llvm-mirror/test/ThinLTO/X86/devirt_local_same_guid.ll
Teresa Johnson 0230a0a970 [ThinLTO/WPD] Fix index-based WPD for available_externally vtables
Summary:
Clang does not add type metadata to available_externally vtables. When
choosing a summary to look at for virtual function definitions, make
sure we skip summaries for any available externally vtables as they will
not describe any virtual function functions, which are only summarized
in the presence of type metadata on the vtable def. Simply look for the
corresponding strong def's summary.

Also add handling for same-named local vtables with the same GUID
because of same-named files without enough distinguishing path.
In that case we return a conservative result with no devirtualization.

Reviewers: pcc, davidxl, evgeny777

Subscribers: mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69452
2019-10-30 17:59:08 -07:00

75 lines
2.5 KiB
LLVM

; REQUIRES: x86-registered-target
; Test that index-based devirtualization in the presence of same-named
; local vtables in same named source files fails.
; Generate unsplit module with summary for ThinLTO index-based WPD.
; RUN: opt -thinlto-bc -o %t3.o %s
; RUN: opt -thinlto-bc -o %t4.o %p/Inputs/devirt_local_same_guid.ll
; RUN: llvm-lto2 run %t3.o %t4.o -save-temps -use-new-pm -pass-remarks=. \
; RUN: -wholeprogramdevirt-print-index-based \
; RUN: -o %t5 \
; RUN: -r=%t3.o,use_B,px \
; RUN: -r=%t3.o,test,px \
; RUN: -r=%t4.o,test2,px
; RUN: llvm-dis %t5.1.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR1
; RUN: llvm-dis %t5.2.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR2
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-grtev4-linux-gnu"
source_filename = "-"
%struct.A = type { i32 (...)** }
%struct.B = type { %struct.A }
@_ZTV1B = internal constant { [4 x i8*] } { [4 x i8*] [i8* null, i8* undef, i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1fEi to i8*), i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1nEi to i8*)] }, !type !0, !type !1
define internal i32 @_ZN1B1fEi(%struct.B* %this, i32 %a) #0 {
ret i32 0;
}
define internal i32 @_ZN1B1nEi(%struct.B* %this, i32 %a) #0 {
ret i32 0;
}
; Ensures that vtable of B is live so that we will attempt devirt.
define dso_local i32 @use_B(%struct.B* %a) {
entry:
%0 = bitcast %struct.B* %a to i32 (...)***
store i32 (...)** bitcast (i8** getelementptr inbounds ({ [4 x i8*] }, { [4 x i8*] }* @_ZTV1B, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
ret i32 0
}
; CHECK-IR1: define i32 @test(
define i32 @test(%struct.A* %obj, i32 %a) {
entry:
%0 = bitcast %struct.A* %obj to i8***
%vtable = load i8**, i8*** %0
%1 = bitcast i8** %vtable to i8*
%p = call i1 @llvm.type.test(i8* %1, metadata !"_ZTS1A")
call void @llvm.assume(i1 %p)
%fptrptr = getelementptr i8*, i8** %vtable, i32 1
%2 = bitcast i8** %fptrptr to i32 (%struct.A*, i32)**
%fptr1 = load i32 (%struct.A*, i32)*, i32 (%struct.A*, i32)** %2, align 8
; Check that the call was not devirtualized.
; CHECK-IR1: %call = tail call i32 %fptr1
%call = tail call i32 %fptr1(%struct.A* nonnull %obj, i32 %a)
ret i32 %call
}
; CHECK-IR2: define i32 @test2
; Check that the call was not devirtualized.
; CHECK-IR2: %call4 = tail call i32 %fptr
declare i1 @llvm.type.test(i8*, metadata)
declare void @llvm.assume(i1)
attributes #0 = { noinline optnone }
!0 = !{i64 16, !"_ZTS1A"}
!1 = !{i64 16, !"_ZTS1B"}