[llvm] r296945 - WholeProgramDevirt: Implement exporting for single-impl devirtualization.
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 3 17:31:02 PST 2017
Author: pcc
Date: Fri Mar 3 19:31:01 2017
New Revision: 296945
URL: http://llvm.org/viewvc/llvm-project?rev=296945&view=rev
Log:
WholeProgramDevirt: Implement exporting for single-impl devirtualization.
Differential Revision: https://reviews.llvm.org/D29811
Added:
llvm/trunk/test/Transforms/WholeProgramDevirt/export-single-impl.ll
Modified:
llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp
Modified: llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp?rev=296945&r1=296944&r2=296945&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp Fri Mar 3 19:31:01 2017
@@ -312,6 +312,10 @@ struct CallSiteInfo {
// These fields are used during the export phase of ThinLTO and reflect
// information collected from function summaries.
+ /// Whether any function summary contains an llvm.assume(llvm.type.test) for
+ /// this slot.
+ bool SummaryHasTypeTestAssumeUsers;
+
/// CFI-specific: a vector containing the list of function summaries that use
/// the llvm.type.checked.load intrinsic and therefore will require
/// resolutions for llvm.type.test in order to implement CFI checks if
@@ -320,6 +324,11 @@ struct CallSiteInfo {
/// non-empty, we will need to add a use of llvm.type.test to each of the
/// function summaries in the vector.
std::vector<FunctionSummary *> SummaryTypeCheckedLoadUsers;
+
+ bool isExported() const {
+ return SummaryHasTypeTestAssumeUsers ||
+ !SummaryTypeCheckedLoadUsers.empty();
+ }
};
// Call site information collected for a specific VTableSlot.
@@ -406,9 +415,11 @@ struct DevirtModule {
const std::set<TypeMemberInfo> &TypeMemberInfos,
uint64_t ByteOffset);
- void applySingleImplDevirt(VTableSlotInfo &SlotInfo, Constant *TheFn);
+ void applySingleImplDevirt(VTableSlotInfo &SlotInfo, Constant *TheFn,
+ bool &IsExported);
bool trySingleImplDevirt(MutableArrayRef<VirtualCallTarget> TargetsForSlot,
- VTableSlotInfo &SlotInfo);
+ VTableSlotInfo &SlotInfo,
+ WholeProgramDevirtResolution *Res);
bool tryEvaluateFunctionsWithArgs(
MutableArrayRef<VirtualCallTarget> TargetsForSlot,
@@ -625,7 +636,7 @@ bool DevirtModule::tryFindVirtualCallTar
}
void DevirtModule::applySingleImplDevirt(VTableSlotInfo &SlotInfo,
- Constant *TheFn) {
+ Constant *TheFn, bool &IsExported) {
auto Apply = [&](CallSiteInfo &CSInfo) {
for (auto &&VCallSite : CSInfo.CallSites) {
if (RemarksEnabled)
@@ -636,6 +647,10 @@ void DevirtModule::applySingleImplDevirt
if (VCallSite.NumUnsafeUses)
--*VCallSite.NumUnsafeUses;
}
+ if (CSInfo.isExported()) {
+ IsExported = true;
+ CSInfo.SummaryTypeCheckedLoadUsers.clear();
+ }
};
Apply(SlotInfo.CSInfo);
for (auto &P : SlotInfo.ConstCSInfo)
@@ -644,7 +659,7 @@ void DevirtModule::applySingleImplDevirt
bool DevirtModule::trySingleImplDevirt(
MutableArrayRef<VirtualCallTarget> TargetsForSlot,
- VTableSlotInfo &SlotInfo) {
+ VTableSlotInfo &SlotInfo, WholeProgramDevirtResolution *Res) {
// See if the program contains a single implementation of this virtual
// function.
Function *TheFn = TargetsForSlot[0].Fn;
@@ -655,7 +670,24 @@ bool DevirtModule::trySingleImplDevirt(
// If so, update each call site to call that implementation directly.
if (RemarksEnabled)
TargetsForSlot[0].WasDevirt = true;
- applySingleImplDevirt(SlotInfo, TheFn);
+
+ bool IsExported = false;
+ applySingleImplDevirt(SlotInfo, TheFn, IsExported);
+ if (!IsExported)
+ return false;
+
+ // If the only implementation has local linkage, we must promote to external
+ // to make it visible to thin LTO objects. We can only get here during the
+ // ThinLTO export phase.
+ if (TheFn->hasLocalLinkage()) {
+ TheFn->setLinkage(GlobalValue::ExternalLinkage);
+ TheFn->setVisibility(GlobalValue::HiddenVisibility);
+ TheFn->setName(TheFn->getName() + "$merged");
+ }
+
+ Res->TheKind = WholeProgramDevirtResolution::SingleImpl;
+ Res->SingleImplName = TheFn->getName();
+
return true;
}
@@ -1102,11 +1134,20 @@ bool DevirtModule::run() {
if (!FS)
continue;
// FIXME: Only add live functions.
+ for (FunctionSummary::VFuncId VF : FS->type_test_assume_vcalls())
+ for (Metadata *MD : MetadataByGUID[VF.GUID])
+ CallSlots[{MD, VF.Offset}].CSInfo.SummaryHasTypeTestAssumeUsers =
+ true;
for (FunctionSummary::VFuncId VF : FS->type_checked_load_vcalls())
for (Metadata *MD : MetadataByGUID[VF.GUID])
CallSlots[{MD, VF.Offset}]
.CSInfo.SummaryTypeCheckedLoadUsers.push_back(FS);
for (const FunctionSummary::ConstVCall &VC :
+ FS->type_test_assume_const_vcalls())
+ for (Metadata *MD : MetadataByGUID[VC.VFunc.GUID])
+ CallSlots[{MD, VC.VFunc.Offset}]
+ .ConstCSInfo[VC.Args].SummaryHasTypeTestAssumeUsers = true;
+ for (const FunctionSummary::ConstVCall &VC :
FS->type_checked_load_const_vcalls())
for (Metadata *MD : MetadataByGUID[VC.VFunc.GUID])
CallSlots[{MD, VC.VFunc.Offset}]
@@ -1126,7 +1167,14 @@ bool DevirtModule::run() {
std::vector<VirtualCallTarget> TargetsForSlot;
if (tryFindVirtualCallTargets(TargetsForSlot, TypeIdMap[S.first.TypeID],
S.first.ByteOffset)) {
- if (!trySingleImplDevirt(TargetsForSlot, S.second) &&
+ WholeProgramDevirtResolution *Res = nullptr;
+ if (Action == PassSummaryAction::Export && isa<MDString>(S.first.TypeID))
+ Res =
+ &Summary
+ ->getTypeIdSummary(cast<MDString>(S.first.TypeID)->getString())
+ .WPDRes[S.first.ByteOffset];
+
+ if (!trySingleImplDevirt(TargetsForSlot, S.second, Res) &&
tryVirtualConstProp(TargetsForSlot, S.second))
DidVirtualConstProp = true;
Added: llvm/trunk/test/Transforms/WholeProgramDevirt/export-single-impl.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/WholeProgramDevirt/export-single-impl.ll?rev=296945&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/WholeProgramDevirt/export-single-impl.ll (added)
+++ llvm/trunk/test/Transforms/WholeProgramDevirt/export-single-impl.ll Fri Mar 3 19:31:01 2017
@@ -0,0 +1,78 @@
+; RUN: opt -wholeprogramdevirt -wholeprogramdevirt-summary-action=export -wholeprogramdevirt-read-summary=%S/Inputs/export.yaml -wholeprogramdevirt-write-summary=%t -S -o - %s | FileCheck %s
+; RUN: FileCheck --check-prefix=SUMMARY %s < %t
+
+; SUMMARY: TypeIdMap:
+; SUMMARY-NEXT: typeid1:
+; SUMMARY-NEXT: TTRes:
+; SUMMARY-NEXT: Kind: Unsat
+; SUMMARY-NEXT: SizeM1BitWidth: 0
+; SUMMARY-NEXT: WPDRes:
+; SUMMARY-NEXT: 0:
+; SUMMARY-NEXT: Kind: SingleImpl
+; SUMMARY-NEXT: SingleImplName: vf1
+; SUMMARY-NEXT: ResByArg:
+; SUMMARY-NEXT: typeid2:
+; SUMMARY-NEXT: TTRes:
+; SUMMARY-NEXT: Kind: Unsat
+; SUMMARY-NEXT: SizeM1BitWidth: 0
+; SUMMARY-NEXT: WPDRes:
+; SUMMARY-NEXT: 0:
+; SUMMARY-NEXT: Kind: SingleImpl
+; SUMMARY-NEXT: SingleImplName: vf2
+; SUMMARY-NEXT: ResByArg:
+; SUMMARY-NEXT: typeid3:
+; SUMMARY-NEXT: TTRes:
+; SUMMARY-NEXT: Kind: Unsat
+; SUMMARY-NEXT: SizeM1BitWidth: 0
+; SUMMARY-NEXT: WPDRes:
+; SUMMARY-NEXT: 0:
+; SUMMARY-NEXT: Kind: SingleImpl
+; SUMMARY-NEXT: SingleImplName: vf3
+; SUMMARY-NEXT: ResByArg:
+; SUMMARY-NEXT: typeid4:
+; SUMMARY-NEXT: TTRes:
+; SUMMARY-NEXT: Kind: Unsat
+; SUMMARY-NEXT: SizeM1BitWidth: 0
+; SUMMARY-NEXT: WPDRes:
+; SUMMARY-NEXT: 0:
+; SUMMARY-NEXT: Kind: SingleImpl
+; SUMMARY-NEXT: SingleImplName: 'vf4$merged'
+; SUMMARY-NEXT: ResByArg:
+; SUMMARY-NEXT: ...
+
+; CHECK: @vt1 = constant void (i8*)* @vf1
+ at vt1 = constant void (i8*)* @vf1, !type !0
+
+; CHECK: @vt2 = constant void (i8*)* @vf2
+ at vt2 = constant void (i8*)* @vf2, !type !1
+
+ at vt3 = constant void (i8*)* @vf3, !type !2
+
+; CHECK: @vt4 = constant void (i8*)* @"vf4$merged"
+ at vt4 = constant void (i8*)* @vf4, !type !3
+
+ at vt5 = constant void (i8*)* @vf5, !type !4
+
+; CHECK: declare void @vf1(i8*)
+declare void @vf1(i8*)
+
+; CHECK: define void @vf2(i8*)
+define void @vf2(i8*) {
+ ret void
+}
+
+declare void @vf3(i8*)
+
+; CHECK: define hidden void @"vf4$merged"
+define internal void @vf4(i8*) {
+ ret void
+}
+
+declare void @vf5(i8*)
+
+!0 = !{i32 0, !"typeid1"}
+!1 = !{i32 0, !"typeid2"}
+!2 = !{i32 0, !"typeid3"}
+!3 = !{i32 0, !"typeid4"}
+!4 = !{i32 0, !5}
+!5 = distinct !{}
More information about the llvm-commits
mailing list