[clang] [llvm] [Clang]: Enable speculative devirtualization (PR #159685)
via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 24 00:54:26 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms
Author: Hassnaa Hamdi (hassnaaHamdi)
<details>
<summary>Changes</summary>
This patch enables speculative devirtualization feature in Clang/frontend.
It depends on this patch: https://github.com/llvm/llvm-project/pull/159048 which enables speculative devirtualization in LLVM/backend.
- Speculative devirtualization feature is working when we have single implementation devirtualization where a virtual call has a single possible callee.
- It enables the -fdevirtualize-speculatively clang option that was disabled previously.
- Right now the feature is supported in non-LTO mode only.
- Feature is disabled by default.
---
Patch is 37.40 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/159685.diff
16 Files Affected:
- (modified) clang/docs/UsersManual.rst (+9)
- (modified) clang/include/clang/Basic/CodeGenOptions.def (+2)
- (modified) clang/include/clang/Driver/Options.td (+9-3)
- (modified) clang/lib/CodeGen/BackendUtil.cpp (+1)
- (modified) clang/lib/CodeGen/CGClass.cpp (+8-6)
- (modified) clang/lib/CodeGen/CGVTables.cpp (+4-2)
- (modified) clang/lib/CodeGen/ItaniumCXXABI.cpp (+8-5)
- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+7)
- (modified) clang/test/CodeGenCXX/type-metadata.cpp (+8)
- (modified) clang/test/Driver/clang_f_opts.c (-2)
- (modified) llvm/include/llvm/Passes/PassBuilder.h (+4)
- (modified) llvm/include/llvm/Transforms/IPO/WholeProgramDevirt.h (+5-2)
- (modified) llvm/lib/Passes/PassBuilderPipelines.cpp (+19)
- (modified) llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp (+72-22)
- (added) llvm/test/Transforms/WholeProgramDevirt/speculative-devirt-single-impl.ll (+130)
- (modified) llvm/test/Transforms/WholeProgramDevirt/virtual-const-prop-check.ll (+7)
``````````diff
diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
index a8bbf146431ea..241f374bcf4c3 100644
--- a/clang/docs/UsersManual.rst
+++ b/clang/docs/UsersManual.rst
@@ -2313,6 +2313,13 @@ are listed below.
This enables better devirtualization. Turned off by default, because it is
still experimental.
+.. option:: -fdevirtualize-speculatively
+
+ Enable speculative devirtualization optimization, such as single-implementation
+ devirtualization. This optimization is used out of LTO mode for now.
+ Turned off by default.
+ TODO: Enable for LTO mode.
+
.. option:: -fwhole-program-vtables
Enable whole-program vtable optimizations, such as single-implementation
@@ -5161,6 +5168,8 @@ Execute ``clang-cl /?`` to see a list of supported options:
-fstandalone-debug Emit full debug info for all types used by the program
-fstrict-aliasing Enable optimizations based on strict aliasing rules
-fsyntax-only Run the preprocessor, parser and semantic analysis stages
+ -fdevirtualize-speculatively
+ Enables speculative devirtualization optimization.
-fwhole-program-vtables Enables whole-program vtable optimization. Requires -flto
-gcodeview-ghash Emit type record hashes in a .debug$H section
-gcodeview Generate CodeView debug information
diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def
index 872f73ebf3810..38174cf13cadf 100644
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -358,6 +358,8 @@ VALUE_CODEGENOPT(WarnStackSize , 32, UINT_MAX, Benign) ///< Set via -fwarn-s
CODEGENOPT(NoStackArgProbe, 1, 0, Benign) ///< Set when -mno-stack-arg-probe is used
CODEGENOPT(EmitLLVMUseLists, 1, 0, Benign) ///< Control whether to serialize use-lists.
+CODEGENOPT(DevirtualizeSpeculatively, 1, 0, Benign) ///< Whether to apply the speculative
+ /// devirtualization optimization.
CODEGENOPT(WholeProgramVTables, 1, 0, Benign) ///< Whether to apply whole-program
/// vtable optimization.
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 47d328f862e07..a3656b80cac32 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -4432,6 +4432,13 @@ defm new_infallible : BoolFOption<"new-infallible",
BothFlags<[], [ClangOption, CC1Option],
" treating throwing global C++ operator new as always returning valid memory "
"(annotates with __attribute__((returns_nonnull)) and throw()). This is detectable in source.">>;
+defm devirtualize_speculatively
+ : BoolFOption<"devirtualize-speculatively",
+ CodeGenOpts<"DevirtualizeSpeculatively">, DefaultFalse,
+ PosFlag<SetTrue, [], [],
+ "Enables speculative devirtualization optimization.">,
+ NegFlag<SetFalse>,
+ BothFlags<[], [ClangOption, CLOption, CC1Option]>>;
defm whole_program_vtables : BoolFOption<"whole-program-vtables",
CodeGenOpts<"WholeProgramVTables">, DefaultFalse,
PosFlag<SetTrue, [], [ClangOption, CC1Option],
@@ -7012,9 +7019,8 @@ defm variable_expansion_in_unroller : BooleanFFlag<"variable-expansion-in-unroll
Group<clang_ignored_gcc_optimization_f_Group>;
defm web : BooleanFFlag<"web">, Group<clang_ignored_gcc_optimization_f_Group>;
defm whole_program : BooleanFFlag<"whole-program">, Group<clang_ignored_gcc_optimization_f_Group>;
-defm devirtualize : BooleanFFlag<"devirtualize">, Group<clang_ignored_gcc_optimization_f_Group>;
-defm devirtualize_speculatively : BooleanFFlag<"devirtualize-speculatively">,
- Group<clang_ignored_gcc_optimization_f_Group>;
+defm devirtualize : BooleanFFlag<"devirtualize">,
+ Group<clang_ignored_gcc_optimization_f_Group>;
// Generic gfortran options.
def A_DASH : Joined<["-"], "A-">, Group<gfortran_Group>;
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 8c99af2bdff83..790467dc557a5 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -907,6 +907,7 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
// non-integrated assemblers don't recognize .cgprofile section.
PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
PTO.UnifiedLTO = CodeGenOpts.UnifiedLTO;
+ PTO.DevirtualizeSpeculatively = CodeGenOpts.DevirtualizeSpeculatively;
LoopAnalysisManager LAM;
FunctionAnalysisManager FAM;
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 8346ee3aa6a8d..bf1724e347a7f 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -2771,10 +2771,11 @@ void CodeGenFunction::EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
SourceLocation Loc) {
if (SanOpts.has(SanitizerKind::CFIVCall))
EmitVTablePtrCheckForCall(RD, VTable, CodeGenFunction::CFITCK_VCall, Loc);
- else if (CGM.getCodeGenOpts().WholeProgramVTables &&
- // Don't insert type test assumes if we are forcing public
- // visibility.
- !CGM.AlwaysHasLTOVisibilityPublic(RD)) {
+ else if ((CGM.getCodeGenOpts().WholeProgramVTables &&
+ // Don't insert type test assumes if we are forcing public
+ // visibility.
+ !CGM.AlwaysHasLTOVisibilityPublic(RD)) ||
+ CGM.getCodeGenOpts().DevirtualizeSpeculatively) {
CanQualType Ty = CGM.getContext().getCanonicalTagType(RD);
llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(Ty);
llvm::Value *TypeId =
@@ -2932,8 +2933,9 @@ void CodeGenFunction::EmitVTablePtrCheck(const CXXRecordDecl *RD,
}
bool CodeGenFunction::ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD) {
- if (!CGM.getCodeGenOpts().WholeProgramVTables ||
- !CGM.HasHiddenLTOVisibility(RD))
+ if ((!CGM.getCodeGenOpts().WholeProgramVTables ||
+ !CGM.HasHiddenLTOVisibility(RD)) &&
+ !CGM.getCodeGenOpts().DevirtualizeSpeculatively)
return false;
if (CGM.getCodeGenOpts().VirtualFunctionElimination)
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index e14e883a55ac5..959ba2031acf4 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -1358,10 +1358,12 @@ llvm::GlobalObject::VCallVisibility CodeGenModule::GetVCallVisibilityLevel(
void CodeGenModule::EmitVTableTypeMetadata(const CXXRecordDecl *RD,
llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout) {
- // Emit type metadata on vtables with LTO or IR instrumentation.
+ // Emit type metadata on vtables with LTO or IR instrumentation or
+ // speculative devirtualization.
// In IR instrumentation, the type metadata is used to find out vtable
// definitions (for type profiling) among all global variables.
- if (!getCodeGenOpts().LTOUnit && !getCodeGenOpts().hasProfileIRInstr())
+ if (!getCodeGenOpts().LTOUnit && !getCodeGenOpts().hasProfileIRInstr() &&
+ !getCodeGenOpts().DevirtualizeSpeculatively)
return;
CharUnits ComponentWidth = GetTargetTypeStoreSize(getVTableComponentType());
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 7dc2eaf1e9f75..71d36b5d6b153 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -717,9 +717,10 @@ CGCallee ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(
bool ShouldEmitVFEInfo = CGM.getCodeGenOpts().VirtualFunctionElimination &&
CGM.HasHiddenLTOVisibility(RD);
bool ShouldEmitWPDInfo =
- CGM.getCodeGenOpts().WholeProgramVTables &&
- // Don't insert type tests if we are forcing public visibility.
- !CGM.AlwaysHasLTOVisibilityPublic(RD);
+ (CGM.getCodeGenOpts().WholeProgramVTables &&
+ // Don't insert type tests if we are forcing public visibility.
+ !CGM.AlwaysHasLTOVisibilityPublic(RD)) ||
+ CGM.getCodeGenOpts().DevirtualizeSpeculatively;
llvm::Value *VirtualFn = nullptr;
{
@@ -2114,13 +2115,15 @@ void ItaniumCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
// definitions to ensure we associate derived classes with base classes
// defined in headers but with a strong definition only in a shared library.
if (!VTable->isDeclarationForLinker() ||
- CGM.getCodeGenOpts().WholeProgramVTables) {
+ CGM.getCodeGenOpts().WholeProgramVTables ||
+ CGM.getCodeGenOpts().DevirtualizeSpeculatively) {
CGM.EmitVTableTypeMetadata(RD, VTable, VTLayout);
// For available_externally definitions, add the vtable to
// @llvm.compiler.used so that it isn't deleted before whole program
// analysis.
if (VTable->isDeclarationForLinker()) {
- assert(CGM.getCodeGenOpts().WholeProgramVTables);
+ assert(CGM.getCodeGenOpts().WholeProgramVTables ||
+ CGM.getCodeGenOpts().DevirtualizeSpeculatively);
CGM.addCompilerUsedGlobal(VTable);
}
}
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 63efb0f02baa8..d91afcbf3fd6c 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -7785,6 +7785,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
addOpenMPHostOffloadingArgs(C, JA, Args, CmdArgs);
+ // Temporarily disable this for LTO if it's not explicitly enabled.
+ // TODO: enable it by default for LTO also.
+ if (Args.hasFlag(options::OPT_fdevirtualize_speculatively,
+ options::OPT_fno_devirtualize_speculatively,
+ /*Default value*/ false))
+ CmdArgs.push_back("-fdevirtualize-speculatively");
+
bool VirtualFunctionElimination =
Args.hasFlag(options::OPT_fvirtual_function_elimination,
options::OPT_fno_virtual_function_elimination, false);
diff --git a/clang/test/CodeGenCXX/type-metadata.cpp b/clang/test/CodeGenCXX/type-metadata.cpp
index 1cb2fed8db3e6..61d36204942dc 100644
--- a/clang/test/CodeGenCXX/type-metadata.cpp
+++ b/clang/test/CodeGenCXX/type-metadata.cpp
@@ -14,6 +14,9 @@
// RUN: %clang_cc1 -O2 -flto -flto-unit -triple x86_64-unknown-linux -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=ITANIUM-OPT --check-prefix=ITANIUM-OPT-LAYOUT %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=MS --check-prefix=MS-TYPEMETADATA --check-prefix=TT-MS %s
+// Test for the speculative devirtualization feature in nonlto mode:
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -fdevirtualize-speculatively -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=TT-ITANIUM-DEFAULT-NOLTO-SPECULATIVE-DEVIRT %s
+
// Tests for cfi + whole-program-vtables:
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-VT --check-prefix=ITANIUM-HIDDEN --check-prefix=ITANIUM-COMMON-MD --check-prefix=TC-ITANIUM --check-prefix=ITANIUM-NO-RV-MD %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-VT --check-prefix=MS --check-prefix=MS-TYPEMETADATA --check-prefix=TC-MS %s
@@ -178,6 +181,7 @@ void af(A *a) {
// TT-ITANIUM-HIDDEN: [[P:%[^ ]*]] = call i1 @llvm.type.test(ptr [[VT:%[^ ]*]], metadata !"_ZTS1A")
// TT-ITANIUM-DEFAULT: [[P:%[^ ]*]] = call i1 @llvm.public.type.test(ptr [[VT:%[^ ]*]], metadata !"_ZTS1A")
// TT-MS: [[P:%[^ ]*]] = call i1 @llvm.type.test(ptr [[VT:%[^ ]*]], metadata !"?AUA@@")
+ // TT-ITANIUM-DEFAULT-NOLTO-SPECULATIVE-DEVIRT: [[P:%[^ ]*]] = call i1 @llvm.public.type.test(ptr [[VT:%[^ ]*]], metadata !"_ZTS1A")
// TC-ITANIUM: [[PAIR:%[^ ]*]] = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 0, metadata !"_ZTS1A")
// TC-ITANIUM-RV: [[PAIR:%[^ ]*]] = call { ptr, i1 } @llvm.type.checked.load.relative(ptr {{%[^ ]*}}, i32 0, metadata !"_ZTS1A")
// TC-MS: [[PAIR:%[^ ]*]] = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 0, metadata !"?AUA@@")
@@ -212,6 +216,7 @@ void df1(D *d) {
// TT-ITANIUM-HIDDEN: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE:[0-9]+]])
// TT-ITANIUM-DEFAULT: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE:[0-9]+]])
// TT-MS: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata !"?AUA@@")
+ // TT-ITANIUM-DEFAULT-NOLTO-SPECULATIVE-DEVIRT: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE:[0-9]+]])
// TC-ITANIUM: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 0, metadata ![[DTYPE:[0-9]+]])
// TC-ITANIUM-RV: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load.relative(ptr {{%[^ ]*}}, i32 0, metadata ![[DTYPE:[0-9]+]])
// TC-MS: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 0, metadata !"?AUA@@")
@@ -224,6 +229,7 @@ void dg1(D *d) {
// TT-ITANIUM-HIDDEN: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata !"_ZTS1B")
// TT-ITANIUM-DEFAULT: {{%[^ ]*}} = call i1 @llvm.public.type.test(ptr {{%[^ ]*}}, metadata !"_ZTS1B")
// TT-MS: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata !"?AUB@@")
+ // TT-ITANIUM-DEFAULT-NOLTO-SPECULATIVE-DEVIRT: {{%[^ ]*}} = call i1 @llvm.public.type.test(ptr {{%[^ ]*}}, metadata !"_ZTS1B")
// TC-ITANIUM: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 8, metadata !"_ZTS1B")
// TC-ITANIUM-RV: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load.relative(ptr {{%[^ ]*}}, i32 4, metadata !"_ZTS1B")
// TC-MS: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 0, metadata !"?AUB@@")
@@ -236,6 +242,7 @@ void dh1(D *d) {
// TT-ITANIUM-HIDDEN: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE]])
// TT-ITANIUM-DEFAULT: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE]])
// TT-MS: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE:[0-9]+]])
+ // TT-ITANIUM-DEFAULT-NOLTO-SPECULATIVE-DEVIRT: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata ![[DTYPE]])
// TC-ITANIUM: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 16, metadata ![[DTYPE]])
// TC-ITANIUM-RV: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load.relative(ptr {{%[^ ]*}}, i32 8, metadata ![[DTYPE]])
// TC-MS: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 8, metadata ![[DTYPE:[0-9]+]])
@@ -297,6 +304,7 @@ void f(D *d) {
// TT-ITANIUM-HIDDEN: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata !"_ZTSN5test21DE")
// TT-ITANIUM-DEFAULT: {{%[^ ]*}} = call i1 @llvm.public.type.test(ptr {{%[^ ]*}}, metadata !"_ZTSN5test21DE")
// TT-MS: {{%[^ ]*}} = call i1 @llvm.type.test(ptr {{%[^ ]*}}, metadata !"?AUA at test2@@")
+ // TT-ITANIUM-DEFAULT-NOLTO-SPECULATIVE-DEVIRT: {{%[^ ]*}} = call i1 @llvm.public.type.test(ptr {{%[^ ]*}}, metadata !"_ZTSN5test21DE")
// TC-ITANIUM: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 8, metadata !"_ZTSN5test21DE")
// TC-ITANIUM-RV: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load.relative(ptr {{%[^ ]*}}, i32 4, metadata !"_ZTSN5test21DE")
// TC-MS: {{%[^ ]*}} = call { ptr, i1 } @llvm.type.checked.load(ptr {{%[^ ]*}}, i32 0, metadata !"?AUA at test2@@")
diff --git a/clang/test/Driver/clang_f_opts.c b/clang/test/Driver/clang_f_opts.c
index eb3994ddabcd3..1e6e1253a7a09 100644
--- a/clang/test/Driver/clang_f_opts.c
+++ b/clang/test/Driver/clang_f_opts.c
@@ -371,7 +371,6 @@
// RUN: -ftree-ter \
// RUN: -ftree-vrp \
// RUN: -fno-devirtualize \
-// RUN: -fno-devirtualize-speculatively \
// RUN: -fslp-vectorize-aggressive \
// RUN: -fno-slp-vectorize-aggressive \
// RUN: %s 2>&1 | FileCheck --check-prefix=CHECK-WARNING %s
@@ -430,7 +429,6 @@
// CHECK-WARNING-DAG: optimization flag '-ftree-ter' is not supported
// CHECK-WARNING-DAG: optimization flag '-ftree-vrp' is not supported
// CHECK-WARNING-DAG: optimization flag '-fno-devirtualize' is not supported
-// CHECK-WARNING-DAG: optimization flag '-fno-devirtualize-speculatively' is not supported
// CHECK-WARNING-DAG: the flag '-fslp-vectorize-aggressive' has been deprecated and will be ignored
// CHECK-WARNING-DAG: the flag '-fno-slp-vectorize-aggressive' has been deprecated and will be ignored
diff --git a/llvm/include/llvm/Passes/PassBuilder.h b/llvm/include/llvm/Passes/PassBuilder.h
index 2742ec1b71b7e..c1fcde24cc420 100644
--- a/llvm/include/llvm/Passes/PassBuilder.h
+++ b/llvm/include/llvm/Passes/PassBuilder.h
@@ -102,6 +102,10 @@ class PipelineTuningOptions {
// analyses after various module->function or cgscc->function adaptors in the
// default pipelines.
bool EagerlyInvalidateAnalyses;
+
+ // Tuning option to enable/disable speculative devirtualization.
+ // Its default value is false.
+ bool DevirtualizeSpeculatively;
};
/// This class provides access to building LLVM's passes.
diff --git a/llvm/include/llvm/Transforms/IPO/WholeProgramDevirt.h b/llvm/include/llvm/Transforms/IPO/WholeProgramDevirt.h
index 7a03405b4f462..2e33a4098be1b 100644
--- a/llvm/include/llvm/Transforms/IPO/WholeProgramDevirt.h
+++ b/llvm/include/llvm/Transforms/IPO/WholeProgramDevirt.h
@@ -226,11 +226,14 @@ struct WholeProgramDevirtPass : public PassInfoMixin<WholeProgramDevirtPass> {
ModuleSummaryIndex *ExportSummary;
const ModuleSummaryIndex *ImportSummary;
bool UseCommandLine = false;
+ bool DevirtSpeculatively = false;
WholeProgramDevirtPass()
: ExportSummary(nullptr), ImportSummary(nullptr), UseCommandLine(true) {}
WholeProgramDevirtPass(ModuleSummaryIndex *ExportSummary,
- const ModuleSummaryIndex *ImportSummary)
- : ExportSummary(ExportSummary), ImportSummary(ImportSummary) {
+ const ModuleSummaryIndex *ImportSummary,
+ bool DevirtSpeculatively = false)
+ : ExportSummary(ExportSummary), ImportSummary(ImportSummary),
+ DevirtSpeculatively(DevirtSpeculatively) {
assert(!(ExportSummary && ImportSummary));
}
LLVM_ABI PreservedAnalyses run(Module &M, ModuleAnalysisManager &);
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 79642e650ac83..bbaa7493445a3 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -322,6 +322,7 @@ PipelineTuningOptions::PipelineTuningOptions() {
MergeFunctions = EnableMergeFunctions;
InlinerThreshold = -1;
EagerlyInvalidateAnalyses = EnableEagerlyInvalidateAnalyses;
+ DevirtualizeSpeculatively = false;
}
namespace llvm {
@@ -1635,6 +1636,24 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
if (!LTOPreLink)
MPM.addPass(RelLookupTableConverterPass());
+ if (PTO.DevirtualizeSpeculatively && LTOPhase == ThinOrFullLTOPhase::None) {
+ MPM.addPass(WholeProgramDevirtPass(
+ /*ExportSummary*/ nullptr,
+ /*ImportSummary*/ nullptr,
+ /*DevirtSpeculatively*/ PTO.DevirtualizeSpeculatively));
+ MPM.addPass(LowerTypeTestsPass(nullptr, nullptr,
+ lowertypetests::DropTestKind::Assume));
+ if (EnableModuleInliner) {
+ MPM.addPass(ModuleInlinerPass(getInlineParamsFromOptLevel(Level),
+ UseInlineAdvisor,
+ ThinOrFullLTOPhase::None));
+ } else {
+ MPM.addPass(ModuleInlinerWrapperPass(
+ getInlineParamsFromOp...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/159685
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