; RUN: llvm-as < %s | opt -gvn -instcombine | llvm-dis | grep {ret i32 0}
; PR4189
@G = external constant [4 x i32]

define i32 @test(i8* %p, i32 %i) nounwind {
entry:
	%P = getelementptr [4 x i32]* @G, i32 0, i32 %i
	%A = load i32* %P
	store i8 4, i8* %p
	%B = load i32* %P
	%C = sub i32 %A, %B
	ret i32 %C
}
