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llvm-6502/lib/Target/PowerPC/PPCAsmPrinter.cpp
Bill Schmidt 1123a81009 [PowerPC] Yet another approach to __tls_get_addr 
This patch is a third attempt to properly handle the local-dynamic and
global-dynamic TLS models.

In my original implementation, calls to __tls_get_addr were hidden
from view until the asm-printer phase, at which point the underlying
branch-and-link instruction was created with proper relocations.  This
mostly worked well, but I used some repellent techniques to ensure
that the TLS_GET_ADDR nodes at the SD and MI levels correctly received
input from GPR3 and produced output into GPR3.  This proved to work
badly in the presence of multiple TLS variable accesses, with the
copies to and from GPR3 being scheduled incorrectly and generally
creating havoc.

In r221703, I addressed that problem by representing the calls to
__tls_get_addr as true calls during instruction lowering.  This had
the advantage of removing all of the bad hacks and relying on the
existing call machinery to properly glue the copies in place. It
looked like this was going to be the right way to go.

However, as a side effect of the recent discovery of problems with
linker optimizations for TLS, we discovered cases of suboptimal code
generation with this strategy.  The problem comes when tls_get_addr is
called for the same address, and there is a resulting CSE
opportunity.  It turns out that in such cases MachineCSE will common
the addis/addi instructions that set up the input value to
tls_get_addr, but will not common the calls themselves.  MachineCSE
does not have any machinery to common idempotent calls.  This is
perfectly sensible, since presumably this would be done at the IR
level, and introducing calls in the back end isn't commonplace.  In
any case, we end up with two calls to __tls_get_addr when one would
suffice, and that isn't good.

I presumed that the original design would have allowed commoning of
the machine-specific nodes that hid the __tls_get_addr calls, so as
suggested by Ulrich Weigand, I went back to that design and cleaned it
up so that the copies were properly held together by glue
nodes.  However, it turned out that this didn't work either...the
presence of copies to physical registers kept the machine-specific
nodes from being commoned also.

All of which leads to the design presented here.  This is a return to
the original design, except that no attempt is made to introduce
copies to and from GPR3 during instruction lowering.  Virtual registers
are used until prior to register allocation.  At that point, a special
pass is run that identifies the machine-specific nodes that hide the
tls_get_addr calls and introduces the copies to and from GPR3 around
them.  The register allocator then coalesces these copies away.  With
this design, MachineCSE succeeds in commoning tls_get_addr calls where
possible, and we get nice optimal code generation (better than GCC at
the moment, which does not common these calls).

One additional problem must be dealt with:  After introducing the
mentions of the physical register GPR3, the aggressive anti-dependence
breaker sees opportunities to improve scheduling by selecting a
different register instead.  Flags must be used on the instruction
descriptions to tell the anti-dependence breaker to keep its hands in
its pockets.

One thing missing from the original design was recording a definition
of the link register on the GET_TLS_ADDR nodes.  Doing this was found
to be insufficient to force a stack frame to be created, which led to
looping behavior because two different LR values were stored at the
same address.  This appears to have been an oversight in
PPCFrameLowering::determineFrameLayout(), which is repaired here.

Because MustSaveLR() returns true for calls to builtin_return_address,
this changed the expected behavior of
test/CodeGen/PowerPC/retaddr2.ll, which now stacks a frame but
formerly did not.  I've fixed the test case to reflect this.

There are existing TLS tests to catch regressions; the checks in
test/CodeGen/PowerPC/tls-store2.ll proved to be too restrictive in the
face of instruction scheduling with these changes, so I fixed that
up.

I've added a new test case based on the PrettyStackTrace module that
demonstrated the original problem. This checks that we get correct
code generation and that CSE of the calls to __get_tls_addr has taken
place.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227976 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-03 16:16:01 +00:00

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//===-- PPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to PowerPC assembly language. This printer is
// the output mechanism used by `llc'.
//
// Documentation at http://developer.apple.com/documentation/DeveloperTools/
// Reference/Assembler/ASMIntroduction/chapter_1_section_1.html
//
//===----------------------------------------------------------------------===//
#include "PPC.h"
#include "InstPrinter/PPCInstPrinter.h"
#include "MCTargetDesc/PPCMCExpr.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "PPCTargetStreamer.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
#define DEBUG_TYPE "asmprinter"
namespace {
class PPCAsmPrinter : public AsmPrinter {
protected:
MapVector<MCSymbol*, MCSymbol*> TOC;
const PPCSubtarget &Subtarget;
uint64_t TOCLabelID;
StackMaps SM;
public:
explicit PPCAsmPrinter(TargetMachine &TM,
std::unique_ptr<MCStreamer> Streamer)
: AsmPrinter(TM, std::move(Streamer)),
Subtarget(TM.getSubtarget<PPCSubtarget>()), TOCLabelID(0), SM(*this) {
}
const char *getPassName() const override {
return "PowerPC Assembly Printer";
}
MCSymbol *lookUpOrCreateTOCEntry(MCSymbol *Sym);
void EmitInstruction(const MachineInstr *MI) override;
void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);
bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant, const char *ExtraCode,
raw_ostream &O) override;
bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant, const char *ExtraCode,
raw_ostream &O) override;
void EmitEndOfAsmFile(Module &M) override;
void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void EmitTlsCall(const MachineInstr *MI, MCSymbolRefExpr::VariantKind VK);
};
/// PPCLinuxAsmPrinter - PowerPC assembly printer, customized for Linux
class PPCLinuxAsmPrinter : public PPCAsmPrinter {
public:
explicit PPCLinuxAsmPrinter(TargetMachine &TM,
std::unique_ptr<MCStreamer> Streamer)
: PPCAsmPrinter(TM, std::move(Streamer)) {}
const char *getPassName() const override {
return "Linux PPC Assembly Printer";
}
bool doFinalization(Module &M) override;
void EmitStartOfAsmFile(Module &M) override;
void EmitFunctionEntryLabel() override;
void EmitFunctionBodyStart() override;
void EmitFunctionBodyEnd() override;
};
/// PPCDarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac
/// OS X
class PPCDarwinAsmPrinter : public PPCAsmPrinter {
public:
explicit PPCDarwinAsmPrinter(TargetMachine &TM,
std::unique_ptr<MCStreamer> Streamer)
: PPCAsmPrinter(TM, std::move(Streamer)) {}
const char *getPassName() const override {
return "Darwin PPC Assembly Printer";
}
bool doFinalization(Module &M) override;
void EmitStartOfAsmFile(Module &M) override;
void EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs);
};
} // end of anonymous namespace
/// stripRegisterPrefix - This method strips the character prefix from a
/// register name so that only the number is left. Used by for linux asm.
static const char *stripRegisterPrefix(const char *RegName) {
switch (RegName[0]) {
case 'r':
case 'f':
case 'v':
if (RegName[1] == 's')
return RegName + 2;
return RegName + 1;
case 'c': if (RegName[1] == 'r') return RegName + 2;
}
return RegName;
}
void PPCAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
raw_ostream &O) {
const DataLayout *DL = TM.getDataLayout();
const MachineOperand &MO = MI->getOperand(OpNo);
switch (MO.getType()) {
case MachineOperand::MO_Register: {
const char *RegName = PPCInstPrinter::getRegisterName(MO.getReg());
// Linux assembler (Others?) does not take register mnemonics.
// FIXME - What about special registers used in mfspr/mtspr?
if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
O << RegName;
return;
}
case MachineOperand::MO_Immediate:
O << MO.getImm();
return;
case MachineOperand::MO_MachineBasicBlock:
O << *MO.getMBB()->getSymbol();
return;
case MachineOperand::MO_ConstantPoolIndex:
O << DL->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
<< '_' << MO.getIndex();
return;
case MachineOperand::MO_BlockAddress:
O << *GetBlockAddressSymbol(MO.getBlockAddress());
return;
case MachineOperand::MO_GlobalAddress: {
// Computing the address of a global symbol, not calling it.
const GlobalValue *GV = MO.getGlobal();
MCSymbol *SymToPrint;
// External or weakly linked global variables need non-lazily-resolved stubs
if (TM.getRelocationModel() != Reloc::Static &&
(GV->isDeclaration() || GV->isWeakForLinker())) {
if (!GV->hasHiddenVisibility()) {
SymToPrint = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
MachineModuleInfoImpl::StubValueTy &StubSym =
MMI->getObjFileInfo<MachineModuleInfoMachO>()
.getGVStubEntry(SymToPrint);
if (!StubSym.getPointer())
StubSym = MachineModuleInfoImpl::
StubValueTy(getSymbol(GV), !GV->hasInternalLinkage());
} else if (GV->isDeclaration() || GV->hasCommonLinkage() ||
GV->hasAvailableExternallyLinkage()) {
SymToPrint = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
MachineModuleInfoImpl::StubValueTy &StubSym =
MMI->getObjFileInfo<MachineModuleInfoMachO>().
getHiddenGVStubEntry(SymToPrint);
if (!StubSym.getPointer())
StubSym = MachineModuleInfoImpl::
StubValueTy(getSymbol(GV), !GV->hasInternalLinkage());
} else {
SymToPrint = getSymbol(GV);
}
} else {
SymToPrint = getSymbol(GV);
}
O << *SymToPrint;
printOffset(MO.getOffset(), O);
return;
}
default:
O << "<unknown operand type: " << (unsigned)MO.getType() << ">";
return;
}
}
/// PrintAsmOperand - Print out an operand for an inline asm expression.
///
bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant,
const char *ExtraCode, raw_ostream &O) {
// Does this asm operand have a single letter operand modifier?
if (ExtraCode && ExtraCode[0]) {
if (ExtraCode[1] != 0) return true; // Unknown modifier.
switch (ExtraCode[0]) {
default:
// See if this is a generic print operand
return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
case 'c': // Don't print "$" before a global var name or constant.
break; // PPC never has a prefix.
case 'L': // Write second word of DImode reference.
// Verify that this operand has two consecutive registers.
if (!MI->getOperand(OpNo).isReg() ||
OpNo+1 == MI->getNumOperands() ||
!MI->getOperand(OpNo+1).isReg())
return true;
++OpNo; // Return the high-part.
break;
case 'I':
// Write 'i' if an integer constant, otherwise nothing. Used to print
// addi vs add, etc.
if (MI->getOperand(OpNo).isImm())
O << "i";
return false;
}
}
printOperand(MI, OpNo, O);
return false;
}
// At the moment, all inline asm memory operands are a single register.
// In any case, the output of this routine should always be just one
// assembler operand.
bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant,
const char *ExtraCode,
raw_ostream &O) {
if (ExtraCode && ExtraCode[0]) {
if (ExtraCode[1] != 0) return true; // Unknown modifier.
switch (ExtraCode[0]) {
default: return true; // Unknown modifier.
case 'y': // A memory reference for an X-form instruction
{
const char *RegName = "r0";
if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
O << RegName << ", ";
printOperand(MI, OpNo, O);
return false;
}
case 'U': // Print 'u' for update form.
case 'X': // Print 'x' for indexed form.
{
// FIXME: Currently for PowerPC memory operands are always loaded
// into a register, so we never get an update or indexed form.
// This is bad even for offset forms, since even if we know we
// have a value in -16(r1), we will generate a load into r<n>
// and then load from 0(r<n>). Until that issue is fixed,
// tolerate 'U' and 'X' but don't output anything.
assert(MI->getOperand(OpNo).isReg());
return false;
}
}
}
assert(MI->getOperand(OpNo).isReg());
O << "0(";
printOperand(MI, OpNo, O);
O << ")";
return false;
}
/// lookUpOrCreateTOCEntry -- Given a symbol, look up whether a TOC entry
/// exists for it. If not, create one. Then return a symbol that references
/// the TOC entry.
MCSymbol *PPCAsmPrinter::lookUpOrCreateTOCEntry(MCSymbol *Sym) {
const DataLayout *DL = TM.getDataLayout();
MCSymbol *&TOCEntry = TOC[Sym];
// To avoid name clash check if the name already exists.
while (!TOCEntry) {
if (OutContext.LookupSymbol(Twine(DL->getPrivateGlobalPrefix()) +
"C" + Twine(TOCLabelID++)) == nullptr) {
TOCEntry = GetTempSymbol("C", TOCLabelID);
}
}
return TOCEntry;
}
void PPCAsmPrinter::EmitEndOfAsmFile(Module &M) {
SM.serializeToStackMapSection();
}
void PPCAsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
unsigned NumNOPBytes = MI.getOperand(1).getImm();
SM.recordStackMap(MI);
assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
// Scan ahead to trim the shadow.
const MachineBasicBlock &MBB = *MI.getParent();
MachineBasicBlock::const_iterator MII(MI);
++MII;
while (NumNOPBytes > 0) {
if (MII == MBB.end() || MII->isCall() ||
MII->getOpcode() == PPC::DBG_VALUE ||
MII->getOpcode() == TargetOpcode::PATCHPOINT ||
MII->getOpcode() == TargetOpcode::STACKMAP)
break;
++MII;
NumNOPBytes -= 4;
}
// Emit nops.
for (unsigned i = 0; i < NumNOPBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::NOP));
}
// Lower a patchpoint of the form:
// [<def>], <id>, <numBytes>, <target>, <numArgs>
void PPCAsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
SM.recordPatchPoint(MI);
PatchPointOpers Opers(&MI);
int64_t CallTarget = Opers.getMetaOper(PatchPointOpers::TargetPos).getImm();
unsigned EncodedBytes = 0;
if (CallTarget) {
assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
"High 16 bits of call target should be zero.");
unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
EncodedBytes = 6*4;
// Materialize the jump address:
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LI8)
.addReg(ScratchReg)
.addImm((CallTarget >> 32) & 0xFFFF));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::RLDIC)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(32).addImm(16));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ORIS8)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm((CallTarget >> 16) & 0xFFFF));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ORI8)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(CallTarget & 0xFFFF));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR8).addReg(ScratchReg));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTRL8));
}
// Emit padding.
unsigned NumBytes = Opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
assert(NumBytes >= EncodedBytes &&
"Patchpoint can't request size less than the length of a call.");
assert((NumBytes - EncodedBytes) % 4 == 0 &&
"Invalid number of NOP bytes requested!");
for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::NOP));
}
/// EmitTlsCall -- Given a GETtls[ld]ADDR[32] instruction, print a
/// call to __tls_get_addr to the current output stream.
void PPCAsmPrinter::EmitTlsCall(const MachineInstr *MI,
MCSymbolRefExpr::VariantKind VK) {
StringRef Name = "__tls_get_addr";
MCSymbol *TlsGetAddr = OutContext.GetOrCreateSymbol(Name);
MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
assert(MI->getOperand(0).isReg() &&
((Subtarget.isPPC64() && MI->getOperand(0).getReg() == PPC::X3) ||
(!Subtarget.isPPC64() && MI->getOperand(0).getReg() == PPC::R3)) &&
"GETtls[ld]ADDR[32] must define GPR3");
assert(MI->getOperand(1).isReg() &&
((Subtarget.isPPC64() && MI->getOperand(1).getReg() == PPC::X3) ||
(!Subtarget.isPPC64() && MI->getOperand(1).getReg() == PPC::R3)) &&
"GETtls[ld]ADDR[32] must read GPR3");
if (!Subtarget.isPPC64() && !Subtarget.isDarwin() &&
TM.getRelocationModel() == Reloc::PIC_)
Kind = MCSymbolRefExpr::VK_PLT;
const MCSymbolRefExpr *TlsRef =
MCSymbolRefExpr::Create(TlsGetAddr, Kind, OutContext);
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymVar = MCSymbolRefExpr::Create(MOSymbol, VK, OutContext);
EmitToStreamer(OutStreamer,
MCInstBuilder(Subtarget.isPPC64() ?
PPC::BL8_NOP_TLS : PPC::BL_TLS)
.addExpr(TlsRef)
.addExpr(SymVar));
}
/// EmitInstruction -- Print out a single PowerPC MI in Darwin syntax to
/// the current output stream.
///
void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
MCInst TmpInst;
bool isPPC64 = Subtarget.isPPC64();
bool isDarwin = Triple(TM.getTargetTriple()).isOSDarwin();
const Module *M = MF->getFunction()->getParent();
PICLevel::Level PL = M->getPICLevel();
// Lower multi-instruction pseudo operations.
switch (MI->getOpcode()) {
default: break;
case TargetOpcode::DBG_VALUE:
llvm_unreachable("Should be handled target independently");
case TargetOpcode::STACKMAP:
return LowerSTACKMAP(OutStreamer, SM, *MI);
case TargetOpcode::PATCHPOINT:
return LowerPATCHPOINT(OutStreamer, SM, *MI);
case PPC::MoveGOTtoLR: {
// Transform %LR = MoveGOTtoLR
// Into this: bl _GLOBAL_OFFSET_TABLE_@local-4
// _GLOBAL_OFFSET_TABLE_@local-4 (instruction preceding
// _GLOBAL_OFFSET_TABLE_) has exactly one instruction:
// blrl
// This will return the pointer to _GLOBAL_OFFSET_TABLE_@local
MCSymbol *GOTSymbol =
OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
const MCExpr *OffsExpr =
MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(GOTSymbol,
MCSymbolRefExpr::VK_PPC_LOCAL,
OutContext),
MCConstantExpr::Create(4, OutContext),
OutContext);
// Emit the 'bl'.
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL).addExpr(OffsExpr));
return;
}
case PPC::MovePCtoLR:
case PPC::MovePCtoLR8: {
// Transform %LR = MovePCtoLR
// Into this, where the label is the PIC base:
// bl L1$pb
// L1$pb:
MCSymbol *PICBase = MF->getPICBaseSymbol();
// Emit the 'bl'.
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL)
// FIXME: We would like an efficient form for this, so we don't have to do
// a lot of extra uniquing.
.addExpr(MCSymbolRefExpr::Create(PICBase, OutContext)));
// Emit the label.
OutStreamer.EmitLabel(PICBase);
return;
}
case PPC::UpdateGBR: {
// Transform %Rd = UpdateGBR(%Rt, %Ri)
// Into: lwz %Rt, .L0$poff - .L0$pb(%Ri)
// add %Rd, %Rt, %Ri
// Get the offset from the GOT Base Register to the GOT
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
MCSymbol *PICOffset =
MF->getInfo<PPCFunctionInfo>()->getPICOffsetSymbol();
TmpInst.setOpcode(PPC::LWZ);
const MCExpr *Exp =
MCSymbolRefExpr::Create(PICOffset, MCSymbolRefExpr::VK_None, OutContext);
const MCExpr *PB =
MCSymbolRefExpr::Create(MF->getPICBaseSymbol(),
MCSymbolRefExpr::VK_None,
OutContext);
const MCOperand TR = TmpInst.getOperand(1);
const MCOperand PICR = TmpInst.getOperand(0);
// Step 1: lwz %Rt, .L$poff - .L$pb(%Ri)
TmpInst.getOperand(1) =
MCOperand::CreateExpr(MCBinaryExpr::CreateSub(Exp, PB, OutContext));
TmpInst.getOperand(0) = TR;
TmpInst.getOperand(2) = PICR;
EmitToStreamer(OutStreamer, TmpInst);
TmpInst.setOpcode(PPC::ADD4);
TmpInst.getOperand(0) = PICR;
TmpInst.getOperand(1) = TR;
TmpInst.getOperand(2) = PICR;
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::LWZtoc: {
// Transform %R3 = LWZtoc <ga:@min1>, %R2
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
// Change the opcode to LWZ, and the global address operand to be a
// reference to the GOT entry we will synthesize later.
TmpInst.setOpcode(PPC::LWZ);
const MachineOperand &MO = MI->getOperand(1);
// Map symbol -> label of TOC entry
assert(MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress());
MCSymbol *MOSymbol = nullptr;
if (MO.isGlobal())
MOSymbol = getSymbol(MO.getGlobal());
else if (MO.isCPI())
MOSymbol = GetCPISymbol(MO.getIndex());
else if (MO.isJTI())
MOSymbol = GetJTISymbol(MO.getIndex());
else if (MO.isBlockAddress())
MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
if (PL == PICLevel::Small) {
const MCExpr *Exp =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_GOT,
OutContext);
TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
} else {
MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);
const MCExpr *Exp =
MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_None,
OutContext);
const MCExpr *PB =
MCSymbolRefExpr::Create(OutContext.GetOrCreateSymbol(Twine(".LTOC")),
OutContext);
Exp = MCBinaryExpr::CreateSub(Exp, PB, OutContext);
TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
}
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::LDtocJTI:
case PPC::LDtocCPT:
case PPC::LDtocBA:
case PPC::LDtoc: {
// Transform %X3 = LDtoc <ga:@min1>, %X2
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
// Change the opcode to LD, and the global address operand to be a
// reference to the TOC entry we will synthesize later.
TmpInst.setOpcode(PPC::LD);
const MachineOperand &MO = MI->getOperand(1);
// Map symbol -> label of TOC entry
assert(MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress());
MCSymbol *MOSymbol = nullptr;
if (MO.isGlobal())
MOSymbol = getSymbol(MO.getGlobal());
else if (MO.isCPI())
MOSymbol = GetCPISymbol(MO.getIndex());
else if (MO.isJTI())
MOSymbol = GetJTISymbol(MO.getIndex());
else if (MO.isBlockAddress())
MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);
const MCExpr *Exp =
MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_PPC_TOC,
OutContext);
TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::ADDIStocHA: {
// Transform %Xd = ADDIStocHA %X2, <ga:@sym>
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
// Change the opcode to ADDIS8. If the global address is external, has
// common linkage, is a non-local function address, or is a jump table
// address, then generate a TOC entry and reference that. Otherwise
// reference the symbol directly.
TmpInst.setOpcode(PPC::ADDIS8);
const MachineOperand &MO = MI->getOperand(2);
assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() ||
MO.isBlockAddress()) &&
"Invalid operand for ADDIStocHA!");
MCSymbol *MOSymbol = nullptr;
bool IsExternal = false;
bool IsNonLocalFunction = false;
bool IsCommon = false;
bool IsAvailExt = false;
if (MO.isGlobal()) {
const GlobalValue *GV = MO.getGlobal();
MOSymbol = getSymbol(GV);
IsExternal = GV->isDeclaration();
IsCommon = GV->hasCommonLinkage();
IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
(GV->isDeclaration() || GV->isWeakForLinker());
IsAvailExt = GV->hasAvailableExternallyLinkage();
} else if (MO.isCPI())
MOSymbol = GetCPISymbol(MO.getIndex());
else if (MO.isJTI())
MOSymbol = GetJTISymbol(MO.getIndex());
else if (MO.isBlockAddress())
MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
if (IsExternal || IsNonLocalFunction || IsCommon || IsAvailExt ||
MO.isJTI() || MO.isBlockAddress() ||
TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
const MCExpr *Exp =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_HA,
OutContext);
TmpInst.getOperand(2) = MCOperand::CreateExpr(Exp);
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::LDtocL: {
// Transform %Xd = LDtocL <ga:@sym>, %Xs
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
// Change the opcode to LD. If the global address is external, has
// common linkage, or is a jump table address, then reference the
// associated TOC entry. Otherwise reference the symbol directly.
TmpInst.setOpcode(PPC::LD);
const MachineOperand &MO = MI->getOperand(1);
assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() ||
MO.isBlockAddress()) &&
"Invalid operand for LDtocL!");
MCSymbol *MOSymbol = nullptr;
if (MO.isJTI())
MOSymbol = lookUpOrCreateTOCEntry(GetJTISymbol(MO.getIndex()));
else if (MO.isBlockAddress()) {
MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
}
else if (MO.isCPI()) {
MOSymbol = GetCPISymbol(MO.getIndex());
if (TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
}
else if (MO.isGlobal()) {
const GlobalValue *GValue = MO.getGlobal();
MOSymbol = getSymbol(GValue);
if (GValue->getType()->getElementType()->isFunctionTy() ||
GValue->isDeclaration() || GValue->hasCommonLinkage() ||
GValue->hasAvailableExternallyLinkage() ||
TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
}
const MCExpr *Exp =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
OutContext);
TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::ADDItocL: {
// Transform %Xd = ADDItocL %Xs, <ga:@sym>
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
// Change the opcode to ADDI8. If the global address is external, then
// generate a TOC entry and reference that. Otherwise reference the
// symbol directly.
TmpInst.setOpcode(PPC::ADDI8);
const MachineOperand &MO = MI->getOperand(2);
assert((MO.isGlobal() || MO.isCPI()) && "Invalid operand for ADDItocL");
MCSymbol *MOSymbol = nullptr;
bool IsExternal = false;
bool IsNonLocalFunction = false;
if (MO.isGlobal()) {
const GlobalValue *GV = MO.getGlobal();
MOSymbol = getSymbol(GV);
IsExternal = GV->isDeclaration();
IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
(GV->isDeclaration() || GV->isWeakForLinker());
} else if (MO.isCPI())
MOSymbol = GetCPISymbol(MO.getIndex());
if (IsNonLocalFunction || IsExternal ||
TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
const MCExpr *Exp =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
OutContext);
TmpInst.getOperand(2) = MCOperand::CreateExpr(Exp);
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::ADDISgotTprelHA: {
// Transform: %Xd = ADDISgotTprelHA %X2, <ga:@sym>
// Into: %Xd = ADDIS8 %X2, sym@got@tlsgd@ha
assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymGotTprel =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA,
OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymGotTprel));
return;
}
case PPC::LDgotTprelL:
case PPC::LDgotTprelL32: {
// Transform %Xd = LDgotTprelL <ga:@sym>, %Xs
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
// Change the opcode to LD.
TmpInst.setOpcode(isPPC64 ? PPC::LD : PPC::LWZ);
const MachineOperand &MO = MI->getOperand(1);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *Exp =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO,
OutContext);
TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case PPC::PPC32PICGOT: {
MCSymbol *GOTSymbol = OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
MCSymbol *GOTRef = OutContext.CreateTempSymbol();
MCSymbol *NextInstr = OutContext.CreateTempSymbol();
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL)
// FIXME: We would like an efficient form for this, so we don't have to do
// a lot of extra uniquing.
.addExpr(MCSymbolRefExpr::Create(NextInstr, OutContext)));
const MCExpr *OffsExpr =
MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(GOTSymbol, OutContext),
MCSymbolRefExpr::Create(GOTRef, OutContext),
OutContext);
OutStreamer.EmitLabel(GOTRef);
OutStreamer.EmitValue(OffsExpr, 4);
OutStreamer.EmitLabel(NextInstr);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR)
.addReg(MI->getOperand(0).getReg()));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LWZ)
.addReg(MI->getOperand(1).getReg())
.addImm(0)
.addReg(MI->getOperand(0).getReg()));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADD4)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addReg(MI->getOperand(0).getReg()));
return;
}
case PPC::PPC32GOT: {
MCSymbol *GOTSymbol = OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
const MCExpr *SymGotTlsL =
MCSymbolRefExpr::Create(GOTSymbol, MCSymbolRefExpr::VK_PPC_LO,
OutContext);
const MCExpr *SymGotTlsHA =
MCSymbolRefExpr::Create(GOTSymbol, MCSymbolRefExpr::VK_PPC_HA,
OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LI)
.addReg(MI->getOperand(0).getReg())
.addExpr(SymGotTlsL));
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(0).getReg())
.addExpr(SymGotTlsHA));
return;
}
case PPC::ADDIStlsgdHA: {
// Transform: %Xd = ADDIStlsgdHA %X2, <ga:@sym>
// Into: %Xd = ADDIS8 %X2, sym@got@tlsgd@ha
assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymGotTlsGD =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA,
OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymGotTlsGD));
return;
}
case PPC::ADDItlsgdL:
// Transform: %Xd = ADDItlsgdL %Xs, <ga:@sym>
// Into: %Xd = ADDI8 %Xs, sym@got@tlsgd@l
case PPC::ADDItlsgdL32: {
// Transform: %Rd = ADDItlsgdL32 %Rs, <ga:@sym>
// Into: %Rd = ADDI %Rs, sym@got@tlsgd
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymGotTlsGD =
MCSymbolRefExpr::Create(MOSymbol, Subtarget.isPPC64() ?
MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO :
MCSymbolRefExpr::VK_PPC_GOT_TLSGD,
OutContext);
EmitToStreamer(OutStreamer,
MCInstBuilder(Subtarget.isPPC64() ? PPC::ADDI8 : PPC::ADDI)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymGotTlsGD));
return;
}
case PPC::GETtlsADDR:
// Transform: %X3 = GETtlsADDR %X3, <ga:@sym>
// Into: BL8_NOP_TLS __tls_get_addr(sym@tlsgd)
case PPC::GETtlsADDR32: {
// Transform: %R3 = GETtlsADDR32 %R3, <ga:@sym>
// Into: BL_TLS __tls_get_addr(sym@tlsgd)@PLT
EmitTlsCall(MI, MCSymbolRefExpr::VK_PPC_TLSGD);
return;
}
case PPC::ADDIStlsldHA: {
// Transform: %Xd = ADDIStlsldHA %X2, <ga:@sym>
// Into: %Xd = ADDIS8 %X2, sym@got@tlsld@ha
assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymGotTlsLD =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA,
OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymGotTlsLD));
return;
}
case PPC::ADDItlsldL:
// Transform: %Xd = ADDItlsldL %Xs, <ga:@sym>
// Into: %Xd = ADDI8 %Xs, sym@got@tlsld@l
case PPC::ADDItlsldL32: {
// Transform: %Rd = ADDItlsldL32 %Rs, <ga:@sym>
// Into: %Rd = ADDI %Rs, sym@got@tlsld
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymGotTlsLD =
MCSymbolRefExpr::Create(MOSymbol, Subtarget.isPPC64() ?
MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO :
MCSymbolRefExpr::VK_PPC_GOT_TLSLD,
OutContext);
EmitToStreamer(OutStreamer,
MCInstBuilder(Subtarget.isPPC64() ? PPC::ADDI8 : PPC::ADDI)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymGotTlsLD));
return;
}
case PPC::GETtlsldADDR:
// Transform: %X3 = GETtlsldADDR %X3, <ga:@sym>
// Into: BL8_NOP_TLS __tls_get_addr(sym@tlsld)
case PPC::GETtlsldADDR32: {
// Transform: %R3 = GETtlsldADDR32 %R3, <ga:@sym>
// Into: BL_TLS __tls_get_addr(sym@tlsld)@PLT
EmitTlsCall(MI, MCSymbolRefExpr::VK_PPC_TLSLD);
return;
}
case PPC::ADDISdtprelHA:
// Transform: %Xd = ADDISdtprelHA %X3, <ga:@sym>
// Into: %Xd = ADDIS8 %X3, sym@dtprel@ha
case PPC::ADDISdtprelHA32: {
// Transform: %Rd = ADDISdtprelHA32 %R3, <ga:@sym>
// Into: %Rd = ADDIS %R3, sym@dtprel@ha
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymDtprel =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_DTPREL_HA,
OutContext);
EmitToStreamer(OutStreamer,
MCInstBuilder(Subtarget.isPPC64() ? PPC::ADDIS8 : PPC::ADDIS)
.addReg(MI->getOperand(0).getReg())
.addReg(Subtarget.isPPC64() ? PPC::X3 : PPC::R3)
.addExpr(SymDtprel));
return;
}
case PPC::ADDIdtprelL:
// Transform: %Xd = ADDIdtprelL %Xs, <ga:@sym>
// Into: %Xd = ADDI8 %Xs, sym@dtprel@l
case PPC::ADDIdtprelL32: {
// Transform: %Rd = ADDIdtprelL32 %Rs, <ga:@sym>
// Into: %Rd = ADDI %Rs, sym@dtprel@l
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymDtprel =
MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_DTPREL_LO,
OutContext);
EmitToStreamer(OutStreamer,
MCInstBuilder(Subtarget.isPPC64() ? PPC::ADDI8 : PPC::ADDI)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymDtprel));
return;
}
case PPC::MFOCRF:
case PPC::MFOCRF8:
if (!Subtarget.hasMFOCRF()) {
// Transform: %R3 = MFOCRF %CR7
// Into: %R3 = MFCR ;; cr7
unsigned NewOpcode =
MI->getOpcode() == PPC::MFOCRF ? PPC::MFCR : PPC::MFCR8;
OutStreamer.AddComment(PPCInstPrinter::
getRegisterName(MI->getOperand(1).getReg()));
EmitToStreamer(OutStreamer, MCInstBuilder(NewOpcode)
.addReg(MI->getOperand(0).getReg()));
return;
}
break;
case PPC::MTOCRF:
case PPC::MTOCRF8:
if (!Subtarget.hasMFOCRF()) {
// Transform: %CR7 = MTOCRF %R3
// Into: MTCRF mask, %R3 ;; cr7
unsigned NewOpcode =
MI->getOpcode() == PPC::MTOCRF ? PPC::MTCRF : PPC::MTCRF8;
unsigned Mask = 0x80 >> OutContext.getRegisterInfo()
->getEncodingValue(MI->getOperand(0).getReg());
OutStreamer.AddComment(PPCInstPrinter::
getRegisterName(MI->getOperand(0).getReg()));
EmitToStreamer(OutStreamer, MCInstBuilder(NewOpcode)
.addImm(Mask)
.addReg(MI->getOperand(1).getReg()));
return;
}
break;
case PPC::LD:
case PPC::STD:
case PPC::LWA_32:
case PPC::LWA: {
// Verify alignment is legal, so we don't create relocations
// that can't be supported.
// FIXME: This test is currently disabled for Darwin. The test
// suite shows a handful of test cases that fail this check for
// Darwin. Those need to be investigated before this sanity test
// can be enabled for those subtargets.
if (!Subtarget.isDarwin()) {
unsigned OpNum = (MI->getOpcode() == PPC::STD) ? 2 : 1;
const MachineOperand &MO = MI->getOperand(OpNum);
if (MO.isGlobal() && MO.getGlobal()->getAlignment() < 4)
llvm_unreachable("Global must be word-aligned for LD, STD, LWA!");
}
// Now process the instruction normally.
break;
}
}
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
EmitToStreamer(OutStreamer, TmpInst);
}
void PPCLinuxAsmPrinter::EmitStartOfAsmFile(Module &M) {
if (Subtarget.isELFv2ABI()) {
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
if (TS)
TS->emitAbiVersion(2);
}
if (Subtarget.isPPC64() || TM.getRelocationModel() != Reloc::PIC_)
return AsmPrinter::EmitStartOfAsmFile(M);
if (M.getPICLevel() == PICLevel::Small)
return AsmPrinter::EmitStartOfAsmFile(M);
OutStreamer.SwitchSection(OutContext.getELFSection(
".got2", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC));
MCSymbol *TOCSym = OutContext.GetOrCreateSymbol(Twine(".LTOC"));
MCSymbol *CurrentPos = OutContext.CreateTempSymbol();
OutStreamer.EmitLabel(CurrentPos);
// The GOT pointer points to the middle of the GOT, in order to reference the
// entire 64kB range. 0x8000 is the midpoint.
const MCExpr *tocExpr =
MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(CurrentPos, OutContext),
MCConstantExpr::Create(0x8000, OutContext),
OutContext);
OutStreamer.EmitAssignment(TOCSym, tocExpr);
OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
}
void PPCLinuxAsmPrinter::EmitFunctionEntryLabel() {
// linux/ppc32 - Normal entry label.
if (!Subtarget.isPPC64() &&
(TM.getRelocationModel() != Reloc::PIC_ ||
MF->getFunction()->getParent()->getPICLevel() == PICLevel::Small))
return AsmPrinter::EmitFunctionEntryLabel();
if (!Subtarget.isPPC64()) {
const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
if (PPCFI->usesPICBase()) {
MCSymbol *RelocSymbol = PPCFI->getPICOffsetSymbol();
MCSymbol *PICBase = MF->getPICBaseSymbol();
OutStreamer.EmitLabel(RelocSymbol);
const MCExpr *OffsExpr =
MCBinaryExpr::CreateSub(
MCSymbolRefExpr::Create(OutContext.GetOrCreateSymbol(Twine(".LTOC")),
OutContext),
MCSymbolRefExpr::Create(PICBase, OutContext),
OutContext);
OutStreamer.EmitValue(OffsExpr, 4);
OutStreamer.EmitLabel(CurrentFnSym);
return;
} else
return AsmPrinter::EmitFunctionEntryLabel();
}
// ELFv2 ABI - Normal entry label.
if (Subtarget.isELFv2ABI())
return AsmPrinter::EmitFunctionEntryLabel();
// Emit an official procedure descriptor.
MCSectionSubPair Current = OutStreamer.getCurrentSection();
const MCSectionELF *Section = OutStreamer.getContext().getELFSection(
".opd", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
OutStreamer.SwitchSection(Section);
OutStreamer.EmitLabel(CurrentFnSym);
OutStreamer.EmitValueToAlignment(8);
MCSymbol *Symbol1 =
OutContext.GetOrCreateSymbol(".L." + Twine(CurrentFnSym->getName()));
// Generates a R_PPC64_ADDR64 (from FK_DATA_8) relocation for the function
// entry point.
OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol1, OutContext),
8 /*size*/);
MCSymbol *Symbol2 = OutContext.GetOrCreateSymbol(StringRef(".TOC."));
// Generates a R_PPC64_TOC relocation for TOC base insertion.
OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol2,
MCSymbolRefExpr::VK_PPC_TOCBASE, OutContext),
8/*size*/);
// Emit a null environment pointer.
OutStreamer.EmitIntValue(0, 8 /* size */);
OutStreamer.SwitchSection(Current.first, Current.second);
MCSymbol *RealFnSym = OutContext.GetOrCreateSymbol(
".L." + Twine(CurrentFnSym->getName()));
OutStreamer.EmitLabel(RealFnSym);
CurrentFnSymForSize = RealFnSym;
}
bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
const DataLayout *TD = TM.getDataLayout();
bool isPPC64 = TD->getPointerSizeInBits() == 64;
PPCTargetStreamer &TS =
static_cast<PPCTargetStreamer &>(*OutStreamer.getTargetStreamer());
if (!TOC.empty()) {
const MCSectionELF *Section;
if (isPPC64)
Section = OutStreamer.getContext().getELFSection(
".toc", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
else
Section = OutStreamer.getContext().getELFSection(
".got2", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
OutStreamer.SwitchSection(Section);
for (MapVector<MCSymbol*, MCSymbol*>::iterator I = TOC.begin(),
E = TOC.end(); I != E; ++I) {
OutStreamer.EmitLabel(I->second);
MCSymbol *S = I->first;
if (isPPC64)
TS.emitTCEntry(*S);
else
OutStreamer.EmitSymbolValue(S, 4);
}
}
MachineModuleInfoELF &MMIELF =
MMI->getObjFileInfo<MachineModuleInfoELF>();
MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
if (!Stubs.empty()) {
OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
// L_foo$stub:
OutStreamer.EmitLabel(Stubs[i].first);
// .long _foo
OutStreamer.EmitValue(MCSymbolRefExpr::Create(Stubs[i].second.getPointer(),
OutContext),
isPPC64 ? 8 : 4/*size*/);
}
Stubs.clear();
OutStreamer.AddBlankLine();
}
return AsmPrinter::doFinalization(M);
}
/// EmitFunctionBodyStart - Emit a global entry point prefix for ELFv2.
void PPCLinuxAsmPrinter::EmitFunctionBodyStart() {
// In the ELFv2 ABI, in functions that use the TOC register, we need to
// provide two entry points. The ABI guarantees that when calling the
// local entry point, r2 is set up by the caller to contain the TOC base
// for this function, and when calling the global entry point, r12 is set
// up by the caller to hold the address of the global entry point. We
// thus emit a prefix sequence along the following lines:
//
// func:
// # global entry point
// addis r2,r12,(.TOC.-func)@ha
// addi r2,r2,(.TOC.-func)@l
// .localentry func, .-func
// # local entry point, followed by function body
//
// This ensures we have r2 set up correctly while executing the function
// body, no matter which entry point is called.
if (Subtarget.isELFv2ABI()
// Only do all that if the function uses r2 in the first place.
&& !MF->getRegInfo().use_empty(PPC::X2)) {
MCSymbol *GlobalEntryLabel = OutContext.CreateTempSymbol();
OutStreamer.EmitLabel(GlobalEntryLabel);
const MCSymbolRefExpr *GlobalEntryLabelExp =
MCSymbolRefExpr::Create(GlobalEntryLabel, OutContext);
MCSymbol *TOCSymbol = OutContext.GetOrCreateSymbol(StringRef(".TOC."));
const MCExpr *TOCDeltaExpr =
MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(TOCSymbol, OutContext),
GlobalEntryLabelExp, OutContext);
const MCExpr *TOCDeltaHi =
PPCMCExpr::CreateHa(TOCDeltaExpr, false, OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
.addReg(PPC::X2)
.addReg(PPC::X12)
.addExpr(TOCDeltaHi));
const MCExpr *TOCDeltaLo =
PPCMCExpr::CreateLo(TOCDeltaExpr, false, OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDI)
.addReg(PPC::X2)
.addReg(PPC::X2)
.addExpr(TOCDeltaLo));
MCSymbol *LocalEntryLabel = OutContext.CreateTempSymbol();
OutStreamer.EmitLabel(LocalEntryLabel);
const MCSymbolRefExpr *LocalEntryLabelExp =
MCSymbolRefExpr::Create(LocalEntryLabel, OutContext);
const MCExpr *LocalOffsetExp =
MCBinaryExpr::CreateSub(LocalEntryLabelExp,
GlobalEntryLabelExp, OutContext);
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
if (TS)
TS->emitLocalEntry(CurrentFnSym, LocalOffsetExp);
}
}
/// EmitFunctionBodyEnd - Print the traceback table before the .size
/// directive.
///
void PPCLinuxAsmPrinter::EmitFunctionBodyEnd() {
// Only the 64-bit target requires a traceback table. For now,
// we only emit the word of zeroes that GDB requires to find
// the end of the function, and zeroes for the eight-byte
// mandatory fields.
// FIXME: We should fill in the eight-byte mandatory fields as described in
// the PPC64 ELF ABI (this is a low-priority item because GDB does not
// currently make use of these fields).
if (Subtarget.isPPC64()) {
OutStreamer.EmitIntValue(0, 4/*size*/);
OutStreamer.EmitIntValue(0, 8/*size*/);
}
}
void PPCDarwinAsmPrinter::EmitStartOfAsmFile(Module &M) {
static const char *const CPUDirectives[] = {
"",
"ppc",
"ppc440",
"ppc601",
"ppc602",
"ppc603",
"ppc7400",
"ppc750",
"ppc970",
"ppcA2",
"ppce500mc",
"ppce5500",
"power3",
"power4",
"power5",
"power5x",
"power6",
"power6x",
"power7",
"ppc64",
"ppc64le"
};
unsigned Directive = Subtarget.getDarwinDirective();
if (Subtarget.hasMFOCRF() && Directive < PPC::DIR_970)
Directive = PPC::DIR_970;
if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
Directive = PPC::DIR_7400;
if (Subtarget.isPPC64() && Directive < PPC::DIR_64)
Directive = PPC::DIR_64;
assert(Directive <= PPC::DIR_64 && "Directive out of range.");
assert(Directive < array_lengthof(CPUDirectives) &&
"CPUDirectives[] might not be up-to-date!");
PPCTargetStreamer &TStreamer =
*static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
TStreamer.emitMachine(CPUDirectives[Directive]);
// Prime text sections so they are adjacent. This reduces the likelihood a
// large data or debug section causes a branch to exceed 16M limit.
const TargetLoweringObjectFileMachO &TLOFMacho =
static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
if (TM.getRelocationModel() == Reloc::PIC_) {
OutStreamer.SwitchSection(
OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
MachO::S_SYMBOL_STUBS |
MachO::S_ATTR_PURE_INSTRUCTIONS,
32, SectionKind::getText()));
} else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
OutStreamer.SwitchSection(
OutContext.getMachOSection("__TEXT","__symbol_stub1",
MachO::S_SYMBOL_STUBS |
MachO::S_ATTR_PURE_INSTRUCTIONS,
16, SectionKind::getText()));
}
OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
}
static MCSymbol *GetLazyPtr(MCSymbol *Sym, MCContext &Ctx) {
// Remove $stub suffix, add $lazy_ptr.
StringRef NoStub = Sym->getName().substr(0, Sym->getName().size()-5);
return Ctx.GetOrCreateSymbol(NoStub + "$lazy_ptr");
}
static MCSymbol *GetAnonSym(MCSymbol *Sym, MCContext &Ctx) {
// Add $tmp suffix to $stub, yielding $stub$tmp.
return Ctx.GetOrCreateSymbol(Sym->getName() + "$tmp");
}
void PPCDarwinAsmPrinter::
EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;
bool isDarwin = Subtarget.isDarwin();
const TargetLoweringObjectFileMachO &TLOFMacho =
static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
// .lazy_symbol_pointer
const MCSection *LSPSection = TLOFMacho.getLazySymbolPointerSection();
// Output stubs for dynamically-linked functions
if (TM.getRelocationModel() == Reloc::PIC_) {
const MCSection *StubSection =
OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
MachO::S_SYMBOL_STUBS |
MachO::S_ATTR_PURE_INSTRUCTIONS,
32, SectionKind::getText());
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
OutStreamer.SwitchSection(StubSection);
EmitAlignment(4);
MCSymbol *Stub = Stubs[i].first;
MCSymbol *RawSym = Stubs[i].second.getPointer();
MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
MCSymbol *AnonSymbol = GetAnonSym(Stub, OutContext);
OutStreamer.EmitLabel(Stub);
OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
const MCExpr *Anon = MCSymbolRefExpr::Create(AnonSymbol, OutContext);
const MCExpr *LazyPtrExpr = MCSymbolRefExpr::Create(LazyPtr, OutContext);
const MCExpr *Sub =
MCBinaryExpr::CreateSub(LazyPtrExpr, Anon, OutContext);
// mflr r0
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR).addReg(PPC::R0));
// bcl 20, 31, AnonSymbol
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCLalways).addExpr(Anon));
OutStreamer.EmitLabel(AnonSymbol);
// mflr r11
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR).addReg(PPC::R11));
// addis r11, r11, ha16(LazyPtr - AnonSymbol)
const MCExpr *SubHa16 = PPCMCExpr::CreateHa(Sub, isDarwin, OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
.addReg(PPC::R11)
.addReg(PPC::R11)
.addExpr(SubHa16));
// mtlr r0
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTLR).addReg(PPC::R0));
// ldu r12, lo16(LazyPtr - AnonSymbol)(r11)
// lwzu r12, lo16(LazyPtr - AnonSymbol)(r11)
const MCExpr *SubLo16 = PPCMCExpr::CreateLo(Sub, isDarwin, OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
.addReg(PPC::R12)
.addExpr(SubLo16).addExpr(SubLo16)
.addReg(PPC::R11));
// mtctr r12
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR).addReg(PPC::R12));
// bctr
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTR));
OutStreamer.SwitchSection(LSPSection);
OutStreamer.EmitLabel(LazyPtr);
OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
MCSymbol *DyldStubBindingHelper =
OutContext.GetOrCreateSymbol(StringRef("dyld_stub_binding_helper"));
if (isPPC64) {
// .quad dyld_stub_binding_helper
OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 8);
} else {
// .long dyld_stub_binding_helper
OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 4);
}
}
OutStreamer.AddBlankLine();
return;
}
const MCSection *StubSection =
OutContext.getMachOSection("__TEXT","__symbol_stub1",
MachO::S_SYMBOL_STUBS |
MachO::S_ATTR_PURE_INSTRUCTIONS,
16, SectionKind::getText());
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
MCSymbol *Stub = Stubs[i].first;
MCSymbol *RawSym = Stubs[i].second.getPointer();
MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
const MCExpr *LazyPtrExpr = MCSymbolRefExpr::Create(LazyPtr, OutContext);
OutStreamer.SwitchSection(StubSection);
EmitAlignment(4);
OutStreamer.EmitLabel(Stub);
OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
// lis r11, ha16(LazyPtr)
const MCExpr *LazyPtrHa16 =
PPCMCExpr::CreateHa(LazyPtrExpr, isDarwin, OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LIS)
.addReg(PPC::R11)
.addExpr(LazyPtrHa16));
// ldu r12, lo16(LazyPtr)(r11)
// lwzu r12, lo16(LazyPtr)(r11)
const MCExpr *LazyPtrLo16 =
PPCMCExpr::CreateLo(LazyPtrExpr, isDarwin, OutContext);
EmitToStreamer(OutStreamer, MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
.addReg(PPC::R12)
.addExpr(LazyPtrLo16).addExpr(LazyPtrLo16)
.addReg(PPC::R11));
// mtctr r12
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR).addReg(PPC::R12));
// bctr
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTR));
OutStreamer.SwitchSection(LSPSection);
OutStreamer.EmitLabel(LazyPtr);
OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
MCSymbol *DyldStubBindingHelper =
OutContext.GetOrCreateSymbol(StringRef("dyld_stub_binding_helper"));
if (isPPC64) {
// .quad dyld_stub_binding_helper
OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 8);
} else {
// .long dyld_stub_binding_helper
OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 4);
}
}
OutStreamer.AddBlankLine();
}
bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;
// Darwin/PPC always uses mach-o.
const TargetLoweringObjectFileMachO &TLOFMacho =
static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
MachineModuleInfoMachO &MMIMacho =
MMI->getObjFileInfo<MachineModuleInfoMachO>();
MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetFnStubList();
if (!Stubs.empty())
EmitFunctionStubs(Stubs);
if (MAI->doesSupportExceptionHandling() && MMI) {
// Add the (possibly multiple) personalities to the set of global values.
// Only referenced functions get into the Personalities list.
const std::vector<const Function*> &Personalities = MMI->getPersonalities();
for (std::vector<const Function*>::const_iterator I = Personalities.begin(),
E = Personalities.end(); I != E; ++I) {
if (*I) {
MCSymbol *NLPSym = getSymbolWithGlobalValueBase(*I, "$non_lazy_ptr");
MachineModuleInfoImpl::StubValueTy &StubSym =
MMIMacho.getGVStubEntry(NLPSym);
StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(*I), true);
}
}
}
// Output stubs for dynamically-linked functions.
Stubs = MMIMacho.GetGVStubList();
// Output macho stubs for external and common global variables.
if (!Stubs.empty()) {
// Switch with ".non_lazy_symbol_pointer" directive.
OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
EmitAlignment(isPPC64 ? 3 : 2);
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
// L_foo$stub:
OutStreamer.EmitLabel(Stubs[i].first);
// .indirect_symbol _foo
MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
if (MCSym.getInt())
// External to current translation unit.
OutStreamer.EmitIntValue(0, isPPC64 ? 8 : 4/*size*/);
else
// Internal to current translation unit.
//
// When we place the LSDA into the TEXT section, the type info pointers
// need to be indirect and pc-rel. We accomplish this by using NLPs.
// However, sometimes the types are local to the file. So we need to
// fill in the value for the NLP in those cases.
OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
OutContext),
isPPC64 ? 8 : 4/*size*/);
}
Stubs.clear();
OutStreamer.AddBlankLine();
}
Stubs = MMIMacho.GetHiddenGVStubList();
if (!Stubs.empty()) {
OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
EmitAlignment(isPPC64 ? 3 : 2);
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
// L_foo$stub:
OutStreamer.EmitLabel(Stubs[i].first);
// .long _foo
OutStreamer.EmitValue(MCSymbolRefExpr::
Create(Stubs[i].second.getPointer(),
OutContext),
isPPC64 ? 8 : 4/*size*/);
}
Stubs.clear();
OutStreamer.AddBlankLine();
}
// Funny Darwin hack: This flag tells the linker that no global symbols
// contain code that falls through to other global symbols (e.g. the obvious
// implementation of multiple entry points). If this doesn't occur, the
// linker can safely perform dead code stripping. Since LLVM never generates
// code that does this, it is always safe to set.
OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
return AsmPrinter::doFinalization(M);
}
/// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
/// for a MachineFunction to the given output stream, in a format that the
/// Darwin assembler can deal with.
///
static AsmPrinter *
createPPCAsmPrinterPass(TargetMachine &tm,
std::unique_ptr<MCStreamer> &&Streamer) {
const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
if (Subtarget->isDarwin())
return new PPCDarwinAsmPrinter(tm, std::move(Streamer));
return new PPCLinuxAsmPrinter(tm, std::move(Streamer));
}
// Force static initialization.
extern "C" void LLVMInitializePowerPCAsmPrinter() {
TargetRegistry::RegisterAsmPrinter(ThePPC32Target, createPPCAsmPrinterPass);
TargetRegistry::RegisterAsmPrinter(ThePPC64Target, createPPCAsmPrinterPass);
TargetRegistry::RegisterAsmPrinter(ThePPC64LETarget, createPPCAsmPrinterPass);
}
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