//===- Construction of codegen pass pipelines ------------------*- C++ -*--===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
///
/// Interfaces for registering analysis passes, producing common pass manager
/// configurations, and parsing of pass pipelines.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_CODEGENPASSBUILDER_H
#define LLVM_CODEGEN_CODEGENPASSBUILDER_H
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/ScopedNoAliasAA.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/TypeBasedAliasAnalysis.h"
#include "llvm/CodeGen/ExpandReductions.h"
#include "llvm/CodeGen/MachinePassManager.h"
#include "llvm/CodeGen/PreISelIntrinsicLowering.h"
#include "llvm/CodeGen/ReplaceWithVeclib.h"
#include "llvm/CodeGen/UnreachableBlockElim.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Verifier.h"
#include "llvm/IRPrinter/IRPrintingPasses.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/CGPassBuilderOption.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/Scalar/ConstantHoisting.h"
#include "llvm/Transforms/Scalar/LoopPassManager.h"
#include "llvm/Transforms/Scalar/LoopStrengthReduce.h"
#include "llvm/Transforms/Scalar/LowerConstantIntrinsics.h"
#include "llvm/Transforms/Scalar/MergeICmps.h"
#include "llvm/Transforms/Scalar/PartiallyInlineLibCalls.h"
#include "llvm/Transforms/Scalar/ScalarizeMaskedMemIntrin.h"
#include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
#include "llvm/Transforms/Utils/LowerInvoke.h"
#include <cassert>
#include <type_traits>
#include <utility>
namespace llvm {
// FIXME: Dummy target independent passes definitions that have not yet been
// ported to new pass manager. Once they do, remove these.
#define DUMMY_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
struct PASS_NAME : public PassInfoMixin<PASS_NAME> { \
template <typename... Ts> PASS_NAME(Ts &&...) {} \
PreservedAnalyses run(Function &, FunctionAnalysisManager &) { \
return PreservedAnalyses::all(); \
} \
};
#define DUMMY_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
struct PASS_NAME : public PassInfoMixin<PASS_NAME> { \
template <typename... Ts> PASS_NAME(Ts &&...) {} \
PreservedAnalyses run(Module &, ModuleAnalysisManager &) { \
return PreservedAnalyses::all(); \
} \
};
#define DUMMY_MACHINE_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
struct PASS_NAME : public PassInfoMixin<PASS_NAME> { \
template <typename... Ts> PASS_NAME(Ts &&...) {} \
Error run(Module &, MachineFunctionAnalysisManager &) { \
return Error::success(); \
} \
PreservedAnalyses run(MachineFunction &, \
MachineFunctionAnalysisManager &) { \
llvm_unreachable("this api is to make new PM api happy"); \
} \
static AnalysisKey Key; \
};
#define DUMMY_MACHINE_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
struct PASS_NAME : public PassInfoMixin<PASS_NAME> { \
template <typename... Ts> PASS_NAME(Ts &&...) {} \
PreservedAnalyses run(MachineFunction &, \
MachineFunctionAnalysisManager &) { \
return PreservedAnalyses::all(); \
} \
static AnalysisKey Key; \
};
#include "MachinePassRegistry.def"
/// This class provides access to building LLVM's passes.
///
/// Its members provide the baseline state available to passes during their
/// construction. The \c MachinePassRegistry.def file specifies how to construct
/// all of the built-in passes, and those may reference these members during
/// construction.
template <typename DerivedT> class CodeGenPassBuilder {
public:
explicit CodeGenPassBuilder(LLVMTargetMachine &TM, CGPassBuilderOption Opts,
PassInstrumentationCallbacks *PIC)
: TM(TM), Opt(Opts), PIC(PIC) {
// Target could set CGPassBuilderOption::MISchedPostRA to true to achieve
// substitutePass(&PostRASchedulerID, &PostMachineSchedulerID)
// Target should override TM.Options.EnableIPRA in their target-specific
// LLVMTM ctor. See TargetMachine::setGlobalISel for example.
if (Opt.EnableIPRA)
TM.Options.EnableIPRA = *Opt.EnableIPRA;
if (Opt.EnableGlobalISelAbort)
TM.Options.GlobalISelAbort = *Opt.EnableGlobalISelAbort;
if (!Opt.OptimizeRegAlloc)
Opt.OptimizeRegAlloc = getOptLevel() != CodeGenOpt::None;
}
Error buildPipeline(ModulePassManager &MPM, MachineFunctionPassManager &MFPM,
raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
CodeGenFileType FileType) const;
void registerModuleAnalyses(ModuleAnalysisManager &) const;
void registerFunctionAnalyses(FunctionAnalysisManager &) const;
void registerMachineFunctionAnalyses(MachineFunctionAnalysisManager &) const;
std::pair<StringRef, bool> getPassNameFromLegacyName(StringRef) const;
void registerAnalyses(MachineFunctionAnalysisManager &MFAM) const {
registerModuleAnalyses(*MFAM.MAM);
registerFunctionAnalyses(*MFAM.FAM);
registerMachineFunctionAnalyses(MFAM);
}
PassInstrumentationCallbacks *getPassInstrumentationCallbacks() const {
return PIC;
}
protected:
template <typename PassT> using has_key_t = decltype(PassT::Key);
template <typename PassT>
using is_module_pass_t = decltype(std::declval<PassT &>().run(
std::declval<Module &>(), std::declval<ModuleAnalysisManager &>()));
template <typename PassT>
using is_function_pass_t = decltype(std::declval<PassT &>().run(
std::declval<Function &>(), std::declval<FunctionAnalysisManager &>()));
// Function object to maintain state while adding codegen IR passes.
class AddIRPass {
public:
AddIRPass(ModulePassManager &MPM, bool DebugPM, bool Check = true)
: MPM(MPM) {
if (Check)
AddingFunctionPasses = false;
}
~AddIRPass() {
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
}
// Add Function Pass
template <typename PassT>
std::enable_if_t<is_detected<is_function_pass_t, PassT>::value>
operator()(PassT &&Pass) {
if (AddingFunctionPasses && !*AddingFunctionPasses)
AddingFunctionPasses = true;
FPM.addPass(std::forward<PassT>(Pass));
}
// Add Module Pass
template <typename PassT>
std::enable_if_t<is_detected<is_module_pass_t, PassT>::value &&
!is_detected<is_function_pass_t, PassT>::value>
operator()(PassT &&Pass) {
assert((!AddingFunctionPasses || !*AddingFunctionPasses) &&
"could not add module pass after adding function pass");
MPM.addPass(std::forward<PassT>(Pass));
}
private:
ModulePassManager &MPM;
FunctionPassManager FPM;
// The codegen IR pipeline are mostly function passes with the exceptions of
// a few loop and module passes. `AddingFunctionPasses` make sures that
// we could only add module passes at the beginning of the pipeline. Once
// we begin adding function passes, we could no longer add module passes.
// This special-casing introduces less adaptor passes. If we have the need
// of adding module passes after function passes, we could change the
// implementation to accommodate that.
std::optional<bool> AddingFunctionPasses;
};
// Function object to maintain state while adding codegen machine passes.
class AddMachinePass {
public:
AddMachinePass(MachineFunctionPassManager &PM) : PM(PM) {}
template <typename PassT> void operator()(PassT &&Pass) {
static_assert(
is_detected<has_key_t, PassT>::value,
"Machine function pass must define a static member variable `Key`.");
for (auto &C : BeforeCallbacks)
if (!C(&PassT::Key))
return;
PM.addPass(std::forward<PassT>(Pass));
for (auto &C : AfterCallbacks)
C(&PassT::Key);
}
template <typename PassT> void insertPass(AnalysisKey *ID, PassT Pass) {
AfterCallbacks.emplace_back(
[this, ID, Pass = std::move(Pass)](AnalysisKey *PassID) {
if (PassID == ID)
this->PM.addPass(std::move(Pass));
});
}
void disablePass(AnalysisKey *ID) {
BeforeCallbacks.emplace_back(
[ID](AnalysisKey *PassID) { return PassID != ID; });
}
MachineFunctionPassManager releasePM() { return std::move(PM); }
private:
MachineFunctionPassManager &PM;
SmallVector<llvm::unique_function<bool(AnalysisKey *)>, 4> BeforeCallbacks;
SmallVector<llvm::unique_function<void(AnalysisKey *)>, 4> AfterCallbacks;
};
LLVMTargetMachine &TM;
CGPassBuilderOption Opt;
PassInstrumentationCallbacks *PIC;
/// Target override these hooks to parse target-specific analyses.
void registerTargetAnalysis(ModuleAnalysisManager &) const {}
void registerTargetAnalysis(FunctionAnalysisManager &) const {}
void registerTargetAnalysis(MachineFunctionAnalysisManager &) const {}
std::pair<StringRef, bool> getTargetPassNameFromLegacyName(StringRef) const {
return {"", false};
}
template <typename TMC> TMC &getTM() const { return static_cast<TMC &>(TM); }
CodeGenOpt::Level getOptLevel() const { return TM.getOptLevel(); }
/// Check whether or not GlobalISel should abort on error.
/// When this is disabled, GlobalISel will fall back on SDISel instead of
/// erroring out.
bool isGlobalISelAbortEnabled() const {
return TM.Options.GlobalISelAbort == GlobalISelAbortMode::Enable;
}
/// Check whether or not a diagnostic should be emitted when GlobalISel
/// uses the fallback path. In other words, it will emit a diagnostic
/// when GlobalISel failed and isGlobalISelAbortEnabled is false.
bool reportDiagnosticWhenGlobalISelFallback() const {
return TM.Options.GlobalISelAbort == GlobalISelAbortMode::DisableWithDiag;
}
/// addInstSelector - This method should install an instruction selector pass,
/// which converts from LLVM code to machine instructions.
Error addInstSelector(AddMachinePass &) const {
return make_error<StringError>("addInstSelector is not overridden",
inconvertibleErrorCode());
}
/// Add passes that optimize instruction level parallelism for out-of-order
/// targets. These passes are run while the machine code is still in SSA
/// form, so they can use MachineTraceMetrics to control their heuristics.
///
/// All passes added here should preserve the MachineDominatorTree,
/// MachineLoopInfo, and MachineTraceMetrics analyses.
void addILPOpts(AddMachinePass &) const {}
/// This method may be implemented by targets that want to run passes
/// immediately before register allocation.
void addPreRegAlloc(AddMachinePass &) const {}
/// addPreRewrite - Add passes to the optimized register allocation pipeline
/// after register allocation is complete, but before virtual registers are
/// rewritten to physical registers.
///
/// These passes must preserve VirtRegMap and LiveIntervals, and when running
/// after RABasic or RAGreedy, they should take advantage of LiveRegMatrix.
/// When these passes run, VirtRegMap contains legal physreg assignments for
/// all virtual registers.
///
/// Note if the target overloads addRegAssignAndRewriteOptimized, this may not
/// be honored. This is also not generally used for the the fast variant,
/// where the allocation and rewriting are done in one pass.
void addPreRewrite(AddMachinePass &) const {}
/// Add passes to be run immediately after virtual registers are rewritten
/// to physical registers.
void addPostRewrite(AddMachinePass &) const {}
/// This method may be implemented by targets that want to run passes after
/// register allocation pass pipeline but before prolog-epilog insertion.
void addPostRegAlloc(AddMachinePass &) const {}
/// This method may be implemented by targets that want to run passes after
/// prolog-epilog insertion and before the second instruction scheduling pass.
void addPreSched2(AddMachinePass &) const {}
/// This pass may be implemented by targets that want to run passes
/// immediately before machine code is emitted.
void addPreEmitPass(AddMachinePass &) const {}
/// Targets may add passes immediately before machine code is emitted in this
/// callback. This is called even later than `addPreEmitPass`.
// FIXME: Rename `addPreEmitPass` to something more sensible given its actual
// position and remove the `2` suffix here as this callback is what
// `addPreEmitPass` *should* be but in reality isn't.
void addPreEmitPass2(AddMachinePass &) const {}
/// {{@ For GlobalISel
///
/// addPreISel - This method should add any "last minute" LLVM->LLVM
/// passes (which are run just before instruction selector).
void addPreISel(AddIRPass &) const {
llvm_unreachable("addPreISel is not overridden");
}
/// This method should install an IR translator pass, which converts from
/// LLVM code to machine instructions with possibly generic opcodes.
Error addIRTranslator(AddMachinePass &) const {
return make_error<StringError>("addIRTranslator is not overridden",
inconvertibleErrorCode());
}
/// This method may be implemented by targets that want to run passes
/// immediately before legalization.
void addPreLegalizeMachineIR(AddMachinePass &) const {}
/// This method should install a legalize pass, which converts the instruction
/// sequence into one that can be selected by the target.
Error addLegalizeMachineIR(AddMachinePass &) const {
return make_error<StringError>("addLegalizeMachineIR is not overridden",
inconvertibleErrorCode());
}
/// This method may be implemented by targets that want to run passes
/// immediately before the register bank selection.
void addPreRegBankSelect(AddMachinePass &) const {}
/// This method should install a register bank selector pass, which
/// assigns register banks to virtual registers without a register
/// class or register banks.
Error addRegBankSelect(AddMachinePass &) const {
return make_error<StringError>("addRegBankSelect is not overridden",
inconvertibleErrorCode());
}
/// This method may be implemented by targets that want to run passes
/// immediately before the (global) instruction selection.
void addPreGlobalInstructionSelect(AddMachinePass &) const {}
/// This method should install a (global) instruction selector pass, which
/// converts possibly generic instructions to fully target-specific
/// instructions, thereby constraining all generic virtual registers to
/// register classes.
Error addGlobalInstructionSelect(AddMachinePass &) const {
return make_error<StringError>(
"addGlobalInstructionSelect is not overridden",
inconvertibleErrorCode());
}
/// @}}
/// High level function that adds all passes necessary to go from llvm IR
/// representation to the MI representation.
/// Adds IR based lowering and target specific optimization passes and finally
/// the core instruction selection passes.
void addISelPasses(AddIRPass &) const;
/// Add the actual instruction selection passes. This does not include
/// preparation passes on IR.
Error addCoreISelPasses(AddMachinePass &) const;
/// Add the complete, standard set of LLVM CodeGen passes.
/// Fully developed targets will not generally override this.
Error addMachinePasses(AddMachinePass &) const;
/// Add passes to lower exception handling for the code generator.
void addPassesToHandleExceptions(AddIRPass &) const;
/// Add common target configurable passes that perform LLVM IR to IR
/// transforms following machine independent optimization.
void addIRPasses(AddIRPass &) const;
/// Add pass to prepare the LLVM IR for code generation. This should be done
/// before exception handling preparation passes.
void addCodeGenPrepare(AddIRPass &) const;
/// Add common passes that perform LLVM IR to IR transforms in preparation for
/// instruction selection.
void addISelPrepare(AddIRPass &) const;
/// Methods with trivial inline returns are convenient points in the common
/// codegen pass pipeline where targets may insert passes. Methods with
/// out-of-line standard implementations are major CodeGen stages called by
/// addMachinePasses. Some targets may override major stages when inserting
/// passes is insufficient, but maintaining overriden stages is more work.
///
/// addMachineSSAOptimization - Add standard passes that optimize machine
/// instructions in SSA form.
void addMachineSSAOptimization(AddMachinePass &) const;
/// addFastRegAlloc - Add the minimum set of target-independent passes that
/// are required for fast register allocation.
Error addFastRegAlloc(AddMachinePass &) const;
/// addOptimizedRegAlloc - Add passes related to register allocation.
/// LLVMTargetMachine provides standard regalloc passes for most targets.
void addOptimizedRegAlloc(AddMachinePass &) const;
/// Add passes that optimize machine instructions after register allocation.
void addMachineLateOptimization(AddMachinePass &) const;
/// addGCPasses - Add late codegen passes that analyze code for garbage
/// collection. This should return true if GC info should be printed after
/// these passes.
void addGCPasses(AddMachinePass &) const {}
/// Add standard basic block placement passes.
void addBlockPlacement(AddMachinePass &) const;
using CreateMCStreamer =
std::function<Expected<std::unique_ptr<MCStreamer>>(MCContext &)>;
void addAsmPrinter(AddMachinePass &, CreateMCStreamer) const {
llvm_unreachable("addAsmPrinter is not overridden");
}
/// Utilities for targets to add passes to the pass manager.
///
/// createTargetRegisterAllocator - Create the register allocator pass for
/// this target at the current optimization level.
void addTargetRegisterAllocator(AddMachinePass &, bool Optimized) const;
/// addMachinePasses helper to create the target-selected or overriden
/// regalloc pass.
void addRegAllocPass(AddMachinePass &, bool Optimized) const;
/// Add core register alloator passes which do the actual register assignment
/// and rewriting. \returns true if any passes were added.
Error addRegAssignmentFast(AddMachinePass &) const;
Error addRegAssignmentOptimized(AddMachinePass &) const;
private:
DerivedT &derived() { return static_cast<DerivedT &>(*this); }
const DerivedT &derived() const {
return static_cast<const DerivedT &>(*this);
}
};
template <typename Derived>
Error CodeGenPassBuilder<Derived>::buildPipeline(
ModulePassManager &MPM, MachineFunctionPassManager &MFPM,
raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
CodeGenFileType FileType) const {
AddIRPass addIRPass(MPM, Opt.DebugPM);
addISelPasses(addIRPass);
AddMachinePass addPass(MFPM);
if (auto Err = addCoreISelPasses(addPass))
return std::move(Err);
if (auto Err = derived().addMachinePasses(addPass))
return std::move(Err);
derived().addAsmPrinter(
addPass, [this, &Out, DwoOut, FileType](MCContext &Ctx) {
return this->TM.createMCStreamer(Out, DwoOut, FileType, Ctx);
});
addPass(FreeMachineFunctionPass());
return Error::success();
}
static inline AAManager registerAAAnalyses() {
AAManager AA;
// The order in which these are registered determines their priority when
// being queried.
// Basic AliasAnalysis support.
// Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
// BasicAliasAnalysis wins if they disagree. This is intended to help
// support "obvious" type-punning idioms.
AA.registerFunctionAnalysis<TypeBasedAA>();
AA.registerFunctionAnalysis<ScopedNoAliasAA>();
AA.registerFunctionAnalysis<BasicAA>();
return AA;
}
template <typename Derived>
void CodeGenPassBuilder<Derived>::registerModuleAnalyses(
ModuleAnalysisManager &MAM) const {
#define MODULE_ANALYSIS(NAME, PASS_NAME, CONSTRUCTOR) \
MAM.registerPass([&] { return PASS_NAME CONSTRUCTOR; });
#include "MachinePassRegistry.def"
derived().registerTargetAnalysis(MAM);
}
template <typename Derived>
void CodeGenPassBuilder<Derived>::registerFunctionAnalyses(
FunctionAnalysisManager &FAM) const {
FAM.registerPass([this] { return registerAAAnalyses(); });
#define FUNCTION_ANALYSIS(NAME, PASS_NAME, CONSTRUCTOR) \
FAM.registerPass([&] { return PASS_NAME CONSTRUCTOR; });
#include "MachinePassRegistry.def"
derived().registerTargetAnalysis(FAM);
}
template <typename Derived>
void CodeGenPassBuilder<Derived>::registerMachineFunctionAnalyses(
MachineFunctionAnalysisManager &MFAM) const {
#define MACHINE_FUNCTION_ANALYSIS(NAME, PASS_NAME, CONSTRUCTOR) \
MFAM.registerPass([&] { return PASS_NAME CONSTRUCTOR; });
#include "MachinePassRegistry.def"
derived().registerTargetAnalysis(MFAM);
}
// FIXME: For new PM, use pass name directly in commandline seems good.
// Translate stringfied pass name to its old commandline name. Returns the
// matching legacy name and a boolean value indicating if the pass is a machine
// pass.
template <typename Derived>
std::pair<StringRef, bool>
CodeGenPassBuilder<Derived>::getPassNameFromLegacyName(StringRef Name) const {
std::pair<StringRef, bool> Ret;
if (Name.empty())
return Ret;
#define FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, false};
#define DUMMY_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, false};
#define MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, false};
#define DUMMY_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, false};
#define MACHINE_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, true};
#define DUMMY_MACHINE_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, true};
#define MACHINE_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, true};
#define DUMMY_MACHINE_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR) \
if (Name == NAME) \
Ret = {#PASS_NAME, true};
#include "llvm/CodeGen/MachinePassRegistry.def"
if (Ret.first.empty())
Ret = derived().getTargetPassNameFromLegacyName(Name);
if (Ret.first.empty())
report_fatal_error(Twine('\"') + Twine(Name) +
Twine("\" pass could not be found."));
return Ret;
}
template <typename Derived>
void CodeGenPassBuilder<Derived>::addISelPasses(AddIRPass &addPass) const {
if (TM.useEmulatedTLS())
addPass(LowerEmuTLSPass());
addPass(PreISelIntrinsicLoweringPass());
derived().addIRPasses(addPass);
derived().addCodeGenPrepare(addPass);
addPassesToHandleExceptions(addPass);
derived().addISelPrepare(addPass);
}
/// Add common target configurable passes that perform LLVM IR to IR transforms
/// following machine independent optimization.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addIRPasses(AddIRPass &addPass) const {
// Before running any passes, run the verifier to determine if the input
// coming from the front-end and/or optimizer is valid.
if (!Opt.DisableVerify)
addPass(VerifierPass());
// Run loop strength reduction before anything else.
if (getOptLevel() != CodeGenOpt::None && !Opt.DisableLSR) {
addPass(createFunctionToLoopPassAdaptor(
LoopStrengthReducePass(), /*UseMemorySSA*/ true, Opt.DebugPM));
// FIXME: use -stop-after so we could remove PrintLSR
if (Opt.PrintLSR)
addPass(PrintFunctionPass(dbgs(), "\n\n*** Code after LSR ***\n"));
}
if (getOptLevel() != CodeGenOpt::None) {
// The MergeICmpsPass tries to create memcmp calls by grouping sequences of
// loads and compares. ExpandMemCmpPass then tries to expand those calls
// into optimally-sized loads and compares. The transforms are enabled by a
// target lowering hook.
if (!Opt.DisableMergeICmps)
addPass(MergeICmpsPass());
addPass(ExpandMemCmpPass());
}
// Run GC lowering passes for builtin collectors
// TODO: add a pass insertion point here
addPass(GCLoweringPass());
addPass(ShadowStackGCLoweringPass());
addPass(LowerConstantIntrinsicsPass());
// Make sure that no unreachable blocks are instruction selected.
addPass(UnreachableBlockElimPass());
// Prepare expensive constants for SelectionDAG.
if (getOptLevel() != CodeGenOpt::None && !Opt.DisableConstantHoisting)
addPass(ConstantHoistingPass());
// Replace calls to LLVM intrinsics (e.g., exp, log) operating on vector
// operands with calls to the corresponding functions in a vector library.
if (getOptLevel() != CodeGenOpt::None)
addPass(ReplaceWithVeclib());
if (getOptLevel() != CodeGenOpt::None && !Opt.DisablePartialLibcallInlining)
addPass(PartiallyInlineLibCallsPass());
// Instrument function entry and exit, e.g. with calls to mcount().
addPass(EntryExitInstrumenterPass(/*PostInlining=*/true));
// Add scalarization of target's unsupported masked memory intrinsics pass.
// the unsupported intrinsic will be replaced with a chain of basic blocks,
// that stores/loads element one-by-one if the appropriate mask bit is set.
addPass(ScalarizeMaskedMemIntrinPass());
// Expand reduction intrinsics into shuffle sequences if the target wants to.
addPass(ExpandReductionsPass());
// Convert conditional moves to conditional jumps when profitable.
if (getOptLevel() != CodeGenOpt::None && !Opt.DisableSelectOptimize)
addPass(SelectOptimizePass());
}
/// Turn exception handling constructs into something the code generators can
/// handle.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addPassesToHandleExceptions(
AddIRPass &addPass) const {
const MCAsmInfo *MCAI = TM.getMCAsmInfo();
assert(MCAI && "No MCAsmInfo");
switch (MCAI->getExceptionHandlingType()) {
case ExceptionHandling::SjLj:
// SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both
// Dwarf EH prepare needs to be run after SjLj prepare. Otherwise,
// catch info can get misplaced when a selector ends up more than one block
// removed from the parent invoke(s). This could happen when a landing
// pad is shared by multiple invokes and is also a target of a normal
// edge from elsewhere.
addPass(SjLjEHPreparePass());
[[fallthrough]];
case ExceptionHandling::DwarfCFI:
case ExceptionHandling::ARM:
case ExceptionHandling::AIX:
addPass(DwarfEHPass(getOptLevel()));
break;
case ExceptionHandling::WinEH:
// We support using both GCC-style and MSVC-style exceptions on Windows, so
// add both preparation passes. Each pass will only actually run if it
// recognizes the personality function.
addPass(WinEHPass());
addPass(DwarfEHPass(getOptLevel()));
break;
case ExceptionHandling::Wasm:
// Wasm EH uses Windows EH instructions, but it does not need to demote PHIs
// on catchpads and cleanuppads because it does not outline them into
// funclets. Catchswitch blocks are not lowered in SelectionDAG, so we
// should remove PHIs there.
addPass(WinEHPass(/*DemoteCatchSwitchPHIOnly=*/false));
addPass(WasmEHPass());
break;
case ExceptionHandling::None:
addPass(LowerInvokePass());
// The lower invoke pass may create unreachable code. Remove it.
addPass(UnreachableBlockElimPass());
break;
}
}
/// Add pass to prepare the LLVM IR for code generation. This should be done
/// before exception handling preparation passes.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addCodeGenPrepare(AddIRPass &addPass) const {
if (getOptLevel() != CodeGenOpt::None && !Opt.DisableCGP)
addPass(CodeGenPreparePass());
// TODO: Default ctor'd RewriteSymbolPass is no-op.
// addPass(RewriteSymbolPass());
}
/// Add common passes that perform LLVM IR to IR transforms in preparation for
/// instruction selection.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addISelPrepare(AddIRPass &addPass) const {
derived().addPreISel(addPass);
// Add both the safe stack and the stack protection passes: each of them will
// only protect functions that have corresponding attributes.
addPass(SafeStackPass());
addPass(StackProtectorPass());
if (Opt.PrintISelInput)
addPass(PrintFunctionPass(dbgs(),
"\n\n*** Final LLVM Code input to ISel ***\n"));
// All passes which modify the LLVM IR are now complete; run the verifier
// to ensure that the IR is valid.
if (!Opt.DisableVerify)
addPass(VerifierPass());
}
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addCoreISelPasses(
AddMachinePass &addPass) const {
// Enable FastISel with -fast-isel, but allow that to be overridden.
TM.setO0WantsFastISel(Opt.EnableFastISelOption.value_or(true));
// Determine an instruction selector.
enum class SelectorType { SelectionDAG, FastISel, GlobalISel };
SelectorType Selector;
if (Opt.EnableFastISelOption && *Opt.EnableFastISelOption == true)
Selector = SelectorType::FastISel;
else if ((Opt.EnableGlobalISelOption &&
*Opt.EnableGlobalISelOption == true) ||
(TM.Options.EnableGlobalISel &&
(!Opt.EnableGlobalISelOption ||
*Opt.EnableGlobalISelOption == false)))
Selector = SelectorType::GlobalISel;
else if (TM.getOptLevel() == CodeGenOpt::None && TM.getO0WantsFastISel())
Selector = SelectorType::FastISel;
else
Selector = SelectorType::SelectionDAG;
// Set consistently TM.Options.EnableFastISel and EnableGlobalISel.
if (Selector == SelectorType::FastISel) {
TM.setFastISel(true);
TM.setGlobalISel(false);
} else if (Selector == SelectorType::GlobalISel) {
TM.setFastISel(false);
TM.setGlobalISel(true);
}
// Add instruction selector passes.
if (Selector == SelectorType::GlobalISel) {
if (auto Err = derived().addIRTranslator(addPass))
return std::move(Err);
derived().addPreLegalizeMachineIR(addPass);
if (auto Err = derived().addLegalizeMachineIR(addPass))
return std::move(Err);
// Before running the register bank selector, ask the target if it
// wants to run some passes.
derived().addPreRegBankSelect(addPass);
if (auto Err = derived().addRegBankSelect(addPass))
return std::move(Err);
derived().addPreGlobalInstructionSelect(addPass);
if (auto Err = derived().addGlobalInstructionSelect(addPass))
return std::move(Err);
// Pass to reset the MachineFunction if the ISel failed.
addPass(ResetMachineFunctionPass(reportDiagnosticWhenGlobalISelFallback(),
isGlobalISelAbortEnabled()));
// Provide a fallback path when we do not want to abort on
// not-yet-supported input.
if (!isGlobalISelAbortEnabled())
if (auto Err = derived().addInstSelector(addPass))
return std::move(Err);
} else if (auto Err = derived().addInstSelector(addPass))
return std::move(Err);
// Expand pseudo-instructions emitted by ISel. Don't run the verifier before
// FinalizeISel.
addPass(FinalizeISelPass());
// // Print the instruction selected machine code...
// printAndVerify("After Instruction Selection");
return Error::success();
}
/// Add the complete set of target-independent postISel code generator passes.
///
/// This can be read as the standard order of major LLVM CodeGen stages. Stages
/// with nontrivial configuration or multiple passes are broken out below in
/// add%Stage routines.
///
/// Any CodeGenPassBuilder<Derived>::addXX routine may be overriden by the
/// Target. The addPre/Post methods with empty header implementations allow
/// injecting target-specific fixups just before or after major stages.
/// Additionally, targets have the flexibility to change pass order within a
/// stage by overriding default implementation of add%Stage routines below. Each
/// technique has maintainability tradeoffs because alternate pass orders are
/// not well supported. addPre/Post works better if the target pass is easily
/// tied to a common pass. But if it has subtle dependencies on multiple passes,
/// the target should override the stage instead.
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addMachinePasses(
AddMachinePass &addPass) const {
// Add passes that optimize machine instructions in SSA form.
if (getOptLevel() != CodeGenOpt::None) {
derived().addMachineSSAOptimization(addPass);
} else {
// If the target requests it, assign local variables to stack slots relative
// to one another and simplify frame index references where possible.
addPass(LocalStackSlotPass());
}
if (TM.Options.EnableIPRA)
addPass(RegUsageInfoPropagationPass());
// Run pre-ra passes.
derived().addPreRegAlloc(addPass);
// Run register allocation and passes that are tightly coupled with it,
// including phi elimination and scheduling.
if (*Opt.OptimizeRegAlloc) {
derived().addOptimizedRegAlloc(addPass);
} else {
if (auto Err = derived().addFastRegAlloc(addPass))
return Err;
}
// Run post-ra passes.
derived().addPostRegAlloc(addPass);
addPass(RemoveRedundantDebugValuesPass());
// Insert prolog/epilog code. Eliminate abstract frame index references...
if (getOptLevel() != CodeGenOpt::None) {
addPass(PostRAMachineSinkingPass());
addPass(ShrinkWrapPass());
}
addPass(PrologEpilogInserterPass());
/// Add passes that optimize machine instructions after register allocation.
if (getOptLevel() != CodeGenOpt::None)
derived().addMachineLateOptimization(addPass);
// Expand pseudo instructions before second scheduling pass.
addPass(ExpandPostRAPseudosPass());
// Run pre-sched2 passes.
derived().addPreSched2(addPass);
if (Opt.EnableImplicitNullChecks)
addPass(ImplicitNullChecksPass());
// Second pass scheduler.
// Let Target optionally insert this pass by itself at some other
// point.
if (getOptLevel() != CodeGenOpt::None &&
!TM.targetSchedulesPostRAScheduling()) {
if (Opt.MISchedPostRA)
addPass(PostMachineSchedulerPass());
else
addPass(PostRASchedulerPass());
}
// GC
derived().addGCPasses(addPass);
// Basic block placement.
if (getOptLevel() != CodeGenOpt::None)
derived().addBlockPlacement(addPass);
// Insert before XRay Instrumentation.
addPass(FEntryInserterPass());
addPass(XRayInstrumentationPass());
addPass(PatchableFunctionPass());
derived().addPreEmitPass(addPass);
if (TM.Options.EnableIPRA)
// Collect register usage information and produce a register mask of
// clobbered registers, to be used to optimize call sites.
addPass(RegUsageInfoCollectorPass());
addPass(FuncletLayoutPass());
addPass(StackMapLivenessPass());
addPass(LiveDebugValuesPass());
addPass(MachineSanitizerBinaryMetadata());
if (TM.Options.EnableMachineOutliner && getOptLevel() != CodeGenOpt::None &&
Opt.EnableMachineOutliner != RunOutliner::NeverOutline) {
bool RunOnAllFunctions =
(Opt.EnableMachineOutliner == RunOutliner::AlwaysOutline);
bool AddOutliner = RunOnAllFunctions || TM.Options.SupportsDefaultOutlining;
if (AddOutliner)
addPass(MachineOutlinerPass(RunOnAllFunctions));
}
// Add passes that directly emit MI after all other MI passes.
derived().addPreEmitPass2(addPass);
return Error::success();
}
/// Add passes that optimize machine instructions in SSA form.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addMachineSSAOptimization(
AddMachinePass &addPass) const {
// Pre-ra tail duplication.
addPass(EarlyTailDuplicatePass());
// Optimize PHIs before DCE: removing dead PHI cycles may make more
// instructions dead.
addPass(OptimizePHIsPass());
// This pass merges large allocas. StackSlotColoring is a different pass
// which merges spill slots.
addPass(StackColoringPass());
// If the target requests it, assign local variables to stack slots relative
// to one another and simplify frame index references where possible.
addPass(LocalStackSlotPass());
// With optimization, dead code should already be eliminated. However
// there is one known exception: lowered code for arguments that are only
// used by tail calls, where the tail calls reuse the incoming stack
// arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
addPass(DeadMachineInstructionElimPass());
// Allow targets to insert passes that improve instruction level parallelism,
// like if-conversion. Such passes will typically need dominator trees and
// loop info, just like LICM and CSE below.
derived().addILPOpts(addPass);
addPass(EarlyMachineLICMPass());
addPass(MachineCSEPass());
addPass(MachineSinkingPass());
addPass(PeepholeOptimizerPass());
// Clean-up the dead code that may have been generated by peephole
// rewriting.
addPass(DeadMachineInstructionElimPass());
}
//===---------------------------------------------------------------------===//
/// Register Allocation Pass Configuration
//===---------------------------------------------------------------------===//
/// Instantiate the default register allocator pass for this target for either
/// the optimized or unoptimized allocation path. This will be added to the pass
/// manager by addFastRegAlloc in the unoptimized case or addOptimizedRegAlloc
/// in the optimized case.
///
/// A target that uses the standard regalloc pass order for fast or optimized
/// allocation may still override this for per-target regalloc
/// selection. But -regalloc=... always takes precedence.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addTargetRegisterAllocator(
AddMachinePass &addPass, bool Optimized) const {
if (Optimized)
addPass(RAGreedyPass());
else
addPass(RAFastPass());
}
/// Find and instantiate the register allocation pass requested by this target
/// at the current optimization level. Different register allocators are
/// defined as separate passes because they may require different analysis.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addRegAllocPass(AddMachinePass &addPass,
bool Optimized) const {
if (Opt.RegAlloc == RegAllocType::Default)
// With no -regalloc= override, ask the target for a regalloc pass.
derived().addTargetRegisterAllocator(addPass, Optimized);
else if (Opt.RegAlloc == RegAllocType::Basic)
addPass(RABasicPass());
else if (Opt.RegAlloc == RegAllocType::Fast)
addPass(RAFastPass());
else if (Opt.RegAlloc == RegAllocType::Greedy)
addPass(RAGreedyPass());
else if (Opt.RegAlloc == RegAllocType::PBQP)
addPass(RAPBQPPass());
else
llvm_unreachable("unknonwn register allocator type");
}
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addRegAssignmentFast(
AddMachinePass &addPass) const {
if (Opt.RegAlloc != RegAllocType::Default &&
Opt.RegAlloc != RegAllocType::Fast)
return make_error<StringError>(
"Must use fast (default) register allocator for unoptimized regalloc.",
inconvertibleErrorCode());
addRegAllocPass(addPass, false);
return Error::success();
}
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addRegAssignmentOptimized(
AddMachinePass &addPass) const {
// Add the selected register allocation pass.
addRegAllocPass(addPass, true);
// Allow targets to change the register assignments before rewriting.
derived().addPreRewrite(addPass);
// Finally rewrite virtual registers.
addPass(VirtRegRewriterPass());
// Perform stack slot coloring and post-ra machine LICM.
//
// FIXME: Re-enable coloring with register when it's capable of adding
// kill markers.
addPass(StackSlotColoringPass());
return Error::success();
}
/// Add the minimum set of target-independent passes that are required for
/// register allocation. No coalescing or scheduling.
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addFastRegAlloc(
AddMachinePass &addPass) const {
addPass(PHIEliminationPass());
addPass(TwoAddressInstructionPass());
return derived().addRegAssignmentFast(addPass);
}
/// Add standard target-independent passes that are tightly coupled with
/// optimized register allocation, including coalescing, machine instruction
/// scheduling, and register allocation itself.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addOptimizedRegAlloc(
AddMachinePass &addPass) const {
addPass(DetectDeadLanesPass());
addPass(ProcessImplicitDefsPass());
// Edge splitting is smarter with machine loop info.
addPass(PHIEliminationPass());
// Eventually, we want to run LiveIntervals before PHI elimination.
if (Opt.EarlyLiveIntervals)
addPass(LiveIntervalsPass());
addPass(TwoAddressInstructionPass());
addPass(RegisterCoalescerPass());
// The machine scheduler may accidentally create disconnected components
// when moving subregister definitions around, avoid this by splitting them to
// separate vregs before. Splitting can also improve reg. allocation quality.
addPass(RenameIndependentSubregsPass());
// PreRA instruction scheduling.
addPass(MachineSchedulerPass());
if (derived().addRegAssignmentOptimized(addPass)) {
// Allow targets to expand pseudo instructions depending on the choice of
// registers before MachineCopyPropagation.
derived().addPostRewrite(addPass);
// Copy propagate to forward register uses and try to eliminate COPYs that
// were not coalesced.
addPass(MachineCopyPropagationPass());
// Run post-ra machine LICM to hoist reloads / remats.
//
// FIXME: can this move into MachineLateOptimization?
addPass(MachineLICMPass());
}
}
//===---------------------------------------------------------------------===//
/// Post RegAlloc Pass Configuration
//===---------------------------------------------------------------------===//
/// Add passes that optimize machine instructions after register allocation.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addMachineLateOptimization(
AddMachinePass &addPass) const {
// Branch folding must be run after regalloc and prolog/epilog insertion.
addPass(BranchFolderPass());
// Tail duplication.
// Note that duplicating tail just increases code size and degrades
// performance for targets that require Structured Control Flow.
// In addition it can also make CFG irreducible. Thus we disable it.
if (!TM.requiresStructuredCFG())
addPass(TailDuplicatePass());
// Cleanup of redundant (identical) address/immediate loads.
addPass(MachineLateInstrsCleanupPass());
// Copy propagation.
addPass(MachineCopyPropagationPass());
}
/// Add standard basic block placement passes.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addBlockPlacement(
AddMachinePass &addPass) const {
addPass(MachineBlockPlacementPass());
// Run a separate pass to collect block placement statistics.
if (Opt.EnableBlockPlacementStats)
addPass(MachineBlockPlacementStatsPass());
}
} // namespace llvm
#endif // LLVM_CODEGEN_CODEGENPASSBUILDER_H