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/* rec_i386.h -- i386 specific parts of the recompile engine

   Copyright (C) 2005 György `nog' Jeney, nog@sdf.lonestar.org

This file is part of OpenRISC 1000 Architectural Simulator.

This program 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.

This program 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 this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include "common_i386.h"

extern void *rec_stack_base;

/* Sets the stack to a specified value */

static inline void or_longjmp(void *loc) __attribute__((noreturn));

static inline void or_longjmp(void *loc)

{

  /* We push a trampoline address (dyn_ret_stack_prot) onto the stack to be able

   * to detect if any ret instructions found their way into an operation. */

  asm("\tmovl %0, %%eax\n"

      "\tmovl %1, %%esp\n"

      "\tmovl $%2, %%ebp\n"

      "\tpush $dyn_ret_stack_prot\n"

      "\tpush $dyn_ret_stack_prot\n"

      "\tpush $dyn_ret_stack_prot\n"

      "\tjmp *%%eax\n"

      :

      : "m" (loc),

        "m" (rec_stack_base),

        "m" (cpu_state));

}

/* Initialises the recompiler (architechture specific). */

static inline void init_dyn_rec(void)

{

  uint64_t add = UINT32_C(-1) | UINT64_C(4) << 32;

  /* Initialises the scheduler handling for future use.  Because the x86 has a

   * very low number of registers (8), I have to use MMX registers.  I could do

   * load/store combination but that takes up space and is slow.  I use packed

   * doublewords to strut my stuff.  The high 32-bits of the first MMX register

   * is the PC, the low 32-bits is the number of cycles that are still

   * outstanding for the next scheduled job to run.  The second MMX register

   * holds the amount that needs to be added to the two values on each cycle.

   * The third MMX register only holds the value that we must use to update the

   * low 32-bits with */

   asm volatile ("movq %0, %%mm1\n"

                 : : "m" (add));

}

/* Gets the current stack pointer */

static inline void *get_sp(void)

{

  void *stack;

  asm("movl %%esp, %0" : "=rm" (stack));

  return stack;

}

/* Updates the number of cycles that it takes to load 1 instruction */

static inline void upd_cycles_dec(int32_t amount)

{

  useless_x86.val3232.high32 = 4;

  useless_x86.val3232.low32 = amount;

  asm volatile ("movq %0, %%mm1" : : "m" (useless_x86.val64));

}

/* Adds the number of cycles to the next job that would be added anyway */

static inline void sched_add_cycles(void)

{

  asm("movd %%mm1, %%eax\n"

      "\tmovd %%eax, %%mm2\n"

      "paddd %%mm2, %%mm0"

      : : : "eax");

}

/* Adds an arbitary amount to the cycle counter */

static inline void add_to_cycles(int32_t val)

{

  val = -val;

  asm("movd %0, %%mm2\n"

      "paddd %%mm2, %%mm0\n"

      : : "rm" (val));

}