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llvm/llvm-project/refs/heads/users/pierre-vh/split-eventtracker-basic/./llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
blob: e2e3d0f70d0e1907189bf349c69daa1789c19d01 [file] [edit]
//===-- PPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly ------===//
//
// 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 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 "MCTargetDesc/PPCInstPrinter.h"
#include "MCTargetDesc/PPCMCAsmInfo.h"
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "MCTargetDesc/PPCTargetStreamer.h"
#include "PPC.h"
#include "PPCInstrInfo.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "TargetInfo/PowerPCTargetInfo.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionXCOFF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCSymbolELF.h"
#include "llvm/MC/MCSymbolXCOFF.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Threading.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/TargetParser/PPCTargetParser.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
#include <cassert>
#include <cstdint>
#include <memory>
#include <new>
using namespace llvm;
using namespace llvm::XCOFF;
using namespace PatternMatch;
#define DEBUG_TYPE "asmprinter"
STATISTIC(NumTOCEntries, "Number of Total TOC Entries Emitted.");
STATISTIC(NumTOCConstPool, "Number of Constant Pool TOC Entries.");
STATISTIC(NumTOCGlobalInternal,
"Number of Internal Linkage Global TOC Entries.");
STATISTIC(NumTOCGlobalExternal,
"Number of External Linkage Global TOC Entries.");
STATISTIC(NumTOCJumpTable, "Number of Jump Table TOC Entries.");
STATISTIC(NumTOCThreadLocal, "Number of Thread Local TOC Entries.");
STATISTIC(NumTOCBlockAddress, "Number of Block Address TOC Entries.");
STATISTIC(NumTOCEHBlock, "Number of EH Block TOC Entries.");
static cl::opt<bool> EnableSSPCanaryBitInTB(
"ppc-aix-ssp-tb-bit", cl::init(false),
cl::desc("Enable Passing SSP Canary info in Trackback on AIX"), cl::Hidden);
static cl::opt<bool> IFuncLocalIfProven(
"ppc-ifunc-local-if-proven", cl::init(false),
cl::desc("During ifunc lowering, the compiler assumes the resolver returns "
"dso-local functions and bails out if non-local functions are "
"detected; this flag flips the assumption: resolver returns "
"preemptible functions unless the compiler can prove all paths "
"return local functions."),
cl::Hidden);
// this flag is used for testing only as it might generate bad code.
static cl::opt<bool> IFuncWarnInsteadOfError("ppc-test-ifunc-warn-noerror",
cl::init(false), cl::ReallyHidden);
// Specialize DenseMapInfo to allow
// std::pair<const MCSymbol *, PPCMCExpr::Specifier> in DenseMap.
// This specialization is needed here because that type is used as keys in the
// map representing TOC entries.
namespace llvm {
template <>
struct DenseMapInfo<std::pair<const MCSymbol *, PPCMCExpr::Specifier>> {
using TOCKey = std::pair<const MCSymbol *, PPCMCExpr::Specifier>;
static unsigned getHashValue(const TOCKey &PairVal) {
return detail::combineHashValue(
DenseMapInfo<const MCSymbol *>::getHashValue(PairVal.first),
DenseMapInfo<int>::getHashValue(PairVal.second));
}
static bool isEqual(const TOCKey &A, const TOCKey &B) { return A == B; }
};
} // end namespace llvm
namespace {
enum {
// GNU attribute tags for PowerPC ABI
Tag_GNU_Power_ABI_FP = 4,
Tag_GNU_Power_ABI_Vector = 8,
Tag_GNU_Power_ABI_Struct_Return = 12,
// GNU attribute values for PowerPC float ABI, as combination of two parts
Val_GNU_Power_ABI_NoFloat = 0b00,
Val_GNU_Power_ABI_HardFloat_DP = 0b01,
Val_GNU_Power_ABI_SoftFloat_DP = 0b10,
Val_GNU_Power_ABI_HardFloat_SP = 0b11,
Val_GNU_Power_ABI_LDBL_IBM128 = 0b0100,
Val_GNU_Power_ABI_LDBL_64 = 0b1000,
Val_GNU_Power_ABI_LDBL_IEEE128 = 0b1100,
};
class PPCAsmPrinter : public AsmPrinter {
protected:
// For TLS on AIX, we need to be able to identify TOC entries of specific
// specifier so we can add the right relocations when we generate the
// entries. So each entry is represented by a pair of MCSymbol and
// VariantKind. For example, we need to be able to identify the following
// entry as a TLSGD entry so we can add the @m relocation:
// .tc .i[TC],i[TL]@m
// By default, 0 is used for the specifier.
MapVector<std::pair<const MCSymbol *, PPCMCExpr::Specifier>, MCSymbol *> TOC;
const PPCSubtarget *Subtarget = nullptr;
// Keep track of the number of TLS variables and their corresponding
// addresses, which is then used for the assembly printing of
// non-TOC-based local-exec variables.
MapVector<const GlobalValue *, uint64_t> TLSVarsToAddressMapping;
public:
explicit PPCAsmPrinter(TargetMachine &TM,
std::unique_ptr<MCStreamer> Streamer, char &ID)
: AsmPrinter(TM, std::move(Streamer), ID) {}
StringRef getPassName() const override { return "PowerPC Assembly Printer"; }
enum TOCEntryType {
TOCType_ConstantPool,
TOCType_GlobalExternal,
TOCType_GlobalInternal,
TOCType_JumpTable,
TOCType_ThreadLocal,
TOCType_BlockAddress,
TOCType_EHBlock
};
MCSymbol *lookUpOrCreateTOCEntry(const MCSymbol *Sym, TOCEntryType Type,
PPCMCExpr::Specifier Kind = PPC::S_None);
bool doInitialization(Module &M) override {
if (!TOC.empty())
TOC.clear();
return AsmPrinter::doInitialization(M);
}
const MCExpr *symbolWithSpecifier(const MCSymbol *S,
PPCMCExpr::Specifier Kind);
void emitInstruction(const MachineInstr *MI) override;
/// This function is for PrintAsmOperand and PrintAsmMemoryOperand,
/// invoked by EmitMSInlineAsmStr and EmitGCCInlineAsmStr only.
/// The \p MI would be INLINEASM ONLY.
void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);
void PrintSymbolOperand(const MachineOperand &MO, raw_ostream &O) override;
bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
const char *ExtraCode, raw_ostream &O) override;
bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
const char *ExtraCode, raw_ostream &O) override;
void LowerSTACKMAP(StackMaps &SM, const MachineInstr &MI);
void LowerPATCHPOINT(StackMaps &SM, const MachineInstr &MI);
void emitTlsCall(const MachineInstr *MI, PPCMCExpr::Specifier VK);
void EmitAIXTlsCallHelper(const MachineInstr *MI);
const MCExpr *getAdjustedFasterLocalExpr(const MachineOperand &MO,
int64_t Offset);
bool runOnMachineFunction(MachineFunction &MF) override {
Subtarget = &MF.getSubtarget<PPCSubtarget>();
bool Changed = AsmPrinter::runOnMachineFunction(MF);
emitXRayTable();
return Changed;
}
};
/// PPCLinuxAsmPrinter - PowerPC assembly printer, customized for Linux
class PPCLinuxAsmPrinter : public PPCAsmPrinter {
public:
static char ID;
explicit PPCLinuxAsmPrinter(TargetMachine &TM,
std::unique_ptr<MCStreamer> Streamer)
: PPCAsmPrinter(TM, std::move(Streamer), ID) {}
StringRef getPassName() const override {
return "Linux PPC Assembly Printer";
}
void emitGNUAttributes(Module &M);
void emitStartOfAsmFile(Module &M) override;
void emitEndOfAsmFile(Module &) override;
void emitFunctionEntryLabel() override;
void emitFunctionBodyStart() override;
void emitFunctionBodyEnd() override;
void emitInstruction(const MachineInstr *MI) override;
};
class PPCAIXAsmPrinter : public PPCAsmPrinter {
private:
/// Symbols lowered from ExternalSymbolSDNodes, we will need to emit extern
/// linkage for them in AIX.
SmallSetVector<MCSymbol *, 8> ExtSymSDNodeSymbols;
/// A format indicator and unique trailing identifier to form part of the
/// sinit/sterm function names.
std::string FormatIndicatorAndUniqueModId;
// Record a list of GlobalAlias associated with a GlobalObject.
// This is used for AIX's extra-label-at-definition aliasing strategy.
DenseMap<const GlobalObject *, SmallVector<const GlobalAlias *, 1>>
GOAliasMap;
uint16_t getNumberOfVRSaved();
void emitTracebackTable();
SmallVector<const GlobalVariable *, 8> TOCDataGlobalVars;
void emitGlobalVariableHelper(const GlobalVariable *);
// Get the offset of an alias based on its AliaseeObject.
uint64_t getAliasOffset(const Constant *C);
public:
static char ID;
PPCAIXAsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
: PPCAsmPrinter(TM, std::move(Streamer), ID) {
if (MAI.isLittleEndian())
report_fatal_error(
"cannot create AIX PPC Assembly Printer for a little-endian target");
}
StringRef getPassName() const override { return "AIX PPC Assembly Printer"; }
bool doInitialization(Module &M) override;
void emitXXStructorList(const DataLayout &DL, const Constant *List,
bool IsCtor) override;
void SetupMachineFunction(MachineFunction &MF) override;
void emitGlobalVariable(const GlobalVariable *GV) override;
void emitFunctionDescriptor() override;
void emitFunctionEntryLabel() override;
void emitFunctionBodyEnd() override;
void emitPGORefs(Module &M);
void emitGCOVRefs();
void emitEndOfAsmFile(Module &) override;
void emitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const override;
void emitInstruction(const MachineInstr *MI) override;
bool doFinalization(Module &M) override;
void emitTTypeReference(const GlobalValue *GV, unsigned Encoding) override;
void emitModuleCommandLines(Module &M) override;
void emitRefMetadata(const GlobalObject *);
void emitGlobalIFunc(Module &M, const GlobalIFunc &GI) override;
};
} // end anonymous namespace
void PPCAsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
raw_ostream &O) {
// Computing the address of a global symbol, not calling it.
const GlobalValue *GV = MO.getGlobal();
getSymbol(GV)->print(O, MAI);
printOffset(MO.getOffset(), O);
}
void PPCAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
raw_ostream &O) {
const DataLayout &DL = getDataLayout();
const MachineOperand &MO = MI->getOperand(OpNo);
switch (MO.getType()) {
case MachineOperand::MO_Register: {
// The MI is INLINEASM ONLY and UseVSXReg is always false.
const char *RegName = PPCInstPrinter::getRegisterName(MO.getReg());
// Linux assembler (Others?) does not take register mnemonics.
// FIXME - What about special registers used in mfspr/mtspr?
O << PPC::stripRegisterPrefix(RegName);
return;
}
case MachineOperand::MO_Immediate:
O << MO.getImm();
return;
case MachineOperand::MO_MachineBasicBlock:
MO.getMBB()->getSymbol()->print(O, MAI);
return;
case MachineOperand::MO_ConstantPoolIndex:
O << DL.getInternalSymbolPrefix() << "CPI" << getFunctionNumber() << '_'
<< MO.getIndex();
return;
case MachineOperand::MO_BlockAddress:
GetBlockAddressSymbol(MO.getBlockAddress())->print(O, MAI);
return;
case MachineOperand::MO_GlobalAddress: {
PrintSymbolOperand(MO, 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,
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, ExtraCode, O);
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;
case 'x':
if(!MI->getOperand(OpNo).isReg())
return true;
// This operand uses VSX numbering.
// If the operand is a VMX register, convert it to a VSX register.
Register Reg = MI->getOperand(OpNo).getReg();
if (PPC::isVRRegister(Reg))
Reg = PPC::VSX32 + (Reg - PPC::V0);
else if (PPC::isVFRegister(Reg))
Reg = PPC::VSX32 + (Reg - PPC::VF0);
const char *RegName;
RegName = PPCInstPrinter::getRegisterName(Reg);
RegName = PPC::stripRegisterPrefix(RegName);
O << RegName;
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,
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 'L': // A memory reference to the upper word of a double word op.
O << getDataLayout().getPointerSize() << "(";
printOperand(MI, OpNo, O);
O << ")";
return false;
case 'y': // A memory reference for an X-form instruction
O << "0, ";
printOperand(MI, OpNo, O);
return false;
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;
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;
}
static void collectTOCStats(PPCAsmPrinter::TOCEntryType Type) {
++NumTOCEntries;
switch (Type) {
case PPCAsmPrinter::TOCType_ConstantPool:
++NumTOCConstPool;
break;
case PPCAsmPrinter::TOCType_GlobalInternal:
++NumTOCGlobalInternal;
break;
case PPCAsmPrinter::TOCType_GlobalExternal:
++NumTOCGlobalExternal;
break;
case PPCAsmPrinter::TOCType_JumpTable:
++NumTOCJumpTable;
break;
case PPCAsmPrinter::TOCType_ThreadLocal:
++NumTOCThreadLocal;
break;
case PPCAsmPrinter::TOCType_BlockAddress:
++NumTOCBlockAddress;
break;
case PPCAsmPrinter::TOCType_EHBlock:
++NumTOCEHBlock;
break;
}
}
static CodeModel::Model getCodeModel(const PPCSubtarget &S,
const TargetMachine &TM,
const MachineOperand &MO) {
CodeModel::Model ModuleModel = TM.getCodeModel();
// If the operand is not a global address then there is no
// global variable to carry an attribute.
if (!(MO.getType() == MachineOperand::MO_GlobalAddress))
return ModuleModel;
const GlobalValue *GV = MO.getGlobal();
assert(GV && "expected global for MO_GlobalAddress");
return S.getCodeModel(TM, GV);
}
static void setOptionalCodeModel(MCSymbolXCOFF *XSym, CodeModel::Model CM) {
switch (CM) {
case CodeModel::Large:
XSym->setPerSymbolCodeModel(MCSymbolXCOFF::CM_Large);
return;
case CodeModel::Small:
XSym->setPerSymbolCodeModel(MCSymbolXCOFF::CM_Small);
return;
default:
report_fatal_error("Invalid code model for AIX");
}
}
/// 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(const MCSymbol *Sym,
TOCEntryType Type,
PPCMCExpr::Specifier Spec) {
// If this is a new TOC entry add statistics about it.
auto [It, Inserted] = TOC.try_emplace({Sym, Spec});
if (Inserted)
collectTOCStats(Type);
MCSymbol *&TOCEntry = It->second;
if (!TOCEntry)
TOCEntry = createTempSymbol("C");
return TOCEntry;
}
void PPCAsmPrinter::LowerSTACKMAP(StackMaps &SM, const MachineInstr &MI) {
unsigned NumNOPBytes = MI.getOperand(1).getImm();
auto &Ctx = OutStreamer->getContext();
MCSymbol *MILabel = Ctx.createTempSymbol();
OutStreamer->emitLabel(MILabel);
SM.recordStackMap(*MILabel, 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(StackMaps &SM, const MachineInstr &MI) {
auto &Ctx = OutStreamer->getContext();
MCSymbol *MILabel = Ctx.createTempSymbol();
OutStreamer->emitLabel(MILabel);
SM.recordPatchPoint(*MILabel, MI);
PatchPointOpers Opers(&MI);
unsigned EncodedBytes = 0;
const MachineOperand &CalleeMO = Opers.getCallTarget();
if (CalleeMO.isImm()) {
int64_t CallTarget = CalleeMO.getImm();
if (CallTarget) {
assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
"High 16 bits of call target should be zero.");
Register ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
EncodedBytes = 0;
// Materialize the jump address:
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::LI8)
.addReg(ScratchReg)
.addImm((CallTarget >> 32) & 0xFFFF));
++EncodedBytes;
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::RLDIC)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(32).addImm(16));
++EncodedBytes;
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ORIS8)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm((CallTarget >> 16) & 0xFFFF));
++EncodedBytes;
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ORI8)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(CallTarget & 0xFFFF));
++EncodedBytes;
// Save the current TOC pointer before the remote call.
int TOCSaveOffset = Subtarget->getFrameLowering()->getTOCSaveOffset();
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::STD)
.addReg(PPC::X2)
.addImm(TOCSaveOffset)
.addReg(PPC::X1));
++EncodedBytes;
// If we're on ELFv1, then we need to load the actual function pointer
// from the function descriptor.
if (!Subtarget->isELFv2ABI()) {
// Load the new TOC pointer and the function address, but not r11
// (needing this is rare, and loading it here would prevent passing it
// via a 'nest' parameter.
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::LD)
.addReg(PPC::X2)
.addImm(8)
.addReg(ScratchReg));
++EncodedBytes;
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::LD)
.addReg(ScratchReg)
.addImm(0)
.addReg(ScratchReg));
++EncodedBytes;
}
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::MTCTR8)
.addReg(ScratchReg));
++EncodedBytes;
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::BCTRL8));
++EncodedBytes;
// Restore the TOC pointer after the call.
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::LD)
.addReg(PPC::X2)
.addImm(TOCSaveOffset)
.addReg(PPC::X1));
++EncodedBytes;
}
} else if (CalleeMO.isGlobal()) {
const GlobalValue *GValue = CalleeMO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymVar = MCSymbolRefExpr::create(MOSymbol, OutContext);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::BL8_NOP)
.addExpr(SymVar));
EncodedBytes += 2;
}
// Each instruction is 4 bytes.
EncodedBytes *= 4;
// Emit padding.
unsigned NumBytes = Opers.getNumPatchBytes();
if (NumBytes < EncodedBytes)
reportFatalUsageError(
"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));
}
/// This helper function creates the TlsGetAddr/TlsGetMod MCSymbol for AIX. We
/// will create the csect and use the qual-name symbol instead of creating just
/// the external symbol.
static MCSymbol *createMCSymbolForTlsGetAddr(MCContext &Ctx, unsigned MIOpc) {
StringRef SymName;
switch (MIOpc) {
default:
SymName = ".__tls_get_addr";
break;
case PPC::GETtlsTpointer32AIX:
SymName = ".__get_tpointer";
break;
case PPC::GETtlsMOD32AIX:
case PPC::GETtlsMOD64AIX:
SymName = ".__tls_get_mod";
break;
}
return Ctx
.getXCOFFSection(SymName, SectionKind::getText(),
XCOFF::CsectProperties(XCOFF::XMC_PR, XCOFF::XTY_ER))
->getQualNameSymbol();
}
void PPCAsmPrinter::EmitAIXTlsCallHelper(const MachineInstr *MI) {
assert(Subtarget->isAIXABI() &&
"Only expecting to emit calls to get the thread pointer on AIX!");
MCSymbol *TlsCall = createMCSymbolForTlsGetAddr(OutContext, MI->getOpcode());
const MCExpr *TlsRef = MCSymbolRefExpr::create(TlsCall, OutContext);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::BLA).addExpr(TlsRef));
}
/// 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,
PPCMCExpr::Specifier VK) {
PPCMCExpr::Specifier Kind = PPC::S_None;
unsigned Opcode = PPC::BL8_NOP_TLS;
assert(MI->getNumOperands() >= 3 && "Expecting at least 3 operands from MI");
if (MI->getOperand(2).getTargetFlags() == PPCII::MO_GOT_TLSGD_PCREL_FLAG ||
MI->getOperand(2).getTargetFlags() == PPCII::MO_GOT_TLSLD_PCREL_FLAG) {
Kind = PPC::S_NOTOC;
Opcode = PPC::BL8_NOTOC_TLS;
}
const Module *M = MF->getFunction().getParent();
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->isAIXABI()) {
// For TLSGD, the variable offset should already be in R4 and the region
// handle should already be in R3. We generate an absolute branch to
// .__tls_get_addr. For TLSLD, the module handle should already be in R3.
// We generate an absolute branch to .__tls_get_mod.
Register VarOffsetReg = Subtarget->isPPC64() ? PPC::X4 : PPC::R4;
(void)VarOffsetReg;
assert((MI->getOpcode() == PPC::GETtlsMOD32AIX ||
MI->getOpcode() == PPC::GETtlsMOD64AIX ||
(MI->getOperand(2).isReg() &&
MI->getOperand(2).getReg() == VarOffsetReg)) &&
"GETtls[ld]ADDR[32] must read GPR4");
EmitAIXTlsCallHelper(MI);
return;
}
MCSymbol *TlsGetAddr = OutContext.getOrCreateSymbol("__tls_get_addr");
if (Subtarget->is32BitELFABI() && isPositionIndependent())
Kind = PPC::S_PLT;
const MCExpr *TlsRef = MCSymbolRefExpr::create(TlsGetAddr, Kind, OutContext);
// Add 32768 offset to the symbol so we follow up the latest GOT/PLT ABI.
if (Kind == PPC::S_PLT && Subtarget->isSecurePlt() &&
M->getPICLevel() == PICLevel::BigPIC)
TlsRef = MCBinaryExpr::createAdd(
TlsRef, MCConstantExpr::create(32768, OutContext), 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() ? Opcode
: (unsigned)PPC::BL_TLS)
.addExpr(TlsRef)
.addExpr(SymVar));
}
/// Map a machine operand for a TOC pseudo-machine instruction to its
/// corresponding MCSymbol.
static MCSymbol *getMCSymbolForTOCPseudoMO(const MachineOperand &MO,
AsmPrinter &AP) {
switch (MO.getType()) {
case MachineOperand::MO_GlobalAddress:
return AP.getSymbol(MO.getGlobal());
case MachineOperand::MO_ConstantPoolIndex:
return AP.GetCPISymbol(MO.getIndex());
case MachineOperand::MO_JumpTableIndex:
return AP.GetJTISymbol(MO.getIndex());
case MachineOperand::MO_BlockAddress:
return AP.GetBlockAddressSymbol(MO.getBlockAddress());
default:
llvm_unreachable("Unexpected operand type to get symbol.");
}
}
static PPCAsmPrinter::TOCEntryType
getTOCEntryTypeForLinkage(GlobalValue::LinkageTypes Linkage) {
if (Linkage == GlobalValue::ExternalLinkage ||
Linkage == GlobalValue::AvailableExternallyLinkage ||
Linkage == GlobalValue::ExternalWeakLinkage)
return PPCAsmPrinter::TOCType_GlobalExternal;
return PPCAsmPrinter::TOCType_GlobalInternal;
}
static PPCAsmPrinter::TOCEntryType
getTOCEntryTypeForMO(const MachineOperand &MO) {
// Use the target flags to determine if this MO is Thread Local.
// If we don't do this it comes out as Global.
if (PPCInstrInfo::hasTLSFlag(MO.getTargetFlags()))
return PPCAsmPrinter::TOCType_ThreadLocal;
switch (MO.getType()) {
case MachineOperand::MO_GlobalAddress: {
const GlobalValue *GlobalV = MO.getGlobal();
return getTOCEntryTypeForLinkage(GlobalV->getLinkage());
}
case MachineOperand::MO_ConstantPoolIndex:
return PPCAsmPrinter::TOCType_ConstantPool;
case MachineOperand::MO_JumpTableIndex:
return PPCAsmPrinter::TOCType_JumpTable;
case MachineOperand::MO_BlockAddress:
return PPCAsmPrinter::TOCType_BlockAddress;
default:
llvm_unreachable("Unexpected operand type to get TOC type.");
}
}
const MCExpr *PPCAsmPrinter::symbolWithSpecifier(const MCSymbol *S,
PPCMCExpr::Specifier Spec) {
return MCSymbolRefExpr::create(S, Spec, OutContext);
}
/// EmitInstruction -- Print out a single PowerPC MI in Darwin syntax to
/// the current output stream.
///
void PPCAsmPrinter::emitInstruction(const MachineInstr *MI) {
PPC_MC::verifyInstructionPredicates(MI->getOpcode(),
getSubtargetInfo().getFeatureBits());
MCInst TmpInst;
const bool IsPPC64 = Subtarget->isPPC64();
const bool IsAIX = Subtarget->isAIXABI();
const bool HasAIXSmallLocalTLS = Subtarget->hasAIXSmallLocalExecTLS() ||
Subtarget->hasAIXSmallLocalDynamicTLS();
const Module *M = MF->getFunction().getParent();
PICLevel::Level PL = M->getPICLevel();
#ifndef NDEBUG
// Validate that SPE and FPU are mutually exclusive in codegen
if (!MI->isInlineAsm()) {
for (const MachineOperand &MO: MI->operands()) {
if (MO.isReg()) {
Register Reg = MO.getReg();
if (Subtarget->hasSPE()) {
if (PPC::F4RCRegClass.contains(Reg) ||
PPC::F8RCRegClass.contains(Reg) ||
PPC::VFRCRegClass.contains(Reg) ||
PPC::VRRCRegClass.contains(Reg) ||
PPC::VSFRCRegClass.contains(Reg) ||
PPC::VSSRCRegClass.contains(Reg)
)
llvm_unreachable("SPE targets cannot have FPRegs!");
} else {
if (PPC::SPERCRegClass.contains(Reg))
llvm_unreachable("SPE register found in FPU-targeted code!");
}
}
}
}
#endif
auto getTOCRelocAdjustedExprForXCOFF = [this](const MCExpr *Expr,
ptrdiff_t OriginalOffset) {
// Apply an offset to the TOC-based expression such that the adjusted
// notional offset from the TOC base (to be encoded into the instruction's D
// or DS field) is the signed 16-bit truncation of the original notional
// offset from the TOC base.
// This is consistent with the treatment used both by XL C/C++ and
// by AIX ld -r.
ptrdiff_t Adjustment =
OriginalOffset - llvm::SignExtend32<16>(OriginalOffset);
return MCBinaryExpr::createAdd(
Expr, MCConstantExpr::create(-Adjustment, OutContext), OutContext);
};
auto getTOCEntryLoadingExprForXCOFF =
[IsPPC64, getTOCRelocAdjustedExprForXCOFF,
this](const MCSymbol *MOSymbol, const MCExpr *Expr,
PPCMCExpr::Specifier VK = PPC::S_None) -> const MCExpr * {
const unsigned EntryByteSize = IsPPC64 ? 8 : 4;
const auto TOCEntryIter = TOC.find({MOSymbol, VK});
assert(TOCEntryIter != TOC.end() &&
"Could not find the TOC entry for this symbol.");
const ptrdiff_t EntryDistanceFromTOCBase =
(TOCEntryIter - TOC.begin()) * EntryByteSize;
constexpr int16_t PositiveTOCRange = INT16_MAX;
if (EntryDistanceFromTOCBase > PositiveTOCRange)
return getTOCRelocAdjustedExprForXCOFF(Expr, EntryDistanceFromTOCBase);
return Expr;
};
auto getSpecifier = [&](const MachineOperand &MO) {
// For TLS initial-exec and local-exec accesses on AIX, we have one TOC
// entry for the symbol (with the variable offset), which is differentiated
// by MO_TPREL_FLAG.
unsigned Flag = MO.getTargetFlags();
if (Flag == PPCII::MO_TPREL_FLAG ||
Flag == PPCII::MO_GOT_TPREL_PCREL_FLAG ||
Flag == PPCII::MO_TPREL_PCREL_FLAG) {
assert(MO.isGlobal() && "Only expecting a global MachineOperand here!\n");
TLSModel::Model Model = TM.getTLSModel(MO.getGlobal());
if (Model == TLSModel::LocalExec)
return PPC::S_AIX_TLSLE;
if (Model == TLSModel::InitialExec)
return PPC::S_AIX_TLSIE;
// On AIX, TLS model opt may have turned local-dynamic accesses into
// initial-exec accesses.
PPCFunctionInfo *FuncInfo = MF->getInfo<PPCFunctionInfo>();
if (Model == TLSModel::LocalDynamic &&
FuncInfo->isAIXFuncUseTLSIEForLD()) {
LLVM_DEBUG(
dbgs() << "Current function uses IE access for default LD vars.\n");
return PPC::S_AIX_TLSIE;
}
llvm_unreachable("Only expecting local-exec or initial-exec accesses!");
}
// For GD TLS access on AIX, we have two TOC entries for the symbol (one for
// the variable offset and the other for the region handle). They are
// differentiated by MO_TLSGD_FLAG and MO_TLSGDM_FLAG.
if (Flag == PPCII::MO_TLSGDM_FLAG)
return PPC::S_AIX_TLSGDM;
if (Flag == PPCII::MO_TLSGD_FLAG || Flag == PPCII::MO_GOT_TLSGD_PCREL_FLAG)
return PPC::S_AIX_TLSGD;
// For local-dynamic TLS access on AIX, we have one TOC entry for the symbol
// (the variable offset) and one shared TOC entry for the module handle.
// They are differentiated by MO_TLSLD_FLAG and MO_TLSLDM_FLAG.
if (Flag == PPCII::MO_TLSLD_FLAG && IsAIX)
return PPC::S_AIX_TLSLD;
if (Flag == PPCII::MO_TLSLDM_FLAG && IsAIX)
return PPC::S_AIX_TLSML;
return PPC::S_None;
};
// Lower multi-instruction pseudo operations.
switch (MI->getOpcode()) {
default: break;
case TargetOpcode::PATCHABLE_FUNCTION_ENTER: {
assert(!Subtarget->isAIXABI() &&
"AIX does not support patchable function entry!");
const Function &F = MF->getFunction();
unsigned Num = F.getFnAttributeAsParsedInteger("patchable-function-entry");
if (!Num)
return;
emitNops(Num);
return;
}
case TargetOpcode::DBG_VALUE:
llvm_unreachable("Should be handled target independently");
case TargetOpcode::STACKMAP:
return LowerSTACKMAP(SM, *MI);
case TargetOpcode::PATCHPOINT:
return LowerPATCHPOINT(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, PPC::S_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 'bcl 20,31,.+4' so the link stack is not corrupted.
EmitToStreamer(*OutStreamer,
MCInstBuilder(PPC::BCLalways)
// 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
// or into (if secure plt mode is on):
// addis r30, r30, {.LTOC,_GLOBAL_OFFSET_TABLE} - .L0$pb@ha
// addi r30, r30, {.LTOC,_GLOBAL_OFFSET_TABLE} - .L0$pb@l
// Get the offset from the GOT Base Register to the GOT
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
if (Subtarget->isSecurePlt() && isPositionIndependent() ) {
MCRegister PICR = TmpInst.getOperand(0).getReg();
MCSymbol *BaseSymbol = OutContext.getOrCreateSymbol(
M->getPICLevel() == PICLevel::SmallPIC ? "_GLOBAL_OFFSET_TABLE_"
: ".LTOC");
const MCExpr *PB =
MCSymbolRefExpr::create(MF->getPICBaseSymbol(), OutContext);
const MCExpr *DeltaExpr = MCBinaryExpr::createSub(
MCSymbolRefExpr::create(BaseSymbol, OutContext), PB, OutContext);
const MCExpr *DeltaHi =
MCSpecifierExpr::create(DeltaExpr, PPC::S_HA, OutContext);
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::ADDIS).addReg(PICR).addReg(PICR).addExpr(DeltaHi));
const MCExpr *DeltaLo =
MCSpecifierExpr::create(DeltaExpr, PPC::S_LO, OutContext);
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::ADDI).addReg(PICR).addReg(PICR).addExpr(DeltaLo));
return;
} else {
MCSymbol *PICOffset =
MF->getInfo<PPCFunctionInfo>()->getPICOffsetSymbol(*MF);
TmpInst.setOpcode(PPC::LWZ);
const MCExpr *Exp = MCSymbolRefExpr::create(PICOffset, OutContext);
const MCExpr *PB =
MCSymbolRefExpr::create(MF->getPICBaseSymbol(),
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 %rN = LWZtoc @op1, %r2
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to LWZ.
TmpInst.setOpcode(PPC::LWZ);
const MachineOperand &MO = MI->getOperand(1);
assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress()) &&
"Invalid operand for LWZtoc.");
// Map the operand to its corresponding MCSymbol.
const MCSymbol *const MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
// Create a reference to the GOT entry for the symbol. The GOT entry will be
// synthesized later.
if (PL == PICLevel::SmallPIC && !IsAIX) {
const MCExpr *Exp = symbolWithSpecifier(MOSymbol, PPC::S_GOT);
TmpInst.getOperand(1) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
PPCMCExpr::Specifier VK = getSpecifier(MO);
// Otherwise, use the TOC. 'TOCEntry' is a label used to reference the
// storage allocated in the TOC which contains the address of
// 'MOSymbol'. Said TOC entry will be synthesized later.
MCSymbol *TOCEntry =
lookUpOrCreateTOCEntry(MOSymbol, getTOCEntryTypeForMO(MO), VK);
const MCExpr *Exp = MCSymbolRefExpr::create(TOCEntry, OutContext);
// AIX uses the label directly as the lwz displacement operand for
// references into the toc section. The displacement value will be generated
// relative to the toc-base.
if (IsAIX) {
assert(
getCodeModel(*Subtarget, TM, MO) == CodeModel::Small &&
"This pseudo should only be selected for 32-bit small code model.");
Exp = getTOCEntryLoadingExprForXCOFF(MOSymbol, Exp, VK);
TmpInst.getOperand(1) = MCOperand::createExpr(Exp);
// Print MO for better readability
if (isVerbose())
OutStreamer->getCommentOS() << MO << '\n';
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
// Create an explicit subtract expression between the local symbol and
// '.LTOC' to manifest the toc-relative offset.
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::ADDItoc:
case PPC::ADDItoc8: {
assert(IsAIX && TM.getCodeModel() == CodeModel::Small &&
"PseudoOp only valid for small code model AIX");
// Transform %rN = ADDItoc/8 %r2, @op1.
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to load address.
TmpInst.setOpcode((!IsPPC64) ? (PPC::LA) : (PPC::LA8));
const MachineOperand &MO = MI->getOperand(2);
assert(MO.isGlobal() && "Invalid operand for ADDItoc[8].");
// Map the operand to its corresponding MCSymbol.
const MCSymbol *const MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
const MCExpr *Exp = MCSymbolRefExpr::create(MOSymbol, OutContext);
TmpInst.getOperand(2) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::LDtocJTI:
case PPC::LDtocCPT:
case PPC::LDtocBA:
case PPC::LDtoc: {
// Transform %x3 = LDtoc @min1, %x2
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to LD.
TmpInst.setOpcode(PPC::LD);
const MachineOperand &MO = MI->getOperand(1);
assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress()) &&
"Invalid operand!");
// Map the operand to its corresponding MCSymbol.
const MCSymbol *const MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
PPCMCExpr::Specifier VK = getSpecifier(MO);
// Map the machine operand to its corresponding MCSymbol, then map the
// global address operand to be a reference to the TOC entry we will
// synthesize later.
MCSymbol *TOCEntry =
lookUpOrCreateTOCEntry(MOSymbol, getTOCEntryTypeForMO(MO), VK);
PPCMCExpr::Specifier VKExpr = IsAIX ? PPC::S_None : PPC::S_TOC;
const MCExpr *Exp = symbolWithSpecifier(TOCEntry, VKExpr);
TmpInst.getOperand(1) = MCOperand::createExpr(
IsAIX ? getTOCEntryLoadingExprForXCOFF(MOSymbol, Exp, VK) : Exp);
// Print MO for better readability
if (isVerbose() && IsAIX)
OutStreamer->getCommentOS() << MO << '\n';
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::ADDIStocHA: {
const MachineOperand &MO = MI->getOperand(2);
assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress()) &&
"Invalid operand for ADDIStocHA.");
assert((IsAIX && !IsPPC64 &&
getCodeModel(*Subtarget, TM, MO) == CodeModel::Large) &&
"This pseudo should only be selected for 32-bit large code model on"
" AIX.");
// Transform %rd = ADDIStocHA %rA, @sym(%r2)
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to ADDIS.
TmpInst.setOpcode(PPC::ADDIS);
// Map the machine operand to its corresponding MCSymbol.
MCSymbol *MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
PPCMCExpr::Specifier VK = getSpecifier(MO);
// Map the global address operand to be a reference to the TOC entry we
// will synthesize later. 'TOCEntry' is a label used to reference the
// storage allocated in the TOC which contains the address of 'MOSymbol'.
// If the symbol does not have the toc-data attribute, then we create the
// TOC entry on AIX. If the toc-data attribute is used, the TOC entry
// contains the data rather than the address of the MOSymbol.
if (![](const MachineOperand &MO) {
if (!MO.isGlobal())
return false;
const GlobalVariable *GV = dyn_cast<GlobalVariable>(MO.getGlobal());
if (!GV)
return false;
return GV->hasAttribute("toc-data");
}(MO)) {
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol, getTOCEntryTypeForMO(MO), VK);
}
const MCExpr *Exp = symbolWithSpecifier(MOSymbol, PPC::S_U);
TmpInst.getOperand(2) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::LWZtocL: {
const MachineOperand &MO = MI->getOperand(1);
assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress()) &&
"Invalid operand for LWZtocL.");
assert(IsAIX && !IsPPC64 &&
getCodeModel(*Subtarget, TM, MO) == CodeModel::Large &&
"This pseudo should only be selected for 32-bit large code model on"
" AIX.");
// Transform %rd = LWZtocL @sym, %rs.
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to lwz.
TmpInst.setOpcode(PPC::LWZ);
// Map the machine operand to its corresponding MCSymbol.
MCSymbol *MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
PPCMCExpr::Specifier VK = getSpecifier(MO);
// Always use TOC on AIX. Map the global address operand to be a reference
// to the TOC entry we will synthesize later. 'TOCEntry' is a label used to
// reference the storage allocated in the TOC which contains the address of
// 'MOSymbol'.
MCSymbol *TOCEntry =
lookUpOrCreateTOCEntry(MOSymbol, getTOCEntryTypeForMO(MO), VK);
const MCExpr *Exp = symbolWithSpecifier(TOCEntry, PPC::S_L);
TmpInst.getOperand(1) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::ADDIStocHA8: {
// Transform %xd = ADDIStocHA8 %x2, @sym
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to ADDIS8. If the global address is the address of
// an external symbol, is a jump table address, is a block address, or is a
// constant pool index with large code model enabled, 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 ADDIStocHA8!");
const MCSymbol *MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
PPCMCExpr::Specifier VK = getSpecifier(MO);
const bool GlobalToc =
MO.isGlobal() && Subtarget->isGVIndirectSymbol(MO.getGlobal());
const CodeModel::Model CM =
IsAIX ? getCodeModel(*Subtarget, TM, MO) : TM.getCodeModel();
if (GlobalToc || MO.isJTI() || MO.isBlockAddress() ||
(MO.isCPI() && CM == CodeModel::Large))
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol, getTOCEntryTypeForMO(MO), VK);
VK = IsAIX ? PPC::S_U : PPC::S_TOC_HA;
const MCExpr *Exp = symbolWithSpecifier(MOSymbol, VK);
if (!MO.isJTI() && MO.getOffset())
Exp = MCBinaryExpr::createAdd(Exp,
MCConstantExpr::create(MO.getOffset(),
OutContext),
OutContext);
TmpInst.getOperand(2) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::LDtocL: {
// Transform %xd = LDtocL @sym, %xs
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// Change the opcode to LD. If the global address is the address of
// an external symbol, is a jump table address, is a block address, or is
// a constant pool index with large code model enabled, then generate a
// TOC entry and reference that. 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!");
LLVM_DEBUG(assert(
(!MO.isGlobal() || Subtarget->isGVIndirectSymbol(MO.getGlobal())) &&
"LDtocL used on symbol that could be accessed directly is "
"invalid. Must match ADDIStocHA8."));
const MCSymbol *MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
PPCMCExpr::Specifier VK = getSpecifier(MO);
CodeModel::Model CM =
IsAIX ? getCodeModel(*Subtarget, TM, MO) : TM.getCodeModel();
if (!MO.isCPI() || CM == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol, getTOCEntryTypeForMO(MO), VK);
VK = IsAIX ? PPC::S_L : PPC::S_TOC_LO;
const MCExpr *Exp = symbolWithSpecifier(MOSymbol, VK);
TmpInst.getOperand(1) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::ADDItocL:
case PPC::ADDItocL8: {
// Transform %xd = ADDItocL %xs, @sym
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
unsigned Op = MI->getOpcode();
// Change the opcode to load address for toc-data.
// ADDItocL is only used for 32-bit toc-data on AIX and will always use LA.
TmpInst.setOpcode(Op == PPC::ADDItocL8 ? (IsAIX ? PPC::LA8 : PPC::ADDI8)
: PPC::LA);
const MachineOperand &MO = MI->getOperand(2);
assert((Op == PPC::ADDItocL8)
? (MO.isGlobal() || MO.isCPI())
: MO.isGlobal() && "Invalid operand for ADDItocL8.");
assert(!(MO.isGlobal() && Subtarget->isGVIndirectSymbol(MO.getGlobal())) &&
"Interposable definitions must use indirect accesses.");
// Map the operand to its corresponding MCSymbol.
const MCSymbol *const MOSymbol = getMCSymbolForTOCPseudoMO(MO, *this);
const MCExpr *Exp = MCSymbolRefExpr::create(
MOSymbol, IsAIX ? PPC::S_L : PPC::S_TOC_LO, OutContext);
TmpInst.getOperand(2) = MCOperand::createExpr(Exp);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case PPC::ADDISgotTprelHA: {
// Transform: %xd = ADDISgotTprelHA %x2, @sym
// Into: %xd = ADDIS8 %x2, sym@got@tlsgd@ha
assert(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 =
symbolWithSpecifier(MOSymbol, PPC::S_GOT_TPREL_HA);
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 @sym, %xs
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
// 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 = symbolWithSpecifier(
MOSymbol, IsPPC64 ? PPC::S_GOT_TPREL_LO : PPC::S_GOT_TPREL);
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 =
MCSpecifierExpr::create(GOTSymbol, PPC::S_LO, OutContext);
const MCExpr *SymGotTlsHA =
MCSpecifierExpr::create(GOTSymbol, PPC::S_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, @sym
// Into: %xd = ADDIS8 %x2, sym@got@tlsgd@ha
assert(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 =
symbolWithSpecifier(MOSymbol, PPC::S_GOT_TLSGD_HA);
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, @sym
// Into: %xd = ADDI8 %xs, sym@got@tlsgd@l
case PPC::ADDItlsgdL32: {
// Transform: %rd = ADDItlsgdL32 %rs, @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 = symbolWithSpecifier(
MOSymbol, IsPPC64 ? PPC::S_GOT_TLSGD_LO : PPC::S_GOT_TLSGD);
EmitToStreamer(*OutStreamer,
MCInstBuilder(IsPPC64 ? PPC::ADDI8 : PPC::ADDI)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymGotTlsGD));
return;
}
case PPC::GETtlsMOD32AIX:
case PPC::GETtlsMOD64AIX:
// Transform: %r3 = GETtlsMODNNAIX %r3 (for NN == 32/64).
// Into: BLA .__tls_get_mod()
// Input parameter is a module handle (_$TLSML[TC]@ml) for all variables.
case PPC::GETtlsADDR:
// Transform: %x3 = GETtlsADDR %x3, @sym
// Into: BL8_NOP_TLS __tls_get_addr(sym at tlsgd)
case PPC::GETtlsADDRPCREL:
case PPC::GETtlsADDR32AIX:
case PPC::GETtlsADDR64AIX:
// Transform: %r3 = GETtlsADDRNNAIX %r3, %r4 (for NN == 32/64).
// Into: BLA .__tls_get_addr()
// Unlike on Linux, there is no symbol or relocation needed for this call.
case PPC::GETtlsADDR32: {
// Transform: %r3 = GETtlsADDR32 %r3, @sym
// Into: BL_TLS __tls_get_addr(sym at tlsgd)@PLT
emitTlsCall(MI, PPC::S_TLSGD);
return;
}
case PPC::GETtlsTpointer32AIX: {
// Transform: %r3 = GETtlsTpointer32AIX
// Into: BLA .__get_tpointer()
EmitAIXTlsCallHelper(MI);
return;
}
case PPC::ADDIStlsldHA: {
// Transform: %xd = ADDIStlsldHA %x2, @sym
// Into: %xd = ADDIS8 %x2, sym@got@tlsld@ha
assert(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 =
symbolWithSpecifier(MOSymbol, PPC::S_GOT_TLSLD_HA);
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, @sym
// Into: %xd = ADDI8 %xs, sym@got@tlsld@l
case PPC::ADDItlsldL32: {
// Transform: %rd = ADDItlsldL32 %rs, @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 = symbolWithSpecifier(
MOSymbol, IsPPC64 ? PPC::S_GOT_TLSLD_LO : PPC::S_GOT_TLSLD);
EmitToStreamer(*OutStreamer,
MCInstBuilder(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, @sym
// Into: BL8_NOP_TLS __tls_get_addr(sym at tlsld)
case PPC::GETtlsldADDRPCREL:
case PPC::GETtlsldADDR32: {
// Transform: %r3 = GETtlsldADDR32 %r3, @sym
// Into: BL_TLS __tls_get_addr(sym at tlsld)@PLT
emitTlsCall(MI, PPC::S_TLSLD);
return;
}
case PPC::ADDISdtprelHA:
// Transform: %xd = ADDISdtprelHA %xs, @sym
// Into: %xd = ADDIS8 %xs, sym@dtprel@ha
case PPC::ADDISdtprelHA32: {
// Transform: %rd = ADDISdtprelHA32 %rs, @sym
// Into: %rd = ADDIS %rs, sym@dtprel@ha
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymDtprel = symbolWithSpecifier(MOSymbol, PPC::S_DTPREL_HA);
EmitToStreamer(
*OutStreamer,
MCInstBuilder(IsPPC64 ? PPC::ADDIS8 : PPC::ADDIS)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymDtprel));
return;
}
case PPC::PADDIdtprel: {
// Transform: %rd = PADDIdtprel %rs, @sym
// Into: %rd = PADDI8 %rs, sym@dtprel
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
const MCExpr *SymDtprel = symbolWithSpecifier(MOSymbol, PPC::S_DTPREL);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::PADDI8)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addExpr(SymDtprel));
return;
}
case PPC::ADDIdtprelL:
// Transform: %xd = ADDIdtprelL %xs, @sym
// Into: %xd = ADDI8 %xs, sym@dtprel@l
case PPC::ADDIdtprelL32: {
// Transform: %rd = ADDIdtprelL32 %rs, @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 = symbolWithSpecifier(MOSymbol, PPC::S_DTPREL_LO);
EmitToStreamer(*OutStreamer,
MCInstBuilder(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.
unsigned OpNum = (MI->getOpcode() == PPC::STD) ? 2 : 1;
// For non-TOC-based local-exec TLS accesses with non-zero offsets, the
// machine operand (which is a TargetGlobalTLSAddress) is expected to be
// the same operand for both loads and stores.
for (const MachineOperand &TempMO : MI->operands()) {
if (((TempMO.getTargetFlags() == PPCII::MO_TPREL_FLAG ||
TempMO.getTargetFlags() == PPCII::MO_TLSLD_FLAG)) &&
TempMO.getOperandNo() == 1)
OpNum = 1;
}
const MachineOperand &MO = MI->getOperand(OpNum);
if (MO.isGlobal()) {
const DataLayout &DL = MO.getGlobal()->getDataLayout();
if (MO.getGlobal()->getPointerAlignment(DL) < 4)
llvm_unreachable("Global must be word-aligned for LD, STD, LWA!");
}
// As these load/stores share common code with the following load/stores,
// fall through to the subsequent cases in order to either process the
// non-TOC-based local-exec sequence or to process the instruction normally.
[[fallthrough]];
}
case PPC::LBZ:
case PPC::LBZ8:
case PPC::LHA:
case PPC::LHA8:
case PPC::LHZ:
case PPC::LHZ8:
case PPC::LWZ:
case PPC::LWZ8:
case PPC::STB:
case PPC::STB8:
case PPC::STH:
case PPC::STH8:
case PPC::STW:
case PPC::STW8:
case PPC::LFS:
case PPC::STFS:
case PPC::LFD:
case PPC::STFD:
case PPC::ADDI8: {
// A faster non-TOC-based local-[exec|dynamic] sequence is represented by
// `addi` or a load/store instruction (that directly loads or stores off of
// the thread pointer) with an immediate operand having the
// [MO_TPREL_FLAG|MO_TLSLD_FLAG]. Such instructions do not otherwise arise.
if (!HasAIXSmallLocalTLS)
break;
bool IsMIADDI8 = MI->getOpcode() == PPC::ADDI8;
unsigned OpNum = IsMIADDI8 ? 2 : 1;
const MachineOperand &MO = MI->getOperand(OpNum);
unsigned Flag = MO.getTargetFlags();
if (Flag == PPCII::MO_TPREL_FLAG ||
Flag == PPCII::MO_GOT_TPREL_PCREL_FLAG ||
Flag == PPCII::MO_TPREL_PCREL_FLAG || Flag == PPCII::MO_TLSLD_FLAG) {
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
const MCExpr *Expr = getAdjustedFasterLocalExpr(MO, MO.getOffset());
if (Expr)
TmpInst.getOperand(OpNum) = MCOperand::createExpr(Expr);
// Change the opcode to load address if the original opcode is an `addi`.
if (IsMIADDI8)
TmpInst.setOpcode(PPC::LA8);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
// Now process the instruction normally.
break;
}
case PPC::PseudoEIEIO: {
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::ORI).addReg(PPC::X2).addReg(PPC::X2).addImm(0));
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::ORI).addReg(PPC::X2).addReg(PPC::X2).addImm(0));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::EnforceIEIO));
return;
}
}
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
EmitToStreamer(*OutStreamer, TmpInst);
}
// For non-TOC-based local-[exec|dynamic] variables that have a non-zero offset,
// we need to create a new MCExpr that adds the non-zero offset to the address
// of the local-[exec|dynamic] variable that will be used in either an addi,
// load or store. However, the final displacement for these instructions must be
// between [-32768, 32768), so if the TLS address + its non-zero offset is
// greater than 32KB, a new MCExpr is produced to accommodate this situation.
const MCExpr *
PPCAsmPrinter::getAdjustedFasterLocalExpr(const MachineOperand &MO,
int64_t Offset) {
// Non-zero offsets (for loads, stores or `addi`) require additional handling.
// When the offset is zero, there is no need to create an adjusted MCExpr.
if (!Offset)
return nullptr;
assert(MO.isGlobal() && "Only expecting a global MachineOperand here!");
const GlobalValue *GValue = MO.getGlobal();
TLSModel::Model Model = TM.getTLSModel(GValue);
assert((Model == TLSModel::LocalExec || Model == TLSModel::LocalDynamic) &&
"Only local-[exec|dynamic] accesses are handled!");
bool IsGlobalADeclaration = GValue->isDeclarationForLinker();
// Find the GlobalVariable that corresponds to the particular TLS variable
// in the TLS variable-to-address mapping. All TLS variables should exist
// within this map, with the exception of TLS variables marked as extern.
const auto TLSVarsMapEntryIter = TLSVarsToAddressMapping.find(GValue);
if (TLSVarsMapEntryIter == TLSVarsToAddressMapping.end())
assert(IsGlobalADeclaration &&
"Only expecting to find extern TLS variables not present in the TLS "
"variable-to-address map!");
unsigned TLSVarAddress =
IsGlobalADeclaration ? 0 : TLSVarsMapEntryIter->second;
ptrdiff_t FinalAddress = (TLSVarAddress + Offset);
// If the address of the TLS variable + the offset is less than 32KB,
// or if the TLS variable is extern, we simply produce an MCExpr to add the
// non-zero offset to the TLS variable address.
// For when TLS variables are extern, this is safe to do because we can
// assume that the address of extern TLS variables are zero.
const MCExpr *Expr = MCSymbolRefExpr::create(
getSymbol(GValue),
(Model == TLSModel::LocalExec ? PPC::S_AIX_TLSLE : PPC::S_AIX_TLSLD),
OutContext);
Expr = MCBinaryExpr::createAdd(
Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
if (FinalAddress >= 32768) {
// Handle the written offset for cases where:
// TLS variable address + Offset > 32KB.
// The assembly that is printed will look like:
// TLSVar@le + Offset - Delta
// where Delta is a multiple of 64KB: ((FinalAddress + 32768) & ~0xFFFF).
ptrdiff_t Delta = ((FinalAddress + 32768) & ~0xFFFF);
// Check that the total instruction displacement fits within [-32768,32768).
[[maybe_unused]] ptrdiff_t InstDisp = TLSVarAddress + Offset - Delta;
assert(
((InstDisp < 32768) && (InstDisp >= -32768)) &&
"Expecting the instruction displacement for local-[exec|dynamic] TLS "
"variables to be between [-32768, 32768)!");
Expr = MCBinaryExpr::createAdd(
Expr, MCConstantExpr::create(-Delta, OutContext), OutContext);
}
return Expr;
}
void PPCLinuxAsmPrinter::emitGNUAttributes(Module &M) {
// Emit long double format into GNU attribute
MDString *LongDoubleType =
cast_or_null<MDString>(M.getModuleFlag("long-double-type"));
if (!LongDoubleType)
return;
// TODO: Support emitting soft-fp and hard double/single attributes.
switch (*parseLongDoubleFormat(LongDoubleType->getString())) {
case LongDoubleFormat::PPCDoubleDouble:
OutStreamer->emitGNUAttribute(Tag_GNU_Power_ABI_FP,
Val_GNU_Power_ABI_HardFloat_DP |
Val_GNU_Power_ABI_LDBL_IBM128);
break;
case LongDoubleFormat::IEEEquad:
OutStreamer->emitGNUAttribute(Tag_GNU_Power_ABI_FP,
Val_GNU_Power_ABI_HardFloat_DP |
Val_GNU_Power_ABI_LDBL_IEEE128);
break;
case LongDoubleFormat::IEEEdouble:
OutStreamer->emitGNUAttribute(Tag_GNU_Power_ABI_FP,
Val_GNU_Power_ABI_HardFloat_DP |
Val_GNU_Power_ABI_LDBL_64);
break;
default:
break;
}
}
void PPCLinuxAsmPrinter::emitInstruction(const MachineInstr *MI) {
if (!Subtarget->isPPC64())
return PPCAsmPrinter::emitInstruction(MI);
switch (MI->getOpcode()) {
default:
break;
case TargetOpcode::PATCHABLE_FUNCTION_ENTER: {
// .begin:
// b .end # lis 0, FuncId[16..32]
// nop # li 0, FuncId[0..15]
// std 0, -8(1)
// mflr 0
// bl __xray_FunctionEntry
// mtlr 0
// .end:
//
// Update compiler-rt/lib/xray/xray_powerpc64.cc accordingly when number
// of instructions change.
// XRAY is only supported on PPC Linux little endian.
const Function &F = MF->getFunction();
unsigned Num = F.getFnAttributeAsParsedInteger("patchable-function-entry");
if (!MAI.isLittleEndian() || Num)
break;
MCSymbol *BeginOfSled = OutContext.createTempSymbol();
MCSymbol *EndOfSled = OutContext.createTempSymbol();
OutStreamer->emitLabel(BeginOfSled);
EmitToStreamer(*OutStreamer,
MCInstBuilder(PPC::B).addExpr(
MCSymbolRefExpr::create(EndOfSled, OutContext)));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::NOP));
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::STD).addReg(PPC::X0).addImm(-8).addReg(PPC::X1));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::MFLR8).addReg(PPC::X0));
EmitToStreamer(*OutStreamer,
MCInstBuilder(PPC::BL8_NOP)
.addExpr(MCSymbolRefExpr::create(
OutContext.getOrCreateSymbol("__xray_FunctionEntry"),
OutContext)));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::MTLR8).addReg(PPC::X0));
OutStreamer->emitLabel(EndOfSled);
recordSled(BeginOfSled, *MI, SledKind::FUNCTION_ENTER, 2);
break;
}
case TargetOpcode::PATCHABLE_RET: {
unsigned RetOpcode = MI->getOperand(0).getImm();
MCInst RetInst;
RetInst.setOpcode(RetOpcode);
for (const auto &MO : llvm::drop_begin(MI->operands())) {
MCOperand MCOp;
if (LowerPPCMachineOperandToMCOperand(MI->getOpcode(), MO, MCOp, *this))
RetInst.addOperand(MCOp);
}
bool IsConditional;
if (RetOpcode == PPC::BCCLR) {
IsConditional = true;
} else if (RetOpcode == PPC::TCRETURNdi8 || RetOpcode == PPC::TCRETURNri8 ||
RetOpcode == PPC::TCRETURNai8) {
break;
} else if (RetOpcode == PPC::BLR8 || RetOpcode == PPC::TAILB8) {
IsConditional = false;
} else {
EmitToStreamer(*OutStreamer, RetInst);
return;
}
MCSymbol *FallthroughLabel;
if (IsConditional) {
// Before:
// bgtlr cr0
//
// After:
// ble cr0, .end
// .p2align 3
// .begin:
// blr # lis 0, FuncId[16..32]
// nop # li 0, FuncId[0..15]
// std 0, -8(1)
// mflr 0
// bl __xray_FunctionExit
// mtlr 0
// blr
// .end:
//
// Update compiler-rt/lib/xray/xray_powerpc64.cc accordingly when number
// of instructions change.
FallthroughLabel = OutContext.createTempSymbol();
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::BCC)
.addImm(PPC::InvertPredicate(
static_cast<PPC::Predicate>(MI->getOperand(1).getImm())))
.addReg(MI->getOperand(2).getReg())
.addExpr(MCSymbolRefExpr::create(FallthroughLabel, OutContext)));
RetInst = MCInst();
RetInst.setOpcode(PPC::BLR8);
}
// .p2align 3
// .begin:
// b(lr)? # lis 0, FuncId[16..32]
// nop # li 0, FuncId[0..15]
// std 0, -8(1)
// mflr 0
// bl __xray_FunctionExit
// mtlr 0
// b(lr)?
//
// Update compiler-rt/lib/xray/xray_powerpc64.cc accordingly when number
// of instructions change.
OutStreamer->emitCodeAlignment(Align(8), getSubtargetInfo());
MCSymbol *BeginOfSled = OutContext.createTempSymbol();
OutStreamer->emitLabel(BeginOfSled);
EmitToStreamer(*OutStreamer, RetInst);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::NOP));
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::STD).addReg(PPC::X0).addImm(-8).addReg(PPC::X1));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::MFLR8).addReg(PPC::X0));
EmitToStreamer(*OutStreamer,
MCInstBuilder(PPC::BL8_NOP)
.addExpr(MCSymbolRefExpr::create(
OutContext.getOrCreateSymbol("__xray_FunctionExit"),
OutContext)));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::MTLR8).addReg(PPC::X0));
EmitToStreamer(*OutStreamer, RetInst);
if (IsConditional)
OutStreamer->emitLabel(FallthroughLabel);
recordSled(BeginOfSled, *MI, SledKind::FUNCTION_EXIT, 2);
return;
}
case TargetOpcode::PATCHABLE_FUNCTION_EXIT:
llvm_unreachable("PATCHABLE_FUNCTION_EXIT should never be emitted");
case TargetOpcode::PATCHABLE_TAIL_CALL:
// TODO: Define a trampoline `__xray_FunctionTailExit` and differentiate a
// normal function exit from a tail exit.
llvm_unreachable("Tail call is handled in the normal case. See comments "
"around this assert.");
}
return PPCAsmPrinter::emitInstruction(MI);
}
void PPCLinuxAsmPrinter::emitStartOfAsmFile(Module &M) {
if (PPCTargetMachine::computeABI(M.getTargetTriple(),
TM.getTargetABIName(M)) == PPC_ABI_ELFv2) {
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
TS->emitAbiVersion(2);
}
if (static_cast<const PPCTargetMachine &>(TM).isPPC64() ||
!isPositionIndependent())
return AsmPrinter::emitStartOfAsmFile(M);
if (M.getPICLevel() == PICLevel::SmallPIC)
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() &&
(!isPositionIndependent() ||
MF->getFunction().getParent()->getPICLevel() == PICLevel::SmallPIC))
return AsmPrinter::emitFunctionEntryLabel();
if (!Subtarget->isPPC64()) {
const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
if (PPCFI->usesPICBase() && !Subtarget->isSecurePlt()) {
MCSymbol *RelocSymbol = PPCFI->getPICOffsetSymbol(*MF);
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()) {
// In the Large code model, we allow arbitrary displacements between
// the text section and its associated TOC section. We place the
// full 8-byte offset to the TOC in memory immediately preceding
// the function global entry point.
if (TM.getCodeModel() == CodeModel::Large
&& !MF->getRegInfo().use_empty(PPC::X2)) {
const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
MCSymbol *TOCSymbol = OutContext.getOrCreateSymbol(StringRef(".TOC."));
MCSymbol *GlobalEPSymbol = PPCFI->getGlobalEPSymbol(*MF);
const MCExpr *TOCDeltaExpr =
MCBinaryExpr::createSub(MCSymbolRefExpr::create(TOCSymbol, OutContext),
MCSymbolRefExpr::create(GlobalEPSymbol,
OutContext),
OutContext);
OutStreamer->emitLabel(PPCFI->getTOCOffsetSymbol(*MF));
OutStreamer->emitValue(TOCDeltaExpr, 8);
}
return AsmPrinter::emitFunctionEntryLabel();
}
// Emit an official procedure descriptor.
MCSectionSubPair Current = OutStreamer->getCurrentSection();
MCSectionELF *Section = OutStreamer->getContext().getELFSection(
".opd", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
OutStreamer->switchSection(Section);
OutStreamer->emitLabel(CurrentFnSym);
OutStreamer->emitValueToAlignment(Align(8));
MCSymbol *Symbol1 = CurrentFnSymForSize;
// 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, PPC::S_TOCBASE, OutContext), 8 /*size*/);
// Emit a null environment pointer.
OutStreamer->emitIntValue(0, 8 /* size */);
OutStreamer->switchSection(Current.first, Current.second);
}
void PPCLinuxAsmPrinter::emitEndOfAsmFile(Module &M) {
const DataLayout &DL = getDataLayout();
bool isPPC64 = DL.getPointerSizeInBits() == 64;
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
// If we are using any values provided by Glibc at fixed addresses,
// we need to ensure that the Glibc used at link time actually provides
// those values. All versions of Glibc that do will define the symbol
// named "__parse_hwcap_and_convert_at_platform".
if (static_cast<const PPCTargetMachine &>(TM).hasGlibcHWCAPAccess())
OutStreamer->emitSymbolValue(
GetExternalSymbolSymbol("__parse_hwcap_and_convert_at_platform"),
MAI.getCodePointerSize());
emitGNUAttributes(M);
if (!TOC.empty()) {
const char *Name = isPPC64 ? ".toc" : ".got2";
MCSectionELF *Section = OutContext.getELFSection(
Name, ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
OutStreamer->switchSection(Section);
if (!isPPC64)
OutStreamer->emitValueToAlignment(Align(4));
for (const auto &TOCMapPair : TOC) {
const MCSymbol *const TOCEntryTarget = TOCMapPair.first.first;
MCSymbol *const TOCEntryLabel = TOCMapPair.second;
OutStreamer->emitLabel(TOCEntryLabel);
if (isPPC64)
TS->emitTCEntry(*TOCEntryTarget, TOCMapPair.first.second);
else
OutStreamer->emitSymbolValue(TOCEntryTarget, 4);
}
}
PPCAsmPrinter::emitEndOfAsmFile(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:
// .Lfunc_gepNN:
// # global entry point
// addis r2,r12,(.TOC.-.Lfunc_gepNN)@ha
// addi r2,r2,(.TOC.-.Lfunc_gepNN)@l
// .Lfunc_lepNN:
// .localentry func, .Lfunc_lepNN-.Lfunc_gepNN
// # local entry point, followed by function body
//
// For the Large code model, we create
//
// .Lfunc_tocNN:
// .quad .TOC.-.Lfunc_gepNN # done by EmitFunctionEntryLabel
// func:
// .Lfunc_gepNN:
// # global entry point
// ld r2,.Lfunc_tocNN-.Lfunc_gepNN(r12)
// add r2,r2,r12
// .Lfunc_lepNN:
// .localentry func, .Lfunc_lepNN-.Lfunc_gepNN
// # 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.
const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
const bool UsesX2OrR2 = !MF->getRegInfo().use_empty(PPC::X2) ||
!MF->getRegInfo().use_empty(PPC::R2);
const bool PCrelGEPRequired = Subtarget->isUsingPCRelativeCalls() &&
UsesX2OrR2 && PPCFI->usesTOCBasePtr();
const bool NonPCrelGEPRequired = !Subtarget->isUsingPCRelativeCalls() &&
Subtarget->isELFv2ABI() && UsesX2OrR2;
// Only do all that if the function uses R2 as the TOC pointer
// in the first place. We don't need the global entry point if the
// function uses R2 as an allocatable register.
if (NonPCrelGEPRequired || PCrelGEPRequired) {
// Note: The logic here must be synchronized with the code in the
// branch-selection pass which sets the offset of the first block in the
// function. This matters because it affects the alignment.
MCSymbol *GlobalEntryLabel = PPCFI->getGlobalEPSymbol(*MF);
OutStreamer->emitLabel(GlobalEntryLabel);
const MCSymbolRefExpr *GlobalEntryLabelExp =
MCSymbolRefExpr::create(GlobalEntryLabel, OutContext);
if (TM.getCodeModel() != CodeModel::Large) {
MCSymbol *TOCSymbol = OutContext.getOrCreateSymbol(StringRef(".TOC."));
const MCExpr *TOCDeltaExpr =
MCBinaryExpr::createSub(MCSymbolRefExpr::create(TOCSymbol, OutContext),
GlobalEntryLabelExp, OutContext);
const MCExpr *TOCDeltaHi =
MCSpecifierExpr::create(TOCDeltaExpr, PPC::S_HA, OutContext);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADDIS)
.addReg(PPC::X2)
.addReg(PPC::X12)
.addExpr(TOCDeltaHi));
const MCExpr *TOCDeltaLo =
MCSpecifierExpr::create(TOCDeltaExpr, PPC::S_LO, OutContext);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADDI)
.addReg(PPC::X2)
.addReg(PPC::X2)
.addExpr(TOCDeltaLo));
} else {
MCSymbol *TOCOffset = PPCFI->getTOCOffsetSymbol(*MF);
const MCExpr *TOCOffsetDeltaExpr =
MCBinaryExpr::createSub(MCSymbolRefExpr::create(TOCOffset, OutContext),
GlobalEntryLabelExp, OutContext);
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::LD)
.addReg(PPC::X2)
.addExpr(TOCOffsetDeltaExpr)
.addReg(PPC::X12));
EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADD8)
.addReg(PPC::X2)
.addReg(PPC::X2)
.addReg(PPC::X12));
}
MCSymbol *LocalEntryLabel = PPCFI->getLocalEPSymbol(*MF);
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());
TS->emitLocalEntry(static_cast<MCSymbolELF *>(CurrentFnSym),
LocalOffsetExp);
} else if (Subtarget->isUsingPCRelativeCalls()) {
// When generating the entry point for a function we have a few scenarios
// based on whether or not that function uses R2 and whether or not that
// function makes calls (or is a leaf function).
// 1) A leaf function that does not use R2 (or treats it as callee-saved
// and preserves it). In this case st_other=0 and both
// the local and global entry points for the function are the same.
// No special entry point code is required.
// 2) A function uses the TOC pointer R2. This function may or may not have
// calls. In this case st_other=[2,6] and the global and local entry
// points are different. Code to correctly setup the TOC pointer in R2
// is put between the global and local entry points. This case is
// covered by the if statatement above.
// 3) A function does not use the TOC pointer R2 but does have calls.
// In this case st_other=1 since we do not know whether or not any
// of the callees clobber R2. This case is dealt with in this else if
// block. Tail calls are considered calls and the st_other should also
// be set to 1 in that case as well.
// 4) The function does not use the TOC pointer but R2 is used inside
// the function. In this case st_other=1 once again.
// 5) This function uses inline asm. We mark R2 as reserved if the function
// has inline asm as we have to assume that it may be used.
if (MF->getFrameInfo().hasCalls() || MF->getFrameInfo().hasTailCall() ||
MF->hasInlineAsm() || (!PPCFI->usesTOCBasePtr() && UsesX2OrR2)) {
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
TS->emitLocalEntry(static_cast<MCSymbolELF *>(CurrentFnSym),
MCConstantExpr::create(1, OutContext));
}
}
}
/// 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*/);
}
}
char PPCLinuxAsmPrinter::ID = 0;
INITIALIZE_PASS(PPCLinuxAsmPrinter, "ppc-linux-asm-printer",
"Linux PPC Assembly Printer", false, false)
void PPCAIXAsmPrinter::emitLinkage(const GlobalValue *GV,
MCSymbol *GVSym) const {
MCSymbolAttr LinkageAttr = MCSA_Invalid;
switch (GV->getLinkage()) {
case GlobalValue::ExternalLinkage:
LinkageAttr = GV->isDeclaration() ? MCSA_Extern : MCSA_Global;
break;
case GlobalValue::LinkOnceAnyLinkage:
case GlobalValue::LinkOnceODRLinkage:
case GlobalValue::WeakAnyLinkage:
case GlobalValue::WeakODRLinkage:
case GlobalValue::ExternalWeakLinkage:
LinkageAttr = MCSA_Weak;
break;
case GlobalValue::AvailableExternallyLinkage:
LinkageAttr = MCSA_Extern;
break;
case GlobalValue::PrivateLinkage:
return;
case GlobalValue::InternalLinkage:
assert(GV->getVisibility() == GlobalValue::DefaultVisibility &&
"InternalLinkage should not have other visibility setting.");
LinkageAttr = MCSA_LGlobal;
break;
case GlobalValue::AppendingLinkage:
llvm_unreachable("Should never emit this");
case GlobalValue::CommonLinkage:
llvm_unreachable("CommonLinkage of XCOFF should not come to this path");
}
assert(LinkageAttr != MCSA_Invalid && "LinkageAttr should not MCSA_Invalid.");
MCSymbolAttr VisibilityAttr = MCSA_Invalid;
if (!TM.getIgnoreXCOFFVisibility()) {
if (GV->hasDLLExportStorageClass() && !GV->hasDefaultVisibility())
report_fatal_error(
"Cannot not be both dllexport and non-default visibility");
switch (GV->getVisibility()) {
// TODO: "internal" Visibility needs to go here.
case GlobalValue::DefaultVisibility:
if (GV->hasDLLExportStorageClass())
VisibilityAttr = MAI.getExportedVisibilityAttr();
break;
case GlobalValue::HiddenVisibility:
VisibilityAttr = MAI.getHiddenVisibilityAttr();
break;
case GlobalValue::ProtectedVisibility:
VisibilityAttr = MAI.getProtectedVisibilityAttr();
break;
}
}
// Do not emit the _$TLSML symbol.
if (GV->getThreadLocalMode() == GlobalVariable::LocalDynamicTLSModel &&
GV->hasName() && GV->getName() == "_$TLSML")
return;
OutStreamer->emitXCOFFSymbolLinkageWithVisibility(GVSym, LinkageAttr,
VisibilityAttr);
}
void PPCAIXAsmPrinter::SetupMachineFunction(MachineFunction &MF) {
// Setup CurrentFnDescSym and its containing csect.
auto *FnDescSec = static_cast<MCSectionXCOFF *>(
getObjFileLowering().getSectionForFunctionDescriptor(&MF.getFunction(),
TM));
FnDescSec->setAlignment(Align(Subtarget->isPPC64() ? 8 : 4));
CurrentFnDescSym = FnDescSec->getQualNameSymbol();
return AsmPrinter::SetupMachineFunction(MF);
}
uint16_t PPCAIXAsmPrinter::getNumberOfVRSaved() {
// Calculate the number of VRs be saved.
// Vector registers 20 through 31 are marked as reserved and cannot be used
// in the default ABI.
const PPCSubtarget &Subtarget = MF->getSubtarget<PPCSubtarget>();
if (Subtarget.isAIXABI() && Subtarget.hasAltivec() &&
Subtarget.isAIXExtendedAltivecABI()) {
const MachineRegisterInfo &MRI = MF->getRegInfo();
for (unsigned Reg = PPC::V20; Reg <= PPC::V31; ++Reg)
if (MRI.isPhysRegModified(Reg))
// Number of VRs saved.
return PPC::V31 - Reg + 1;
}
return 0;
}
void PPCAIXAsmPrinter::emitFunctionBodyEnd() {
if (!TM.getXCOFFTracebackTable())
return;
emitTracebackTable();
// If ShouldEmitEHBlock returns true, then the eh info table
// will be emitted via `AIXException::endFunction`. Otherwise, we
// need to emit a dumy eh info table when VRs are saved. We could not
// consolidate these two places into one because there is no easy way
// to access register information in `AIXException` class.
if (!TargetLoweringObjectFileXCOFF::ShouldEmitEHBlock(MF) &&
(getNumberOfVRSaved() > 0)) {
// Emit dummy EH Info Table.
OutStreamer->switchSection(getObjFileLowering().getCompactUnwindSection());
MCSymbol *EHInfoLabel =
TargetLoweringObjectFileXCOFF::getEHInfoTableSymbol(MF);
OutStreamer->emitLabel(EHInfoLabel);
// Version number.
OutStreamer->emitInt32(0);
const DataLayout &DL = MMI->getModule()->getDataLayout();
const unsigned PointerSize = DL.getPointerSize();
// Add necessary paddings in 64 bit mode.
OutStreamer->emitValueToAlignment(Align(PointerSize));
OutStreamer->emitIntValue(0, PointerSize);
OutStreamer->emitIntValue(0, PointerSize);
OutStreamer->switchSection(MF->getSection());
}
}
void PPCAIXAsmPrinter::emitTracebackTable() {
// Create a symbol for the end of function.
MCSymbol *FuncEnd = createTempSymbol(MF->getName());
OutStreamer->emitLabel(FuncEnd);
OutStreamer->AddComment("Traceback table begin");
// Begin with a fullword of zero.
OutStreamer->emitIntValueInHexWithPadding(0, 4 /*size*/);
SmallString<128> CommentString;
raw_svector_ostream CommentOS(CommentString);
auto EmitComment = [&]() {
OutStreamer->AddComment(CommentOS.str());
CommentString.clear();
};
auto EmitCommentAndValue = [&](uint64_t Value, int Size) {
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(Value, Size);
};
unsigned int Version = 0;
CommentOS << "Version = " << Version;
EmitCommentAndValue(Version, 1);
// There is a lack of information in the IR to assist with determining the
// source language. AIX exception handling mechanism would only search for
// personality routine and LSDA area when such language supports exception
// handling. So to be conservatively correct and allow runtime to do its job,
// we need to set it to C++ for now.
TracebackTable::LanguageID LanguageIdentifier =
TracebackTable::CPlusPlus; // C++
CommentOS << "Language = "
<< getNameForTracebackTableLanguageId(LanguageIdentifier);
EmitCommentAndValue(LanguageIdentifier, 1);
// This is only populated for the third and fourth bytes.
uint32_t FirstHalfOfMandatoryField = 0;
// Emit the 3rd byte of the mandatory field.
// We always set traceback offset bit to true.
FirstHalfOfMandatoryField |= TracebackTable::HasTraceBackTableOffsetMask;
const PPCFunctionInfo *FI = MF->getInfo<PPCFunctionInfo>();
const MachineRegisterInfo &MRI = MF->getRegInfo();
// Check the function uses floating-point processor instructions or not
for (unsigned Reg = PPC::F0; Reg <= PPC::F31; ++Reg) {
if (MRI.isPhysRegUsed(Reg, /* SkipRegMaskTest */ true)) {
FirstHalfOfMandatoryField |= TracebackTable::IsFloatingPointPresentMask;
break;
}
}
#define GENBOOLCOMMENT(Prefix, V, Field) \
CommentOS << (Prefix) << ((V) & (TracebackTable::Field##Mask) ? "+" : "-") \
<< #Field
#define GENVALUECOMMENT(PrefixAndName, V, Field) \
CommentOS << (PrefixAndName) << " = " \
<< static_cast<unsigned>(((V) & (TracebackTable::Field##Mask)) >> \
(TracebackTable::Field##Shift))
GENBOOLCOMMENT("", FirstHalfOfMandatoryField, IsGlobalLinkage);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsOutOfLineEpilogOrPrologue);
EmitComment();
GENBOOLCOMMENT("", FirstHalfOfMandatoryField, HasTraceBackTableOffset);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsInternalProcedure);
EmitComment();
GENBOOLCOMMENT("", FirstHalfOfMandatoryField, HasControlledStorage);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsTOCless);
EmitComment();
GENBOOLCOMMENT("", FirstHalfOfMandatoryField, IsFloatingPointPresent);
EmitComment();
GENBOOLCOMMENT("", FirstHalfOfMandatoryField,
IsFloatingPointOperationLogOrAbortEnabled);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(
(FirstHalfOfMandatoryField & 0x0000ff00) >> 8, 1);
// Set the 4th byte of the mandatory field.
FirstHalfOfMandatoryField |= TracebackTable::IsFunctionNamePresentMask;
const PPCRegisterInfo *RegInfo = Subtarget->getRegisterInfo();
Register FrameReg = RegInfo->getFrameRegister(*MF);
if (FrameReg == (Subtarget->isPPC64() ? PPC::X31 : PPC::R31))
FirstHalfOfMandatoryField |= TracebackTable::IsAllocaUsedMask;
const SmallVectorImpl<Register> &MustSaveCRs = FI->getMustSaveCRs();
if (!MustSaveCRs.empty())
FirstHalfOfMandatoryField |= TracebackTable::IsCRSavedMask;
if (FI->mustSaveLR())
FirstHalfOfMandatoryField |= TracebackTable::IsLRSavedMask;
GENBOOLCOMMENT("", FirstHalfOfMandatoryField, IsInterruptHandler);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsFunctionNamePresent);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsAllocaUsed);
EmitComment();
GENVALUECOMMENT("OnConditionDirective", FirstHalfOfMandatoryField,
OnConditionDirective);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsCRSaved);
GENBOOLCOMMENT(", ", FirstHalfOfMandatoryField, IsLRSaved);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding((FirstHalfOfMandatoryField & 0xff),
1);
// Set the 5th byte of mandatory field.
uint32_t SecondHalfOfMandatoryField = 0;
SecondHalfOfMandatoryField |= MF->getFrameInfo().getStackSize()
? TracebackTable::IsBackChainStoredMask
: 0;
uint32_t FPRSaved = 0;
for (unsigned Reg = PPC::F14; Reg <= PPC::F31; ++Reg) {
if (MRI.isPhysRegModified(Reg)) {
FPRSaved = PPC::F31 - Reg + 1;
break;
}
}
SecondHalfOfMandatoryField |= (FPRSaved << TracebackTable::FPRSavedShift) &
TracebackTable::FPRSavedMask;
GENBOOLCOMMENT("", SecondHalfOfMandatoryField, IsBackChainStored);
GENBOOLCOMMENT(", ", SecondHalfOfMandatoryField, IsFixup);
GENVALUECOMMENT(", NumOfFPRsSaved", SecondHalfOfMandatoryField, FPRSaved);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(
(SecondHalfOfMandatoryField & 0xff000000) >> 24, 1);
// Set the 6th byte of mandatory field.
// Check whether has Vector Instruction,We only treat instructions uses vector
// register as vector instructions.
bool HasVectorInst = false;
for (unsigned Reg = PPC::V0; Reg <= PPC::V31; ++Reg)
if (MRI.isPhysRegUsed(Reg, /* SkipRegMaskTest */ true)) {
// Has VMX instruction.
HasVectorInst = true;
break;
}
if (FI->hasVectorParms() || HasVectorInst)
SecondHalfOfMandatoryField |= TracebackTable::HasVectorInfoMask;
uint16_t NumOfVRSaved = getNumberOfVRSaved();
bool ShouldEmitEHBlock =
TargetLoweringObjectFileXCOFF::ShouldEmitEHBlock(MF) || NumOfVRSaved > 0;
if (ShouldEmitEHBlock)
SecondHalfOfMandatoryField |= TracebackTable::HasExtensionTableMask;
uint32_t GPRSaved = 0;
// X13 is reserved under 64-bit environment.
unsigned GPRBegin = Subtarget->isPPC64() ? PPC::X14 : PPC::R13;
unsigned GPREnd = Subtarget->isPPC64() ? PPC::X31 : PPC::R31;
for (unsigned Reg = GPRBegin; Reg <= GPREnd; ++Reg) {
if (MRI.isPhysRegModified(Reg)) {
GPRSaved = GPREnd - Reg + 1;
break;
}
}
SecondHalfOfMandatoryField |= (GPRSaved << TracebackTable::GPRSavedShift) &
TracebackTable::GPRSavedMask;
GENBOOLCOMMENT("", SecondHalfOfMandatoryField, HasExtensionTable);
GENBOOLCOMMENT(", ", SecondHalfOfMandatoryField, HasVectorInfo);
GENVALUECOMMENT(", NumOfGPRsSaved", SecondHalfOfMandatoryField, GPRSaved);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(
(SecondHalfOfMandatoryField & 0x00ff0000) >> 16, 1);
// Set the 7th byte of mandatory field.
uint32_t NumberOfFixedParms = FI->getFixedParmsNum();
SecondHalfOfMandatoryField |=
(NumberOfFixedParms << TracebackTable::NumberOfFixedParmsShift) &
TracebackTable::NumberOfFixedParmsMask;
GENVALUECOMMENT("NumberOfFixedParms", SecondHalfOfMandatoryField,
NumberOfFixedParms);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(
(SecondHalfOfMandatoryField & 0x0000ff00) >> 8, 1);
// Set the 8th byte of mandatory field.
// Always set parameter on stack.
SecondHalfOfMandatoryField |= TracebackTable::HasParmsOnStackMask;
uint32_t NumberOfFPParms = FI->getFloatingPointParmsNum();
SecondHalfOfMandatoryField |=
(NumberOfFPParms << TracebackTable::NumberOfFloatingPointParmsShift) &
TracebackTable::NumberOfFloatingPointParmsMask;
GENVALUECOMMENT("NumberOfFPParms", SecondHalfOfMandatoryField,
NumberOfFloatingPointParms);
GENBOOLCOMMENT(", ", SecondHalfOfMandatoryField, HasParmsOnStack);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(SecondHalfOfMandatoryField & 0xff,
1);
// Generate the optional fields of traceback table.
// Parameter type.
if (NumberOfFixedParms || NumberOfFPParms) {
uint32_t ParmsTypeValue = FI->getParmsType();
Expected<SmallString<32>> ParmsType =
FI->hasVectorParms()
? XCOFF::parseParmsTypeWithVecInfo(
ParmsTypeValue, NumberOfFixedParms, NumberOfFPParms,
FI->getVectorParmsNum())
: XCOFF::parseParmsType(ParmsTypeValue, NumberOfFixedParms,
NumberOfFPParms);
assert(ParmsType && toString(ParmsType.takeError()).c_str());
if (ParmsType) {
CommentOS << "Parameter type = " << ParmsType.get();
EmitComment();
}
OutStreamer->emitIntValueInHexWithPadding(ParmsTypeValue,
sizeof(ParmsTypeValue));
}
// Traceback table offset.
OutStreamer->AddComment("Function size");
if (FirstHalfOfMandatoryField & TracebackTable::HasTraceBackTableOffsetMask) {
MCSymbol *FuncSectSym = getObjFileLowering().getFunctionEntryPointSymbol(
&(MF->getFunction()), TM);
OutStreamer->emitAbsoluteSymbolDiff(FuncEnd, FuncSectSym, 4);
}
// Since we unset the Int_Handler.
if (FirstHalfOfMandatoryField & TracebackTable::IsInterruptHandlerMask)
report_fatal_error("Hand_Mask not implement yet");
if (FirstHalfOfMandatoryField & TracebackTable::HasControlledStorageMask)
report_fatal_error("Ctl_Info not implement yet");
if (FirstHalfOfMandatoryField & TracebackTable::IsFunctionNamePresentMask) {
StringRef Name = MF->getName().substr(0, INT16_MAX);
int16_t NameLength = Name.size();
CommentOS << "Function name len = "
<< static_cast<unsigned int>(NameLength);
EmitCommentAndValue(NameLength, 2);
OutStreamer->AddComment("Function Name");
OutStreamer->emitBytes(Name);
}
if (FirstHalfOfMandatoryField & TracebackTable::IsAllocaUsedMask) {
uint8_t AllocReg = XCOFF::AllocRegNo;
OutStreamer->AddComment("AllocaUsed");
OutStreamer->emitIntValueInHex(AllocReg, sizeof(AllocReg));
}
if (SecondHalfOfMandatoryField & TracebackTable::HasVectorInfoMask) {
uint16_t VRData = 0;
if (NumOfVRSaved) {
// Number of VRs saved.
VRData |= (NumOfVRSaved << TracebackTable::NumberOfVRSavedShift) &
TracebackTable::NumberOfVRSavedMask;
// This bit is supposed to set only when the special register
// VRSAVE is saved on stack.
// However, IBM XL compiler sets the bit when any vector registers
// are saved on the stack. We will follow XL's behavior on AIX
// so that we don't get surprise behavior change for C code.
VRData |= TracebackTable::IsVRSavedOnStackMask;
}
// Set has_varargs.
if (FI->getVarArgsFrameIndex())
VRData |= TracebackTable::HasVarArgsMask;
// Vector parameters number.
unsigned VectorParmsNum = FI->getVectorParmsNum();
VRData |= (VectorParmsNum << TracebackTable::NumberOfVectorParmsShift) &
TracebackTable::NumberOfVectorParmsMask;
if (HasVectorInst)
VRData |= TracebackTable::HasVMXInstructionMask;
GENVALUECOMMENT("NumOfVRsSaved", VRData, NumberOfVRSaved);
GENBOOLCOMMENT(", ", VRData, IsVRSavedOnStack);
GENBOOLCOMMENT(", ", VRData, HasVarArgs);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding((VRData & 0xff00) >> 8, 1);
GENVALUECOMMENT("NumOfVectorParams", VRData, NumberOfVectorParms);
GENBOOLCOMMENT(", ", VRData, HasVMXInstruction);
EmitComment();
OutStreamer->emitIntValueInHexWithPadding(VRData & 0x00ff, 1);
uint32_t VecParmTypeValue = FI->getVecExtParmsType();
Expected<SmallString<32>> VecParmsType =
XCOFF::parseVectorParmsType(VecParmTypeValue, VectorParmsNum);
assert(VecParmsType && toString(VecParmsType.takeError()).c_str());
if (VecParmsType) {
CommentOS << "Vector Parameter type = " << VecParmsType.get();
EmitComment();
}
OutStreamer->emitIntValueInHexWithPadding(VecParmTypeValue,
sizeof(VecParmTypeValue));
// Padding 2 bytes.
CommentOS << "Padding";
EmitCommentAndValue(0, 2);
}
uint8_t ExtensionTableFlag = 0;
if (SecondHalfOfMandatoryField & TracebackTable::HasExtensionTableMask) {
if (ShouldEmitEHBlock)
ExtensionTableFlag |= ExtendedTBTableFlag::TB_EH_INFO;
if (EnableSSPCanaryBitInTB &&
TargetLoweringObjectFileXCOFF::ShouldSetSSPCanaryBitInTB(MF))
ExtensionTableFlag |= ExtendedTBTableFlag::TB_SSP_CANARY;
CommentOS << "ExtensionTableFlag = "
<< getExtendedTBTableFlagString(ExtensionTableFlag);
EmitCommentAndValue(ExtensionTableFlag, sizeof(ExtensionTableFlag));
}
if (ExtensionTableFlag & ExtendedTBTableFlag::TB_EH_INFO) {
auto &Ctx = OutStreamer->getContext();
MCSymbol *EHInfoSym =
TargetLoweringObjectFileXCOFF::getEHInfoTableSymbol(MF);
MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(EHInfoSym, TOCType_EHBlock);
const MCSymbol *TOCBaseSym = static_cast<const MCSectionXCOFF *>(
getObjFileLowering().getTOCBaseSection())
->getQualNameSymbol();
const MCExpr *Exp =
MCBinaryExpr::createSub(MCSymbolRefExpr::create(TOCEntry, Ctx),
MCSymbolRefExpr::create(TOCBaseSym, Ctx), Ctx);
const DataLayout &DL = getDataLayout();
OutStreamer->emitValueToAlignment(Align(4));
OutStreamer->AddComment("EHInfo Table");
OutStreamer->emitValue(Exp, DL.getPointerSize());
}
#undef GENBOOLCOMMENT
#undef GENVALUECOMMENT
}
static bool isSpecialLLVMGlobalArrayToSkip(const GlobalVariable *GV) {
return GV->hasAppendingLinkage() &&
StringSwitch<bool>(GV->getName())
// TODO: Linker could still eliminate the GV if we just skip
// handling llvm.used array. Skipping them for now until we or the
// AIX OS team come up with a good solution.
.Case("llvm.used", true)
// It's correct to just skip llvm.compiler.used array here.
.Case("llvm.compiler.used", true)
.Default(false);
}
static bool isSpecialLLVMGlobalArrayForStaticInit(const GlobalVariable *GV) {
return StringSwitch<bool>(GV->getName())
.Cases({"llvm.global_ctors", "llvm.global_dtors"}, true)
.Default(false);
}
uint64_t PPCAIXAsmPrinter::getAliasOffset(const Constant *C) {
if (auto *GA = dyn_cast<GlobalAlias>(C))
return getAliasOffset(GA->getAliasee());
if (auto *CE = dyn_cast<ConstantExpr>(C)) {
const MCExpr *LowC = lowerConstant(CE);
const MCBinaryExpr *CBE = dyn_cast<MCBinaryExpr>(LowC);
if (!CBE)
return 0;
if (CBE->getOpcode() != MCBinaryExpr::Add)
report_fatal_error("Only adding an offset is supported now.");
auto *RHS = dyn_cast<MCConstantExpr>(CBE->getRHS());
if (!RHS)
report_fatal_error("Unable to get the offset of alias.");
return RHS->getValue();
}
return 0;
}
static void tocDataChecks(unsigned PointerSize, const GlobalVariable *GV) {
// TODO: These asserts should be updated as more support for the toc data
// transformation is added (struct support, etc.).
assert(
PointerSize >= GV->getAlign().valueOrOne().value() &&
"GlobalVariables with an alignment requirement stricter than TOC entry "
"size not supported by the toc data transformation.");
Type *GVType = GV->getValueType();
assert(GVType->isSized() && "A GlobalVariable's size must be known to be "
"supported by the toc data transformation.");
if (GV->getDataLayout().getTypeSizeInBits(GVType) >
PointerSize * 8)
report_fatal_error(
"A GlobalVariable with size larger than a TOC entry is not currently "
"supported by the toc data transformation.");
if (GV->hasPrivateLinkage())
report_fatal_error("A GlobalVariable with private linkage is not "
"currently supported by the toc data transformation.");
}
void PPCAIXAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
// Special LLVM global arrays have been handled at the initialization.
if (isSpecialLLVMGlobalArrayToSkip(GV) || isSpecialLLVMGlobalArrayForStaticInit(GV))
return;
// Ignore non-emitted data.
if (GV->getSection() == "llvm.metadata")
return;
// If the Global Variable has the toc-data attribute, it needs to be emitted
// when we emit the .toc section.
if (GV->hasAttribute("toc-data")) {
unsigned PointerSize = GV->getDataLayout().getPointerSize();
tocDataChecks(PointerSize, GV);
TOCDataGlobalVars.push_back(GV);
return;
}
emitGlobalVariableHelper(GV);
}
void PPCAIXAsmPrinter::emitGlobalVariableHelper(const GlobalVariable *GV) {
assert(!GV->getName().starts_with("llvm.") &&
"Unhandled intrinsic global variable.");
if (GV->hasComdat())
report_fatal_error("COMDAT not yet supported by AIX.");
auto *GVSym = static_cast<MCSymbolXCOFF *>(getSymbol(GV));
if (GV->isDeclarationForLinker()) {
emitLinkage(GV, GVSym);
return;
}
SectionKind GVKind = getObjFileLowering().getKindForGlobal(GV, TM);
if (!GVKind.isGlobalWriteableData() && !GVKind.isReadOnly() &&
!GVKind.isThreadLocal()) // Checks for both ThreadData and ThreadBSS.
report_fatal_error("Encountered a global variable kind that is "
"not supported yet.");
// Print GV in verbose mode
if (isVerbose()) {
if (GV->hasInitializer()) {
GV->printAsOperand(OutStreamer->getCommentOS(),
/*PrintType=*/false, GV->getParent());
OutStreamer->getCommentOS() << '\n';
}
}
auto *Csect = static_cast<MCSectionXCOFF *>(
getObjFileLowering().SectionForGlobal(GV, GVKind, TM));
// Switch to the containing csect.
OutStreamer->switchSection(Csect);
if (GV->hasMetadata(LLVMContext::MD_implicit_ref)) {
emitRefMetadata(GV);
}
const DataLayout &DL = GV->getDataLayout();
// Handle common and zero-initialized local symbols.
if (GV->hasCommonLinkage() || GVKind.isBSSLocal() ||
GVKind.isThreadBSSLocal()) {
Align Alignment = GV->getAlign().value_or(DL.getPreferredAlign(GV));
uint64_t Size = GV->getGlobalSize(DL);
GVSym->setStorageClass(
TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GV));
if (GVKind.isBSSLocal() && Csect->getMappingClass() == XCOFF::XMC_TD) {
OutStreamer->emitZeros(Size);
} else if (GVKind.isBSSLocal() || GVKind.isThreadBSSLocal()) {
assert(Csect->getMappingClass() != XCOFF::XMC_TD &&
"BSS local toc-data already handled and TLS variables "
"incompatible with XMC_TD");
OutStreamer->emitXCOFFLocalCommonSymbol(
OutContext.getOrCreateSymbol(GVSym->getSymbolTableName()), Size,
GVSym, Alignment);
} else {
OutStreamer->emitCommonSymbol(GVSym, Size, Alignment);
}
return;
}
MCSymbol *EmittedInitSym = GVSym;
// Emit linkage for the global variable and its aliases.
emitLinkage(GV, EmittedInitSym);
for (const GlobalAlias *GA : GOAliasMap[GV])
emitLinkage(GA, getSymbol(GA));
emitAlignment(getGVAlignment(GV, DL), GV);
// When -fdata-sections is enabled, every GlobalVariable will
// be put into its own csect; therefore, label is not necessary here.
if (!TM.getDataSections() || GV->hasSection()) {
if (Csect->getMappingClass() != XCOFF::XMC_TD)
OutStreamer->emitLabel(EmittedInitSym);
}
// No alias to emit.
if (!GOAliasMap[GV].size()) {
emitGlobalConstant(GV->getDataLayout(), GV->getInitializer());
return;
}
// Aliases with the same offset should be aligned. Record the list of aliases
// associated with the offset.
AliasMapTy AliasList;
for (const GlobalAlias *GA : GOAliasMap[GV])
AliasList[getAliasOffset(GA->getAliasee())].push_back(GA);
// Emit alias label and element value for global variable.
emitGlobalConstant(GV->getDataLayout(), GV->getInitializer(),
&AliasList);
}
void PPCAIXAsmPrinter::emitFunctionDescriptor() {
const DataLayout &DL = getDataLayout();
const unsigned PointerSize = DL.getPointerSizeInBits() == 64 ? 8 : 4;
MCSectionSubPair Current = OutStreamer->getCurrentSection();
// Emit function descriptor.
OutStreamer->switchSection(
static_cast<MCSymbolXCOFF *>(CurrentFnDescSym)->getRepresentedCsect());
// Emit aliasing label for function descriptor csect.
// An Ifunc doesn't have a corresponding machine function.
if (MF)
for (const GlobalAlias *Alias : GOAliasMap[&MF->getFunction()])
OutStreamer->emitLabel(getSymbol(Alias));
// Emit function entry point address.
OutStreamer->emitValue(MCSymbolRefExpr::create(CurrentFnSym, OutContext),
PointerSize);
// Emit TOC base address.
const MCSymbol *TOCBaseSym = static_cast<const MCSectionXCOFF *>(
getObjFileLowering().getTOCBaseSection())
->getQualNameSymbol();
OutStreamer->emitValue(MCSymbolRefExpr::create(TOCBaseSym, OutContext),
PointerSize);
// Emit a null environment pointer.
OutStreamer->emitIntValue(0, PointerSize);
OutStreamer->switchSection(Current.first, Current.second);
}
void PPCAIXAsmPrinter::emitFunctionEntryLabel() {
// For functions without user defined section, it's not necessary to emit the
// label when we have individual function in its own csect.
if (!TM.getFunctionSections() || (MF && MF->getFunction().hasSection()))
PPCAsmPrinter::emitFunctionEntryLabel();
// an ifunc does not have an associated MachineFunction
if (!MF)
return;
const Function *F = &MF->getFunction();
// Emit aliasing label for function entry point label.
for (const GlobalAlias *Alias : GOAliasMap[F])
OutStreamer->emitLabel(
getObjFileLowering().getFunctionEntryPointSymbol(Alias, TM));
if (F->hasMetadata(LLVMContext::MD_implicit_ref)) {
emitRefMetadata(F);
}
}
void PPCAIXAsmPrinter::emitPGORefs(Module &M) {
if (!OutContext.hasXCOFFSection(
"__llvm_prf_cnts",
XCOFF::CsectProperties(XCOFF::XMC_RW, XCOFF::XTY_SD)))
return;
// When inside a csect `foo`, a .ref directive referring to a csect `bar`
// translates into a relocation entry from `foo` to` bar`. The referring
// csect, `foo`, is identified by its address. If multiple csects have the
// same address (because one or more of them are zero-length), the referring
// csect cannot be determined. Hence, we don't generate the .ref directives
// if `__llvm_prf_cnts` is an empty section.
bool HasNonZeroLengthPrfCntsSection = false;
const DataLayout &DL = M.getDataLayout();
for (GlobalVariable &GV : M.globals())
if (GV.hasSection() && GV.getSection() == "__llvm_prf_cnts" &&
GV.getGlobalSize(DL) > 0) {
HasNonZeroLengthPrfCntsSection = true;
break;
}
if (HasNonZeroLengthPrfCntsSection) {
MCSection *CntsSection = OutContext.getXCOFFSection(
"__llvm_prf_cnts", SectionKind::getData(),
XCOFF::CsectProperties(XCOFF::XMC_RW, XCOFF::XTY_SD),
/*MultiSymbolsAllowed*/ true);
OutStreamer->switchSection(CntsSection);
if (OutContext.hasXCOFFSection(
"__llvm_prf_data",
XCOFF::CsectProperties(XCOFF::XMC_RW, XCOFF::XTY_SD))) {
MCSymbol *S = OutContext.getOrCreateSymbol("__llvm_prf_data[RW]");
OutStreamer->emitXCOFFRefDirective(S);
}
if (OutContext.hasXCOFFSection(
"__llvm_prf_names",
XCOFF::CsectProperties(XCOFF::XMC_RO, XCOFF::XTY_SD))) {
MCSymbol *S = OutContext.getOrCreateSymbol("__llvm_prf_names[RO]");
OutStreamer->emitXCOFFRefDirective(S);
}
if (OutContext.hasXCOFFSection(
"__llvm_prf_vnds",
XCOFF::CsectProperties(XCOFF::XMC_RW, XCOFF::XTY_SD))) {
MCSymbol *S = OutContext.getOrCreateSymbol("__llvm_prf_vnds[RW]");
OutStreamer->emitXCOFFRefDirective(S);
}
}
}
void PPCAIXAsmPrinter::emitGCOVRefs() {
if (!OutContext.hasXCOFFSection(
"__llvm_gcov_ctr_section",
XCOFF::CsectProperties(XCOFF::XMC_RW, XCOFF::XTY_SD)))
return;
MCSection *CtrSection = OutContext.getXCOFFSection(
"__llvm_gcov_ctr_section", SectionKind::getData(),
XCOFF::CsectProperties(XCOFF::XMC_RW, XCOFF::XTY_SD),
/*MultiSymbolsAllowed*/ true);
OutStreamer->switchSection(CtrSection);
const XCOFF::StorageMappingClass MappingClass =
TM.Options.XCOFFReadOnlyPointers ? XCOFF::XMC_RO : XCOFF::XMC_RW;
if (OutContext.hasXCOFFSection(
"__llvm_covinit",
XCOFF::CsectProperties(MappingClass, XCOFF::XTY_SD))) {
const char *SymbolStr = TM.Options.XCOFFReadOnlyPointers
? "__llvm_covinit[RO]"
: "__llvm_covinit[RW]";
MCSymbol *S = OutContext.getOrCreateSymbol(SymbolStr);
OutStreamer->emitXCOFFRefDirective(S);
}
}
void PPCAIXAsmPrinter::emitEndOfAsmFile(Module &M) {
// If there are no functions and there are no toc-data definitions in this
// module, we will never need to reference the TOC base.
if (M.empty() && TOCDataGlobalVars.empty())
return;
emitPGORefs(M);
emitGCOVRefs();
// Switch to section to emit TOC base.
OutStreamer->switchSection(getObjFileLowering().getTOCBaseSection());
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
for (auto &I : TOC) {
MCSectionXCOFF *TCEntry;
// Setup the csect for the current TC entry. If the variant kind is
// VK_AIX_TLSGDM the entry represents the region handle, we create a
// new symbol to prefix the name with a dot.
// If TLS model opt is turned on, create a new symbol to prefix the name
// with a dot.
if (I.first.second == PPC::S_AIX_TLSGDM ||
(Subtarget->hasAIXShLibTLSModelOpt() &&
I.first.second == PPC::S_AIX_TLSLD)) {
SmallString<128> Name;
StringRef Prefix = ".";
Name += Prefix;
Name += static_cast<const MCSymbolXCOFF *>(I.first.first)
->getSymbolTableName();
MCSymbol *S = OutContext.getOrCreateSymbol(Name);
TCEntry = static_cast<MCSectionXCOFF *>(
getObjFileLowering().getSectionForTOCEntry(S, TM));
} else {
TCEntry = static_cast<MCSectionXCOFF *>(
getObjFileLowering().getSectionForTOCEntry(I.first.first, TM));
}
OutStreamer->switchSection(TCEntry);
OutStreamer->emitLabel(I.second);
TS->emitTCEntry(*I.first.first, I.first.second);
}
// Traverse the list of global variables twice, emitting all of the
// non-common global variables before the common ones, as emitting a
// .comm directive changes the scope from .toc to the common symbol.
for (const auto *GV : TOCDataGlobalVars) {
if (!GV->hasCommonLinkage())
emitGlobalVariableHelper(GV);
}
for (const auto *GV : TOCDataGlobalVars) {
if (GV->hasCommonLinkage())
emitGlobalVariableHelper(GV);
}
}
bool PPCAIXAsmPrinter::doInitialization(Module &M) {
const bool Result = PPCAsmPrinter::doInitialization(M);
// Emit the .machine directive on AIX.
const Triple &Target = M.getTargetTriple();
XCOFF::CFileCpuId TargetCpuId = XCOFF::TCPU_INVALID;
// Walk through the "target-cpu" attribute of functions and use the newest
// level as the CPU of the module.
for (auto &F : M) {
XCOFF::CFileCpuId FunCpuId =
XCOFF::getCpuID(TM.getSubtargetImpl(F)->getCPU());
if (FunCpuId > TargetCpuId)
TargetCpuId = FunCpuId;
}
// If there is no "target-cpu" attribute within the functions, take the
// "-mcpu" value. If both are omitted, use getNormalizedPPCTargetCPU() to
// determine the default CPU.
if (!TargetCpuId) {
StringRef TargetCPU = TM.getTargetCPU();
TargetCpuId = XCOFF::getCpuID(
TargetCPU.empty() ? PPC::getNormalizedPPCTargetCPU(Target) : TargetCPU);
}
PPCTargetStreamer *TS =
static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
TS->emitMachine(XCOFF::getTCPUString(TargetCpuId));
auto setCsectAlignment = [this](const GlobalObject *GO) {
// Declarations have 0 alignment which is set by default.
if (GO->isDeclarationForLinker())
return;
SectionKind GOKind = getObjFileLowering().getKindForGlobal(GO, TM);
auto *Csect = static_cast<MCSectionXCOFF *>(
getObjFileLowering().SectionForGlobal(GO, GOKind, TM));
Align GOAlign = getGVAlignment(GO, GO->getDataLayout());
Csect->ensureMinAlignment(GOAlign);
};
// For all TLS variables, calculate their corresponding addresses and store
// them into TLSVarsToAddressMapping, which will be used to determine whether
// or not local-exec TLS variables require special assembly printing.
uint64_t TLSVarAddress = 0;
auto DL = M.getDataLayout();
for (const auto &G : M.globals()) {
if (G.isThreadLocal() && !G.isDeclaration()) {
TLSVarAddress = alignTo(TLSVarAddress, getGVAlignment(&G, DL));
TLSVarsToAddressMapping[&G] = TLSVarAddress;
TLSVarAddress += G.getGlobalSize(DL);
}
}
// We need to know, up front, the alignment of csects for the assembly path,
// because once a .csect directive gets emitted, we could not change the
// alignment value on it.
for (const auto &G : M.globals()) {
if (isSpecialLLVMGlobalArrayToSkip(&G))
continue;
if (isSpecialLLVMGlobalArrayForStaticInit(&G)) {
// Generate a format indicator and a unique module id to be a part of
// the sinit and sterm function names.
if (FormatIndicatorAndUniqueModId.empty()) {
std::string UniqueModuleId = getUniqueModuleId(&M);
if (UniqueModuleId != "")
// TODO: Use source file full path to generate the unique module id
// and add a format indicator as a part of function name in case we
// will support more than one format.
FormatIndicatorAndUniqueModId = "clang_" + UniqueModuleId.substr(1);
else {
// Use threadId, Pid, and current time as the unique module id when we
// cannot generate one based on a module's strong external symbols.
auto CurTime =
std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::steady_clock::now().time_since_epoch())
.count();
FormatIndicatorAndUniqueModId =
"clangPidTidTime_" + llvm::itostr(sys::Process::getProcessId()) +
"_" + llvm::itostr(llvm::get_threadid()) + "_" +
llvm::itostr(CurTime);
}
}
emitSpecialLLVMGlobal(&G);
continue;
}
setCsectAlignment(&G);
std::optional<CodeModel::Model> OptionalCodeModel = G.getCodeModel();
if (OptionalCodeModel)
setOptionalCodeModel(static_cast<MCSymbolXCOFF *>(getSymbol(&G)),
*OptionalCodeModel);
}
for (const auto &F : M)
setCsectAlignment(&F);
// Construct an aliasing list for each GlobalObject.
for (const auto &Alias : M.aliases()) {
const GlobalObject *Aliasee = Alias.getAliaseeObject();
if (!Aliasee)
report_fatal_error(
"alias without a base object is not yet supported on AIX");
if (Aliasee->hasCommonLinkage()) {
report_fatal_error("Aliases to common variables are not allowed on AIX:"
"\n\tAlias attribute for " +
Alias.getName() + " is invalid because " +
Aliasee->getName() + " is common.",
false);
}
const GlobalVariable *GVar =
dyn_cast_or_null<GlobalVariable>(Alias.getAliaseeObject());
if (GVar) {
std::optional<CodeModel::Model> OptionalCodeModel = GVar->getCodeModel();
if (OptionalCodeModel)
setOptionalCodeModel(static_cast<MCSymbolXCOFF *>(getSymbol(&Alias)),
*OptionalCodeModel);
}
GOAliasMap[Aliasee].push_back(&Alias);
}
return Result;
}
void PPCAIXAsmPrinter::emitInstruction(const MachineInstr *MI) {
switch (MI->getOpcode()) {
default:
break;
case PPC::TW:
case PPC::TWI:
case PPC::TD:
case PPC::TDI: {
if (MI->getNumOperands() < 5)
break;
const MachineOperand &LangMO = MI->getOperand(3);
const MachineOperand &ReasonMO = MI->getOperand(4);
if (!LangMO.isImm() || !ReasonMO.isImm())
break;
MCSymbol *TempSym = OutContext.createNamedTempSymbol();
OutStreamer->emitLabel(TempSym);
OutStreamer->emitXCOFFExceptDirective(
CurrentFnSym, TempSym, LangMO.getImm(), ReasonMO.getImm(),
Subtarget->isPPC64() ? MI->getMF()->getInstructionCount() * 8
: MI->getMF()->getInstructionCount() * 4,
hasDebugInfo());
break;
}
case PPC::GETtlsMOD32AIX:
case PPC::GETtlsMOD64AIX:
case PPC::GETtlsTpointer32AIX:
case PPC::GETtlsADDR64AIX:
case PPC::GETtlsADDR32AIX: {
// A reference to .__tls_get_mod/.__tls_get_addr/.__get_tpointer is unknown
// to the assembler so we need to emit an external symbol reference.
MCSymbol *TlsGetAddr =
createMCSymbolForTlsGetAddr(OutContext, MI->getOpcode());
ExtSymSDNodeSymbols.insert(TlsGetAddr);
break;
}
case PPC::BL8:
case PPC::BL:
case PPC::BL8_NOP:
case PPC::BL_NOP:
case PPC::BL_LWZinto_toc:
case PPC::BL_LWZinto_toc_RM:
case PPC::BL8_LDinto_toc:
case PPC::BL8_LDinto_toc_RM: {
const MachineOperand &MO = MI->getOperand(0);
if (MO.isSymbol()) {
auto *S = static_cast<MCSymbolXCOFF *>(
OutContext.getOrCreateSymbol(MO.getSymbolName()));
ExtSymSDNodeSymbols.insert(S);
}
} break;
case PPC::BL_TLS:
case PPC::BL8_TLS:
case PPC::BL8_TLS_:
case PPC::BL8_NOP_TLS:
report_fatal_error("TLS call not yet implemented");
case PPC::TAILB:
case PPC::TAILB8:
case PPC::TAILBA:
case PPC::TAILBA8:
case PPC::TAILBCTR:
case PPC::TAILBCTR8:
if (MI->getOperand(0).isSymbol())
report_fatal_error("Tail call for extern symbol not yet supported.");
break;
case PPC::DST:
case PPC::DST64:
case PPC::DSTT:
case PPC::DSTT64:
case PPC::DSTST:
case PPC::DSTST64:
case PPC::DSTSTT:
case PPC::DSTSTT64:
EmitToStreamer(
*OutStreamer,
MCInstBuilder(PPC::ORI).addReg(PPC::R0).addReg(PPC::R0).addImm(0));
return;
}
return PPCAsmPrinter::emitInstruction(MI);
}
bool PPCAIXAsmPrinter::doFinalization(Module &M) {
for (MCSymbol *Sym : ExtSymSDNodeSymbols)
OutStreamer->emitSymbolAttribute(Sym, MCSA_Extern);
return PPCAsmPrinter::doFinalization(M);
}
static unsigned mapToSinitPriority(int P) {
if (P < 0 || P > 65535)
report_fatal_error("invalid init priority");
if (P <= 20)
return P;
if (P < 81)
return 20 + (P - 20) * 16;
if (P <= 1124)
return 1004 + (P - 81);
if (P < 64512)
return 2047 + (P - 1124) * 33878;
return 2147482625u + (P - 64512);
}
static std::string convertToSinitPriority(int Priority) {
// This helper function converts clang init priority to values used in sinit
// and sterm functions.
//
// The conversion strategies are:
// We map the reserved clang/gnu priority range [0, 100] into the sinit/sterm
// reserved priority range [0, 1023] by
// - directly mapping the first 21 and the last 20 elements of the ranges
// - linear interpolating the intermediate values with a step size of 16.
//
// We map the non reserved clang/gnu priority range of [101, 65535] into the
// sinit/sterm priority range [1024, 2147483648] by:
// - directly mapping the first and the last 1024 elements of the ranges
// - linear interpolating the intermediate values with a step size of 33878.
unsigned int P = mapToSinitPriority(Priority);
std::string PrioritySuffix;
llvm::raw_string_ostream os(PrioritySuffix);
os << llvm::format_hex_no_prefix(P, 8);
return PrioritySuffix;
}
void PPCAIXAsmPrinter::emitXXStructorList(const DataLayout &DL,
const Constant *List, bool IsCtor) {
SmallVector<Structor, 8> Structors;
preprocessXXStructorList(DL, List, Structors);
if (Structors.empty())
return;
unsigned Index = 0;
for (Structor &S : Structors) {
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(S.Func))
S.Func = CE->getOperand(0);
llvm::GlobalAlias::create(
GlobalValue::ExternalLinkage,
(IsCtor ? llvm::Twine("__sinit") : llvm::Twine("__sterm")) +
llvm::Twine(convertToSinitPriority(S.Priority)) +
llvm::Twine("_", FormatIndicatorAndUniqueModId) +
llvm::Twine("_", llvm::utostr(Index++)),
cast<Function>(S.Func));
}
}
void PPCAIXAsmPrinter::emitTTypeReference(const GlobalValue *GV,
unsigned Encoding) {
if (GV) {
TOCEntryType GlobalType = TOCType_GlobalInternal;
GlobalValue::LinkageTypes Linkage = GV->getLinkage();
if (Linkage == GlobalValue::ExternalLinkage ||
Linkage == GlobalValue::AvailableExternallyLinkage ||
Linkage == GlobalValue::ExternalWeakLinkage)
GlobalType = TOCType_GlobalExternal;
MCSymbol *TypeInfoSym = TM.getSymbol(GV);
MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(TypeInfoSym, GlobalType);
const MCSymbol *TOCBaseSym = static_cast<const MCSectionXCOFF *>(
getObjFileLowering().getTOCBaseSection())
->getQualNameSymbol();
auto &Ctx = OutStreamer->getContext();
const MCExpr *Exp =
MCBinaryExpr::createSub(MCSymbolRefExpr::create(TOCEntry, Ctx),
MCSymbolRefExpr::create(TOCBaseSym, Ctx), Ctx);
OutStreamer->emitValue(Exp, GetSizeOfEncodedValue(Encoding));
} else
OutStreamer->emitIntValue(0, GetSizeOfEncodedValue(Encoding));
}
void PPCAIXAsmPrinter::emitRefMetadata(const GlobalObject *GO) {
SmallVector<MDNode *> MDs;
GO->getMetadata(LLVMContext::MD_implicit_ref, MDs);
assert(MDs.size() && "Expected !implicit.ref metadata nodes");
for (const MDNode *MD : MDs) {
const ValueAsMetadata *VAM = cast<ValueAsMetadata>(MD->getOperand(0).get());
const GlobalValue *GV = cast<GlobalValue>(VAM->getValue());
MCSymbol *Referenced =
isa<Function>(GV)
? getObjFileLowering().getFunctionEntryPointSymbol(GV, TM)
: TM.getSymbol(GV);
OutStreamer->emitXCOFFRefDirective(Referenced);
}
}
// Return a pass that prints the PPC assembly code for a MachineFunction to the
// given output stream.
static AsmPrinter *
createPPCAsmPrinterPass(TargetMachine &tm,
std::unique_ptr<MCStreamer> &&Streamer) {
if (tm.getTargetTriple().isOSAIX())
return new PPCAIXAsmPrinter(tm, std::move(Streamer));
return new PPCLinuxAsmPrinter(tm, std::move(Streamer));
}
void PPCAIXAsmPrinter::emitModuleCommandLines(Module &M) {
const NamedMDNode *NMD = M.getNamedMetadata("llvm.commandline");
if (!NMD || !NMD->getNumOperands())
return;
std::string S;
raw_string_ostream RSOS(S);
for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
const MDNode *N = NMD->getOperand(i);
assert(N->getNumOperands() == 1 &&
"llvm.commandline metadata entry can have only one operand");
const MDString *MDS = cast<MDString>(N->getOperand(0));
// Add "@(#)" to support retrieving the command line information with the
// AIX "what" command
RSOS << "@(#)opt " << MDS->getString() << "\n";
RSOS.write('\0');
}
OutStreamer->emitXCOFFCInfoSym(".GCC.command.line", RSOS.str());
}
static bool TOCRestoreNeededForCallToImplementation(const GlobalIFunc &GI) {
enum class IsLocal {
Unknown, // Structure of the llvm::Value is not one of the recognizable
// structures, and so it's unknown if the llvm::Value is the
// address of a local function at runtime.
True, // We can statically prove that all runtime values of the
// llvm::Value is an address of a local function.
False // We can statically prove that one of the runtime values of the
// llvm::Value is the address of a non-local function; it could be
// the case that at runtime the non-local function is never
// selected but we don't care.
};
auto Combine = [](IsLocal LHS, IsLocal RHS) -> IsLocal {
if (LHS == IsLocal::False || RHS == IsLocal::False)
return IsLocal::False;
if (LHS == IsLocal::True && RHS == IsLocal::True)
return IsLocal::True;
return IsLocal::Unknown;
};
// Query if the given function is local to the load module.
auto IsLocalFunc = [](const Function *F) -> IsLocal {
bool Result = F->isDSOLocal();
LLVM_DEBUG(dbgs() << F->getName() << " is "
<< (Result ? "dso_local\n" : "not dso_local\n"));
return Result ? IsLocal::True : IsLocal::False;
};
// Recursive walker that visits certain patterns that make up the given Value,
// and returns
// - false if at least one non-local function was seen,
// - otherwise, return unknown if some unrecognizable pattern was seen,
// - otherwise, return true (which means only recognizable patterns were seen
// and all possible values are local functions).
std::function<IsLocal(const Value *)> ValueIsALocalFunc =
[&IsLocalFunc, &Combine, &ValueIsALocalFunc](const Value *V) -> IsLocal {
if (auto *F = dyn_cast<Function>(V))
return IsLocalFunc(F);
if (!isa<Instruction>(V))
return IsLocal::Unknown;
auto *I = cast<Instruction>(V);
// return isP9 ? foo_p9 : foo_default;
if (auto *SI = dyn_cast<SelectInst>(I))
return Combine(ValueIsALocalFunc(SI->getTrueValue()),
ValueIsALocalFunc(SI->getFalseValue()));
else if (auto *PN = dyn_cast<PHINode>(I)) {
IsLocal Res = IsLocal::True;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Res = Combine(Res, ValueIsALocalFunc(PN->getIncomingValue(i)));
if (Res == IsLocal::False)
return Res;
}
return Res;
}
// clang-format off
// @switch.table.resolve_foo = private unnamed_addr constant [3 x ptr] [ptr @foo_static, ptr @foo_hidden, ptr @foo_protected]
// %switch.gep = getelementptr inbounds nuw ptr, ptr @switch.table, i64 %2
// V = load ptr, ptr %switch.gep,
// clang-format on
else if (auto *Op = getPointerOperand(I)) {
while (isa<GEPOperator>(Op))
Op = cast<GEPOperator>(Op)->getPointerOperand();
if (!isa<GlobalVariable>(Op))
return IsLocal::Unknown;
auto *GV = dyn_cast<GlobalVariable>(Op);
if (!GV->hasInitializer() || !isa<ConstantArray>(GV->getInitializer()))
return IsLocal::Unknown;
auto *Init = cast<ConstantArray>(GV->getInitializer());
IsLocal Res = IsLocal::True;
for (unsigned Idx = 0, End = Init->getNumOperands(); Idx != End; ++Idx) {
Res = Combine(Res, ValueIsALocalFunc(Init->getOperand(Idx)));
if (Res == IsLocal::False)
return Res;
}
return Res;
}
return IsLocal::Unknown;
};
auto *Resolver = GI.getResolverFunction();
// If the resolver is preemptible then we cannot rely on its implementation.
if (IsLocalFunc(Resolver) == IsLocal::False && IFuncLocalIfProven)
return true;
// If one of the return values of the resolver function is not a
// local function, then we have to conservatively do a TOC save/restore.
IsLocal Res = IsLocal::True;
for (auto &BB : *Resolver) {
if (!isa<ReturnInst>(BB.getTerminator()))
continue;
auto *Ret = cast<ReturnInst>(BB.getTerminator());
Value *RV = Ret->getReturnValue();
assert(RV);
Res = Combine(Res, ValueIsALocalFunc(RV));
if (Res == IsLocal::False)
break;
}
// no TOC save/restore needed if either all functions were local or we're
// being optimistic and no preemptible functions were seen.
if (Res == IsLocal::True || (Res == IsLocal::Unknown && !IFuncLocalIfProven))
return false;
return true;
}
/*
* .csect .foo[PR],5
* .globl foo[DS]
* .globl .foo[PR]
* .lglobl ifunc_sec.foo[RW]
* .align 4
* .csect foo[DS],2
* .vbyte 4, .foo[PR]
* .vbyte 4, TOC[TC0]
* .vbyte 4, 0
* .csect .foo[PR],5
* .ref ifunc_sec.foo[RW]
* lwz 12, L..foo_desc(2) # load foo's descriptor address
* lwz 11, 8(12) # load the env pointer (for non-C/C++ functions)
* lwz 12, 0(12) # load foo.addr
* mtctr 12
* bctr # branch to CR without setting LR so that callee
* # returns to the caller of .foo
* # -- End function
*/
void PPCAIXAsmPrinter::emitGlobalIFunc(Module &M, const GlobalIFunc &GI) {
// Set the Subtarget to that of the resolver.
const TargetSubtargetInfo *STI =
TM.getSubtargetImpl(*GI.getResolverFunction());
bool IsPPC64 = static_cast<const PPCSubtarget *>(STI)->isPPC64();
// Create syms and sections that are part of the ifunc implementation:
// - Function descriptor symbol foo[RW]
// - Function entry symbol .foo[PR]
MCSectionXCOFF *FnDescSec = static_cast<MCSectionXCOFF *>(
getObjFileLowering().getSectionForFunctionDescriptor(&GI, TM));
FnDescSec->setAlignment(Align(IsPPC64 ? 8 : 4));
CurrentFnDescSym = FnDescSec->getQualNameSymbol();
CurrentFnSym = getObjFileLowering().getFunctionEntryPointSymbol(&GI, TM);
// Start codegen:
if (TM.getFunctionSections())
OutStreamer->switchSection(
static_cast<MCSymbolXCOFF *>(CurrentFnSym)->getRepresentedCsect());
else
OutStreamer->switchSection(getObjFileLowering().getTextSection());
if (GI.hasMetadata(LLVMContext::MD_implicit_ref))
emitRefMetadata(&GI);
// generate linkage for foo and .foo
emitLinkage(&GI, CurrentFnDescSym);
emitLinkage(&GI, CurrentFnSym);
// .align 4
Align Alignment(STI->getTargetLowering()->getMinFunctionAlignment());
emitAlignment(Alignment, nullptr);
// generate foo's function descriptor
emitFunctionDescriptor();
emitFunctionEntryLabel();
// generate the code for .foo now:
if (TOCRestoreNeededForCallToImplementation(GI)) {
SmallString<128> Msg;
Msg.append("unimplemented: TOC register save/restore needed for ifunc \"");
getNameWithPrefix(Msg, &GI);
Msg.append("\", because couldn't prove all candidates are static or "
"hidden/protected visibility definitions");
if (!IFuncWarnInsteadOfError)
reportFatalUsageError(Msg.str());
else
dbgs() << Msg << "\n";
}
auto FnDescTOCEntryType = getTOCEntryTypeForLinkage(GI.getLinkage());
auto *FnDescTOCEntrySym =
lookUpOrCreateTOCEntry(CurrentFnDescSym, FnDescTOCEntryType);
if (TM.getCodeModel() == CodeModel::Large) {
// addis 12, L..foo_desc@u(2)
// lwz 12, L..foo_desc@l(12)
auto *Exp_U = symbolWithSpecifier(FnDescTOCEntrySym, PPC::S_U);
OutStreamer->emitInstruction(MCInstBuilder(PPC::ADDIS)
.addReg(PPC::X12)
.addReg(PPC::X2)
.addExpr(Exp_U),
*Subtarget);
auto *Exp_L = symbolWithSpecifier(FnDescTOCEntrySym, PPC::S_L);
OutStreamer->emitInstruction(MCInstBuilder(IsPPC64 ? PPC::LD : PPC::LWZ)
.addReg(PPC::X12)
.addExpr(Exp_L)
.addReg(PPC::X12),
*Subtarget);
} else {
// lwz 12, L..foo_desc(2)
auto *Exp = MCSymbolRefExpr::create(FnDescTOCEntrySym, OutContext);
// Exp = getTOCEntryLoadingExprForXCOFF(MOSymbol, Exp, VK);
// TODO: do we need to uncomment this?
OutStreamer->emitInstruction(MCInstBuilder(IsPPC64 ? PPC::LD : PPC::LWZ)
.addReg(PPC::X12)
.addExpr(Exp)
.addReg(PPC::X2),
*Subtarget);
}
// lwz 11, 8(12)
OutStreamer->emitInstruction(MCInstBuilder(IsPPC64 ? PPC::LD : PPC::LWZ)
.addReg(PPC::X11)
.addImm(IsPPC64 ? 16 : 8)
.addReg(PPC::X12),
*Subtarget);
// lwz 12, 0(12)
OutStreamer->emitInstruction(MCInstBuilder(IsPPC64 ? PPC::LD : PPC::LWZ)
.addReg(PPC::X12)
.addImm(0)
.addReg(PPC::X12),
*Subtarget);
// mtctr 12
OutStreamer->emitInstruction(
MCInstBuilder(IsPPC64 ? PPC::MTCTR8 : PPC::MTCTR).addReg(PPC::X12),
*Subtarget);
// bctr
OutStreamer->emitInstruction(MCInstBuilder(IsPPC64 ? PPC::BCTR8 : PPC::BCTR),
*Subtarget);
}
char PPCAIXAsmPrinter::ID = 0;
INITIALIZE_PASS(PPCAIXAsmPrinter, "ppc-aix-asm-printer",
"AIX PPC Assembly Printer", false, false)
// Force static initialization.
extern "C" LLVM_ABI LLVM_EXTERNAL_VISIBILITY void
LLVMInitializePowerPCAsmPrinter() {
TargetRegistry::RegisterAsmPrinter(getThePPC32Target(),
createPPCAsmPrinterPass);
TargetRegistry::RegisterAsmPrinter(getThePPC32LETarget(),
createPPCAsmPrinterPass);
TargetRegistry::RegisterAsmPrinter(getThePPC64Target(),
createPPCAsmPrinterPass);
TargetRegistry::RegisterAsmPrinter(getThePPC64LETarget(),
createPPCAsmPrinterPass);
}