forked from OSchip/llvm-project
133 lines
4.9 KiB
C++
133 lines
4.9 KiB
C++
//===-- AArch64Subtarget.cpp - AArch64 Subtarget Information ----*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements the AArch64 specific subclass of TargetSubtarget.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "AArch64InstrInfo.h"
|
|
#include "AArch64PBQPRegAlloc.h"
|
|
#include "AArch64Subtarget.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/CodeGen/MachineScheduler.h"
|
|
#include "llvm/IR/GlobalValue.h"
|
|
#include "llvm/Support/TargetRegistry.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "aarch64-subtarget"
|
|
|
|
#define GET_SUBTARGETINFO_CTOR
|
|
#define GET_SUBTARGETINFO_TARGET_DESC
|
|
#include "AArch64GenSubtargetInfo.inc"
|
|
|
|
static cl::opt<bool>
|
|
EnableEarlyIfConvert("aarch64-early-ifcvt", cl::desc("Enable the early if "
|
|
"converter pass"), cl::init(true), cl::Hidden);
|
|
|
|
AArch64Subtarget &
|
|
AArch64Subtarget::initializeSubtargetDependencies(StringRef FS) {
|
|
// Determine default and user-specified characteristics
|
|
|
|
if (CPUString.empty())
|
|
CPUString = "generic";
|
|
|
|
ParseSubtargetFeatures(CPUString, FS);
|
|
return *this;
|
|
}
|
|
|
|
AArch64Subtarget::AArch64Subtarget(const std::string &TT,
|
|
const std::string &CPU,
|
|
const std::string &FS,
|
|
const TargetMachine &TM, bool LittleEndian)
|
|
: AArch64GenSubtargetInfo(TT, CPU, FS), ARMProcFamily(Others),
|
|
HasV8_1aOps(false),
|
|
HasFPARMv8(false), HasNEON(false), HasCrypto(false), HasCRC(false),
|
|
HasZeroCycleRegMove(false), HasZeroCycleZeroing(false),
|
|
IsLittle(LittleEndian), CPUString(CPU), TargetTriple(TT), FrameLowering(),
|
|
InstrInfo(initializeSubtargetDependencies(FS)),
|
|
TSInfo(TM.getDataLayout()), TLInfo(TM, *this) {}
|
|
|
|
/// ClassifyGlobalReference - Find the target operand flags that describe
|
|
/// how a global value should be referenced for the current subtarget.
|
|
unsigned char
|
|
AArch64Subtarget::ClassifyGlobalReference(const GlobalValue *GV,
|
|
const TargetMachine &TM) const {
|
|
bool isDecl = GV->isDeclarationForLinker();
|
|
|
|
// MachO large model always goes via a GOT, simply to get a single 8-byte
|
|
// absolute relocation on all global addresses.
|
|
if (TM.getCodeModel() == CodeModel::Large && isTargetMachO())
|
|
return AArch64II::MO_GOT;
|
|
|
|
// The small code mode's direct accesses use ADRP, which cannot necessarily
|
|
// produce the value 0 (if the code is above 4GB).
|
|
if (TM.getCodeModel() == CodeModel::Small &&
|
|
GV->isWeakForLinker() && isDecl) {
|
|
// In PIC mode use the GOT, but in absolute mode use a constant pool load.
|
|
if (TM.getRelocationModel() == Reloc::Static)
|
|
return AArch64II::MO_CONSTPOOL;
|
|
else
|
|
return AArch64II::MO_GOT;
|
|
}
|
|
|
|
// If symbol visibility is hidden, the extra load is not needed if
|
|
// the symbol is definitely defined in the current translation unit.
|
|
|
|
// The handling of non-hidden symbols in PIC mode is rather target-dependent:
|
|
// + On MachO, if the symbol is defined in this module the GOT can be
|
|
// skipped.
|
|
// + On ELF, the R_AARCH64_COPY relocation means that even symbols actually
|
|
// defined could end up in unexpected places. Use a GOT.
|
|
if (TM.getRelocationModel() != Reloc::Static && GV->hasDefaultVisibility()) {
|
|
if (isTargetMachO())
|
|
return (isDecl || GV->isWeakForLinker()) ? AArch64II::MO_GOT
|
|
: AArch64II::MO_NO_FLAG;
|
|
else
|
|
// No need to go through the GOT for local symbols on ELF.
|
|
return GV->hasLocalLinkage() ? AArch64II::MO_NO_FLAG : AArch64II::MO_GOT;
|
|
}
|
|
|
|
return AArch64II::MO_NO_FLAG;
|
|
}
|
|
|
|
/// This function returns the name of a function which has an interface
|
|
/// like the non-standard bzero function, if such a function exists on
|
|
/// the current subtarget and it is considered prefereable over
|
|
/// memset with zero passed as the second argument. Otherwise it
|
|
/// returns null.
|
|
const char *AArch64Subtarget::getBZeroEntry() const {
|
|
// Prefer bzero on Darwin only.
|
|
if(isTargetDarwin())
|
|
return "bzero";
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
void AArch64Subtarget::overrideSchedPolicy(MachineSchedPolicy &Policy,
|
|
MachineInstr *begin, MachineInstr *end,
|
|
unsigned NumRegionInstrs) const {
|
|
// LNT run (at least on Cyclone) showed reasonably significant gains for
|
|
// bi-directional scheduling. 253.perlbmk.
|
|
Policy.OnlyTopDown = false;
|
|
Policy.OnlyBottomUp = false;
|
|
}
|
|
|
|
bool AArch64Subtarget::enableEarlyIfConversion() const {
|
|
return EnableEarlyIfConvert;
|
|
}
|
|
|
|
std::unique_ptr<PBQPRAConstraint>
|
|
AArch64Subtarget::getCustomPBQPConstraints() const {
|
|
if (!isCortexA57())
|
|
return nullptr;
|
|
|
|
return llvm::make_unique<A57ChainingConstraint>();
|
|
}
|