/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
#include "q_shared.h"
#include "qcommon.h"


typedef enum {
	OP_UNDEF,

	OP_IGNORE,

	OP_BREAK,

	OP_ENTER,
	OP_LEAVE,
	OP_CALL,
	OP_PUSH,
	OP_POP,

	OP_CONST,
	OP_LOCAL,

	OP_JUMP,

	//-------------------

	OP_EQ,
	OP_NE,

	OP_LTI,
	OP_LEI,
	OP_GTI,
	OP_GEI,

	OP_LTU,
	OP_LEU,
	OP_GTU,
	OP_GEU,

	OP_EQF,
	OP_NEF,

	OP_LTF,
	OP_LEF,
	OP_GTF,
	OP_GEF,

	//-------------------

	OP_LOAD1,
	OP_LOAD2,
	OP_LOAD4,
	OP_STORE1,
	OP_STORE2,
	OP_STORE4,				// *(stack[top-1]) = stack[top]
	OP_ARG,

	OP_BLOCK_COPY,

	//-------------------

	OP_SEX8,
	OP_SEX16,

	OP_NEGI,
	OP_ADD,
	OP_SUB,
	OP_DIVI,
	OP_DIVU,
	OP_MODI,
	OP_MODU,
	OP_MULI,
	OP_MULU,

	OP_BAND,
	OP_BOR,
	OP_BXOR,
	OP_BCOM,

	OP_LSH,
	OP_RSHI,
	OP_RSHU,

	OP_NEGF,
	OP_ADDF,
	OP_SUBF,
	OP_DIVF,
	OP_MULF,

	OP_CVIF,
	OP_CVFI
} opcode_t;


typedef struct vmSymbol_s {
	struct vmSymbol_s	*next;
	int		symValue;
	int		profileCount;
	char	symName[1];		// variable sized
} vmSymbol_t;

#define	VM_OFFSET_PROGRAM_STACK		0
#define	VM_OFFSET_SYSTEM_CALL		4

struct vm_s {
	// DO NOT MOVE OR CHANGE THESE WITHOUT CHANGING THE VM_OFFSET_* DEFINES
	// USED BY THE ASM CODE
	int			programStack;		// the vm may be recursively entered
	intptr_t	(*systemCall)( intptr_t *parms );

	//------------------------------------

	char		name[MAX_QPATH];

	// for dynamic linked modules
	void		*dllHandle;
	intptr_t	(QDECL *entryPoint)( int callNum, ... );
	void (*destroy)(vm_t* self);

	qbool	compiled;
	byte		*codeBase;
	int			codeLength;

	int			*instructionPointers;
	int			instructionPointersLength;

	byte		*dataBase;
	int			dataMask;

	int			numSymbols;
	vmSymbol_t	*symbols;

	int			stackBottom;		// if programStack < stackBottom, error
#if defined(NO_VM_COMPILED)
	int			callLevel;			// for debug indenting
	int			breakFunction;		// increment breakCount on function entry to this
	int			breakCount;
#endif

	byte		*jumpTableTargets;
	int			numJumpTableTargets;
};


#define	VM_MAGIC		0x12721444
#define	VM_MAGIC_VER2	0x12721445

typedef struct {
	int		vmMagic;

	int		instructionCount;

	int		codeOffset;
	int		codeLength;

	int		dataOffset;
	int		dataLength;
	int		litLength;			// ( dataLength - litLength ) should be byteswapped on load
	int		bssLength;			// zero filled memory appended to datalength

	//!!! below here is VM_MAGIC_VER2 !!!
	int		jtrgLength;			// number of jump table targets
} vmHeader_t;


extern	vm_t	*currentVM;
extern	int		vm_debugLevel;

void VM_Compile( vm_t* vm, const vmHeader_t* header );
int VM_CallCompiled( vm_t* vm, int* args );

#if defined(NO_VM_COMPILED)
void VM_PrepareInterpreter( vm_t* vm, const vmHeader_t* header );
int VM_CallInterpreted( vm_t *vm, int *args );
#endif

const char* VM_ValueToSymbol( const vm_t* vm, int value );
const vmSymbol_t* VM_ValueToFunctionSymbol( const vm_t* vm, int value );
void VM_LogSyscalls( int *args );

intptr_t VM_ArgPtr( intptr_t intValue );
intptr_t VM_ExplicitArgPtr( const vm_t* vm, intptr_t intValue );

static ID_INLINE float _vmf(intptr_t x)
{
	union {
		intptr_t l;
		float f;
	} t;
	t.l = x;
	return t.f;
}
#define VMF(x) _vmf(args[x])