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1; RUN: opt -S -passes=globalopt < %s | FileCheck %s2 3; CHECK: @llvm.global_ctors = appending global [1 x {{.*}}@_GLOBAL__I_c4@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 }]5 6; CHECK: @tmp = local_unnamed_addr global i32 427; CHECK: @tmp2 = local_unnamed_addr global i32 428; CHECK: @tmp3 = global i32 429@tmp = global i32 010@tmp2 = global i32 011@tmp3 = global i32 012@ptrToTmp3 = global ptr null13 14define i32 @TheAnswerToLifeTheUniverseAndEverything() {15 ret i32 4216}17 18define void @_GLOBAL__I_a() {19enter:20 call void @_optimizable()21 call void @_not_optimizable()22 ret void23}24 25define void @_optimizable() {26enter:27 %valptr = alloca i3228 29 %val = call i32 @TheAnswerToLifeTheUniverseAndEverything()30 store i32 %val, ptr @tmp31 store i32 %val, ptr %valptr32 33 %barr = call ptr @llvm.launder.invariant.group(ptr %valptr)34 35 %val2 = load i32, ptr %barr36 store i32 %val2, ptr @tmp237 ret void38}39 40; We can't step through launder.invariant.group here, because that would change41; this load in @usage_of_globals()42; %val = load i32, ptr %ptrVal, !invariant.group !043; into44; %val = load i32, ptr @tmp3, !invariant.group !045; and then we could assume that %val and %val2 to be the same, which coud be46; false, because @changeTmp3ValAndCallBarrierInside() may change the value47; of @tmp3.48define void @_not_optimizable() {49enter:50 store i32 13, ptr @tmp3, !invariant.group !051 52 %barr = call ptr @llvm.launder.invariant.group(ptr @tmp3)53 54 store ptr %barr, ptr @ptrToTmp355 store i32 42, ptr %barr, !invariant.group !056 57 ret void58}59 60define void @usage_of_globals() {61entry:62 %ptrVal = load ptr, ptr @ptrToTmp363 %val = load i32, ptr %ptrVal, !invariant.group !064 65 call void @changeTmp3ValAndCallBarrierInside()66 %val2 = load i32, ptr @tmp3, !invariant.group !067 ret void;68}69 70@tmp4 = global i32 071 72define void @_GLOBAL__I_b() {73enter:74 %val = call i32 @TheAnswerToLifeTheUniverseAndEverything()75 %p2 = call ptr @llvm.strip.invariant.group.p0(ptr @tmp4)76 store i32 %val, ptr %p277 ret void78}79 80@tmp5 = global i32 081@tmp6 = global ptr null82; CHECK: @tmp6 = local_unnamed_addr global ptr null83 84define ptr @_dont_return_param(ptr %p) {85 %p2 = call ptr @llvm.launder.invariant.group(ptr %p)86 ret ptr %p287}88 89; We should bail out if we return any pointers derived via invariant.group intrinsics at any point.90define void @_GLOBAL__I_c() {91enter:92 %tmp5 = call ptr @_dont_return_param(ptr @tmp5)93 store ptr %tmp5, ptr @tmp694 ret void95}96 97 98declare void @changeTmp3ValAndCallBarrierInside()99 100declare ptr @llvm.launder.invariant.group(ptr)101declare ptr @llvm.strip.invariant.group.p0(ptr)102 103!0 = !{}104