109467b48Spatrick //===-- AVRAsmPrinter.cpp - AVR LLVM assembly writer ----------------------===//
209467b48Spatrick //
309467b48Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
409467b48Spatrick // See https://llvm.org/LICENSE.txt for license information.
509467b48Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
609467b48Spatrick //
709467b48Spatrick //===----------------------------------------------------------------------===//
809467b48Spatrick //
909467b48Spatrick // This file contains a printer that converts from our internal representation
1009467b48Spatrick // of machine-dependent LLVM code to GAS-format AVR assembly language.
1109467b48Spatrick //
1209467b48Spatrick //===----------------------------------------------------------------------===//
1309467b48Spatrick
1409467b48Spatrick #include "AVR.h"
1509467b48Spatrick #include "AVRMCInstLower.h"
1609467b48Spatrick #include "AVRSubtarget.h"
17*d415bd75Srobert #include "AVRTargetMachine.h"
1809467b48Spatrick #include "MCTargetDesc/AVRInstPrinter.h"
1973471bf0Spatrick #include "MCTargetDesc/AVRMCExpr.h"
2009467b48Spatrick #include "TargetInfo/AVRTargetInfo.h"
2109467b48Spatrick
22*d415bd75Srobert #include "llvm/BinaryFormat/ELF.h"
2309467b48Spatrick #include "llvm/CodeGen/AsmPrinter.h"
2409467b48Spatrick #include "llvm/CodeGen/MachineFunction.h"
2509467b48Spatrick #include "llvm/CodeGen/MachineInstr.h"
26*d415bd75Srobert #include "llvm/CodeGen/MachineModuleInfo.h"
2709467b48Spatrick #include "llvm/CodeGen/TargetRegisterInfo.h"
2809467b48Spatrick #include "llvm/CodeGen/TargetSubtargetInfo.h"
2909467b48Spatrick #include "llvm/IR/Mangler.h"
30*d415bd75Srobert #include "llvm/MC/MCContext.h"
3109467b48Spatrick #include "llvm/MC/MCInst.h"
32*d415bd75Srobert #include "llvm/MC/MCSectionELF.h"
3309467b48Spatrick #include "llvm/MC/MCStreamer.h"
3409467b48Spatrick #include "llvm/MC/MCSymbol.h"
35*d415bd75Srobert #include "llvm/MC/TargetRegistry.h"
3609467b48Spatrick #include "llvm/Support/ErrorHandling.h"
3709467b48Spatrick #include "llvm/Support/raw_ostream.h"
38*d415bd75Srobert #include "llvm/Target/TargetLoweringObjectFile.h"
3909467b48Spatrick
4009467b48Spatrick #define DEBUG_TYPE "avr-asm-printer"
4109467b48Spatrick
4209467b48Spatrick namespace llvm {
4309467b48Spatrick
4409467b48Spatrick /// An AVR assembly code printer.
4509467b48Spatrick class AVRAsmPrinter : public AsmPrinter {
4609467b48Spatrick public:
AVRAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)47*d415bd75Srobert AVRAsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
4809467b48Spatrick : AsmPrinter(TM, std::move(Streamer)), MRI(*TM.getMCRegisterInfo()) {}
4909467b48Spatrick
getPassName() const5009467b48Spatrick StringRef getPassName() const override { return "AVR Assembly Printer"; }
5109467b48Spatrick
5209467b48Spatrick void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);
5309467b48Spatrick
5409467b48Spatrick bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
5509467b48Spatrick const char *ExtraCode, raw_ostream &O) override;
5609467b48Spatrick
5709467b48Spatrick bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
5809467b48Spatrick const char *ExtraCode, raw_ostream &O) override;
5909467b48Spatrick
60097a140dSpatrick void emitInstruction(const MachineInstr *MI) override;
6109467b48Spatrick
6273471bf0Spatrick const MCExpr *lowerConstant(const Constant *CV) override;
6373471bf0Spatrick
64*d415bd75Srobert void emitXXStructor(const DataLayout &DL, const Constant *CV) override;
65*d415bd75Srobert
66*d415bd75Srobert bool doFinalization(Module &M) override;
67*d415bd75Srobert
68*d415bd75Srobert void emitStartOfAsmFile(Module &M) override;
69*d415bd75Srobert
7009467b48Spatrick private:
7109467b48Spatrick const MCRegisterInfo &MRI;
72*d415bd75Srobert bool EmittedStructorSymbolAttrs = false;
7309467b48Spatrick };
7409467b48Spatrick
printOperand(const MachineInstr * MI,unsigned OpNo,raw_ostream & O)7509467b48Spatrick void AVRAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
7609467b48Spatrick raw_ostream &O) {
7709467b48Spatrick const MachineOperand &MO = MI->getOperand(OpNo);
7809467b48Spatrick
7909467b48Spatrick switch (MO.getType()) {
8009467b48Spatrick case MachineOperand::MO_Register:
8109467b48Spatrick O << AVRInstPrinter::getPrettyRegisterName(MO.getReg(), MRI);
8209467b48Spatrick break;
8309467b48Spatrick case MachineOperand::MO_Immediate:
8409467b48Spatrick O << MO.getImm();
8509467b48Spatrick break;
8609467b48Spatrick case MachineOperand::MO_GlobalAddress:
8709467b48Spatrick O << getSymbol(MO.getGlobal());
8809467b48Spatrick break;
8909467b48Spatrick case MachineOperand::MO_ExternalSymbol:
9009467b48Spatrick O << *GetExternalSymbolSymbol(MO.getSymbolName());
9109467b48Spatrick break;
9209467b48Spatrick case MachineOperand::MO_MachineBasicBlock:
9309467b48Spatrick O << *MO.getMBB()->getSymbol();
9409467b48Spatrick break;
9509467b48Spatrick default:
9609467b48Spatrick llvm_unreachable("Not implemented yet!");
9709467b48Spatrick }
9809467b48Spatrick }
9909467b48Spatrick
PrintAsmOperand(const MachineInstr * MI,unsigned OpNum,const char * ExtraCode,raw_ostream & O)10009467b48Spatrick bool AVRAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
10109467b48Spatrick const char *ExtraCode, raw_ostream &O) {
10209467b48Spatrick // Default asm printer can only deal with some extra codes,
10309467b48Spatrick // so try it first.
10409467b48Spatrick bool Error = AsmPrinter::PrintAsmOperand(MI, OpNum, ExtraCode, O);
10509467b48Spatrick
10609467b48Spatrick if (Error && ExtraCode && ExtraCode[0]) {
10709467b48Spatrick if (ExtraCode[1] != 0)
10809467b48Spatrick return true; // Unknown modifier.
10909467b48Spatrick
11009467b48Spatrick if (ExtraCode[0] >= 'A' && ExtraCode[0] <= 'Z') {
11109467b48Spatrick const MachineOperand &RegOp = MI->getOperand(OpNum);
11209467b48Spatrick
11309467b48Spatrick assert(RegOp.isReg() && "Operand must be a register when you're"
11409467b48Spatrick "using 'A'..'Z' operand extracodes.");
11509467b48Spatrick Register Reg = RegOp.getReg();
11609467b48Spatrick
11709467b48Spatrick unsigned ByteNumber = ExtraCode[0] - 'A';
11809467b48Spatrick
11909467b48Spatrick unsigned OpFlags = MI->getOperand(OpNum - 1).getImm();
12009467b48Spatrick unsigned NumOpRegs = InlineAsm::getNumOperandRegisters(OpFlags);
12109467b48Spatrick (void)NumOpRegs;
12209467b48Spatrick
12309467b48Spatrick const AVRSubtarget &STI = MF->getSubtarget<AVRSubtarget>();
12409467b48Spatrick const TargetRegisterInfo &TRI = *STI.getRegisterInfo();
12509467b48Spatrick
12609467b48Spatrick const TargetRegisterClass *RC = TRI.getMinimalPhysRegClass(Reg);
12709467b48Spatrick unsigned BytesPerReg = TRI.getRegSizeInBits(*RC) / 8;
12809467b48Spatrick assert(BytesPerReg <= 2 && "Only 8 and 16 bit regs are supported.");
12909467b48Spatrick
13009467b48Spatrick unsigned RegIdx = ByteNumber / BytesPerReg;
131*d415bd75Srobert if (RegIdx >= NumOpRegs)
132*d415bd75Srobert return true;
13309467b48Spatrick Reg = MI->getOperand(OpNum + RegIdx).getReg();
13409467b48Spatrick
13509467b48Spatrick if (BytesPerReg == 2) {
13609467b48Spatrick Reg = TRI.getSubReg(Reg, ByteNumber % BytesPerReg ? AVR::sub_hi
13709467b48Spatrick : AVR::sub_lo);
13809467b48Spatrick }
13909467b48Spatrick
14009467b48Spatrick O << AVRInstPrinter::getPrettyRegisterName(Reg, MRI);
14109467b48Spatrick return false;
14209467b48Spatrick }
14309467b48Spatrick }
14409467b48Spatrick
145*d415bd75Srobert // Print global symbols.
146*d415bd75Srobert const auto &MO = MI->getOperand(OpNum);
147*d415bd75Srobert if (Error && MO.getType() == MachineOperand::MO_GlobalAddress) {
148*d415bd75Srobert PrintSymbolOperand(MO, O);
149*d415bd75Srobert return false;
150*d415bd75Srobert }
151*d415bd75Srobert
15209467b48Spatrick if (Error)
15309467b48Spatrick printOperand(MI, OpNum, O);
15409467b48Spatrick
15509467b48Spatrick return false;
15609467b48Spatrick }
15709467b48Spatrick
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNum,const char * ExtraCode,raw_ostream & O)15809467b48Spatrick bool AVRAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
15909467b48Spatrick unsigned OpNum, const char *ExtraCode,
16009467b48Spatrick raw_ostream &O) {
161*d415bd75Srobert if (ExtraCode && ExtraCode[0])
162*d415bd75Srobert return true; // Unknown modifier
16309467b48Spatrick
16409467b48Spatrick const MachineOperand &MO = MI->getOperand(OpNum);
16509467b48Spatrick (void)MO;
16609467b48Spatrick assert(MO.isReg() && "Unexpected inline asm memory operand");
16709467b48Spatrick
16809467b48Spatrick // TODO: We should be able to look up the alternative name for
16909467b48Spatrick // the register if it's given.
17009467b48Spatrick // TableGen doesn't expose a way of getting retrieving names
17109467b48Spatrick // for registers.
17209467b48Spatrick if (MI->getOperand(OpNum).getReg() == AVR::R31R30) {
17309467b48Spatrick O << "Z";
174*d415bd75Srobert } else if (MI->getOperand(OpNum).getReg() == AVR::R29R28) {
17509467b48Spatrick O << "Y";
176*d415bd75Srobert } else if (MI->getOperand(OpNum).getReg() == AVR::R27R26) {
177*d415bd75Srobert O << "X";
178*d415bd75Srobert } else {
179*d415bd75Srobert assert(false && "Wrong register class for memory operand.");
18009467b48Spatrick }
18109467b48Spatrick
18209467b48Spatrick // If NumOpRegs == 2, then we assume it is product of a FrameIndex expansion
18309467b48Spatrick // and the second operand is an Imm.
18409467b48Spatrick unsigned OpFlags = MI->getOperand(OpNum - 1).getImm();
18509467b48Spatrick unsigned NumOpRegs = InlineAsm::getNumOperandRegisters(OpFlags);
18609467b48Spatrick
18709467b48Spatrick if (NumOpRegs == 2) {
188*d415bd75Srobert assert(MI->getOperand(OpNum).getReg() != AVR::R27R26 &&
189*d415bd75Srobert "Base register X can not have offset/displacement.");
19009467b48Spatrick O << '+' << MI->getOperand(OpNum + 1).getImm();
19109467b48Spatrick }
19209467b48Spatrick
19309467b48Spatrick return false;
19409467b48Spatrick }
19509467b48Spatrick
emitInstruction(const MachineInstr * MI)196097a140dSpatrick void AVRAsmPrinter::emitInstruction(const MachineInstr *MI) {
197*d415bd75Srobert // FIXME: Enable feature predicate checks once all the test pass.
198*d415bd75Srobert // AVR_MC::verifyInstructionPredicates(MI->getOpcode(),
199*d415bd75Srobert // getSubtargetInfo().getFeatureBits());
200*d415bd75Srobert
20109467b48Spatrick AVRMCInstLower MCInstLowering(OutContext, *this);
20209467b48Spatrick
20309467b48Spatrick MCInst I;
20409467b48Spatrick MCInstLowering.lowerInstruction(*MI, I);
20509467b48Spatrick EmitToStreamer(*OutStreamer, I);
20609467b48Spatrick }
20709467b48Spatrick
lowerConstant(const Constant * CV)20873471bf0Spatrick const MCExpr *AVRAsmPrinter::lowerConstant(const Constant *CV) {
20973471bf0Spatrick MCContext &Ctx = OutContext;
21073471bf0Spatrick
21173471bf0Spatrick if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
21273471bf0Spatrick bool IsProgMem = GV->getAddressSpace() == AVR::ProgramMemory;
21373471bf0Spatrick if (IsProgMem) {
21473471bf0Spatrick const MCExpr *Expr = MCSymbolRefExpr::create(getSymbol(GV), Ctx);
21573471bf0Spatrick return AVRMCExpr::create(AVRMCExpr::VK_AVR_PM, Expr, false, Ctx);
21673471bf0Spatrick }
21773471bf0Spatrick }
21873471bf0Spatrick
21973471bf0Spatrick return AsmPrinter::lowerConstant(CV);
22073471bf0Spatrick }
22173471bf0Spatrick
emitXXStructor(const DataLayout & DL,const Constant * CV)222*d415bd75Srobert void AVRAsmPrinter::emitXXStructor(const DataLayout &DL, const Constant *CV) {
223*d415bd75Srobert if (!EmittedStructorSymbolAttrs) {
224*d415bd75Srobert OutStreamer->emitRawComment(
225*d415bd75Srobert " Emitting these undefined symbol references causes us to link the"
226*d415bd75Srobert " libgcc code that runs our constructors/destructors");
227*d415bd75Srobert OutStreamer->emitRawComment(" This matches GCC's behavior");
228*d415bd75Srobert
229*d415bd75Srobert MCSymbol *CtorsSym = OutContext.getOrCreateSymbol("__do_global_ctors");
230*d415bd75Srobert OutStreamer->emitSymbolAttribute(CtorsSym, MCSA_Global);
231*d415bd75Srobert
232*d415bd75Srobert MCSymbol *DtorsSym = OutContext.getOrCreateSymbol("__do_global_dtors");
233*d415bd75Srobert OutStreamer->emitSymbolAttribute(DtorsSym, MCSA_Global);
234*d415bd75Srobert
235*d415bd75Srobert EmittedStructorSymbolAttrs = true;
236*d415bd75Srobert }
237*d415bd75Srobert
238*d415bd75Srobert AsmPrinter::emitXXStructor(DL, CV);
239*d415bd75Srobert }
240*d415bd75Srobert
doFinalization(Module & M)241*d415bd75Srobert bool AVRAsmPrinter::doFinalization(Module &M) {
242*d415bd75Srobert const TargetLoweringObjectFile &TLOF = getObjFileLowering();
243*d415bd75Srobert const AVRTargetMachine &TM = (const AVRTargetMachine &)MMI->getTarget();
244*d415bd75Srobert const AVRSubtarget *SubTM = (const AVRSubtarget *)TM.getSubtargetImpl();
245*d415bd75Srobert
246*d415bd75Srobert bool NeedsCopyData = false;
247*d415bd75Srobert bool NeedsClearBSS = false;
248*d415bd75Srobert for (const auto &GO : M.globals()) {
249*d415bd75Srobert if (!GO.hasInitializer() || GO.hasAvailableExternallyLinkage())
250*d415bd75Srobert // These globals aren't defined in the current object file.
251*d415bd75Srobert continue;
252*d415bd75Srobert
253*d415bd75Srobert if (GO.hasCommonLinkage()) {
254*d415bd75Srobert // COMMON symbols are put in .bss.
255*d415bd75Srobert NeedsClearBSS = true;
256*d415bd75Srobert continue;
257*d415bd75Srobert }
258*d415bd75Srobert
259*d415bd75Srobert auto *Section = cast<MCSectionELF>(TLOF.SectionForGlobal(&GO, TM));
260*d415bd75Srobert if (Section->getName().startswith(".data"))
261*d415bd75Srobert NeedsCopyData = true;
262*d415bd75Srobert else if (Section->getName().startswith(".rodata") && SubTM->hasPROGMEM())
263*d415bd75Srobert // AVRs that have a separate PROGMEM (that's most AVRs) store .rodata
264*d415bd75Srobert // sections in RAM.
265*d415bd75Srobert NeedsCopyData = true;
266*d415bd75Srobert else if (Section->getName().startswith(".bss"))
267*d415bd75Srobert NeedsClearBSS = true;
268*d415bd75Srobert }
269*d415bd75Srobert
270*d415bd75Srobert MCSymbol *DoCopyData = OutContext.getOrCreateSymbol("__do_copy_data");
271*d415bd75Srobert MCSymbol *DoClearBss = OutContext.getOrCreateSymbol("__do_clear_bss");
272*d415bd75Srobert
273*d415bd75Srobert if (NeedsCopyData) {
274*d415bd75Srobert OutStreamer->emitRawComment(
275*d415bd75Srobert " Declaring this symbol tells the CRT that it should");
276*d415bd75Srobert OutStreamer->emitRawComment(
277*d415bd75Srobert "copy all variables from program memory to RAM on startup");
278*d415bd75Srobert OutStreamer->emitSymbolAttribute(DoCopyData, MCSA_Global);
279*d415bd75Srobert }
280*d415bd75Srobert
281*d415bd75Srobert if (NeedsClearBSS) {
282*d415bd75Srobert OutStreamer->emitRawComment(
283*d415bd75Srobert " Declaring this symbol tells the CRT that it should");
284*d415bd75Srobert OutStreamer->emitRawComment("clear the zeroed data section on startup");
285*d415bd75Srobert OutStreamer->emitSymbolAttribute(DoClearBss, MCSA_Global);
286*d415bd75Srobert }
287*d415bd75Srobert
288*d415bd75Srobert return AsmPrinter::doFinalization(M);
289*d415bd75Srobert }
290*d415bd75Srobert
emitStartOfAsmFile(Module & M)291*d415bd75Srobert void AVRAsmPrinter::emitStartOfAsmFile(Module &M) {
292*d415bd75Srobert const AVRTargetMachine &TM = (const AVRTargetMachine &)MMI->getTarget();
293*d415bd75Srobert const AVRSubtarget *SubTM = (const AVRSubtarget *)TM.getSubtargetImpl();
294*d415bd75Srobert if (!SubTM)
295*d415bd75Srobert return;
296*d415bd75Srobert
297*d415bd75Srobert // Emit __tmp_reg__.
298*d415bd75Srobert OutStreamer->emitAssignment(
299*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__tmp_reg__")),
300*d415bd75Srobert MCConstantExpr::create(SubTM->getRegTmpIndex(), MMI->getContext()));
301*d415bd75Srobert // Emit __zero_reg__.
302*d415bd75Srobert OutStreamer->emitAssignment(
303*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__zero_reg__")),
304*d415bd75Srobert MCConstantExpr::create(SubTM->getRegZeroIndex(), MMI->getContext()));
305*d415bd75Srobert // Emit __SREG__.
306*d415bd75Srobert OutStreamer->emitAssignment(
307*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__SREG__")),
308*d415bd75Srobert MCConstantExpr::create(SubTM->getIORegSREG(), MMI->getContext()));
309*d415bd75Srobert // Emit __SP_H__ if available.
310*d415bd75Srobert if (!SubTM->hasSmallStack())
311*d415bd75Srobert OutStreamer->emitAssignment(
312*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__SP_H__")),
313*d415bd75Srobert MCConstantExpr::create(SubTM->getIORegSPH(), MMI->getContext()));
314*d415bd75Srobert // Emit __SP_L__.
315*d415bd75Srobert OutStreamer->emitAssignment(
316*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__SP_L__")),
317*d415bd75Srobert MCConstantExpr::create(SubTM->getIORegSPL(), MMI->getContext()));
318*d415bd75Srobert // Emit __EIND__ if available.
319*d415bd75Srobert if (SubTM->hasEIJMPCALL())
320*d415bd75Srobert OutStreamer->emitAssignment(
321*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__EIND__")),
322*d415bd75Srobert MCConstantExpr::create(SubTM->getIORegEIND(), MMI->getContext()));
323*d415bd75Srobert // Emit __RAMPZ__ if available.
324*d415bd75Srobert if (SubTM->hasELPM())
325*d415bd75Srobert OutStreamer->emitAssignment(
326*d415bd75Srobert MMI->getContext().getOrCreateSymbol(StringRef("__RAMPZ__")),
327*d415bd75Srobert MCConstantExpr::create(SubTM->getIORegRAMPZ(), MMI->getContext()));
328*d415bd75Srobert }
329*d415bd75Srobert
33009467b48Spatrick } // end of namespace llvm
33109467b48Spatrick
LLVMInitializeAVRAsmPrinter()33209467b48Spatrick extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAVRAsmPrinter() {
33309467b48Spatrick llvm::RegisterAsmPrinter<llvm::AVRAsmPrinter> X(llvm::getTheAVRTarget());
33409467b48Spatrick }
335