Files
archived-llvm/lib/Target/ARM64/ARM64AsmPrinter.cpp
Tim Northover 369e565f23 ARM64: model pre/post-indexed operations properly.
We should be keeping track of the writeback on these instructions,
otherwise we're relying on LLVM's stupidity for correct code.

Fortunately, the MC layer can now handle all required constraints,
which means we can get rid of the CodeGen only PseudoInsts too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209426 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-22 11:56:20 +00:00

512 lines
18 KiB
C++

//===-- ARM64AsmPrinter.cpp - ARM64 LLVM assembly writer ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to the ARM64 assembly language.
//
//===----------------------------------------------------------------------===//
#include "ARM64.h"
#include "ARM64MachineFunctionInfo.h"
#include "ARM64MCInstLower.h"
#include "ARM64RegisterInfo.h"
#include "ARM64Subtarget.h"
#include "InstPrinter/ARM64InstPrinter.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCLinkerOptimizationHint.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
#define DEBUG_TYPE "asm-printer"
namespace {
class ARM64AsmPrinter : public AsmPrinter {
/// Subtarget - Keep a pointer to the ARM64Subtarget around so that we can
/// make the right decision when printing asm code for different targets.
const ARM64Subtarget *Subtarget;
ARM64MCInstLower MCInstLowering;
StackMaps SM;
public:
ARM64AsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
: AsmPrinter(TM, Streamer), Subtarget(&TM.getSubtarget<ARM64Subtarget>()),
MCInstLowering(OutContext, *Mang, *this), SM(*this), ARM64FI(nullptr),
LOHLabelCounter(0) {}
const char *getPassName() const override { return "ARM64 Assembly Printer"; }
/// \brief Wrapper for MCInstLowering.lowerOperand() for the
/// tblgen'erated pseudo lowering.
bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const {
return MCInstLowering.lowerOperand(MO, MCOp);
}
void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
/// \brief tblgen'erated driver function for lowering simple MI->MC
/// pseudo instructions.
bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
const MachineInstr *MI);
void EmitInstruction(const MachineInstr *MI) override;
void getAnalysisUsage(AnalysisUsage &AU) const override {
AsmPrinter::getAnalysisUsage(AU);
AU.setPreservesAll();
}
bool runOnMachineFunction(MachineFunction &F) override {
ARM64FI = F.getInfo<ARM64FunctionInfo>();
return AsmPrinter::runOnMachineFunction(F);
}
private:
MachineLocation getDebugValueLocation(const MachineInstr *MI) const;
void printOperand(const MachineInstr *MI, unsigned OpNum, raw_ostream &O);
bool printAsmMRegister(const MachineOperand &MO, char Mode, raw_ostream &O);
bool printAsmRegInClass(const MachineOperand &MO,
const TargetRegisterClass *RC, bool isVector,
raw_ostream &O);
bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
unsigned AsmVariant, const char *ExtraCode,
raw_ostream &O) override;
bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
unsigned AsmVariant, const char *ExtraCode,
raw_ostream &O) override;
void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
void EmitFunctionBodyEnd() override;
MCSymbol *GetCPISymbol(unsigned CPID) const override;
void EmitEndOfAsmFile(Module &M) override;
ARM64FunctionInfo *ARM64FI;
/// \brief Emit the LOHs contained in ARM64FI.
void EmitLOHs();
typedef std::map<const MachineInstr *, MCSymbol *> MInstToMCSymbol;
MInstToMCSymbol LOHInstToLabel;
unsigned LOHLabelCounter;
};
} // end of anonymous namespace
//===----------------------------------------------------------------------===//
void ARM64AsmPrinter::EmitEndOfAsmFile(Module &M) {
if (Subtarget->isTargetMachO()) {
// Funny Darwin hack: This flag tells the linker that no global symbols
// contain code that falls through to other global symbols (e.g. the obvious
// implementation of multiple entry points). If this doesn't occur, the
// linker can safely perform dead code stripping. Since LLVM never
// generates code that does this, it is always safe to set.
OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
SM.serializeToStackMapSection();
}
// Emit a .data.rel section containing any stubs that were created.
if (Subtarget->isTargetELF()) {
const TargetLoweringObjectFileELF &TLOFELF =
static_cast<const TargetLoweringObjectFileELF &>(getObjFileLowering());
MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
// Output stubs for external and common global variables.
MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
if (!Stubs.empty()) {
OutStreamer.SwitchSection(TLOFELF.getDataRelSection());
const DataLayout *TD = TM.getDataLayout();
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
OutStreamer.EmitLabel(Stubs[i].first);
OutStreamer.EmitSymbolValue(Stubs[i].second.getPointer(),
TD->getPointerSize(0));
}
Stubs.clear();
}
}
}
MachineLocation
ARM64AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
MachineLocation Location;
assert(MI->getNumOperands() == 4 && "Invalid no. of machine operands!");
// Frame address. Currently handles register +- offset only.
if (MI->getOperand(0).isReg() && MI->getOperand(1).isImm())
Location.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
else {
DEBUG(dbgs() << "DBG_VALUE instruction ignored! " << *MI << "\n");
}
return Location;
}
void ARM64AsmPrinter::EmitLOHs() {
SmallVector<MCSymbol *, 3> MCArgs;
for (const auto &D : ARM64FI->getLOHContainer()) {
for (const MachineInstr *MI : D.getArgs()) {
MInstToMCSymbol::iterator LabelIt = LOHInstToLabel.find(MI);
assert(LabelIt != LOHInstToLabel.end() &&
"Label hasn't been inserted for LOH related instruction");
MCArgs.push_back(LabelIt->second);
}
OutStreamer.EmitLOHDirective(D.getKind(), MCArgs);
MCArgs.clear();
}
}
void ARM64AsmPrinter::EmitFunctionBodyEnd() {
if (!ARM64FI->getLOHRelated().empty())
EmitLOHs();
}
/// GetCPISymbol - Return the symbol for the specified constant pool entry.
MCSymbol *ARM64AsmPrinter::GetCPISymbol(unsigned CPID) const {
// Darwin uses a linker-private symbol name for constant-pools (to
// avoid addends on the relocation?), ELF has no such concept and
// uses a normal private symbol.
if (getDataLayout().getLinkerPrivateGlobalPrefix()[0])
return OutContext.GetOrCreateSymbol(
Twine(getDataLayout().getLinkerPrivateGlobalPrefix()) + "CPI" +
Twine(getFunctionNumber()) + "_" + Twine(CPID));
return OutContext.GetOrCreateSymbol(
Twine(getDataLayout().getPrivateGlobalPrefix()) + "CPI" +
Twine(getFunctionNumber()) + "_" + Twine(CPID));
}
void ARM64AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNum,
raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(OpNum);
switch (MO.getType()) {
default:
assert(0 && "<unknown operand type>");
case MachineOperand::MO_Register: {
unsigned Reg = MO.getReg();
assert(TargetRegisterInfo::isPhysicalRegister(Reg));
assert(!MO.getSubReg() && "Subregs should be eliminated!");
O << ARM64InstPrinter::getRegisterName(Reg);
break;
}
case MachineOperand::MO_Immediate: {
int64_t Imm = MO.getImm();
O << '#' << Imm;
break;
}
}
}
bool ARM64AsmPrinter::printAsmMRegister(const MachineOperand &MO, char Mode,
raw_ostream &O) {
unsigned Reg = MO.getReg();
switch (Mode) {
default:
return true; // Unknown mode.
case 'w':
Reg = getWRegFromXReg(Reg);
break;
case 'x':
Reg = getXRegFromWReg(Reg);
break;
}
O << ARM64InstPrinter::getRegisterName(Reg);
return false;
}
// Prints the register in MO using class RC using the offset in the
// new register class. This should not be used for cross class
// printing.
bool ARM64AsmPrinter::printAsmRegInClass(const MachineOperand &MO,
const TargetRegisterClass *RC,
bool isVector, raw_ostream &O) {
assert(MO.isReg() && "Should only get here with a register!");
const ARM64RegisterInfo *RI =
static_cast<const ARM64RegisterInfo *>(TM.getRegisterInfo());
unsigned Reg = MO.getReg();
unsigned RegToPrint = RC->getRegister(RI->getEncodingValue(Reg));
assert(RI->regsOverlap(RegToPrint, Reg));
O << ARM64InstPrinter::getRegisterName(
RegToPrint, isVector ? ARM64::vreg : ARM64::NoRegAltName);
return false;
}
bool ARM64AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
unsigned AsmVariant,
const char *ExtraCode, raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(OpNum);
// 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:
return true; // Unknown modifier.
case 'w': // Print W register
case 'x': // Print X register
if (MO.isReg())
return printAsmMRegister(MO, ExtraCode[0], O);
if (MO.isImm() && MO.getImm() == 0) {
unsigned Reg = ExtraCode[0] == 'w' ? ARM64::WZR : ARM64::XZR;
O << ARM64InstPrinter::getRegisterName(Reg);
return false;
}
printOperand(MI, OpNum, O);
return false;
case 'b': // Print B register.
case 'h': // Print H register.
case 's': // Print S register.
case 'd': // Print D register.
case 'q': // Print Q register.
if (MO.isReg()) {
const TargetRegisterClass *RC;
switch (ExtraCode[0]) {
case 'b':
RC = &ARM64::FPR8RegClass;
break;
case 'h':
RC = &ARM64::FPR16RegClass;
break;
case 's':
RC = &ARM64::FPR32RegClass;
break;
case 'd':
RC = &ARM64::FPR64RegClass;
break;
case 'q':
RC = &ARM64::FPR128RegClass;
break;
default:
return true;
}
return printAsmRegInClass(MO, RC, false /* vector */, O);
}
printOperand(MI, OpNum, O);
return false;
}
}
// According to ARM, we should emit x and v registers unless we have a
// modifier.
if (MO.isReg()) {
unsigned Reg = MO.getReg();
// If this is a w or x register, print an x register.
if (ARM64::GPR32allRegClass.contains(Reg) ||
ARM64::GPR64allRegClass.contains(Reg))
return printAsmMRegister(MO, 'x', O);
// If this is a b, h, s, d, or q register, print it as a v register.
return printAsmRegInClass(MO, &ARM64::FPR128RegClass, true /* vector */, O);
}
printOperand(MI, OpNum, O);
return false;
}
bool ARM64AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
unsigned OpNum, unsigned AsmVariant,
const char *ExtraCode,
raw_ostream &O) {
if (ExtraCode && ExtraCode[0])
return true; // Unknown modifier.
const MachineOperand &MO = MI->getOperand(OpNum);
assert(MO.isReg() && "unexpected inline asm memory operand");
O << "[" << ARM64InstPrinter::getRegisterName(MO.getReg()) << "]";
return false;
}
void ARM64AsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
raw_ostream &OS) {
unsigned NOps = MI->getNumOperands();
assert(NOps == 4);
OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
// cast away const; DIetc do not take const operands for some reason.
DIVariable V(const_cast<MDNode *>(MI->getOperand(NOps - 1).getMetadata()));
OS << V.getName();
OS << " <- ";
// Frame address. Currently handles register +- offset only.
assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
OS << '[';
printOperand(MI, 0, OS);
OS << '+';
printOperand(MI, 1, OS);
OS << ']';
OS << "+";
printOperand(MI, NOps - 2, OS);
}
void ARM64AsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
unsigned NumNOPBytes = MI.getOperand(1).getImm();
SM.recordStackMap(MI);
// Emit padding.
assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
for (unsigned i = 0; i < NumNOPBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(ARM64::HINT).addImm(0));
}
// Lower a patchpoint of the form:
// [<def>], <id>, <numBytes>, <target>, <numArgs>
void ARM64AsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
SM.recordPatchPoint(MI);
PatchPointOpers Opers(&MI);
int64_t CallTarget = Opers.getMetaOper(PatchPointOpers::TargetPos).getImm();
unsigned EncodedBytes = 0;
if (CallTarget) {
assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
"High 16 bits of call target should be zero.");
unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
EncodedBytes = 16;
// Materialize the jump address:
EmitToStreamer(OutStreamer, MCInstBuilder(ARM64::MOVZWi)
.addReg(ScratchReg)
.addImm((CallTarget >> 32) & 0xFFFF)
.addImm(32));
EmitToStreamer(OutStreamer, MCInstBuilder(ARM64::MOVKWi)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm((CallTarget >> 16) & 0xFFFF)
.addImm(16));
EmitToStreamer(OutStreamer, MCInstBuilder(ARM64::MOVKWi)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(CallTarget & 0xFFFF)
.addImm(0));
EmitToStreamer(OutStreamer, MCInstBuilder(ARM64::BLR).addReg(ScratchReg));
}
// Emit padding.
unsigned NumBytes = Opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
assert(NumBytes >= EncodedBytes &&
"Patchpoint can't request size less than the length of a call.");
assert((NumBytes - EncodedBytes) % 4 == 0 &&
"Invalid number of NOP bytes requested!");
for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(ARM64::HINT).addImm(0));
}
// Simple pseudo-instructions have their lowering (with expansion to real
// instructions) auto-generated.
#include "ARM64GenMCPseudoLowering.inc"
void ARM64AsmPrinter::EmitInstruction(const MachineInstr *MI) {
// Do any auto-generated pseudo lowerings.
if (emitPseudoExpansionLowering(OutStreamer, MI))
return;
if (ARM64FI->getLOHRelated().count(MI)) {
// Generate a label for LOH related instruction
MCSymbol *LOHLabel = GetTempSymbol("loh", LOHLabelCounter++);
// Associate the instruction with the label
LOHInstToLabel[MI] = LOHLabel;
OutStreamer.EmitLabel(LOHLabel);
}
// Do any manual lowerings.
switch (MI->getOpcode()) {
default:
break;
case ARM64::DBG_VALUE: {
if (isVerbose() && OutStreamer.hasRawTextSupport()) {
SmallString<128> TmpStr;
raw_svector_ostream OS(TmpStr);
PrintDebugValueComment(MI, OS);
OutStreamer.EmitRawText(StringRef(OS.str()));
}
return;
}
// Tail calls use pseudo instructions so they have the proper code-gen
// attributes (isCall, isReturn, etc.). We lower them to the real
// instruction here.
case ARM64::TCRETURNri: {
MCInst TmpInst;
TmpInst.setOpcode(ARM64::BR);
TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case ARM64::TCRETURNdi: {
MCOperand Dest;
MCInstLowering.lowerOperand(MI->getOperand(0), Dest);
MCInst TmpInst;
TmpInst.setOpcode(ARM64::B);
TmpInst.addOperand(Dest);
EmitToStreamer(OutStreamer, TmpInst);
return;
}
case ARM64::TLSDESC_BLR: {
MCOperand Callee, Sym;
MCInstLowering.lowerOperand(MI->getOperand(0), Callee);
MCInstLowering.lowerOperand(MI->getOperand(1), Sym);
// First emit a relocation-annotation. This expands to no code, but requests
// the following instruction gets an R_AARCH64_TLSDESC_CALL.
MCInst TLSDescCall;
TLSDescCall.setOpcode(ARM64::TLSDESCCALL);
TLSDescCall.addOperand(Sym);
EmitToStreamer(OutStreamer, TLSDescCall);
// Other than that it's just a normal indirect call to the function loaded
// from the descriptor.
MCInst BLR;
BLR.setOpcode(ARM64::BLR);
BLR.addOperand(Callee);
EmitToStreamer(OutStreamer, BLR);
return;
}
case TargetOpcode::STACKMAP:
return LowerSTACKMAP(OutStreamer, SM, *MI);
case TargetOpcode::PATCHPOINT:
return LowerPATCHPOINT(OutStreamer, SM, *MI);
}
// Finally, do the automated lowerings for everything else.
MCInst TmpInst;
MCInstLowering.Lower(MI, TmpInst);
EmitToStreamer(OutStreamer, TmpInst);
}
// Force static initialization.
extern "C" void LLVMInitializeARM64AsmPrinter() {
RegisterAsmPrinter<ARM64AsmPrinter> X(TheARM64leTarget);
RegisterAsmPrinter<ARM64AsmPrinter> Y(TheARM64beTarget);
}