; RUN: opt -S -passes=globalopt < %s | FileCheck %s ; CHECK: @llvm.global_ctors = appending global [1 x {{.*}}@_GLOBAL__I_c @llvm.global_ctors = appending global [3 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__I_a, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__I_b, ptr null }, { i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__I_c, ptr null }] ; CHECK: @tmp = local_unnamed_addr global i32 42 ; CHECK: @tmp2 = local_unnamed_addr global i32 42 ; CHECK: @tmp3 = global i32 42 @tmp = global i32 0 @tmp2 = global i32 0 @tmp3 = global i32 0 @ptrToTmp3 = global ptr null define i32 @TheAnswerToLifeTheUniverseAndEverything() { ret i32 42 } define void @_GLOBAL__I_a() { enter: call void @_optimizable() call void @_not_optimizable() ret void } define void @_optimizable() { enter: %valptr = alloca i32 %val = call i32 @TheAnswerToLifeTheUniverseAndEverything() store i32 %val, ptr @tmp store i32 %val, ptr %valptr %barr = call ptr @llvm.launder.invariant.group(ptr %valptr) %val2 = load i32, ptr %barr store i32 %val2, ptr @tmp2 ret void } ; We can't step through launder.invariant.group here, because that would change ; this load in @usage_of_globals() ; %val = load i32, ptr %ptrVal, !invariant.group !0 ; into ; %val = load i32, ptr @tmp3, !invariant.group !0 ; and then we could assume that %val and %val2 to be the same, which coud be ; false, because @changeTmp3ValAndCallBarrierInside() may change the value ; of @tmp3. define void @_not_optimizable() { enter: store i32 13, ptr @tmp3, !invariant.group !0 %barr = call ptr @llvm.launder.invariant.group(ptr @tmp3) store ptr %barr, ptr @ptrToTmp3 store i32 42, ptr %barr, !invariant.group !0 ret void } define void @usage_of_globals() { entry: %ptrVal = load ptr, ptr @ptrToTmp3 %val = load i32, ptr %ptrVal, !invariant.group !0 call void @changeTmp3ValAndCallBarrierInside() %val2 = load i32, ptr @tmp3, !invariant.group !0 ret void; } @tmp4 = global i32 0 define void @_GLOBAL__I_b() { enter: %val = call i32 @TheAnswerToLifeTheUniverseAndEverything() %p2 = call ptr @llvm.strip.invariant.group.p0(ptr @tmp4) store i32 %val, ptr %p2 ret void } @tmp5 = global i32 0 @tmp6 = global ptr null ; CHECK: @tmp6 = local_unnamed_addr global ptr null define ptr @_dont_return_param(ptr %p) { %p2 = call ptr @llvm.launder.invariant.group(ptr %p) ret ptr %p2 } ; We should bail out if we return any pointers derived via invariant.group intrinsics at any point. define void @_GLOBAL__I_c() { enter: %tmp5 = call ptr @_dont_return_param(ptr @tmp5) store ptr %tmp5, ptr @tmp6 ret void } declare void @changeTmp3ValAndCallBarrierInside() declare ptr @llvm.launder.invariant.group(ptr) declare ptr @llvm.strip.invariant.group.p0(ptr) !0 = !{}