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Diffstat (limited to 'contrib/llvm/lib/Target/Mips/MipsAsmPrinter.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/Mips/MipsAsmPrinter.cpp | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/contrib/llvm/lib/Target/Mips/MipsAsmPrinter.cpp new file mode 100644 index 0000000..bd28a9b --- /dev/null +++ b/contrib/llvm/lib/Target/Mips/MipsAsmPrinter.cpp @@ -0,0 +1,393 @@ +//===-- MipsAsmPrinter.cpp - Mips 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 GAS-format MIPS assembly language. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "mips-asm-printer" +#include "Mips.h" +#include "MipsSubtarget.h" +#include "MipsInstrInfo.h" +#include "MipsTargetMachine.h" +#include "MipsMachineFunction.h" +#include "llvm/BasicBlock.h" +#include "llvm/Instructions.h" +#include "llvm/CodeGen/AsmPrinter.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineConstantPool.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Target/Mangler.h" +#include "llvm/Target/TargetData.h" +#include "llvm/Target/TargetLoweringObjectFile.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Target/TargetRegistry.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/Twine.h" +#include "llvm/Support/raw_ostream.h" +using namespace llvm; + +namespace { + class MipsAsmPrinter : public AsmPrinter { + const MipsSubtarget *Subtarget; + public: + explicit MipsAsmPrinter(TargetMachine &TM, MCStreamer &Streamer) + : AsmPrinter(TM, Streamer) { + Subtarget = &TM.getSubtarget<MipsSubtarget>(); + } + + virtual const char *getPassName() const { + return "Mips Assembly Printer"; + } + + bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, + unsigned AsmVariant, const char *ExtraCode, + raw_ostream &O); + void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O); + void printUnsignedImm(const MachineInstr *MI, int opNum, raw_ostream &O); + void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O, + const char *Modifier = 0); + void printFCCOperand(const MachineInstr *MI, int opNum, raw_ostream &O, + const char *Modifier = 0); + void printSavedRegsBitmask(raw_ostream &O); + void printHex32(unsigned int Value, raw_ostream &O); + + const char *getCurrentABIString() const; + void emitFrameDirective(); + + void printInstruction(const MachineInstr *MI, raw_ostream &O); // autogen'd. + void EmitInstruction(const MachineInstr *MI) { + SmallString<128> Str; + raw_svector_ostream OS(Str); + printInstruction(MI, OS); + OutStreamer.EmitRawText(OS.str()); + } + virtual void EmitFunctionBodyStart(); + virtual void EmitFunctionBodyEnd(); + virtual bool isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const; + static const char *getRegisterName(unsigned RegNo); + + virtual void EmitFunctionEntryLabel(); + void EmitStartOfAsmFile(Module &M); + }; +} // end of anonymous namespace + +#include "MipsGenAsmWriter.inc" + +//===----------------------------------------------------------------------===// +// +// Mips Asm Directives +// +// -- Frame directive "frame Stackpointer, Stacksize, RARegister" +// Describe the stack frame. +// +// -- Mask directives "(f)mask bitmask, offset" +// Tells the assembler which registers are saved and where. +// bitmask - contain a little endian bitset indicating which registers are +// saved on function prologue (e.g. with a 0x80000000 mask, the +// assembler knows the register 31 (RA) is saved at prologue. +// offset - the position before stack pointer subtraction indicating where +// the first saved register on prologue is located. (e.g. with a +// +// Consider the following function prologue: +// +// .frame $fp,48,$ra +// .mask 0xc0000000,-8 +// addiu $sp, $sp, -48 +// sw $ra, 40($sp) +// sw $fp, 36($sp) +// +// With a 0xc0000000 mask, the assembler knows the register 31 (RA) and +// 30 (FP) are saved at prologue. As the save order on prologue is from +// left to right, RA is saved first. A -8 offset means that after the +// stack pointer subtration, the first register in the mask (RA) will be +// saved at address 48-8=40. +// +//===----------------------------------------------------------------------===// + +//===----------------------------------------------------------------------===// +// Mask directives +//===----------------------------------------------------------------------===// + +// Create a bitmask with all callee saved registers for CPU or Floating Point +// registers. For CPU registers consider RA, GP and FP for saving if necessary. +void MipsAsmPrinter::printSavedRegsBitmask(raw_ostream &O) { + const TargetFrameLowering *TFI = TM.getFrameLowering(); + const TargetRegisterInfo *RI = TM.getRegisterInfo(); + const MipsFunctionInfo *MipsFI = MF->getInfo<MipsFunctionInfo>(); + + // CPU and FPU Saved Registers Bitmasks + unsigned int CPUBitmask = 0; + unsigned int FPUBitmask = 0; + + // Set the CPU and FPU Bitmasks + const MachineFrameInfo *MFI = MF->getFrameInfo(); + const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); + for (unsigned i = 0, e = CSI.size(); i != e; ++i) { + unsigned Reg = CSI[i].getReg(); + unsigned RegNum = MipsRegisterInfo::getRegisterNumbering(Reg); + if (Mips::CPURegsRegisterClass->contains(Reg)) + CPUBitmask |= (1 << RegNum); + else + FPUBitmask |= (1 << RegNum); + } + + // Return Address and Frame registers must also be set in CPUBitmask. + // FIXME: Do we really need hasFP() call here? When no FP is present SP is + // just returned -- will it be ok? + if (TFI->hasFP(*MF)) + CPUBitmask |= (1 << MipsRegisterInfo:: + getRegisterNumbering(RI->getFrameRegister(*MF))); + + if (MFI->adjustsStack()) + CPUBitmask |= (1 << MipsRegisterInfo:: + getRegisterNumbering(RI->getRARegister())); + + // Print CPUBitmask + O << "\t.mask \t"; printHex32(CPUBitmask, O); + O << ',' << MipsFI->getCPUTopSavedRegOff() << '\n'; + + // Print FPUBitmask + O << "\t.fmask\t"; printHex32(FPUBitmask, O); O << "," + << MipsFI->getFPUTopSavedRegOff() << '\n'; +} + +// Print a 32 bit hex number with all numbers. +void MipsAsmPrinter::printHex32(unsigned Value, raw_ostream &O) { + O << "0x"; + for (int i = 7; i >= 0; i--) + O << utohexstr((Value & (0xF << (i*4))) >> (i*4)); +} + +//===----------------------------------------------------------------------===// +// Frame and Set directives +//===----------------------------------------------------------------------===// + +/// Frame Directive +void MipsAsmPrinter::emitFrameDirective() { + const TargetRegisterInfo &RI = *TM.getRegisterInfo(); + + unsigned stackReg = RI.getFrameRegister(*MF); + unsigned returnReg = RI.getRARegister(); + unsigned stackSize = MF->getFrameInfo()->getStackSize(); + + OutStreamer.EmitRawText("\t.frame\t$" + + Twine(LowercaseString(getRegisterName(stackReg))) + + "," + Twine(stackSize) + ",$" + + Twine(LowercaseString(getRegisterName(returnReg)))); +} + +/// Emit Set directives. +const char *MipsAsmPrinter::getCurrentABIString() const { + switch (Subtarget->getTargetABI()) { + case MipsSubtarget::O32: return "abi32"; + case MipsSubtarget::O64: return "abiO64"; + case MipsSubtarget::N32: return "abiN32"; + case MipsSubtarget::N64: return "abi64"; + case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64 + default: break; + } + + llvm_unreachable("Unknown Mips ABI"); + return NULL; +} + +void MipsAsmPrinter::EmitFunctionEntryLabel() { + OutStreamer.EmitRawText("\t.ent\t" + Twine(CurrentFnSym->getName())); + OutStreamer.EmitLabel(CurrentFnSym); +} + +/// EmitFunctionBodyStart - Targets can override this to emit stuff before +/// the first basic block in the function. +void MipsAsmPrinter::EmitFunctionBodyStart() { + emitFrameDirective(); + + SmallString<128> Str; + raw_svector_ostream OS(Str); + printSavedRegsBitmask(OS); + OutStreamer.EmitRawText(OS.str()); +} + +/// EmitFunctionBodyEnd - Targets can override this to emit stuff after +/// the last basic block in the function. +void MipsAsmPrinter::EmitFunctionBodyEnd() { + // There are instruction for this macros, but they must + // always be at the function end, and we can't emit and + // break with BB logic. + OutStreamer.EmitRawText(StringRef("\t.set\tmacro")); + OutStreamer.EmitRawText(StringRef("\t.set\treorder")); + OutStreamer.EmitRawText("\t.end\t" + Twine(CurrentFnSym->getName())); +} + + +/// isBlockOnlyReachableByFallthough - Return true if the basic block has +/// exactly one predecessor and the control transfer mechanism between +/// the predecessor and this block is a fall-through. +bool MipsAsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) + const { + // The predecessor has to be immediately before this block. + const MachineBasicBlock *Pred = *MBB->pred_begin(); + + // If the predecessor is a switch statement, assume a jump table + // implementation, so it is not a fall through. + if (const BasicBlock *bb = Pred->getBasicBlock()) + if (isa<SwitchInst>(bb->getTerminator())) + return false; + + return AsmPrinter::isBlockOnlyReachableByFallthrough(MBB); +} + +// Print out an operand for an inline asm expression. +bool MipsAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, + unsigned AsmVariant,const char *ExtraCode, + raw_ostream &O) { + // Does this asm operand have a single letter operand modifier? + if (ExtraCode && ExtraCode[0]) + return true; // Unknown modifier. + + printOperand(MI, OpNo, O); + return false; +} + +void MipsAsmPrinter::printOperand(const MachineInstr *MI, int opNum, + raw_ostream &O) { + const MachineOperand &MO = MI->getOperand(opNum); + bool closeP = false; + + if (MO.getTargetFlags()) + closeP = true; + + switch(MO.getTargetFlags()) { + case MipsII::MO_GPREL: O << "%gp_rel("; break; + case MipsII::MO_GOT_CALL: O << "%call16("; break; + case MipsII::MO_GOT: { + const MachineOperand &LastMO = MI->getOperand(opNum-1); + bool LastMOIsGP = LastMO.getType() == MachineOperand::MO_Register + && LastMO.getReg() == Mips::GP; + if (MI->getOpcode() == Mips::LW || LastMOIsGP) + O << "%got("; + else + O << "%lo("; + break; + } + case MipsII::MO_ABS_HILO: + if (MI->getOpcode() == Mips::LUi) + O << "%hi("; + else + O << "%lo("; + break; + } + + switch (MO.getType()) { + case MachineOperand::MO_Register: + O << '$' << LowercaseString(getRegisterName(MO.getReg())); + break; + + case MachineOperand::MO_Immediate: + O << (short int)MO.getImm(); + break; + + case MachineOperand::MO_MachineBasicBlock: + O << *MO.getMBB()->getSymbol(); + return; + + case MachineOperand::MO_GlobalAddress: + O << *Mang->getSymbol(MO.getGlobal()); + break; + + case MachineOperand::MO_ExternalSymbol: + O << *GetExternalSymbolSymbol(MO.getSymbolName()); + break; + + case MachineOperand::MO_JumpTableIndex: + O << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() + << '_' << MO.getIndex(); + break; + + case MachineOperand::MO_ConstantPoolIndex: + O << MAI->getPrivateGlobalPrefix() << "CPI" + << getFunctionNumber() << "_" << MO.getIndex(); + if (MO.getOffset()) + O << "+" << MO.getOffset(); + break; + + default: + llvm_unreachable("<unknown operand type>"); + } + + if (closeP) O << ")"; +} + +void MipsAsmPrinter::printUnsignedImm(const MachineInstr *MI, int opNum, + raw_ostream &O) { + const MachineOperand &MO = MI->getOperand(opNum); + if (MO.isImm()) + O << (unsigned short int)MO.getImm(); + else + printOperand(MI, opNum, O); +} + +void MipsAsmPrinter:: +printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O, + const char *Modifier) { + // when using stack locations for not load/store instructions + // print the same way as all normal 3 operand instructions. + if (Modifier && !strcmp(Modifier, "stackloc")) { + printOperand(MI, opNum+1, O); + O << ", "; + printOperand(MI, opNum, O); + return; + } + + // Load/Store memory operands -- imm($reg) + // If PIC target the target is loaded as the + // pattern lw $25,%call16($28) + printOperand(MI, opNum, O); + O << "("; + printOperand(MI, opNum+1, O); + O << ")"; +} + +void MipsAsmPrinter:: +printFCCOperand(const MachineInstr *MI, int opNum, raw_ostream &O, + const char *Modifier) { + const MachineOperand& MO = MI->getOperand(opNum); + O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm()); +} + +void MipsAsmPrinter::EmitStartOfAsmFile(Module &M) { + // FIXME: Use SwitchSection. + + // Tell the assembler which ABI we are using + OutStreamer.EmitRawText("\t.section .mdebug." + Twine(getCurrentABIString())); + + // TODO: handle O64 ABI + if (Subtarget->isABI_EABI()) { + if (Subtarget->isGP32bit()) + OutStreamer.EmitRawText(StringRef("\t.section .gcc_compiled_long32")); + else + OutStreamer.EmitRawText(StringRef("\t.section .gcc_compiled_long64")); + } + + // return to previous section + OutStreamer.EmitRawText(StringRef("\t.previous")); +} + +// Force static initialization. +extern "C" void LLVMInitializeMipsAsmPrinter() { + RegisterAsmPrinter<MipsAsmPrinter> X(TheMipsTarget); + RegisterAsmPrinter<MipsAsmPrinter> Y(TheMipselTarget); +} |