1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 04:32:44 +01:00
llvm-mirror/lib/Target/AArch64/AArch64TargetMachine.cpp
Roman Lebedev 4a9109b967 [SimplifyCFG][LoopRotate] SimplifyCFG: disable common instruction hoisting by default, enable late in pipeline
I've been looking at missed vectorizations in one codebase.
One particular thing that stands out is that some of the loops
reach vectorizer in a rather mangled form, with weird PHI's,
and some of the loops aren't even in a rotated form.

After taking a more detailed look, that happened because
the loop's headers were too big by then. It is evident that
SimplifyCFG's common code hoisting transform is at fault there,
because the pattern it handles is precisely the unrotated
loop basic block structure.

Surprizingly, `SimplifyCFGOpt::HoistThenElseCodeToIf()` is enabled
by default, and is always run, unlike it's friend, common code sinking
transform, `SinkCommonCodeFromPredecessors()`, which is not enabled
by default and is only run once very late in the pipeline.

I'm proposing to harmonize this, and disable common code hoisting
until //late// in pipeline. Definition of //late// may vary,
here currently i've picked the same one as for code sinking,
but i suppose we could enable it as soon as right after
loop rotation happens.

Experimentation shows that this does indeed unsurprizingly help,
more loops got rotated, although other issues remain elsewhere.

Now, this undoubtedly seriously shakes phase ordering.
This will undoubtedly be a mixed bag in terms of both compile- and
run- time performance, codesize. Since we no longer aggressively
hoist+deduplicate common code, we don't pay the price of said hoisting
(which wasn't big). That may allow more loops to be rotated,
so we pay that price. That, in turn, that may enable all the transforms
that require canonical (rotated) loop form, including but not limited to
vectorization, so we pay that too. And in general, no deduplication means
more [duplicate] instructions going through the optimizations. But there's still
late hoisting, some of them will be caught late.

As per benchmarks i've run {F12360204}, this is mostly within the noise,
there are some small improvements, some small regressions.
One big regression i saw i fixed in rG8d487668d09fb0e4e54f36207f07c1480ffabbfd, but i'm sure
this will expose many more pre-existing missed optimizations, as usual :S

llvm-compile-time-tracker.com thoughts on this:
http://llvm-compile-time-tracker.com/compare.php?from=e40315d2b4ed1e38962a8f33ff151693ed4ada63&to=c8289c0ecbf235da9fb0e3bc052e3c0d6bff5cf9&stat=instructions
* this does regress compile-time by +0.5% geomean (unsurprizingly)
* size impact varies; for ThinLTO it's actually an improvement

The largest fallout appears to be in GVN's load partial redundancy
elimination, it spends *much* more time in
`MemoryDependenceResults::getNonLocalPointerDependency()`.
Non-local `MemoryDependenceResults` is widely-known to be, uh, costly.
There does not appear to be a proper solution to this issue,
other than silencing the compile-time performance regression
by tuning cut-off thresholds in `MemoryDependenceResults`,
at the cost of potentially regressing run-time performance.
D84609 attempts to move in that direction, but the path is unclear
and is going to take some time.

If we look at stats before/after diffs, some excerpts:
* RawSpeed (the target) {F12360200}
  * -14 (-73.68%) loops not rotated due to the header size (yay)
  * -272 (-0.67%) `"Number of live out of a loop variables"` - good for vectorizer
  * -3937 (-64.19%) common instructions hoisted
  * +561 (+0.06%) x86 asm instructions
  * -2 basic blocks
  * +2418 (+0.11%) IR instructions
* vanilla test-suite + RawSpeed + darktable  {F12360201}
  * -36396 (-65.29%) common instructions hoisted
  * +1676 (+0.02%) x86 asm instructions
  * +662 (+0.06%) basic blocks
  * +4395 (+0.04%) IR instructions

It is likely to be sub-optimal for when optimizing for code size,
so one might want to change tune pipeline by enabling sinking/hoisting
when optimizing for size.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D84108
2020-07-29 20:05:30 +03:00

706 lines
27 KiB
C++

//===-- AArch64TargetMachine.cpp - Define TargetMachine for AArch64 -------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
#include "AArch64TargetMachine.h"
#include "AArch64.h"
#include "AArch64MachineFunctionInfo.h"
#include "AArch64MacroFusion.h"
#include "AArch64Subtarget.h"
#include "AArch64TargetObjectFile.h"
#include "AArch64TargetTransformInfo.h"
#include "MCTargetDesc/AArch64MCTargetDesc.h"
#include "TargetInfo/AArch64TargetInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/CodeGen/CSEConfigBase.h"
#include "llvm/CodeGen/GlobalISel/IRTranslator.h"
#include "llvm/CodeGen/GlobalISel/InstructionSelect.h"
#include "llvm/CodeGen/GlobalISel/Legalizer.h"
#include "llvm/CodeGen/GlobalISel/Localizer.h"
#include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
#include "llvm/CodeGen/MIRParser/MIParser.h"
#include "llvm/CodeGen/MachineScheduler.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/Function.h"
#include "llvm/InitializePasses.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Pass.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Transforms/CFGuard.h"
#include "llvm/Transforms/Scalar.h"
#include <memory>
#include <string>
using namespace llvm;
static cl::opt<bool> EnableCCMP("aarch64-enable-ccmp",
cl::desc("Enable the CCMP formation pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableCondBrTuning("aarch64-enable-cond-br-tune",
cl::desc("Enable the conditional branch tuning pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool> EnableMCR("aarch64-enable-mcr",
cl::desc("Enable the machine combiner pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool> EnableStPairSuppress("aarch64-enable-stp-suppress",
cl::desc("Suppress STP for AArch64"),
cl::init(true), cl::Hidden);
static cl::opt<bool> EnableAdvSIMDScalar(
"aarch64-enable-simd-scalar",
cl::desc("Enable use of AdvSIMD scalar integer instructions"),
cl::init(false), cl::Hidden);
static cl::opt<bool>
EnablePromoteConstant("aarch64-enable-promote-const",
cl::desc("Enable the promote constant pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool> EnableCollectLOH(
"aarch64-enable-collect-loh",
cl::desc("Enable the pass that emits the linker optimization hints (LOH)"),
cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableDeadRegisterElimination("aarch64-enable-dead-defs", cl::Hidden,
cl::desc("Enable the pass that removes dead"
" definitons and replaces stores to"
" them with stores to the zero"
" register"),
cl::init(true));
static cl::opt<bool> EnableRedundantCopyElimination(
"aarch64-enable-copyelim",
cl::desc("Enable the redundant copy elimination pass"), cl::init(true),
cl::Hidden);
static cl::opt<bool> EnableLoadStoreOpt("aarch64-enable-ldst-opt",
cl::desc("Enable the load/store pair"
" optimization pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool> EnableAtomicTidy(
"aarch64-enable-atomic-cfg-tidy", cl::Hidden,
cl::desc("Run SimplifyCFG after expanding atomic operations"
" to make use of cmpxchg flow-based information"),
cl::init(true));
static cl::opt<bool>
EnableEarlyIfConversion("aarch64-enable-early-ifcvt", cl::Hidden,
cl::desc("Run early if-conversion"),
cl::init(true));
static cl::opt<bool>
EnableCondOpt("aarch64-enable-condopt",
cl::desc("Enable the condition optimizer pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableA53Fix835769("aarch64-fix-cortex-a53-835769", cl::Hidden,
cl::desc("Work around Cortex-A53 erratum 835769"),
cl::init(false));
static cl::opt<bool>
EnableGEPOpt("aarch64-enable-gep-opt", cl::Hidden,
cl::desc("Enable optimizations on complex GEPs"),
cl::init(false));
static cl::opt<bool>
BranchRelaxation("aarch64-enable-branch-relax", cl::Hidden, cl::init(true),
cl::desc("Relax out of range conditional branches"));
static cl::opt<bool> EnableCompressJumpTables(
"aarch64-enable-compress-jump-tables", cl::Hidden, cl::init(true),
cl::desc("Use smallest entry possible for jump tables"));
// FIXME: Unify control over GlobalMerge.
static cl::opt<cl::boolOrDefault>
EnableGlobalMerge("aarch64-enable-global-merge", cl::Hidden,
cl::desc("Enable the global merge pass"));
static cl::opt<bool>
EnableLoopDataPrefetch("aarch64-enable-loop-data-prefetch", cl::Hidden,
cl::desc("Enable the loop data prefetch pass"),
cl::init(true));
static cl::opt<int> EnableGlobalISelAtO(
"aarch64-enable-global-isel-at-O", cl::Hidden,
cl::desc("Enable GlobalISel at or below an opt level (-1 to disable)"),
cl::init(0));
static cl::opt<bool>
EnableSVEIntrinsicOpts("aarch64-enable-sve-intrinsic-opts", cl::Hidden,
cl::desc("Enable SVE intrinsic opts"),
cl::init(true));
static cl::opt<bool> EnableFalkorHWPFFix("aarch64-enable-falkor-hwpf-fix",
cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableBranchTargets("aarch64-enable-branch-targets", cl::Hidden,
cl::desc("Enable the AAcrh64 branch target pass"),
cl::init(true));
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64Target() {
// Register the target.
RegisterTargetMachine<AArch64leTargetMachine> X(getTheAArch64leTarget());
RegisterTargetMachine<AArch64beTargetMachine> Y(getTheAArch64beTarget());
RegisterTargetMachine<AArch64leTargetMachine> Z(getTheARM64Target());
RegisterTargetMachine<AArch64leTargetMachine> W(getTheARM64_32Target());
RegisterTargetMachine<AArch64leTargetMachine> V(getTheAArch64_32Target());
auto PR = PassRegistry::getPassRegistry();
initializeGlobalISel(*PR);
initializeAArch64A53Fix835769Pass(*PR);
initializeAArch64A57FPLoadBalancingPass(*PR);
initializeAArch64AdvSIMDScalarPass(*PR);
initializeAArch64BranchTargetsPass(*PR);
initializeAArch64CollectLOHPass(*PR);
initializeAArch64CompressJumpTablesPass(*PR);
initializeAArch64ConditionalComparesPass(*PR);
initializeAArch64ConditionOptimizerPass(*PR);
initializeAArch64DeadRegisterDefinitionsPass(*PR);
initializeAArch64ExpandPseudoPass(*PR);
initializeAArch64LoadStoreOptPass(*PR);
initializeAArch64SIMDInstrOptPass(*PR);
initializeAArch64PreLegalizerCombinerPass(*PR);
initializeAArch64PostLegalizerCombinerPass(*PR);
initializeAArch64PromoteConstantPass(*PR);
initializeAArch64RedundantCopyEliminationPass(*PR);
initializeAArch64StorePairSuppressPass(*PR);
initializeFalkorHWPFFixPass(*PR);
initializeFalkorMarkStridedAccessesLegacyPass(*PR);
initializeLDTLSCleanupPass(*PR);
initializeSVEIntrinsicOptsPass(*PR);
initializeAArch64SpeculationHardeningPass(*PR);
initializeAArch64SLSHardeningPass(*PR);
initializeAArch64StackTaggingPass(*PR);
initializeAArch64StackTaggingPreRAPass(*PR);
}
//===----------------------------------------------------------------------===//
// AArch64 Lowering public interface.
//===----------------------------------------------------------------------===//
static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
if (TT.isOSBinFormatMachO())
return std::make_unique<AArch64_MachoTargetObjectFile>();
if (TT.isOSBinFormatCOFF())
return std::make_unique<AArch64_COFFTargetObjectFile>();
return std::make_unique<AArch64_ELFTargetObjectFile>();
}
// Helper function to build a DataLayout string
static std::string computeDataLayout(const Triple &TT,
const MCTargetOptions &Options,
bool LittleEndian) {
if (Options.getABIName() == "ilp32")
return "e-m:e-p:32:32-i8:8-i16:16-i64:64-S128";
if (TT.isOSBinFormatMachO()) {
if (TT.getArch() == Triple::aarch64_32)
return "e-m:o-p:32:32-i64:64-i128:128-n32:64-S128";
return "e-m:o-i64:64-i128:128-n32:64-S128";
}
if (TT.isOSBinFormatCOFF())
return "e-m:w-p:64:64-i32:32-i64:64-i128:128-n32:64-S128";
if (LittleEndian)
return "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128";
return "E-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128";
}
static Reloc::Model getEffectiveRelocModel(const Triple &TT,
Optional<Reloc::Model> RM) {
// AArch64 Darwin and Windows are always PIC.
if (TT.isOSDarwin() || TT.isOSWindows())
return Reloc::PIC_;
// On ELF platforms the default static relocation model has a smart enough
// linker to cope with referencing external symbols defined in a shared
// library. Hence DynamicNoPIC doesn't need to be promoted to PIC.
if (!RM.hasValue() || *RM == Reloc::DynamicNoPIC)
return Reloc::Static;
return *RM;
}
static CodeModel::Model
getEffectiveAArch64CodeModel(const Triple &TT, Optional<CodeModel::Model> CM,
bool JIT) {
if (CM) {
if (*CM != CodeModel::Small && *CM != CodeModel::Tiny &&
*CM != CodeModel::Large) {
report_fatal_error(
"Only small, tiny and large code models are allowed on AArch64");
} else if (*CM == CodeModel::Tiny && !TT.isOSBinFormatELF())
report_fatal_error("tiny code model is only supported on ELF");
return *CM;
}
// The default MCJIT memory managers make no guarantees about where they can
// find an executable page; JITed code needs to be able to refer to globals
// no matter how far away they are.
// We should set the CodeModel::Small for Windows ARM64 in JIT mode,
// since with large code model LLVM generating 4 MOV instructions, and
// Windows doesn't support relocating these long branch (4 MOVs).
if (JIT && !TT.isOSWindows())
return CodeModel::Large;
return CodeModel::Small;
}
/// Create an AArch64 architecture model.
///
AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
StringRef CPU, StringRef FS,
const TargetOptions &Options,
Optional<Reloc::Model> RM,
Optional<CodeModel::Model> CM,
CodeGenOpt::Level OL, bool JIT,
bool LittleEndian)
: LLVMTargetMachine(T,
computeDataLayout(TT, Options.MCOptions, LittleEndian),
TT, CPU, FS, Options, getEffectiveRelocModel(TT, RM),
getEffectiveAArch64CodeModel(TT, CM, JIT), OL),
TLOF(createTLOF(getTargetTriple())), isLittle(LittleEndian) {
initAsmInfo();
if (TT.isOSBinFormatMachO()) {
this->Options.TrapUnreachable = true;
this->Options.NoTrapAfterNoreturn = true;
}
if (getMCAsmInfo()->usesWindowsCFI()) {
// Unwinding can get confused if the last instruction in an
// exception-handling region (function, funclet, try block, etc.)
// is a call.
//
// FIXME: We could elide the trap if the next instruction would be in
// the same region anyway.
this->Options.TrapUnreachable = true;
}
if (this->Options.TLSSize == 0) // default
this->Options.TLSSize = 24;
if ((getCodeModel() == CodeModel::Small ||
getCodeModel() == CodeModel::Kernel) &&
this->Options.TLSSize > 32)
// for the small (and kernel) code model, the maximum TLS size is 4GiB
this->Options.TLSSize = 32;
else if (getCodeModel() == CodeModel::Tiny && this->Options.TLSSize > 24)
// for the tiny code model, the maximum TLS size is 1MiB (< 16MiB)
this->Options.TLSSize = 24;
// Enable GlobalISel at or below EnableGlobalISelAt0, unless this is
// MachO/CodeModel::Large, which GlobalISel does not support.
if (getOptLevel() <= EnableGlobalISelAtO &&
TT.getArch() != Triple::aarch64_32 &&
!(getCodeModel() == CodeModel::Large && TT.isOSBinFormatMachO())) {
setGlobalISel(true);
setGlobalISelAbort(GlobalISelAbortMode::Disable);
}
// AArch64 supports the MachineOutliner.
setMachineOutliner(true);
// AArch64 supports default outlining behaviour.
setSupportsDefaultOutlining(true);
// AArch64 supports the debug entry values.
setSupportsDebugEntryValues(true);
}
AArch64TargetMachine::~AArch64TargetMachine() = default;
const AArch64Subtarget *
AArch64TargetMachine::getSubtargetImpl(const Function &F) const {
Attribute CPUAttr = F.getFnAttribute("target-cpu");
Attribute FSAttr = F.getFnAttribute("target-features");
std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
? CPUAttr.getValueAsString().str()
: TargetCPU;
std::string FS = !FSAttr.hasAttribute(Attribute::None)
? FSAttr.getValueAsString().str()
: TargetFS;
auto &I = SubtargetMap[CPU + FS];
if (!I) {
// This needs to be done before we create a new subtarget since any
// creation will depend on the TM and the code generation flags on the
// function that reside in TargetOptions.
resetTargetOptions(F);
I = std::make_unique<AArch64Subtarget>(TargetTriple, CPU, FS, *this,
isLittle);
}
return I.get();
}
void AArch64leTargetMachine::anchor() { }
AArch64leTargetMachine::AArch64leTargetMachine(
const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
const TargetOptions &Options, Optional<Reloc::Model> RM,
Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
: AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, JIT, true) {}
void AArch64beTargetMachine::anchor() { }
AArch64beTargetMachine::AArch64beTargetMachine(
const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
const TargetOptions &Options, Optional<Reloc::Model> RM,
Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
: AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, JIT, false) {}
namespace {
/// AArch64 Code Generator Pass Configuration Options.
class AArch64PassConfig : public TargetPassConfig {
public:
AArch64PassConfig(AArch64TargetMachine &TM, PassManagerBase &PM)
: TargetPassConfig(TM, PM) {
if (TM.getOptLevel() != CodeGenOpt::None)
substitutePass(&PostRASchedulerID, &PostMachineSchedulerID);
}
AArch64TargetMachine &getAArch64TargetMachine() const {
return getTM<AArch64TargetMachine>();
}
ScheduleDAGInstrs *
createMachineScheduler(MachineSchedContext *C) const override {
const AArch64Subtarget &ST = C->MF->getSubtarget<AArch64Subtarget>();
ScheduleDAGMILive *DAG = createGenericSchedLive(C);
DAG->addMutation(createLoadClusterDAGMutation(DAG->TII, DAG->TRI));
DAG->addMutation(createStoreClusterDAGMutation(DAG->TII, DAG->TRI));
if (ST.hasFusion())
DAG->addMutation(createAArch64MacroFusionDAGMutation());
return DAG;
}
ScheduleDAGInstrs *
createPostMachineScheduler(MachineSchedContext *C) const override {
const AArch64Subtarget &ST = C->MF->getSubtarget<AArch64Subtarget>();
if (ST.hasFusion()) {
// Run the Macro Fusion after RA again since literals are expanded from
// pseudos then (v. addPreSched2()).
ScheduleDAGMI *DAG = createGenericSchedPostRA(C);
DAG->addMutation(createAArch64MacroFusionDAGMutation());
return DAG;
}
return nullptr;
}
void addIRPasses() override;
bool addPreISel() override;
bool addInstSelector() override;
bool addIRTranslator() override;
void addPreLegalizeMachineIR() override;
bool addLegalizeMachineIR() override;
void addPreRegBankSelect() override;
bool addRegBankSelect() override;
void addPreGlobalInstructionSelect() override;
bool addGlobalInstructionSelect() override;
bool addILPOpts() override;
void addPreRegAlloc() override;
void addPostRegAlloc() override;
void addPreSched2() override;
void addPreEmitPass() override;
std::unique_ptr<CSEConfigBase> getCSEConfig() const override;
};
} // end anonymous namespace
TargetTransformInfo
AArch64TargetMachine::getTargetTransformInfo(const Function &F) {
return TargetTransformInfo(AArch64TTIImpl(this, F));
}
TargetPassConfig *AArch64TargetMachine::createPassConfig(PassManagerBase &PM) {
return new AArch64PassConfig(*this, PM);
}
std::unique_ptr<CSEConfigBase> AArch64PassConfig::getCSEConfig() const {
return getStandardCSEConfigForOpt(TM->getOptLevel());
}
void AArch64PassConfig::addIRPasses() {
// Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
// ourselves.
addPass(createAtomicExpandPass());
// Expand any SVE vector library calls that we can't code generate directly.
if (EnableSVEIntrinsicOpts && TM->getOptLevel() == CodeGenOpt::Aggressive)
addPass(createSVEIntrinsicOptsPass());
// Cmpxchg instructions are often used with a subsequent comparison to
// determine whether it succeeded. We can exploit existing control-flow in
// ldrex/strex loops to simplify this, but it needs tidying up.
if (TM->getOptLevel() != CodeGenOpt::None && EnableAtomicTidy)
addPass(createCFGSimplificationPass(SimplifyCFGOptions()
.forwardSwitchCondToPhi(true)
.convertSwitchToLookupTable(true)
.needCanonicalLoops(false)
.hoistCommonInsts(true)
.sinkCommonInsts(true)));
// Run LoopDataPrefetch
//
// Run this before LSR to remove the multiplies involved in computing the
// pointer values N iterations ahead.
if (TM->getOptLevel() != CodeGenOpt::None) {
if (EnableLoopDataPrefetch)
addPass(createLoopDataPrefetchPass());
if (EnableFalkorHWPFFix)
addPass(createFalkorMarkStridedAccessesPass());
}
TargetPassConfig::addIRPasses();
addPass(createAArch64StackTaggingPass(
/*IsOptNone=*/TM->getOptLevel() == CodeGenOpt::None));
// Match interleaved memory accesses to ldN/stN intrinsics.
if (TM->getOptLevel() != CodeGenOpt::None) {
addPass(createInterleavedLoadCombinePass());
addPass(createInterleavedAccessPass());
}
if (TM->getOptLevel() == CodeGenOpt::Aggressive && EnableGEPOpt) {
// Call SeparateConstOffsetFromGEP pass to extract constants within indices
// and lower a GEP with multiple indices to either arithmetic operations or
// multiple GEPs with single index.
addPass(createSeparateConstOffsetFromGEPPass(true));
// Call EarlyCSE pass to find and remove subexpressions in the lowered
// result.
addPass(createEarlyCSEPass());
// Do loop invariant code motion in case part of the lowered result is
// invariant.
addPass(createLICMPass());
}
// Add Control Flow Guard checks.
if (TM->getTargetTriple().isOSWindows())
addPass(createCFGuardCheckPass());
}
// Pass Pipeline Configuration
bool AArch64PassConfig::addPreISel() {
// Run promote constant before global merge, so that the promoted constants
// get a chance to be merged
if (TM->getOptLevel() != CodeGenOpt::None && EnablePromoteConstant)
addPass(createAArch64PromoteConstantPass());
// FIXME: On AArch64, this depends on the type.
// Basically, the addressable offsets are up to 4095 * Ty.getSizeInBytes().
// and the offset has to be a multiple of the related size in bytes.
if ((TM->getOptLevel() != CodeGenOpt::None &&
EnableGlobalMerge == cl::BOU_UNSET) ||
EnableGlobalMerge == cl::BOU_TRUE) {
bool OnlyOptimizeForSize = (TM->getOptLevel() < CodeGenOpt::Aggressive) &&
(EnableGlobalMerge == cl::BOU_UNSET);
// Merging of extern globals is enabled by default on non-Mach-O as we
// expect it to be generally either beneficial or harmless. On Mach-O it
// is disabled as we emit the .subsections_via_symbols directive which
// means that merging extern globals is not safe.
bool MergeExternalByDefault = !TM->getTargetTriple().isOSBinFormatMachO();
// FIXME: extern global merging is only enabled when we optimise for size
// because there are some regressions with it also enabled for performance.
if (!OnlyOptimizeForSize)
MergeExternalByDefault = false;
addPass(createGlobalMergePass(TM, 4095, OnlyOptimizeForSize,
MergeExternalByDefault));
}
return false;
}
bool AArch64PassConfig::addInstSelector() {
addPass(createAArch64ISelDag(getAArch64TargetMachine(), getOptLevel()));
// For ELF, cleanup any local-dynamic TLS accesses (i.e. combine as many
// references to _TLS_MODULE_BASE_ as possible.
if (TM->getTargetTriple().isOSBinFormatELF() &&
getOptLevel() != CodeGenOpt::None)
addPass(createAArch64CleanupLocalDynamicTLSPass());
return false;
}
bool AArch64PassConfig::addIRTranslator() {
addPass(new IRTranslator());
return false;
}
void AArch64PassConfig::addPreLegalizeMachineIR() {
bool IsOptNone = getOptLevel() == CodeGenOpt::None;
addPass(createAArch64PreLegalizeCombiner(IsOptNone));
}
bool AArch64PassConfig::addLegalizeMachineIR() {
addPass(new Legalizer());
return false;
}
void AArch64PassConfig::addPreRegBankSelect() {
// For now we don't add this to the pipeline for -O0. We could do in future
// if we split the combines into separate O0/opt groupings.
bool IsOptNone = getOptLevel() == CodeGenOpt::None;
if (!IsOptNone)
addPass(createAArch64PostLegalizeCombiner(IsOptNone));
}
bool AArch64PassConfig::addRegBankSelect() {
addPass(new RegBankSelect());
return false;
}
void AArch64PassConfig::addPreGlobalInstructionSelect() {
addPass(new Localizer());
}
bool AArch64PassConfig::addGlobalInstructionSelect() {
addPass(new InstructionSelect());
return false;
}
bool AArch64PassConfig::addILPOpts() {
if (EnableCondOpt)
addPass(createAArch64ConditionOptimizerPass());
if (EnableCCMP)
addPass(createAArch64ConditionalCompares());
if (EnableMCR)
addPass(&MachineCombinerID);
if (EnableCondBrTuning)
addPass(createAArch64CondBrTuning());
if (EnableEarlyIfConversion)
addPass(&EarlyIfConverterID);
if (EnableStPairSuppress)
addPass(createAArch64StorePairSuppressPass());
addPass(createAArch64SIMDInstrOptPass());
if (TM->getOptLevel() != CodeGenOpt::None)
addPass(createAArch64StackTaggingPreRAPass());
return true;
}
void AArch64PassConfig::addPreRegAlloc() {
// Change dead register definitions to refer to the zero register.
if (TM->getOptLevel() != CodeGenOpt::None && EnableDeadRegisterElimination)
addPass(createAArch64DeadRegisterDefinitions());
// Use AdvSIMD scalar instructions whenever profitable.
if (TM->getOptLevel() != CodeGenOpt::None && EnableAdvSIMDScalar) {
addPass(createAArch64AdvSIMDScalar());
// The AdvSIMD pass may produce copies that can be rewritten to
// be register coalescer friendly.
addPass(&PeepholeOptimizerID);
}
}
void AArch64PassConfig::addPostRegAlloc() {
// Remove redundant copy instructions.
if (TM->getOptLevel() != CodeGenOpt::None && EnableRedundantCopyElimination)
addPass(createAArch64RedundantCopyEliminationPass());
if (TM->getOptLevel() != CodeGenOpt::None && usingDefaultRegAlloc())
// Improve performance for some FP/SIMD code for A57.
addPass(createAArch64A57FPLoadBalancing());
}
void AArch64PassConfig::addPreSched2() {
// Expand some pseudo instructions to allow proper scheduling.
addPass(createAArch64ExpandPseudoPass());
// Use load/store pair instructions when possible.
if (TM->getOptLevel() != CodeGenOpt::None) {
if (EnableLoadStoreOpt)
addPass(createAArch64LoadStoreOptimizationPass());
}
// The AArch64SpeculationHardeningPass destroys dominator tree and natural
// loop info, which is needed for the FalkorHWPFFixPass and also later on.
// Therefore, run the AArch64SpeculationHardeningPass before the
// FalkorHWPFFixPass to avoid recomputing dominator tree and natural loop
// info.
addPass(createAArch64SpeculationHardeningPass());
addPass(createAArch64IndirectThunks());
addPass(createAArch64SLSHardeningPass());
if (TM->getOptLevel() != CodeGenOpt::None) {
if (EnableFalkorHWPFFix)
addPass(createFalkorHWPFFixPass());
}
}
void AArch64PassConfig::addPreEmitPass() {
// Machine Block Placement might have created new opportunities when run
// at O3, where the Tail Duplication Threshold is set to 4 instructions.
// Run the load/store optimizer once more.
if (TM->getOptLevel() >= CodeGenOpt::Aggressive && EnableLoadStoreOpt)
addPass(createAArch64LoadStoreOptimizationPass());
if (EnableA53Fix835769)
addPass(createAArch64A53Fix835769());
if (EnableBranchTargets)
addPass(createAArch64BranchTargetsPass());
// Relax conditional branch instructions if they're otherwise out of
// range of their destination.
if (BranchRelaxation)
addPass(&BranchRelaxationPassID);
// Identify valid longjmp targets for Windows Control Flow Guard.
if (TM->getTargetTriple().isOSWindows())
addPass(createCFGuardLongjmpPass());
if (TM->getOptLevel() != CodeGenOpt::None && EnableCompressJumpTables)
addPass(createAArch64CompressJumpTablesPass());
if (TM->getOptLevel() != CodeGenOpt::None && EnableCollectLOH &&
TM->getTargetTriple().isOSBinFormatMachO())
addPass(createAArch64CollectLOHPass());
// SVE bundles move prefixes with destructive operations.
addPass(createUnpackMachineBundles(nullptr));
}
yaml::MachineFunctionInfo *
AArch64TargetMachine::createDefaultFuncInfoYAML() const {
return new yaml::AArch64FunctionInfo();
}
yaml::MachineFunctionInfo *
AArch64TargetMachine::convertFuncInfoToYAML(const MachineFunction &MF) const {
const auto *MFI = MF.getInfo<AArch64FunctionInfo>();
return new yaml::AArch64FunctionInfo(*MFI);
}
bool AArch64TargetMachine::parseMachineFunctionInfo(
const yaml::MachineFunctionInfo &MFI, PerFunctionMIParsingState &PFS,
SMDiagnostic &Error, SMRange &SourceRange) const {
const auto &YamlMFI =
reinterpret_cast<const yaml::AArch64FunctionInfo &>(MFI);
MachineFunction &MF = PFS.MF;
MF.getInfo<AArch64FunctionInfo>()->initializeBaseYamlFields(YamlMFI);
return false;
}