text: /*
              Copyright Oliver Kowalke 2009.
     Distributed under the Boost Software License, Version 1.0.
        (See accompanying file LICENSE_1_0.txt or copy at
            http://www.boost.org/LICENSE_1_0.txt)
  */
  
  /****************************************************************************************
   *                                                                                      *
   *  ----------------------------------------------------------------------------------  *
   *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
   *  ----------------------------------------------------------------------------------  *
   *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
   *  ----------------------------------------------------------------------------------  *
   *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |    to   |  *
   *  ----------------------------------------------------------------------------------  *
   *  ----------------------------------------------------------------------------------  *
   *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
   *  ----------------------------------------------------------------------------------  *
   *  |   0x20  |                                                                      |  *
   *  ----------------------------------------------------------------------------------  *
   *  |   data  |                                                                      |  *
   *  ----------------------------------------------------------------------------------  *
   *                                                                                      *
   ****************************************************************************************/
  
  .text
  .globl _copp_jump_fcontext
  .align 2
  _copp_jump_fcontext:
      leal  -0x18(%esp), %esp  /* prepare stack */
  
  #if !defined(LIBCOPP_FCONTEXT_USE_TSX)
      stmxcsr  (%esp)     /* save MMX control- and status-word */
      fnstcw   0x4(%esp)  /* save x87 control-word */
  #endif
  
      movl  %edi, 0x8(%esp)  /* save EDI */
      movl  %esi, 0xc(%esp)  /* save ESI */
      movl  %ebx, 0x10(%esp)  /* save EBX */
      movl  %ebp, 0x14(%esp)  /* save EBP */
  
      /* store ESP (pointing to context-data) in ECX */
      movl  %esp, %ecx
  
      /* first arg of copp_jump_fcontext() == fcontext to jump to */
      movl  0x1c(%esp), %eax
  
      /* second arg of copp_jump_fcontext() == data to be transferred */
      movl  0x20(%esp), %edx
  
      /* restore ESP (pointing to context-data) from EAX */
      movl  %eax, %esp
  
      /* return parent fcontext_t */
      movl  %ecx, %eax
      /* returned data is stored in EDX */ 
   
      movl  0x18(%esp), %ecx  /* restore EIP */
  
  #if !defined(LIBCOPP_FCONTEXT_USE_TSX)
      ldmxcsr  (%esp)     /* restore MMX control- and status-word */
      fldcw    0x4(%esp)  /* restore x87 control-word */
  #endif
  
      movl  0x8(%esp), %edi  /* restore EDI */
      movl  0xc(%esp), %esi  /* restore ESI */
      movl  0x10(%esp), %ebx  /* restore EBX */
      movl  0x14(%esp), %ebp  /* restore EBP */
  
      leal  0x1c(%esp), %esp  /* prepare stack */
  
      /* jump to context */
      jmp *%ecx
  