llvm-6502/lib/Target/AArch64/AArch64TargetMachine.cpp
2014-12-11 23:18:03 +00:00

310 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 "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/IR/Function.h"
#include "llvm/PassManager.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));
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>();
}
/// 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)
: LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
TLOF(createTLOF(Triple(getTargetTriple()))),
Subtarget(TT, CPU, FS, *this, LittleEndian), isLittle(LittleEndian) {
initAsmInfo();
}
AArch64TargetMachine::~AArch64TargetMachine() {}
const AArch64Subtarget *
AArch64TargetMachine::getSubtargetImpl(const Function &F) const {
AttributeSet FnAttrs = F.getAttributes();
Attribute CPUAttr =
FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-cpu");
Attribute FSAttr =
FnAttrs.getAttribute(AttributeSet::FunctionIndex, "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
void AArch64TargetMachine::addAnalysisPasses(PassManagerBase &PM) {
// Add first the target-independent BasicTTI pass, then our AArch64 pass. This
// allows the AArch64 pass to delegate to the target independent layer when
// appropriate.
PM.add(createBasicTargetTransformInfoPass(this));
PM.add(createAArch64TargetTransformInfoPass(this));
}
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());
if (TM->getOptLevel() != CodeGenOpt::None)
addPass(createGlobalMergePass(TM));
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 (TM->getSubtarget<AArch64Subtarget>().isTargetELF() &&
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 &&
(TM->getSubtarget<AArch64Subtarget>().isCortexA53() ||
TM->getSubtarget<AArch64Subtarget>().isCortexA57()) &&
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 &&
TM->getSubtarget<AArch64Subtarget>().isTargetMachO())
addPass(createAArch64CollectLOHPass());
}