|  | ; RUN: opt < %s -tsan -S | FileCheck %s | 
|  | ; Check that tsan does not instrument reads from constant globals. | 
|  |  | 
|  | target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" | 
|  |  | 
|  | @const_global = external constant i32 | 
|  | define i32 @read_from_const_global() nounwind uwtable readnone { | 
|  | entry: | 
|  | %0 = load i32* @const_global, align 4 | 
|  | ret i32 %0 | 
|  | } | 
|  | ; CHECK: define i32 @read_from_const_global | 
|  | ; CHECK-NOT: __tsan | 
|  | ; CHECK: ret i32 | 
|  |  | 
|  | @non_const_global = global i32 0, align 4 | 
|  | define i32 @read_from_non_const_global() nounwind uwtable readonly { | 
|  | entry: | 
|  | %0 = load i32* @non_const_global, align 4 | 
|  | ret i32 %0 | 
|  | } | 
|  |  | 
|  | ; CHECK:  define i32 @read_from_non_const_global | 
|  | ; CHECK: __tsan_read | 
|  | ; CHECK: ret i32 | 
|  |  | 
|  | @const_global_array = external constant [10 x i32] | 
|  | define i32 @read_from_const_global_array(i32 %idx) nounwind uwtable readnone { | 
|  | entry: | 
|  | %idxprom = sext i32 %idx to i64 | 
|  | %arrayidx = getelementptr inbounds [10 x i32]* @const_global_array, i64 0, i64 %idxprom | 
|  | %0 = load i32* %arrayidx, align 4 | 
|  | ret i32 %0 | 
|  | } | 
|  |  | 
|  | ; CHECK: define i32 @read_from_const_global_array | 
|  | ; CHECK-NOT: __tsan | 
|  | ; CHECK: ret i32 | 
|  |  | 
|  | %struct.Foo = type { i32 (...)** } | 
|  | define void @call_virtual_func(%struct.Foo* %f) uwtable { | 
|  | entry: | 
|  | %0 = bitcast %struct.Foo* %f to void (%struct.Foo*)*** | 
|  | %vtable = load void (%struct.Foo*)*** %0, align 8, !tbaa !3 | 
|  | %1 = load void (%struct.Foo*)** %vtable, align 8 | 
|  | call void %1(%struct.Foo* %f) | 
|  | ret void | 
|  | } | 
|  |  | 
|  | ; CHECK: define void @call_virtual_func | 
|  | ; CHECK: __tsan_read | 
|  | ; CHECK: = load | 
|  | ; CHECK-NOT: __tsan_read | 
|  | ; CHECK: = load | 
|  | ; CHECK: ret void | 
|  |  | 
|  | !0 = metadata !{metadata !"int", metadata !1} | 
|  | !1 = metadata !{metadata !"omnipotent char", metadata !2} | 
|  | !2 = metadata !{metadata !"Simple C/C++ TBAA", null} | 
|  | !3 = metadata !{metadata !"vtable pointer", metadata !2} | 
|  |  |