/**

  * $Id$

  * 

  * Provides the implementation for the ia32 ABI (eg prologue, epilogue, and

  * calling conventions)

  *

  * 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.

  */

 #ifndef __lxdream_ia32abi_H

 #define __lxdream_ia32abi_H 1

 #define load_ptr( reg, ptr ) load_imm32( reg, (uint32_t)ptr );

 /**

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

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

  */

 #define CALL_FUNC0_SIZE 13

 static inline void call_func0( void *ptr )

 {

     int adj = (-sh4_x86.stack_posn)&0x0F;

     SUB_imm8s_r32( adj, R_ESP );

     load_imm32(R_EAX, (uint32_t)ptr);

     CALL_r32(R_EAX);

     ADD_imm8s_r32( adj, R_ESP );

 }

 #define CALL_FUNC1_SIZE 14

 static inline void call_func1( void *ptr, int arg1 )

 {

     int adj = (-4-sh4_x86.stack_posn)&0x0F;

     SUB_imm8s_r32( adj, R_ESP );

     PUSH_r32(arg1);

     load_imm32(R_EAX, (uint32_t)ptr);

     CALL_r32(R_EAX);

     ADD_imm8s_r32( adj+4, R_ESP );

     sh4_x86.stack_posn -= 4;

 }

 #define CALL_FUNC2_SIZE 15

 static inline void call_func2( void *ptr, int arg1, int arg2 )

 {

     int adj = (-8-sh4_x86.stack_posn)&0x0F;

     SUB_imm8s_r32( adj, R_ESP );

     PUSH_r32(arg2);

     PUSH_r32(arg1);

     load_imm32(R_EAX, (uint32_t)ptr);

     CALL_r32(R_EAX);

     ADD_imm8s_r32( adj+8, R_ESP );

     sh4_x86.stack_posn -= 8;

 }

 /**

  * Write a double (64-bit) value into memory, with the first word in arg2a, and

  * the second in arg2b

  * NB: 30 bytes

  */

 #define MEM_WRITE_DOUBLE_SIZE 36

 static inline void MEM_WRITE_DOUBLE( int addr, int arg2a, int arg2b )

 {

     int adj = (-8-sh4_x86.stack_posn)&0x0F;

     SUB_imm8s_r32( adj, R_ESP );

     ADD_imm8s_r32( 4, addr );

     PUSH_r32(arg2b);

     PUSH_r32(addr);

     ADD_imm8s_r32( -4, addr );

     SUB_imm8s_r32( 8, R_ESP );

     PUSH_r32(arg2a);

     PUSH_r32(addr);

     load_imm32(R_EAX, (uint32_t)sh4_write_long);

     CALL_r32(R_EAX);

     ADD_imm8s_r32( 16, R_ESP );

     load_imm32(R_EAX, (uint32_t)sh4_write_long);

     CALL_r32(R_EAX);

     ADD_imm8s_r32( adj+8, R_ESP );

     sh4_x86.stack_posn -= 16;

 }

 /**

  * Read a double (64-bit) value from memory, writing the first word into arg2a

  * and the second into arg2b. The addr must not be in EAX

  * NB: 27 bytes

  */

 #define MEM_READ_DOUBLE_SIZE 36

 static inline void MEM_READ_DOUBLE( int addr, int arg2a, int arg2b )

 {

     int adj = (-4-sh4_x86.stack_posn)&0x0F;

     int adj2 = (-8-sh4_x86.stack_posn)&0x0F;

     SUB_imm8s_r32( adj, R_ESP );

     PUSH_r32(addr);

     load_imm32(R_EAX, (uint32_t)sh4_read_long);

     CALL_r32(R_EAX);

     POP_r32(addr);

     SUB_imm8s_r32( adj2-adj, R_ESP );

     PUSH_r32(R_EAX);

     ADD_imm8s_r32( 4, addr );

     PUSH_r32(addr);

     load_imm32(R_EAX, (uint32_t)sh4_read_long);

     CALL_r32(R_EAX);

     ADD_imm8s_r32( 4, R_ESP );

     MOV_r32_r32( R_EAX, arg2b );

     POP_r32(arg2a);

     ADD_imm8s_r32( adj2, R_ESP );

     sh4_x86.stack_posn -= 4;

 }

 #define EXIT_BLOCK_SIZE 29

 /**

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

  * SI/DI as required

  */

 void sh4_translate_begin_block( sh4addr_t pc ) 

 {

     PUSH_r32(R_EBP);

     /* mov &sh4r, ebp */

     load_ptr( R_EBP, &sh4r );

     sh4_x86.in_delay_slot = FALSE;

     sh4_x86.priv_checked = FALSE;

     sh4_x86.fpuen_checked = FALSE;

     sh4_x86.branch_taken = FALSE;

     sh4_x86.backpatch_posn = 0;

     sh4_x86.block_start_pc = pc;

     sh4_x86.tstate = TSTATE_NONE;

     sh4_x86.stack_posn = 8;

 }

 /**

  * Exit the block with sh4r.pc already written

  * Bytes: 15

  */

 void exit_block_pcset( pc )

 {

     load_imm32( R_ECX, ((pc - sh4_x86.block_start_pc)>>1)*sh4_cpu_period ); // 5

     ADD_r32_sh4r( R_ECX, REG_OFFSET(slice_cycle) );    // 6

     load_spreg( R_EAX, REG_OFFSET(pc) );

     call_func1(xlat_get_code,R_EAX);

     POP_r32(R_EBP);

     RET();

 }

 /**

  * Exit the block to an absolute PC

  */

 void exit_block( sh4addr_t pc, sh4addr_t endpc )

 {

     load_imm32( R_ECX, pc );                            // 5

     store_spreg( R_ECX, REG_OFFSET(pc) );               // 3

     MOV_moff32_EAX( xlat_get_lut_entry(pc) ); // 5

     AND_imm8s_r32( 0xFC, R_EAX ); // 3

     load_imm32( R_ECX, ((endpc - sh4_x86.block_start_pc)>>1)*sh4_cpu_period ); // 5

     ADD_r32_sh4r( R_ECX, REG_OFFSET(slice_cycle) );     // 6

     POP_r32(R_EBP);

     RET();

 }

 /**

  * Write the block trailer (exception handling block)

  */

 void sh4_translate_end_block( sh4addr_t pc ) {

     if( sh4_x86.branch_taken == FALSE ) {

 	// Didn't exit unconditionally already, so write the termination here

 	exit_block( pc, pc );

     }

     if( sh4_x86.backpatch_posn != 0 ) {

 	unsigned int i;

 	// Raise exception

 	uint8_t *end_ptr = xlat_output;

 	load_spreg( R_ECX, REG_OFFSET(pc) );

 	ADD_r32_r32( R_EDX, R_ECX );

 	ADD_r32_r32( R_EDX, R_ECX );

 	store_spreg( R_ECX, REG_OFFSET(pc) );

 	MOV_moff32_EAX( &sh4_cpu_period );

 	MUL_r32( R_EDX );

 	ADD_r32_sh4r( R_EAX, REG_OFFSET(slice_cycle) );

         POP_r32(R_EDX);

         call_func1( sh4_raise_exception, R_EDX );

 	load_spreg( R_EAX, REG_OFFSET(pc) );

 	call_func1(xlat_get_code,R_EAX);

 	POP_r32(R_EBP);

 	RET();

 	// Exception already raised - just cleanup

 	uint8_t *preexc_ptr = xlat_output;

 	load_imm32( R_ECX, sh4_x86.block_start_pc );

 	ADD_r32_r32( R_EDX, R_ECX );

 	ADD_r32_r32( R_EDX, R_ECX );

 	store_spreg( R_ECX, REG_OFFSET(spc) );

 	MOV_moff32_EAX( &sh4_cpu_period );

 	MUL_r32( R_EDX );

 	ADD_r32_sh4r( R_EAX, REG_OFFSET(slice_cycle) );

 	load_spreg( R_EAX, REG_OFFSET(pc) );

 	call_func1(xlat_get_code,R_EAX);

 	POP_r32(R_EBP);

 	RET();

 	for( i=0; i< sh4_x86.backpatch_posn; i++ ) {

 	    *sh4_x86.backpatch_list[i].fixup_addr =

 		xlat_output - ((uint8_t *)sh4_x86.backpatch_list[i].fixup_addr) - 4;

 	    if( sh4_x86.backpatch_list[i].exc_code == -1 ) {

 		load_imm32( R_EDX, sh4_x86.backpatch_list[i].fixup_icount );

 		int rel = preexc_ptr - xlat_output;

 		JMP_rel(rel);

 	    } else {

 		PUSH_imm32( sh4_x86.backpatch_list[i].exc_code );

 		load_imm32( R_EDX, sh4_x86.backpatch_list[i].fixup_icount );

 		int rel = end_ptr - xlat_output;

 		JMP_rel(rel);

 	    }

 	}

     }

 }

 #endif