bad test

enzyme/test/Enzyme/globalptr.ll

@@ -0,0 +1,44 @@
+; RUN: opt < %s %loadEnzyme -enzyme -enzyme_preopt=false -mem2reg -instsimplify -adce -correlated-propagation -simplifycfg -S | FileCheck %s
+
+; XFAIL: *
+; a function returning a pointer/float with no arguments is mistakenly marked as constant in spite of accessing a global
+
+@global = external dso_local local_unnamed_addr global double*, align 8
+
+; Function Attrs: noinline norecurse nounwind readonly uwtable
+define dso_local double* @myglobal() local_unnamed_addr #0 {
+entry:
+  %0 = load double*, double** @global, align 8
+  ret double* %0
+}
+
+; Function Attrs: noinline norecurse nounwind readonly uwtable
+define dso_local double @mulglobal(double %x) #0 {
+entry:
+  %call = tail call double* @myglobal()
+  %arrayidx = getelementptr inbounds double, double* %call, i64 2
+  %0 = load double, double* %arrayidx, align 8
+  %mul = fmul fast double %0, %x
+  ret double %mul
+}
+
+; Function Attrs: noinline nounwind uwtable
+define dso_local double @derivative(double %x) local_unnamed_addr #1 {
+entry:
+  %0 = tail call double (...) @__enzyme_autodiff.f64(double (double)* nonnull @mulglobal, double %x) #2
+  ret double %0
+}
+
+declare double @__enzyme_autodiff.f64(...) local_unnamed_addr
+
+attributes #0 = { noinline norecurse nounwind readonly uwtable }
+attributes #1 = { noinline nounwind uwtable }
+attributes #2 = { nounwind }
+
+; CHECK: define internal { double } @diffemulglobal(double %x, double %differeturn)
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %call = tail call double* @myglobal()
+; CHECK-NEXT:    %arrayidx = getelementptr inbounds double, double* %call, i64 2
+; CHECK-NEXT:    %0 = load double, double* %arrayidx, align 8
+; CHECK-NEXT:    %[[tmul:.+]] = fmul fast double %0, %x
+; CHECK-NEXT:    %[[tcall.+]] = call {} @diffemyglobal(double %x)