Philipp Krones c2f819af73 [MC] Refactor MCObjectFileInfo initialization and allow targets to create MCObjectFileInfo
This makes it possible for targets to define their own MCObjectFileInfo.
This MCObjectFileInfo is then used to determine things like section alignment.

This is a follow up to D101462 and prepares for the RISCV backend defining the
text section alignment depending on the enabled extensions.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D101921
2021-05-23 14:15:23 -07:00

83 lines
3.4 KiB
C++

//===-- LlvmState.cpp -------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
#include "LlvmState.h"
#include "Target.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
namespace llvm {
namespace exegesis {
LLVMState::LLVMState(const std::string &Triple, const std::string &CpuName,
const std::string &Features) {
std::string Error;
const Target *const TheTarget = TargetRegistry::lookupTarget(Triple, Error);
assert(TheTarget && "unknown target for host");
const TargetOptions Options;
TheTargetMachine.reset(
static_cast<LLVMTargetMachine *>(TheTarget->createTargetMachine(
Triple, CpuName, Features, Options, Reloc::Model::Static)));
assert(TheTargetMachine && "unable to create target machine");
TheExegesisTarget = ExegesisTarget::lookup(TheTargetMachine->getTargetTriple());
if (!TheExegesisTarget) {
errs() << "no exegesis target for " << Triple << ", using default\n";
TheExegesisTarget = &ExegesisTarget::getDefault();
}
PfmCounters = &TheExegesisTarget->getPfmCounters(CpuName);
BitVector ReservedRegs = getFunctionReservedRegs(getTargetMachine());
for (const unsigned Reg : TheExegesisTarget->getUnavailableRegisters())
ReservedRegs.set(Reg);
RATC.reset(
new RegisterAliasingTrackerCache(getRegInfo(), std::move(ReservedRegs)));
IC.reset(new InstructionsCache(getInstrInfo(), getRATC()));
}
LLVMState::LLVMState(const std::string &CpuName)
: LLVMState(sys::getProcessTriple(),
CpuName.empty() ? sys::getHostCPUName().str() : CpuName, "") {}
std::unique_ptr<LLVMTargetMachine> LLVMState::createTargetMachine() const {
return std::unique_ptr<LLVMTargetMachine>(static_cast<LLVMTargetMachine *>(
TheTargetMachine->getTarget().createTargetMachine(
TheTargetMachine->getTargetTriple().normalize(),
TheTargetMachine->getTargetCPU(),
TheTargetMachine->getTargetFeatureString(), TheTargetMachine->Options,
Reloc::Model::Static)));
}
bool LLVMState::canAssemble(const MCInst &Inst) const {
MCContext Context(TheTargetMachine->getTargetTriple(),
TheTargetMachine->getMCAsmInfo(),
TheTargetMachine->getMCRegisterInfo(),
TheTargetMachine->getMCSubtargetInfo());
std::unique_ptr<const MCCodeEmitter> CodeEmitter(
TheTargetMachine->getTarget().createMCCodeEmitter(
*TheTargetMachine->getMCInstrInfo(), *TheTargetMachine->getMCRegisterInfo(),
Context));
assert(CodeEmitter && "unable to create code emitter");
SmallVector<char, 16> Tmp;
raw_svector_ostream OS(Tmp);
SmallVector<MCFixup, 4> Fixups;
CodeEmitter->encodeInstruction(Inst, OS, Fixups,
*TheTargetMachine->getMCSubtargetInfo());
return Tmp.size() > 0;
}
} // namespace exegesis
} // namespace llvm