[ThinLTOCodeGenerator] Add support for index-based WPD
Differential revision: https://reviews.llvm.org/D68950
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375219 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/LTO/ThinLTOCodeGenerator.cpp b/lib/LTO/ThinLTOCodeGenerator.cpp
index db3ca90..d151de1 100644
--- a/lib/LTO/ThinLTOCodeGenerator.cpp
+++ b/lib/LTO/ThinLTOCodeGenerator.cpp
@@ -53,6 +53,7 @@
#include "llvm/Transforms/IPO/FunctionImport.h"
#include "llvm/Transforms/IPO/Internalize.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/IPO/WholeProgramDevirt.h"
#include "llvm/Transforms/ObjCARC.h"
#include "llvm/Transforms/Utils/FunctionImportUtils.h"
@@ -225,7 +226,8 @@
}
static void optimizeModule(Module &TheModule, TargetMachine &TM,
- unsigned OptLevel, bool Freestanding) {
+ unsigned OptLevel, bool Freestanding,
+ ModuleSummaryIndex *Index) {
// Populate the PassManager
PassManagerBuilder PMB;
PMB.LibraryInfo = new TargetLibraryInfoImpl(TM.getTargetTriple());
@@ -239,6 +241,7 @@
// Already did this in verifyLoadedModule().
PMB.VerifyInput = false;
PMB.VerifyOutput = false;
+ PMB.ImportSummary = Index;
legacy::PassManager PM;
@@ -433,7 +436,7 @@
saveTempBitcode(TheModule, SaveTempsDir, count, ".3.imported.bc");
}
- optimizeModule(TheModule, TM, OptLevel, Freestanding);
+ optimizeModule(TheModule, TM, OptLevel, Freestanding, &Index);
saveTempBitcode(TheModule, SaveTempsDir, count, ".4.opt.bc");
@@ -577,29 +580,36 @@
return CombinedIndex;
}
-static void internalizeAndPromoteInIndex(
- const StringMap<FunctionImporter::ExportSetTy> &ExportLists,
- const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols,
- const DenseMap<GlobalValue::GUID, const GlobalValueSummary *>
- &PrevailingCopy,
- ModuleSummaryIndex &Index) {
- auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) {
+struct IsExported {
+ const StringMap<FunctionImporter::ExportSetTy> &ExportLists;
+ const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols;
+
+ IsExported(const StringMap<FunctionImporter::ExportSetTy> &ExportLists,
+ const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols)
+ : ExportLists(ExportLists), GUIDPreservedSymbols(GUIDPreservedSymbols) {}
+
+ bool operator()(StringRef ModuleIdentifier, GlobalValue::GUID GUID) const {
const auto &ExportList = ExportLists.find(ModuleIdentifier);
return (ExportList != ExportLists.end() &&
ExportList->second.count(GUID)) ||
GUIDPreservedSymbols.count(GUID);
- };
+ }
+};
- auto isPrevailing = [&](GlobalValue::GUID GUID, const GlobalValueSummary *S) {
+struct IsPrevailing {
+ const DenseMap<GlobalValue::GUID, const GlobalValueSummary *> &PrevailingCopy;
+ IsPrevailing(const DenseMap<GlobalValue::GUID, const GlobalValueSummary *>
+ &PrevailingCopy)
+ : PrevailingCopy(PrevailingCopy) {}
+
+ bool operator()(GlobalValue::GUID GUID, const GlobalValueSummary *S) const {
const auto &Prevailing = PrevailingCopy.find(GUID);
// Not in map means that there was only one copy, which must be prevailing.
if (Prevailing == PrevailingCopy.end())
return true;
return Prevailing->second == S;
};
-
- thinLTOInternalizeAndPromoteInIndex(Index, isExported, isPrevailing);
-}
+};
static void computeDeadSymbolsInIndex(
ModuleSummaryIndex &Index,
@@ -656,8 +666,9 @@
// Promote the exported values in the index, so that they are promoted
// in the module.
- internalizeAndPromoteInIndex(ExportLists, GUIDPreservedSymbols,
- PrevailingCopy, Index);
+ thinLTOInternalizeAndPromoteInIndex(
+ Index, IsExported(ExportLists, GUIDPreservedSymbols),
+ IsPrevailing(PrevailingCopy));
promoteModule(TheModule, Index);
}
@@ -814,8 +825,9 @@
// Promote the exported values in the index, so that they are promoted
// in the module.
- internalizeAndPromoteInIndex(ExportLists, GUIDPreservedSymbols,
- PrevailingCopy, Index);
+ thinLTOInternalizeAndPromoteInIndex(
+ Index, IsExported(ExportLists, GUIDPreservedSymbols),
+ IsPrevailing(PrevailingCopy));
promoteModule(TheModule, Index);
@@ -834,7 +846,8 @@
initTMBuilder(TMBuilder, Triple(TheModule.getTargetTriple()));
// Optimize now
- optimizeModule(TheModule, *TMBuilder.create(), OptLevel, Freestanding);
+ optimizeModule(TheModule, *TMBuilder.create(), OptLevel, Freestanding,
+ nullptr);
}
/// Write out the generated object file, either from CacheEntryPath or from
@@ -955,6 +968,15 @@
// Synthesize entry counts for functions in the combined index.
computeSyntheticCounts(*Index);
+ // Perform index-based WPD. This will return immediately if there are
+ // no index entries in the typeIdMetadata map (e.g. if we are instead
+ // performing IR-based WPD in hybrid regular/thin LTO mode).
+ std::map<ValueInfo, std::vector<VTableSlotSummary>> LocalWPDTargetsMap;
+ std::set<GlobalValue::GUID> ExportedGUIDs;
+ runWholeProgramDevirtOnIndex(*Index, ExportedGUIDs, LocalWPDTargetsMap);
+ for (auto GUID : ExportedGUIDs)
+ GUIDPreservedSymbols.insert(GUID);
+
// Collect the import/export lists for all modules from the call-graph in the
// combined index.
StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
@@ -979,8 +1001,12 @@
// Use global summary-based analysis to identify symbols that can be
// internalized (because they aren't exported or preserved as per callback).
// Changes are made in the index, consumed in the ThinLTO backends.
- internalizeAndPromoteInIndex(ExportLists, GUIDPreservedSymbols,
- PrevailingCopy, *Index);
+ updateIndexWPDForExports(*Index,
+ IsExported(ExportLists, GUIDPreservedSymbols),
+ LocalWPDTargetsMap);
+ thinLTOInternalizeAndPromoteInIndex(
+ *Index, IsExported(ExportLists, GUIDPreservedSymbols),
+ IsPrevailing(PrevailingCopy));
// Make sure that every module has an entry in the ExportLists, ImportList,
// GVSummary and ResolvedODR maps to enable threaded access to these maps
diff --git a/test/ThinLTO/X86/devirt_promote_legacy.ll b/test/ThinLTO/X86/devirt_promote_legacy.ll
new file mode 100644
index 0000000..1d17b3f
--- /dev/null
+++ b/test/ThinLTO/X86/devirt_promote_legacy.ll
@@ -0,0 +1,57 @@
+; REQUIRES: x86-registered-target
+
+; Test devirtualization requiring promotion of local targets, where the
+; promotion is required by one devirtualization and needs to be updated
+; for a second devirtualization in the defining module as a post-pass
+; update.
+
+; 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_promote.ll
+
+; RUN: llvm-lto -thinlto-action=run %t3.o %t4.o --thinlto-save-temps=%t5. \
+; RUN: --pass-remarks=. \
+; RUN: --exported-symbol=test \
+; RUN: --exported-symbol=test2 \
+; RUN: --exported-symbol=_ZTV1B 2>&1 | FileCheck %s --check-prefix=REMARK
+; RUN: llvm-dis %t5.0.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR1
+; RUN: llvm-dis %t5.1.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR2
+
+; We should devirt call to _ZN1A1nEi once in importing module and once
+; in original (exporting) module.
+; REMARK-COUNT-2: single-impl: devirtualized a call to _ZN1A1nEi.llvm.
+
+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"
+
+%struct.A = type { i32 (...)** }
+
+; CHECK-IR1-LABEL: 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 devirtualized.
+ ; CHECK-IR1: %call = tail call i32 bitcast (void ()* @_ZN1A1nEi
+ %call = tail call i32 %fptr1(%struct.A* nonnull %obj, i32 %a)
+
+ ret i32 %call
+}
+; CHECK-IR1-LABEL: ret i32
+; CHECK-IR1-LABEL: }
+
+; CHECK-IR2: define i32 @test2
+; Check that the call was devirtualized.
+; CHECK-IR2: %call4 = tail call i32 @_ZN1A1nEi
+
+declare i1 @llvm.type.test(i8*, metadata)
+declare void @llvm.assume(i1)
+
+attributes #0 = { noinline optnone }
