llvm/llvm/lib/Target/PowerPC/PPCTLSDynamicCall.cpp

//===---------- PPCTLSDynamicCall.cpp - TLS Dynamic Call Fixup ------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This pass expands ADDItls{ld,gd}LADDR[32] machine instructions into
// separate ADDItls[gd]L[32] and GETtlsADDR[32] instructions, both of
// which define GPR3.  A copy is added from GPR3 to the target virtual
// register of the original instruction.  The GETtlsADDR[32] is really
// a call instruction, so its target register is constrained to be GPR3.
// This is not true of ADDItls[gd]L[32], but there is a legacy linker
// optimization bug that requires the target register of the addi of
// a local- or general-dynamic TLS access sequence to be GPR3.
//
// This is done in a late pass so that TLS variable accesses can be
// fully commoned by MachineCSE.
//
//===----------------------------------------------------------------------===//

#include "PPC.h"
#include "PPCInstrBuilder.h"
#include "PPCInstrInfo.h"
#include "PPCTargetMachine.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"

usingnamespacellvm;

#define DEBUG_TYPE …

namespace {
  struct PPCTLSDynamicCall : public MachineFunctionPass { … };
}

INITIALIZE_PASS_BEGIN(PPCTLSDynamicCall, DEBUG_TYPE,
                      "PowerPC TLS Dynamic Call Fixup", false, false)
INITIALIZE_PASS_DEPENDENCY(LiveIntervalsWrapperPass)
INITIALIZE_PASS_DEPENDENCY(SlotIndexesWrapperPass)
INITIALIZE_PASS_END(PPCTLSDynamicCall, DEBUG_TYPE,
                    "PowerPC TLS Dynamic Call Fixup", false, false)

char PPCTLSDynamicCall::ID = …;
FunctionPass*
llvm::createPPCTLSDynamicCallPass() { … }