| ; Tests that VFE is not performed when the Virtual Function Elim metadata set |
| ; to 0. This is the same as virtual-functions.ll otherwise. |
| ; RUN: opt < %s -passes=globaldce -S | FileCheck %s |
| |
| target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" |
| |
| declare dso_local noalias nonnull ptr @_Znwm(i64) |
| declare { ptr, i1 } @llvm.type.checked.load(ptr, i32, metadata) |
| |
| ; %struct.A is a C++ struct with two virtual functions, A::foo and A::bar. The |
| ; !vcall_visibility metadata is set on the vtable, so we know that all virtual |
| ; calls through this vtable are visible and use the @llvm.type.checked.load |
| ; intrinsic. Function test_A makes a call to A::foo, but there is no call to |
| ; A::bar anywhere, so A::bar can be deleted, and its vtable slot replaced with |
| ; null. |
| ; However, with the metadata set to 0 we should not perform this VFE. |
| |
| %struct.A = type { ptr } |
| |
| ; We should retain @_ZN1A3barEv in the vtable. |
| ; CHECK: @_ZTV1A = internal unnamed_addr constant { [4 x ptr] } { [4 x ptr] [ptr null, ptr null, ptr @_ZN1A3fooEv, ptr @_ZN1A3barEv] } |
| @_ZTV1A = internal unnamed_addr constant { [4 x ptr] } { [4 x ptr] [ptr null, ptr null, ptr @_ZN1A3fooEv, ptr @_ZN1A3barEv] }, align 8, !type !0, !type !1, !type !2, !vcall_visibility !3 |
| |
| ; A::foo is called, so must be retained. |
| ; CHECK: define internal i32 @_ZN1A3fooEv( |
| define internal i32 @_ZN1A3fooEv(ptr nocapture readnone %this) { |
| entry: |
| ret i32 42 |
| } |
| |
| ; A::bar is not used, so can be deleted with VFE, however, we should not be |
| ; performing that elimination here. |
| ; CHECK: define internal i32 @_ZN1A3barEv( |
| define internal i32 @_ZN1A3barEv(ptr nocapture readnone %this) { |
| entry: |
| ret i32 1337 |
| } |
| |
| define dso_local i32 @test_A() { |
| entry: |
| %call = tail call ptr @_Znwm(i64 8) |
| store ptr getelementptr inbounds ({ [4 x ptr] }, ptr @_ZTV1A, i64 0, inrange i32 0, i64 2), ptr %call, align 8 |
| %0 = tail call { ptr, i1 } @llvm.type.checked.load(ptr getelementptr inbounds ({ [4 x ptr] }, ptr @_ZTV1A, i64 0, inrange i32 0, i64 2), i32 0, metadata !"_ZTS1A"), !nosanitize !9 |
| %1 = extractvalue { ptr, i1 } %0, 0, !nosanitize !9 |
| %call1 = tail call i32 %1(ptr nonnull %call) |
| ret i32 %call1 |
| } |
| |
| !llvm.module.flags = !{!4} |
| |
| !0 = !{i64 16, !"_ZTS1A"} |
| !1 = !{i64 16, !"_ZTSM1AFivE.virtual"} |
| !2 = !{i64 24, !"_ZTSM1AFivE.virtual"} |
| !3 = !{i64 2} |
| !4 = !{i32 1, !"Virtual Function Elim", i32 0} |
| !9 = !{} |