/**

 * $Id$

 * 

 * Provides the implementation for the ia32 ABI variant 

 * (eg prologue, epilogue, and calling conventions). Stack frame is

 * aligned on 16-byte boundaries for the benefit of OS X (which 

 * requires it).

 * 

 * Note: These should only be included from x86op.h

 *

 * Copyright (c) 2007 Nathan Keynes.

 *

 * 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.

 */

#define REG_ARG1 REG_EAX

#define REG_ARG2 REG_EDX

#define REG_ARG3 REG_ECX

#define REG_RESULT1 REG_EAX

#define MAX_REG_ARG 3

#define REG_SAVE1 REG_ESI

#define REG_SAVE2 REG_EDI

#define REG_CALLPTR REG_EBX

static inline void decode_address( uintptr_t base, int addr_reg, int target_reg )

{

    MOVL_r32_r32( addr_reg, target_reg );

    SHRL_imm_r32( 12, target_reg );

    MOVP_sib_rptr( 2, target_reg, -1, base, target_reg );

}

/**

 * Note: clobbers ECX to make the indirect call - this isn't usually

 * a problem since the callee will generally clobber it anyway.

 */

static inline void CALL_ptr( void *ptr )

{

    MOVP_immptr_rptr( (uintptr_t)ptr, REG_ECX );

    CALL_r32(REG_ECX);

}

#ifdef HAVE_FASTCALL

#define CALL1_PTR_MIN_SIZE 7

static inline void CALL1_ptr_r32( void *ptr, int arg1 )

{

    if( arg1 != REG_ARG1 ) {

        MOVL_r32_r32( arg1, REG_ARG1 );

    }

    CALL_ptr(ptr);

}

static inline void CALL1_r32disp_r32( int preg, uint32_t disp, int arg1 )

{

    if( arg1 != REG_ARG1 ) {

        MOVL_r32_r32( arg1, REG_ARG1 );

    }

    CALL_r32disp(preg, disp);

}

static inline void CALL2_ptr_r32_r32( void *ptr, int arg1, int arg2 )

{

    if( arg2 != REG_ARG2 ) {

        MOVL_r32_r32( arg2, REG_ARG2 );

    }

    if( arg1 != REG_ARG1 ) {

        MOVL_r32_r32( arg1, REG_ARG1 );

    }

    CALL_ptr(ptr);

}

static inline void CALL2_r32disp_r32_r32( int preg, uint32_t disp, int arg1, int arg2 )

{

    if( arg2 != REG_ARG2 ) {

        MOVL_r32_r32( arg2, REG_ARG2 );

    }

    if( arg1 != REG_ARG1 ) {

        MOVL_r32_r32( arg1, REG_ARG1 );

    }

    CALL_r32disp(preg, disp);

}

static inline void CALL3_r32disp_r32_r32_r32( int preg, uint32_t disp, int arg1, int arg2, int arg3)

{

    if( arg3 != REG_ARG3 ) {

        MOVL_r32_r32( arg3, REG_ARG3 );

    }

    if( arg2 != REG_ARG2 ) {

        MOVL_r32_r32( arg2, REG_ARG2 );

    }

    if( arg1 != REG_ARG1 ) {

        MOVL_r32_r32( arg1, REG_ARG1 );

    }

    CALL_r32disp(preg, disp);

}

#else

#define CALL1_PTR_MIN_SIZE (3+1+7+3)

static inline void CALL1_ptr_r32( void *ptr, int arg1 )

{

    SUBL_imms_r32( 12, REG_ESP );

    PUSH_r32(arg1);

    CALL_ptr(ptr);

    ADDL_imms_r32( 16, REG_ESP );

}

static inline void CALL1_r32disp_r32( int preg, uint32_t disp, int arg1 )

{

    SUBL_imms_r32( 12, REG_ESP );

    PUSH_r32(arg1);

    CALL_r32disp(preg, disp);

    ADDL_imms_r32( 16, REG_ESP );

}

static inline void CALL2_ptr_r32_r32( void *ptr, int arg1, int arg2 )

{

    SUBL_imms_r32( 8, REG_ESP );

    PUSH_r32(arg2);

    PUSH_r32(arg1);

    CALL_ptr(ptr);

    ADDL_imms_r32( 16, REG_ESP );

}

static inline void CALL2_r32disp_r32_r32( int preg, uint32_t disp, int arg1, int arg2 )

{

    SUBL_imms_r32( 8, REG_ESP );

    PUSH_r32(arg2);

    PUSH_r32(arg1);

    CALL_r32disp(preg, disp);

    ADDL_imms_r32( 16, REG_ESP );

}

static inline void CALL3_r32disp_r32_r32_r32( int preg, uint32_t disp, int arg1, int arg2, int arg3 )

{

    SUBL_imms_r32( 8, REG_ESP );

    PUSH_r32(arg2);

    PUSH_r32(arg1);

    MOVL_rspdisp_r32( 16, REG_EAX );

    MOVL_r32_rspdisp( REG_EAX, 8 );

    CALL_r32disp(preg,disp);

    ADDL_imms_r32( 16, REG_ESP );

}

#endif

#define PROLOGUE_SIZE 9

/**

 * Emit the 'start of block' assembly. Sets up the stack frame and save

 * SI/DI as required

 * Allocates 8 bytes for local variables, which also has the convenient

 * side-effect of aligning the stack.

 */

static inline void emit_prologue( )

{

    PUSH_r32(REG_EBP);

    SUBL_imms_r32( 8, REG_ESP ); 

    MOVP_immptr_rptr( ((uint8_t *)&sh4r) + 128, REG_EBP );

}

static inline void emit_epilogue( )

{

    ADDL_imms_r32( 8, REG_ESP );

    POP_r32(REG_EBP);

}