llvm-6502/include/llvm/CodeGen/AsmPrinter.h
Jingyue Wu f15b696b79 [NVPTX] Emit .pragma "nounroll" for loops marked with nounroll
Summary:
CUDA driver can unroll loops when jit-compiling PTX. To prevent CUDA
driver from unrolling a loop marked with llvm.loop.unroll.disable is not
unrolled by CUDA driver, we need to emit .pragma "nounroll" at the
header of that loop.

This patch also extracts getting unroll metadata from loop ID metadata
into a shared helper function.

Test Plan: test/CodeGen/NVPTX/nounroll.ll

Reviewers: eliben, meheff, jholewinski

Reviewed By: jholewinski

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D7041

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227703 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 02:27:45 +00:00

528 lines
20 KiB
C++

//===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===//
//
// 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 class to be used as the base class for target specific
// asm writers. This class primarily handles common functionality used by
// all asm writers.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_ASMPRINTER_H
#define LLVM_CODEGEN_ASMPRINTER_H
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ErrorHandling.h"
namespace llvm {
class AsmPrinterHandler;
class BlockAddress;
class ByteStreamer;
class GCStrategy;
class Constant;
class ConstantArray;
class GCMetadataPrinter;
class GlobalValue;
class GlobalVariable;
class MachineBasicBlock;
class MachineFunction;
class MachineInstr;
class MachineLocation;
class MachineLoopInfo;
class MachineLoop;
class MachineConstantPoolValue;
class MachineJumpTableInfo;
class MachineModuleInfo;
class MCAsmInfo;
class MCCFIInstruction;
class MCContext;
class MCExpr;
class MCInst;
class MCInstrInfo;
class MCSection;
class MCStreamer;
class MCSubtargetInfo;
class MCSymbol;
class MDNode;
class DwarfDebug;
class Mangler;
class TargetLoweringObjectFile;
class DataLayout;
class TargetMachine;
/// This class is intended to be used as a driving class for all asm writers.
class AsmPrinter : public MachineFunctionPass {
public:
/// Target machine description.
///
TargetMachine &TM;
/// Target Asm Printer information.
///
const MCAsmInfo *MAI;
const MCInstrInfo *MII;
/// This is the context for the output file that we are streaming. This owns
/// all of the global MC-related objects for the generated translation unit.
MCContext &OutContext;
/// This is the MCStreamer object for the file we are generating. This
/// contains the transient state for the current translation unit that we are
/// generating (such as the current section etc).
MCStreamer &OutStreamer;
/// The current machine function.
const MachineFunction *MF;
/// This is a pointer to the current MachineModuleInfo.
MachineModuleInfo *MMI;
/// Name-mangler for global names.
///
Mangler *Mang;
/// The symbol for the current function. This is recalculated at the beginning
/// of each call to runOnMachineFunction().
///
MCSymbol *CurrentFnSym;
/// The symbol used to represent the start of the current function for the
/// purpose of calculating its size (e.g. using the .size directive). By
/// default, this is equal to CurrentFnSym.
MCSymbol *CurrentFnSymForSize;
private:
// The garbage collection metadata printer table.
void *GCMetadataPrinters; // Really a DenseMap.
/// Emit comments in assembly output if this is true.
///
bool VerboseAsm;
static char ID;
/// If VerboseAsm is set, a pointer to the loop info for this function.
MachineLoopInfo *LI;
struct HandlerInfo {
AsmPrinterHandler *Handler;
const char *TimerName, *TimerGroupName;
HandlerInfo(AsmPrinterHandler *Handler, const char *TimerName,
const char *TimerGroupName)
: Handler(Handler), TimerName(TimerName),
TimerGroupName(TimerGroupName) {}
};
/// A vector of all debug/EH info emitters we should use. This vector
/// maintains ownership of the emitters.
SmallVector<HandlerInfo, 1> Handlers;
/// If the target supports dwarf debug info, this pointer is non-null.
DwarfDebug *DD;
protected:
explicit AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer);
public:
virtual ~AsmPrinter();
DwarfDebug *getDwarfDebug() { return DD; }
DwarfDebug *getDwarfDebug() const { return DD; }
/// Return true if assembly output should contain comments.
///
bool isVerbose() const { return VerboseAsm; }
/// Return a unique ID for the current function.
///
unsigned getFunctionNumber() const;
/// Return information about object file lowering.
const TargetLoweringObjectFile &getObjFileLowering() const;
/// Return information about data layout.
const DataLayout &getDataLayout() const;
/// Return information about subtarget.
const MCSubtargetInfo &getSubtargetInfo() const;
void EmitToStreamer(MCStreamer &S, const MCInst &Inst);
/// Return the target triple string.
StringRef getTargetTriple() const;
/// Return the current section we are emitting to.
const MCSection *getCurrentSection() const;
void getNameWithPrefix(SmallVectorImpl<char> &Name,
const GlobalValue *GV) const;
MCSymbol *getSymbol(const GlobalValue *GV) const;
//===------------------------------------------------------------------===//
// MachineFunctionPass Implementation.
//===------------------------------------------------------------------===//
/// Record analysis usage.
///
void getAnalysisUsage(AnalysisUsage &AU) const override;
/// Set up the AsmPrinter when we are working on a new module. If your pass
/// overrides this, it must make sure to explicitly call this implementation.
bool doInitialization(Module &M) override;
/// Shut down the asmprinter. If you override this in your pass, you must make
/// sure to call it explicitly.
bool doFinalization(Module &M) override;
/// Emit the specified function out to the OutStreamer.
bool runOnMachineFunction(MachineFunction &MF) override {
SetupMachineFunction(MF);
EmitFunctionHeader();
EmitFunctionBody();
return false;
}
//===------------------------------------------------------------------===//
// Coarse grained IR lowering routines.
//===------------------------------------------------------------------===//
/// This should be called when a new MachineFunction is being processed from
/// runOnMachineFunction.
void SetupMachineFunction(MachineFunction &MF);
/// This method emits the header for the current function.
void EmitFunctionHeader();
/// This method emits the body and trailer for a function.
void EmitFunctionBody();
void emitCFIInstruction(const MachineInstr &MI);
void emitFrameAlloc(const MachineInstr &MI);
enum CFIMoveType { CFI_M_None, CFI_M_EH, CFI_M_Debug };
CFIMoveType needsCFIMoves();
bool needsSEHMoves();
/// Print to the current output stream assembly representations of the
/// constants in the constant pool MCP. This is used to print out constants
/// which have been "spilled to memory" by the code generator.
///
virtual void EmitConstantPool();
/// Print assembly representations of the jump tables used by the current
/// function to the current output stream.
///
void EmitJumpTableInfo();
/// Emit the specified global variable to the .s file.
virtual void EmitGlobalVariable(const GlobalVariable *GV);
/// Check to see if the specified global is a special global used by LLVM. If
/// so, emit it and return true, otherwise do nothing and return false.
bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
/// Emit an alignment directive to the specified power of two boundary. For
/// example, if you pass in 3 here, you will get an 8 byte alignment. If a
/// global value is specified, and if that global has an explicit alignment
/// requested, it will override the alignment request if required for
/// correctness.
///
void EmitAlignment(unsigned NumBits, const GlobalObject *GO = nullptr) const;
/// Lower the specified LLVM Constant to an MCExpr.
const MCExpr *lowerConstant(const Constant *CV);
/// \brief Print a general LLVM constant to the .s file.
void EmitGlobalConstant(const Constant *CV);
//===------------------------------------------------------------------===//
// Overridable Hooks
//===------------------------------------------------------------------===//
// Targets can, or in the case of EmitInstruction, must implement these to
// customize output.
/// This virtual method can be overridden by targets that want to emit
/// something at the start of their file.
virtual void EmitStartOfAsmFile(Module &) {}
/// This virtual method can be overridden by targets that want to emit
/// something at the end of their file.
virtual void EmitEndOfAsmFile(Module &) {}
/// Targets can override this to emit stuff before the first basic block in
/// the function.
virtual void EmitFunctionBodyStart() {}
/// Targets can override this to emit stuff after the last basic block in the
/// function.
virtual void EmitFunctionBodyEnd() {}
/// Targets can override this to emit stuff at the start of a basic block.
/// By default, this method prints the label for the specified
/// MachineBasicBlock, an alignment (if present) and a comment describing it
/// if appropriate.
virtual void EmitBasicBlockStart(const MachineBasicBlock &MBB) const;
/// Targets can override this to emit stuff at the end of a basic block.
virtual void EmitBasicBlockEnd(const MachineBasicBlock &MBB) {}
/// Targets should implement this to emit instructions.
virtual void EmitInstruction(const MachineInstr *) {
llvm_unreachable("EmitInstruction not implemented");
}
/// Return the symbol for the specified constant pool entry.
virtual MCSymbol *GetCPISymbol(unsigned CPID) const;
virtual void EmitFunctionEntryLabel();
virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
/// Targets can override this to change how global constants that are part of
/// a C++ static/global constructor list are emitted.
virtual void EmitXXStructor(const Constant *CV) { EmitGlobalConstant(CV); }
/// 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.
virtual bool
isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
/// Targets can override this to customize the output of IMPLICIT_DEF
/// instructions in verbose mode.
virtual void emitImplicitDef(const MachineInstr *MI) const;
//===------------------------------------------------------------------===//
// Symbol Lowering Routines.
//===------------------------------------------------------------------===//
public:
/// Return the MCSymbol corresponding to the assembler temporary label with
/// the specified stem and unique ID.
MCSymbol *GetTempSymbol(Twine Name, unsigned ID) const;
/// Return an assembler temporary label with the specified stem.
MCSymbol *GetTempSymbol(Twine Name) const;
/// Return the MCSymbol for a private symbol with global value name as its
/// base, with the specified suffix.
MCSymbol *getSymbolWithGlobalValueBase(const GlobalValue *GV,
StringRef Suffix) const;
/// Return the MCSymbol for the specified ExternalSymbol.
MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;
/// Return the symbol for the specified jump table entry.
MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;
/// Return the symbol for the specified jump table .set
/// FIXME: privatize to AsmPrinter.
MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;
/// Return the MCSymbol used to satisfy BlockAddress uses of the specified
/// basic block.
MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;
//===------------------------------------------------------------------===//
// Emission Helper Routines.
//===------------------------------------------------------------------===//
public:
/// This is just convenient handler for printing offsets.
void printOffset(int64_t Offset, raw_ostream &OS) const;
/// Emit a byte directive and value.
///
void EmitInt8(int Value) const;
/// Emit a short directive and value.
///
void EmitInt16(int Value) const;
/// Emit a long directive and value.
///
void EmitInt32(int Value) const;
/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
/// .set if it is available.
void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
unsigned Size) const;
/// Emit something like ".long Label+Offset" where the size in bytes of the
/// directive is specified by Size and Label specifies the label. This
/// implicitly uses .set if it is available.
void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
unsigned Size, bool IsSectionRelative = false) const;
/// Emit something like ".long Label" where the size in bytes of the directive
/// is specified by Size and Label specifies the label.
void EmitLabelReference(const MCSymbol *Label, unsigned Size,
bool IsSectionRelative = false) const {
EmitLabelPlusOffset(Label, 0, Size, IsSectionRelative);
}
//===------------------------------------------------------------------===//
// Dwarf Emission Helper Routines
//===------------------------------------------------------------------===//
/// Emit the specified signed leb128 value.
void EmitSLEB128(int64_t Value, const char *Desc = nullptr) const;
/// Emit the specified unsigned leb128 value.
void EmitULEB128(uint64_t Value, const char *Desc = nullptr,
unsigned PadTo = 0) const;
/// Emit a .byte 42 directive for a DW_CFA_xxx value.
void EmitCFAByte(unsigned Val) const;
/// Emit a .byte 42 directive that corresponds to an encoding. If verbose
/// assembly output is enabled, we output comments describing the encoding.
/// Desc is a string saying what the encoding is specifying (e.g. "LSDA").
void EmitEncodingByte(unsigned Val, const char *Desc = nullptr) const;
/// Return the size of the encoding in bytes.
unsigned GetSizeOfEncodedValue(unsigned Encoding) const;
/// Emit reference to a ttype global with a specified encoding.
void EmitTTypeReference(const GlobalValue *GV, unsigned Encoding) const;
/// Emit the 4-byte offset of Label from the start of its section. This can
/// be done with a special directive if the target supports it (e.g. cygwin)
/// or by emitting it as an offset from a label at the start of the section.
///
/// SectionLabel is a temporary label emitted at the start of the section
/// that Label lives in.
void EmitSectionOffset(const MCSymbol *Label,
const MCSymbol *SectionLabel) const;
/// Get the value for DW_AT_APPLE_isa. Zero if no isa encoding specified.
virtual unsigned getISAEncoding() { return 0; }
/// Emit a dwarf register operation for describing
/// - a small value occupying only part of a register or
/// - a register representing only part of a value.
void EmitDwarfOpPiece(ByteStreamer &Streamer, unsigned SizeInBits,
unsigned OffsetInBits = 0) const;
/// \brief Emit a partial DWARF register operation.
/// \param MLoc the register
/// \param PieceSize size and
/// \param PieceOffset offset of the piece in bits, if this is one
/// piece of an aggregate value.
///
/// If size and offset is zero an operation for the entire
/// register is emitted: Some targets do not provide a DWARF
/// register number for every register. If this is the case, this
/// function will attempt to emit a DWARF register by emitting a
/// piece of a super-register or by piecing together multiple
/// subregisters that alias the register.
void EmitDwarfRegOpPiece(ByteStreamer &BS, const MachineLocation &MLoc,
unsigned PieceSize = 0,
unsigned PieceOffset = 0) const;
/// EmitDwarfRegOp - Emit a dwarf register operation.
virtual void EmitDwarfRegOp(ByteStreamer &BS,
const MachineLocation &MLoc) const;
//===------------------------------------------------------------------===//
// Dwarf Lowering Routines
//===------------------------------------------------------------------===//
/// \brief Emit frame instruction to describe the layout of the frame.
void emitCFIInstruction(const MCCFIInstruction &Inst) const;
//===------------------------------------------------------------------===//
// Inline Asm Support
//===------------------------------------------------------------------===//
public:
// These are hooks that targets can override to implement inline asm
// support. These should probably be moved out of AsmPrinter someday.
/// Print information related to the specified machine instr that is
/// independent of the operand, and may be independent of the instr itself.
/// This can be useful for portably encoding the comment character or other
/// bits of target-specific knowledge into the asmstrings. The syntax used is
/// ${:comment}. Targets can override this to add support for their own
/// strange codes.
virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
const char *Code) const;
/// Print the specified operand of MI, an INLINEASM instruction, using the
/// specified assembler variant. Targets should override this to format as
/// appropriate. This method can return true if the operand is erroneous.
virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant, const char *ExtraCode,
raw_ostream &OS);
/// Print the specified operand of MI, an INLINEASM instruction, using the
/// specified assembler variant as an address. Targets should override this to
/// format as appropriate. This method can return true if the operand is
/// erroneous.
virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant, const char *ExtraCode,
raw_ostream &OS);
/// Let the target do anything it needs to do before emitting inlineasm.
/// \p StartInfo - the subtarget info before parsing inline asm
virtual void emitInlineAsmStart(const MCSubtargetInfo &StartInfo) const;
/// Let the target do anything it needs to do after emitting inlineasm.
/// This callback can be used restore the original mode in case the
/// inlineasm contains directives to switch modes.
/// \p StartInfo - the original subtarget info before inline asm
/// \p EndInfo - the final subtarget info after parsing the inline asm,
/// or NULL if the value is unknown.
virtual void emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
const MCSubtargetInfo *EndInfo) const;
private:
/// Private state for PrintSpecial()
// Assign a unique ID to this machine instruction.
mutable const MachineInstr *LastMI;
mutable unsigned LastFn;
mutable unsigned Counter;
mutable unsigned SetCounter;
/// Emit a blob of inline asm to the output streamer.
void
EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = nullptr,
InlineAsm::AsmDialect AsmDialect = InlineAsm::AD_ATT) const;
/// This method formats and emits the specified machine instruction that is an
/// inline asm.
void EmitInlineAsm(const MachineInstr *MI) const;
//===------------------------------------------------------------------===//
// Internal Implementation Details
//===------------------------------------------------------------------===//
/// This emits visibility information about symbol, if this is suported by the
/// target.
void EmitVisibility(MCSymbol *Sym, unsigned Visibility,
bool IsDefinition = true) const;
void EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const;
void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
const MachineBasicBlock *MBB, unsigned uid) const;
void EmitLLVMUsedList(const ConstantArray *InitList);
/// Emit llvm.ident metadata in an '.ident' directive.
void EmitModuleIdents(Module &M);
void EmitXXStructorList(const Constant *List, bool isCtor);
GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy &C);
};
}
#endif