1; RUN: opt < %s -globalopt -S | FileCheck %s 2 3declare void @wait() 4declare void @signal() 5declare void @start_thread(void ()*) 6 7@x = internal thread_local global [100 x i32] zeroinitializer, align 16 8@ip = internal global i32* null, align 8 9 10; PR14309: GlobalOpt would think that the value of @ip is always the address of 11; x[1]. However, that address is different for different threads so @ip cannot 12; be replaced with a constant. 13 14define i32 @f() { 15entry: 16 ; Set @ip to point to x[1] for thread 1. 17 store i32* getelementptr inbounds ([100 x i32]* @x, i64 0, i64 1), i32** @ip, align 8 18 19 ; Run g on a new thread. 20 tail call void @start_thread(void ()* @g) nounwind 21 tail call void @wait() nounwind 22 23 ; Reset x[1] for thread 1. 24 store i32 0, i32* getelementptr inbounds ([100 x i32]* @x, i64 0, i64 1), align 4 25 26 ; Read the value of @ip, which now points at x[1] for thread 2. 27 %0 = load i32** @ip, align 8 28 29 %1 = load i32* %0, align 4 30 ret i32 %1 31 32; CHECK: @f 33; Make sure that the load from @ip hasn't been removed. 34; CHECK: load i32** @ip 35; CHECK: ret 36} 37 38define internal void @g() nounwind uwtable { 39entry: 40 ; Set @ip to point to x[1] for thread 2. 41 store i32* getelementptr inbounds ([100 x i32]* @x, i64 0, i64 1), i32** @ip, align 8 42 43 ; Store 50 in x[1] for thread 2. 44 store i32 50, i32* getelementptr inbounds ([100 x i32]* @x, i64 0, i64 1), align 4 45 46 tail call void @signal() nounwind 47 ret void 48 49; CHECK: @g 50; Make sure that the store to @ip hasn't been removed. 51; CHECK: store {{.*}} @ip 52; CHECK: ret 53} 54