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-rw-r--r--llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp16
-rw-r--r--llvm/test/ThinLTO/X86/lower_type_test_phi.ll163
2 files changed, 174 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
index 74fb3f0..2e838de 100644
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -2311,6 +2311,13 @@ void DevirtIndex::run() {
DenseMap<GlobalValue::GUID, std::vector<StringRef>> NameByGUID;
for (const auto &P : ExportSummary.typeIdCompatibleVtableMap()) {
NameByGUID[GlobalValue::getGUID(P.first)].push_back(P.first);
+ // Create the type id summary resolution regardlness of whether we can
+ // devirtualize, so that lower type tests knows the type id is used on
+ // a global and not Unsat. We do this here rather than in the loop over the
+ // CallSlots, since that handling will only see type tests that directly
+ // feed assumes, and we would miss any that aren't currently handled by WPD
+ // (such as type tests that feed assumes via phis).
+ ExportSummary.getOrInsertTypeIdSummary(P.first);
}
// Collect information from summary about which calls to try to devirtualize.
@@ -2358,12 +2365,11 @@ void DevirtIndex::run() {
std::vector<ValueInfo> TargetsForSlot;
auto TidSummary = ExportSummary.getTypeIdCompatibleVtableSummary(S.first.TypeID);
assert(TidSummary);
- // Create the type id summary resolution regardlness of whether we can
- // devirtualize, so that lower type tests knows the type id is used on
- // a global and not Unsat.
+ // The type id summary would have been created while building the NameByGUID
+ // map earlier.
WholeProgramDevirtResolution *Res =
- &ExportSummary.getOrInsertTypeIdSummary(S.first.TypeID)
- .WPDRes[S.first.ByteOffset];
+ &ExportSummary.getTypeIdSummary(S.first.TypeID)
+ ->WPDRes[S.first.ByteOffset];
if (tryFindVirtualCallTargets(TargetsForSlot, *TidSummary,
S.first.ByteOffset)) {
diff --git a/llvm/test/ThinLTO/X86/lower_type_test_phi.ll b/llvm/test/ThinLTO/X86/lower_type_test_phi.ll
new file mode 100644
index 0000000..722ffe3
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/lower_type_test_phi.ll
@@ -0,0 +1,163 @@
+; Test to ensure that type tests feeding assumes via a phi are lowered
+; correctly after ThinLTO index-only WPD, which needs to set up the necessary
+; type id summaries.
+
+; RUN: rm -rf %t && split-file %s %t && cd %t
+
+; RUN: opt -thinlto-bc y.ll -o y.bc
+; RUN: opt -thinlto-bc z.ll -o z.bc
+
+; RUN: llvm-lto2 run y.bc z.bc -o out \
+; RUN: -r y.bc,main,plx \
+; RUN: -r y.bc,_Z2b1v, \
+; RUN: -r y.bc,_Z2b2v, \
+; RUN: -r z.bc,_Z2b1v,pl \
+; RUN: -r z.bc,_Znwm, \
+; RUN: -r z.bc,_Z2b2v,pl \
+; RUN: -r z.bc,_ZN2D11fEv,pl \
+; RUN: -r z.bc,_ZN1B1fEv,pl \
+; RUN: -r z.bc,_ZN2D21fEv,pl \
+; RUN: -r z.bc,_ZTV2D1,pl \
+; RUN: -r z.bc,_ZTV1B,pl \
+; RUN: -r z.bc,_ZTV2D2,pl \
+; RUN: -print-after=lowertypetests -filter-print-funcs=main 2>&1 | FileCheck %s
+
+; The first LTT should leave the type tests as is (instead of lowering
+; them to false incorrectly).
+; CHECK: *** IR Dump After LowerTypeTestsPass on [module] ***
+; CHECK: 4:
+; CHECK: %7 = tail call i1 @llvm.type.test(ptr %6, metadata !"_ZTS2D1")
+; CHECK: br label %12
+; CHECK: 8:
+; CHECK: %11 = tail call i1 @llvm.type.test(ptr %10, metadata !"_ZTS2D2")
+; CHECK: br label %12
+; CHECK: 12:
+; CHECK: %13 = phi i1 [ %11, %8 ], [ %7, %4 ]
+
+; The second LTT should lower them to true.
+; CHECK: *** IR Dump After LowerTypeTestsPass on [module] ***
+; CHECK-NOT: @llvm.type.test
+; CHECK: 10:
+; CHECK: %11 = phi i1 [ true, %7 ], [ true, %4 ]
+
+
+;--- y.ll
+; ModuleID = 'y.cc'
+source_filename = "y.cc"
+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-unknown-linux-gnu"
+
+define i32 @main(i32 %argc, ptr %argv) {
+entry:
+ %tobool.not = icmp eq i32 %argc, 0
+ br i1 %tobool.not, label %if.else, label %if.then
+
+if.then:
+ %call = tail call ptr @_Z2b1v()
+ %vtable = load ptr, ptr %call, align 8
+ %0 = tail call i1 @llvm.type.test(ptr %vtable, metadata !"_ZTS2D1")
+ br label %if.end
+
+if.else:
+ %call1 = tail call ptr @_Z2b2v()
+ %vtable2 = load ptr, ptr %call1, align 8
+ %1 = tail call i1 @llvm.type.test(ptr %vtable2, metadata !"_ZTS2D2")
+ br label %if.end
+
+if.end:
+ %.sink = phi i1 [ %1, %if.else ], [ %0, %if.then ]
+ %vtable2.sink = phi ptr [ %vtable2, %if.else ], [ %vtable, %if.then ]
+ %call1.sink = phi ptr [ %call1, %if.else ], [ %call, %if.then ]
+ tail call void @llvm.assume(i1 %.sink)
+ %2 = load ptr, ptr %vtable2.sink, align 8
+ tail call void %2(ptr align 8 %call1.sink)
+ ret i32 0
+}
+
+declare ptr @_Z2b1v()
+
+declare i1 @llvm.type.test(ptr, metadata)
+
+declare void @llvm.assume(i1)
+
+declare ptr @_Z2b2v()
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4}
+!llvm.ident = !{!5}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, !"Virtual Function Elim", i32 0}
+!2 = !{i32 7, !"PIC Level", i32 2}
+!3 = !{i32 7, !"PIE Level", i32 2}
+!4 = !{i32 7, !"uwtable", i32 2}
+!5 = !{!"clang version 15.0.0 (git@github.com:llvm/llvm-project.git e6f39e3f31ba88f2084a5d987f9a827aff4e17b1)"}
+
+;--- z.ll
+; ModuleID = 'z.cc'
+source_filename = "z.cc"
+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-unknown-linux-gnu"
+
+$_ZN2D11fEv = comdat any
+
+$_ZN1B1fEv = comdat any
+
+$_ZN2D21fEv = comdat any
+
+$_ZTV2D1 = comdat any
+
+$_ZTV1B = comdat any
+
+$_ZTV2D2 = comdat any
+
+@_ZTV2D1 = linkonce_odr constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN2D11fEv] }, comdat, align 8, !type !0, !type !1, !type !2, !type !3, !vcall_visibility !4
+@_ZTV1B = linkonce_odr constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN1B1fEv] }, comdat, align 8, !type !0, !type !1, !vcall_visibility !4
+@_ZTV2D2 = linkonce_odr constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN2D21fEv] }, comdat, align 8, !type !0, !type !1, !type !5, !type !6, !vcall_visibility !4
+
+define ptr @_Z2b1v() {
+entry:
+ %call = tail call ptr @_Znwm(i64 8)
+ store ptr getelementptr inbounds ({ [3 x ptr] }, ptr @_ZTV2D1, i64 0, inrange i32 0, i64 2), ptr %call, align 8
+ ret ptr %call
+}
+
+declare ptr @_Znwm(i64)
+
+define ptr @_Z2b2v() {
+entry:
+ %call = tail call ptr @_Znwm(i64 8)
+ store ptr getelementptr inbounds ({ [3 x ptr] }, ptr @_ZTV2D2, i64 0, inrange i32 0, i64 2), ptr %call, align 8
+ ret ptr %call
+}
+
+define linkonce_odr void @_ZN2D11fEv(ptr %this) comdat align 2 {
+entry:
+ ret void
+}
+
+define linkonce_odr void @_ZN1B1fEv(ptr %this) comdat align 2 {
+entry:
+ ret void
+}
+
+define linkonce_odr void @_ZN2D21fEv(ptr %this) comdat align 2 {
+entry:
+ ret void
+}
+
+!llvm.module.flags = !{!7, !8, !9, !10, !11}
+!llvm.ident = !{!12}
+
+!0 = !{i64 16, !"_ZTS1B"}
+!1 = !{i64 16, !"_ZTSM1BFvvE.virtual"}
+!2 = !{i64 16, !"_ZTS2D1"}
+!3 = !{i64 16, !"_ZTSM2D1FvvE.virtual"}
+!4 = !{i64 1}
+!5 = !{i64 16, !"_ZTS2D2"}
+!6 = !{i64 16, !"_ZTSM2D2FvvE.virtual"}
+!7 = !{i32 1, !"wchar_size", i32 4}
+!8 = !{i32 1, !"Virtual Function Elim", i32 0}
+!9 = !{i32 7, !"PIC Level", i32 2}
+!10 = !{i32 7, !"PIE Level", i32 2}
+!11 = !{i32 7, !"uwtable", i32 2}
+!12 = !{!"clang version 15.0.0 (git@github.com:llvm/llvm-project.git e6f39e3f31ba88f2084a5d987f9a827aff4e17b1)"}
generated by cgit v1.1 at 2025-08-04 01:40:55 +0000