src/asmjit/codeemitter.h

/* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Copyright (c) 2008-2017, Petr Kobalicek

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not
   claim that you wrote the original software. If you use this software
   in a product, an acknowledgment in the product documentation would be
   appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
#ifndef __PLUMED_asmjit_codeemitter_h
#define __PLUMED_asmjit_codeemitter_h
#ifdef __PLUMED_HAS_ASMJIT
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
// [AsmJit]
// Complete x86/x64 JIT and Remote Assembler for C++.
//
// [License]
// Zlib - See LICENSE.md file in the package.

// [Guard]
#ifndef _ASMJIT_BASE_CODEEMITTER_H
#define _ASMJIT_BASE_CODEEMITTER_H

// [Dependencies]
#include "./arch.h"
#include "./codeholder.h"
#include "./operand.h"

// [Api-Begin]
#include "./asmjit_apibegin.h"

namespace PLMD {
namespace asmjit {

//! \addtogroup asmjit_base
//! \{

// ============================================================================
// [Forward Declarations]
// ============================================================================

class ConstPool;

// ============================================================================
// [asmjit::CodeEmitter]
// ============================================================================

//! Provides a base foundation to emit code - specialized by \ref Assembler and
//! \ref CodeBuilder.
class ASMJIT_VIRTAPI CodeEmitter {
public:
  //! CodeEmitter type.
  ASMJIT_ENUM(Type) {
    kTypeNone       = 0,
    kTypeAssembler  = 1,
    kTypeBuilder    = 2,
    kTypeCompiler   = 3,
    kTypeCount      = 4
  };

  //! CodeEmitter hints - global settings that affect machine-code generation.
  ASMJIT_ENUM(Hints) {
    //! Emit optimized code-alignment sequences.
    //!
    //! Default `true`.
    //!
    //! X86/X64 Specific
    //! ----------------
    //!
    //! Default align sequence used by X86/X64 architecture is one-byte (0x90)
    //! opcode that is often shown by disassemblers as nop. However there are
    //! more optimized align sequences for 2-11 bytes that may execute faster.
    //! If this feature is enabled AsmJit will generate specialized sequences
    //! for alignment between 2 to 11 bytes.
    kHintOptimizedAlign = 0x00000001U,

    //! Emit jump-prediction hints.
    //!
    //! Default `false`.
    //!
    //! X86/X64 Specific
    //! ----------------
    //!
    //! Jump prediction is usually based on the direction of the jump. If the
    //! jump is backward it is usually predicted as taken; and if the jump is
    //! forward it is usually predicted as not-taken. The reason is that loops
    //! generally use backward jumps and conditions usually use forward jumps.
    //! However this behavior can be overridden by using instruction prefixes.
    //! If this option is enabled these hints will be emitted.
    //!
    //! This feature is disabled by default, because the only processor that
    //! used to take into consideration prediction hints was P4. Newer processors
    //! implement heuristics for branch prediction that ignores any static hints.
    kHintPredictedJumps = 0x00000002U
  };

  //! CodeEmitter options that are merged with instruction options.
  ASMJIT_ENUM(Options) {
    //! Reserved, used to check for errors in `Assembler::_emit()`. In addition,
    //! if an emitter is in error state it will have `kOptionMaybeFailureCase`
    //! set
    kOptionMaybeFailureCase = 0x00000001U,

    //! Perform a strict validation before the instruction is emitted.
    kOptionStrictValidation = 0x00000002U,

    //! Logging is enabled and `CodeHolder::getLogger()` should return a valid
    //! \ref Logger pointer.
    kOptionLoggingEnabled   = 0x00000004U,

    //! Mask of all internal options that are not used to represent instruction
    //! options, but are used to instrument Assembler and CodeBuilder. These
    //! options are internal and should not be used outside of AsmJit itself.
    //!
    //! NOTE: Reserved options should never appear in `CBInst` options.
    kOptionReservedMask = 0x00000007U,

    //! Used only by Assembler to mark `_op4` and `_op5` are used.
    kOptionOp4Op5Used = 0x00000008U,

    //! Prevents following a jump during compilation (CodeCompiler).
    kOptionUnfollow = 0x00000010U,

    //! Overwrite the destination operand (CodeCompiler).
    //!
    //! Hint that is important for register liveness analysis. It tells the
    //! compiler that the destination operand will be overwritten now or by
    //! adjacent instructions. CodeCompiler knows when a register is completely
    //! overwritten by a single instruction, for example you don't have to
    //! mark "movaps" or "pxor x, x", however, if a pair of instructions is
    //! used and the first of them doesn't completely overwrite the content
    //! of the destination, CodeCompiler fails to mark that register as dead.
    //!
    //! X86/X64 Specific
    //! ----------------
    //!
    //!   - All instructions that always overwrite at least the size of the
    //!     register the virtual-register uses , for example "mov", "movq",
    //!     "movaps" don't need the overwrite option to be used - conversion,
    //!     shuffle, and other miscellaneous instructions included.
    //!
    //!   - All instructions that clear the destination register if all operands
    //!     are the same, for example "xor x, x", "pcmpeqb x x", etc...
    //!
    //!   - Consecutive instructions that partially overwrite the variable until
    //!     there is no old content require the `overwrite()` to be used. Some
    //!     examples (not always the best use cases thought):
    //!
    //!     - `movlps xmm0, ?` followed by `movhps xmm0, ?` and vice versa
    //!     - `movlpd xmm0, ?` followed by `movhpd xmm0, ?` and vice versa
    //!     - `mov al, ?` followed by `and ax, 0xFF`
    //!     - `mov al, ?` followed by `mov ah, al`
    //!     - `pinsrq xmm0, ?, 0` followed by `pinsrq xmm0, ?, 1`
    //!
    //!   - If allocated variable is used temporarily for scalar operations. For
    //!     example if you allocate a full vector like `X86Compiler::newXmm()`
    //!     and then use that vector for scalar operations you should use
    //!     `overwrite()` directive:
    //!
    //!     - `sqrtss x, y` - only LO element of `x` is changed, if you don't use
    //!       HI elements, use `X86Compiler.overwrite().sqrtss(x, y)`.
    kOptionOverwrite = 0x00000020U
  };

  // --------------------------------------------------------------------------
  // [Construction / Destruction]
  // --------------------------------------------------------------------------

  ASMJIT_API CodeEmitter(uint32_t type) noexcept;
  ASMJIT_API virtual ~CodeEmitter() noexcept;

  // --------------------------------------------------------------------------
  // [Events]
  // --------------------------------------------------------------------------

  //! Called after the \ref CodeEmitter was attached to the \ref CodeHolder.
  virtual Error onAttach(CodeHolder* code) noexcept = 0;
  //! Called after the \ref CodeEmitter was detached from the \ref CodeHolder.
  virtual Error onDetach(CodeHolder* code) noexcept = 0;

  // --------------------------------------------------------------------------
  // [Code-Generation]
  // --------------------------------------------------------------------------

  //! Emit instruction having max 4 operands.
  virtual Error _emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3) = 0;
  //! Emit instruction having max 6 operands.
  virtual Error _emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4, const Operand_& o5) = 0;
  //! Emit instruction having operands stored in array.
  virtual Error _emitOpArray(uint32_t instId, const Operand_* opArray, size_t opCount);

  //! Create a new label.
  virtual Label newLabel() = 0;
  //! Create a new named label.
  virtual Label newNamedLabel(
    const char* name,
    size_t nameLength = Globals::kInvalidIndex,
    uint32_t type = Label::kTypeGlobal,
    uint32_t parentId = 0) = 0;

  //! Get a label by name.
  //!
  //! Returns invalid Label in case that the name is invalid or label was not found.
  //!
  //! NOTE: This function doesn't trigger ErrorHandler in case the name is
  //! invalid or no such label exist. You must always check the validity of the
  //! \ref Label returned.
  ASMJIT_API Label getLabelByName(
    const char* name,
    size_t nameLength = Globals::kInvalidIndex,
    uint32_t parentId = 0) noexcept;

  //! Bind the `label` to the current position of the current section.
  //!
  //! NOTE: Attempt to bind the same label multiple times will return an error.
  virtual Error bind(const Label& label) = 0;

  //! Align to the `alignment` specified.
  //!
  //! The sequence that is used to fill the gap between the aligned location
  //! and the current location depends on the align `mode`, see \ref AlignMode.
  virtual Error align(uint32_t mode, uint32_t alignment) = 0;

  //! Embed raw data into the code-buffer.
  virtual Error embed(const void* data, uint32_t size) = 0;

  //! Embed absolute label address as data (4 or 8 bytes).
  virtual Error embedLabel(const Label& label) = 0;

  //! Embed a constant pool into the code-buffer in the following steps:
  //!   1. Align by using kAlignData to the minimum `pool` alignment.
  //!   2. Bind `label` so it's bound to an aligned location.
  //!   3. Emit constant pool data.
  virtual Error embedConstPool(const Label& label, const ConstPool& pool) = 0;

  //! Emit a comment string `s` with an optional `len` parameter.
  virtual Error comment(const char* s, size_t len = Globals::kInvalidIndex) = 0;

  // --------------------------------------------------------------------------
  // [Code-Generation Status]
  // --------------------------------------------------------------------------

  //! Get if the CodeEmitter is initialized (i.e. attached to a \ref CodeHolder).
  ASMJIT_INLINE bool isInitialized() const noexcept { return _code != nullptr; }

  ASMJIT_API virtual Error finalize();

  // --------------------------------------------------------------------------
  // [Code Information]
  // --------------------------------------------------------------------------

  //! Get information about the code, see \ref CodeInfo.
  ASMJIT_INLINE const CodeInfo& getCodeInfo() const noexcept { return _codeInfo; }
  //! Get \ref CodeHolder this CodeEmitter is attached to.
  ASMJIT_INLINE CodeHolder* getCode() const noexcept { return _code; }

  //! Get information about the architecture, see \ref ArchInfo.
  ASMJIT_INLINE const ArchInfo& getArchInfo() const noexcept { return _codeInfo.getArchInfo(); }

  //! Get if the target architecture is 32-bit.
  ASMJIT_INLINE bool is32Bit() const noexcept { return getArchInfo().is32Bit(); }
  //! Get if the target architecture is 64-bit.
  ASMJIT_INLINE bool is64Bit() const noexcept { return getArchInfo().is64Bit(); }

  //! Get the target architecture type.
  ASMJIT_INLINE uint32_t getArchType() const noexcept { return getArchInfo().getType(); }
  //! Get the target architecture sub-type.
  ASMJIT_INLINE uint32_t getArchSubType() const noexcept { return getArchInfo().getSubType(); }
  //! Get the target architecture's GP register size (4 or 8 bytes).
  ASMJIT_INLINE uint32_t getGpSize() const noexcept { return getArchInfo().getGpSize(); }
  //! Get the number of target GP registers.
  ASMJIT_INLINE uint32_t getGpCount() const noexcept { return getArchInfo().getGpCount(); }

  // --------------------------------------------------------------------------
  // [Code-Emitter Type]
  // --------------------------------------------------------------------------

  //! Get the type of this CodeEmitter, see \ref Type.
  ASMJIT_INLINE uint32_t getType() const noexcept { return _type; }

  ASMJIT_INLINE bool isAssembler() const noexcept { return _type == kTypeAssembler; }
  ASMJIT_INLINE bool isCodeBuilder() const noexcept { return _type == kTypeBuilder; }
  ASMJIT_INLINE bool isCodeCompiler() const noexcept { return _type == kTypeCompiler; }

  // --------------------------------------------------------------------------
  // [Global Information]
  // --------------------------------------------------------------------------

  //! Get global hints.
  ASMJIT_INLINE uint32_t getGlobalHints() const noexcept { return _globalHints; }

  //! Get global options.
  //!
  //! Global options are merged with instruction options before the instruction
  //! is encoded. These options have some bits reserved that are used for error
  //! checking, logging, and strict validation. Other options are globals that
  //! affect each instruction, for example if VEX3 is set globally, it will all
  //! instructions, even those that don't have such option set.
  ASMJIT_INLINE uint32_t getGlobalOptions() const noexcept { return _globalOptions; }

  // --------------------------------------------------------------------------
  // [Error Handling]
  // --------------------------------------------------------------------------

  //! Get if the object is in error state.
  //!
  //! Error state means that it does not consume anything unless the error
  //! state is reset by calling `resetLastError()`. Use `getLastError()` to
  //! get the last error that put the object into the error state.
  ASMJIT_INLINE bool isInErrorState() const noexcept { return _lastError != kErrorOk; }

  //! Get the last error code.
  ASMJIT_INLINE Error getLastError() const noexcept { return _lastError; }
  //! Set the last error code and propagate it through the error handler.
  ASMJIT_API Error setLastError(Error error, const char* message = nullptr);
  //! Clear the last error code and return `kErrorOk`.
  ASMJIT_INLINE Error resetLastError() noexcept { return setLastError(kErrorOk); }

  // --------------------------------------------------------------------------
  // [Accessors That Affect the Next Instruction]
  // --------------------------------------------------------------------------

  //! Get options of the next instruction.
  ASMJIT_INLINE uint32_t getOptions() const noexcept { return _options; }
  //! Set options of the next instruction.
  ASMJIT_INLINE void setOptions(uint32_t options) noexcept { _options = options; }
  //! Add options of the next instruction.
  ASMJIT_INLINE void addOptions(uint32_t options) noexcept { _options |= options; }
  //! Reset options of the next instruction.
  ASMJIT_INLINE void resetOptions() noexcept { _options = 0; }

  //! Get if the extra register operand is valid.
  ASMJIT_INLINE bool hasExtraReg() const noexcept { return _extraReg.isValid(); }
  //! Get an extra operand that will be used by the next instruction (architecture specific).
  ASMJIT_INLINE const RegOnly& getExtraReg() const noexcept { return _extraReg; }
  //! Set an extra operand that will be used by the next instruction (architecture specific).
  ASMJIT_INLINE void setExtraReg(const Reg& reg) noexcept { _extraReg.init(reg); }
  //! Set an extra operand that will be used by the next instruction (architecture specific).
  ASMJIT_INLINE void setExtraReg(const RegOnly& reg) noexcept { _extraReg.init(reg); }
  //! Reset an extra operand that will be used by the next instruction (architecture specific).
  ASMJIT_INLINE void resetExtraReg() noexcept { _extraReg.reset(); }

  //! Get annotation of the next instruction.
  ASMJIT_INLINE const char* getInlineComment() const noexcept { return _inlineComment; }
  //! Set annotation of the next instruction.
  //!
  //! NOTE: This string is set back to null by `_emit()`, but until that it has
  //! to remain valid as `CodeEmitter` is not required to make a copy of it (and
  //! it would be slow to do that for each instruction).
  ASMJIT_INLINE void setInlineComment(const char* s) noexcept { _inlineComment = s; }
  //! Reset annotation of the next instruction to null.
  ASMJIT_INLINE void resetInlineComment() noexcept { _inlineComment = nullptr; }

  // --------------------------------------------------------------------------
  // [Helpers]
  // --------------------------------------------------------------------------

  //! Get if the `label` is valid (i.e. registered).
  ASMJIT_INLINE bool isLabelValid(const Label& label) const noexcept {
    return isLabelValid(label.getId());
  }

  //! Get if the label `id` is valid (i.e. registered).
  ASMJIT_API bool isLabelValid(uint32_t id) const noexcept;

  //! Emit a formatted string `fmt`.
  ASMJIT_API Error commentf(const char* fmt, ...);
  //! Emit a formatted string `fmt` (va_list version).
  ASMJIT_API Error commentv(const char* fmt, va_list ap);

  // --------------------------------------------------------------------------
  // [Emit]
  // --------------------------------------------------------------------------

  // NOTE: These `emit()` helpers are designed to address a code-bloat generated
  // by C++ compilers to call a function having many arguments. Each parameter to
  // `_emit()` requires code to pass it, which means that if we default to 4
  // operand parameters in `_emit()` and instId the C++ compiler would have to
  // generate a virtual function call having 5 parameters, which is quite a lot.
  // Since by default asm instructions have 2 to 3 operands it's better to
  // introduce helpers that pass those and fill all the remaining with `_none`.

  //! Emit an instruction.
  ASMJIT_API Error emit(uint32_t instId);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4, const Operand_& o5);

  //! Emit an instruction that has a 32-bit signed immediate operand.
  ASMJIT_API Error emit(uint32_t instId, int o0);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, int o1);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, int o2);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, int o3);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, int o4);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4, int o5);

  //! Emit an instruction that has a 64-bit signed immediate operand.
  ASMJIT_API Error emit(uint32_t instId, int64_t o0);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, int64_t o1);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, int64_t o2);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, int64_t o3);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, int64_t o4);
  //! \overload
  ASMJIT_API Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4, int64_t o5);

  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, unsigned int o0) {
    return emit(instId, static_cast<int64_t>(o0));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, unsigned int o1) {
    return emit(instId, o0, static_cast<int64_t>(o1));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, unsigned int o2) {
    return emit(instId, o0, o1, static_cast<int64_t>(o2));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, unsigned int o3) {
    return emit(instId, o0, o1, o2, static_cast<int64_t>(o3));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, unsigned int o4) {
    return emit(instId, o0, o1, o2, o3, static_cast<int64_t>(o4));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4, unsigned int o5) {
    return emit(instId, o0, o1, o2, o3, o4, static_cast<int64_t>(o5));
  }

  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, uint64_t o0) {
    return emit(instId, static_cast<int64_t>(o0));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, uint64_t o1) {
    return emit(instId, o0, static_cast<int64_t>(o1));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, uint64_t o2) {
    return emit(instId, o0, o1, static_cast<int64_t>(o2));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, uint64_t o3) {
    return emit(instId, o0, o1, o2, static_cast<int64_t>(o3));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, uint64_t o4) {
    return emit(instId, o0, o1, o2, o3, static_cast<int64_t>(o4));
  }
  //! \overload
  ASMJIT_INLINE Error emit(uint32_t instId, const Operand_& o0, const Operand_& o1, const Operand_& o2, const Operand_& o3, const Operand_& o4, uint64_t o5) {
    return emit(instId, o0, o1, o2, o3, o4, static_cast<int64_t>(o5));
  }

  ASMJIT_INLINE Error emitOpArray(uint32_t instId, const Operand_* opArray, size_t opCount) {
    return _emitOpArray(instId, opArray, opCount);
  }

  // --------------------------------------------------------------------------
  // [Members]
  // --------------------------------------------------------------------------

  CodeInfo _codeInfo;                    //!< Basic information about the code (matches CodeHolder::_codeInfo).
  CodeHolder* _code;                     //!< CodeHolder the CodeEmitter is attached to.
  CodeEmitter* _nextEmitter;             //!< Linked list of `CodeEmitter`s attached to the same \ref CodeHolder.

  uint8_t _type;                         //!< See CodeEmitter::Type.
  uint8_t _destroyed;                    //!< Set by ~CodeEmitter() before calling `_code->detach()`.
  uint8_t _finalized;                    //!< True if the CodeEmitter is finalized (CodeBuilder & CodeCompiler).
  uint8_t _reserved;                     //!< \internal
  Error _lastError;                      //!< Last error code.

  uint32_t _privateData;                 //!< Internal private data used freely by any CodeEmitter.
  uint32_t _globalHints;                 //!< Global hints, always in sync with CodeHolder.
  uint32_t _globalOptions;               //!< Global options, combined with `_options` before used by each instruction.

  uint32_t _options;                     //!< Used to pass instruction options        (affects the next instruction).
  RegOnly _extraReg;                     //!< Extra register (op-mask {k} on AVX-512) (affects the next instruction).
  const char* _inlineComment;            //!< Inline comment of the next instruction  (affects the next instruction).

  Operand_ _none;                        //!< Used to pass unused operands to `_emit()` instead of passing null.
  Reg _nativeGpReg;                      //!< Native GP register with zero id.
  const Reg* _nativeGpArray;             //!< Array of native registers indexed from zero.
};

//! \}

} // asmjit namespace
} // namespace PLMD

// [Api-End]
#include "./asmjit_apiend.h"

// [Guard]
#endif // _ASMJIT_BASE_CODEEMITTER_H
#pragma GCC diagnostic pop
#endif // __PLUMED_HAS_ASMJIT
#endif