llvm-6502/lib/Target/AArch64/AArch64TargetMachine.cpp
Ahmed Bougacha d2069333ee [CodeGen] Split -enable-global-merge into ARM and AArch64 options.
Currently, there's a single flag, checked by the pass itself.
It can't force-enable the pass (and is on by default), because it
might not even have been created, as that's the targets decision.
Instead, have separate explicit flags, so that the decision is
consistently made in the target.

Keep the flag as a last-resort "force-disable GlobalMerge" for now,
for backwards compatibility.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234666 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-11 00:06:36 +00:00

326 lines
12 KiB
C++

//===-- AArch64TargetMachine.cpp - Define TargetMachine for AArch64 -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
#include "AArch64.h"
#include "AArch64TargetMachine.h"
#include "AArch64TargetObjectFile.h"
#include "AArch64TargetTransformInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Transforms/Scalar.h"
using namespace llvm;
static cl::opt<bool>
EnableCCMP("aarch64-ccmp", cl::desc("Enable the CCMP formation pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool> EnableMCR("aarch64-mcr",
cl::desc("Enable the machine combiner pass"),
cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableStPairSuppress("aarch64-stp-suppress", cl::desc("Suppress STP for AArch64"),
cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableAdvSIMDScalar("aarch64-simd-scalar", cl::desc("Enable use of AdvSIMD scalar"
" integer instructions"), cl::init(false), cl::Hidden);
static cl::opt<bool>
EnablePromoteConstant("aarch64-promote-const", cl::desc("Enable the promote "
"constant pass"), cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableCollectLOH("aarch64-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-dead-def-elimination", 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>
EnableLoadStoreOpt("aarch64-load-store-opt", cl::desc("Enable the load/store pair"
" optimization pass"), cl::init(true), cl::Hidden);
static cl::opt<bool>
EnableAtomicTidy("aarch64-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-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-gep-opt", cl::Hidden,
cl::desc("Enable optimizations on complex GEPs"),
cl::init(true));
// FIXME: Unify control over GlobalMerge.
static cl::opt<cl::boolOrDefault>
EnableGlobalMerge("aarch64-global-merge", cl::Hidden,
cl::desc("Enable the global merge pass"));
extern "C" void LLVMInitializeAArch64Target() {
// Register the target.
RegisterTargetMachine<AArch64leTargetMachine> X(TheAArch64leTarget);
RegisterTargetMachine<AArch64beTargetMachine> Y(TheAArch64beTarget);
RegisterTargetMachine<AArch64leTargetMachine> Z(TheARM64Target);
}
//===----------------------------------------------------------------------===//
// AArch64 Lowering public interface.
//===----------------------------------------------------------------------===//
static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
if (TT.isOSBinFormatMachO())
return make_unique<AArch64_MachoTargetObjectFile>();
return make_unique<AArch64_ELFTargetObjectFile>();
}
// Helper function to build a DataLayout string
static std::string computeDataLayout(StringRef TT, bool LittleEndian) {
Triple Triple(TT);
if (Triple.isOSBinFormatMachO())
return "e-m:o-i64:64-i128:128-n32:64-S128";
if (LittleEndian)
return "e-m:e-i64:64-i128:128-n32:64-S128";
return "E-m:e-i64:64-i128:128-n32:64-S128";
}
/// TargetMachine ctor - Create an AArch64 architecture model.
///
AArch64TargetMachine::AArch64TargetMachine(const Target &T, StringRef TT,
StringRef CPU, StringRef FS,
const TargetOptions &Options,
Reloc::Model RM, CodeModel::Model CM,
CodeGenOpt::Level OL,
bool LittleEndian)
// This nested ternary is horrible, but DL needs to be properly
// initialized before TLInfo is constructed.
: LLVMTargetMachine(T, computeDataLayout(TT, LittleEndian), TT, CPU, FS,
Options, RM, CM, OL),
TLOF(createTLOF(Triple(getTargetTriple()))),
isLittle(LittleEndian) {
initAsmInfo();
}
AArch64TargetMachine::~AArch64TargetMachine() {}
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 = llvm::make_unique<AArch64Subtarget>(TargetTriple, CPU, FS, *this, isLittle);
}
return I.get();
}
void AArch64leTargetMachine::anchor() { }
AArch64leTargetMachine::
AArch64leTargetMachine(const Target &T, StringRef TT,
StringRef CPU, StringRef FS, const TargetOptions &Options,
Reloc::Model RM, CodeModel::Model CM,
CodeGenOpt::Level OL)
: AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, true) {}
void AArch64beTargetMachine::anchor() { }
AArch64beTargetMachine::
AArch64beTargetMachine(const Target &T, StringRef TT,
StringRef CPU, StringRef FS, const TargetOptions &Options,
Reloc::Model RM, CodeModel::Model CM,
CodeGenOpt::Level OL)
: AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, 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>();
}
void addIRPasses() override;
bool addPreISel() override;
bool addInstSelector() override;
bool addILPOpts() override;
void addPreRegAlloc() override;
void addPostRegAlloc() override;
void addPreSched2() override;
void addPreEmitPass() override;
};
} // namespace
TargetIRAnalysis AArch64TargetMachine::getTargetIRAnalysis() {
return TargetIRAnalysis([this](Function &F) {
return TargetTransformInfo(AArch64TTIImpl(this, F));
});
}
TargetPassConfig *AArch64TargetMachine::createPassConfig(PassManagerBase &PM) {
return new AArch64PassConfig(this, PM);
}
void AArch64PassConfig::addIRPasses() {
// Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
// ourselves.
addPass(createAtomicExpandPass(TM));
// 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());
TargetPassConfig::addIRPasses();
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(TM, 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());
}
}
// 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::Aggressive &&
EnableGlobalMerge == cl::BOU_UNSET) ||
EnableGlobalMerge == cl::BOU_TRUE)
addPass(createGlobalMergePass(TM, 4095));
if (TM->getOptLevel() != CodeGenOpt::None)
addPass(createAArch64AddressTypePromotionPass());
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 (Triple(TM->getTargetTriple()).isOSBinFormatELF() &&
getOptLevel() != CodeGenOpt::None)
addPass(createAArch64CleanupLocalDynamicTLSPass());
return false;
}
bool AArch64PassConfig::addILPOpts() {
if (EnableCondOpt)
addPass(createAArch64ConditionOptimizerPass());
if (EnableCCMP)
addPass(createAArch64ConditionalCompares());
if (EnableMCR)
addPass(&MachineCombinerID);
if (EnableEarlyIfConversion)
addPass(&EarlyIfConverterID);
if (EnableStPairSuppress)
addPass(createAArch64StorePairSuppressPass());
return true;
}
void AArch64PassConfig::addPreRegAlloc() {
// 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 coaleascer friendly.
addPass(&PeepholeOptimizerID);
}
}
void AArch64PassConfig::addPostRegAlloc() {
// Change dead register definitions to refer to the zero register.
if (TM->getOptLevel() != CodeGenOpt::None && EnableDeadRegisterElimination)
addPass(createAArch64DeadRegisterDefinitions());
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 && EnableLoadStoreOpt)
addPass(createAArch64LoadStoreOptimizationPass());
}
void AArch64PassConfig::addPreEmitPass() {
if (EnableA53Fix835769)
addPass(createAArch64A53Fix835769());
// Relax conditional branch instructions if they're otherwise out of
// range of their destination.
addPass(createAArch64BranchRelaxation());
if (TM->getOptLevel() != CodeGenOpt::None && EnableCollectLOH &&
Triple(TM->getTargetTriple()).isOSBinFormatMachO())
addPass(createAArch64CollectLOHPass());
}