/**

  * $Id: sh4x86.in,v 1.20 2007-11-08 11:54:16 nkeynes Exp $

  * 

  * 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 7

 static inline void call_func0( void *ptr )

 {

     load_imm32(R_EAX, (uint32_t)ptr);

     CALL_r32(R_EAX);

 }

 #define CALL_FUNC1_SIZE 11

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

 {

     PUSH_r32(arg1);

     call_func0(ptr);

     ADD_imm8s_r32( 4, R_ESP );

 }

 #define CALL_FUNC2_SIZE 12

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

 {

     PUSH_r32(arg2);

     PUSH_r32(arg1);

     call_func0(ptr);

     ADD_imm8s_r32( 8, R_ESP );

 }

 /**

  * 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 30

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

 {

     ADD_imm8s_r32( 4, addr );

     PUSH_r32(arg2b);

     PUSH_r32(addr);

     ADD_imm8s_r32( -4, addr );

     PUSH_r32(arg2a);

     PUSH_r32(addr);

     call_func0(sh4_write_long);

     ADD_imm8s_r32( 8, R_ESP );

     call_func0(sh4_write_long);

     ADD_imm8s_r32( 8, R_ESP );

 }

 /**

  * 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 27

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

 {

     PUSH_r32(addr);

     call_func0(sh4_read_long);

     POP_r32(addr);

     PUSH_r32(R_EAX);

     ADD_imm8s_r32( 4, addr );

     PUSH_r32(addr);

     call_func0(sh4_read_long);

     ADD_imm8s_r32( 4, R_ESP );

     MOV_r32_r32( R_EAX, arg2b );

     POP_r32(arg2a);

 }

 #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;

 #ifdef STACK_ALIGN

 	sh4_x86.stack_posn = 8;

 #endif

 }

 /**

  * 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 ) {

 	uint8_t *end_ptr = xlat_output;

 	// Exception termination. Jump block for various exception codes:

 	PUSH_imm32( EXC_DATA_ADDR_READ );

 	JMP_rel8( 33, target1 );

 	PUSH_imm32( EXC_DATA_ADDR_WRITE );

 	JMP_rel8( 26, target2 );

 	PUSH_imm32( EXC_ILLEGAL );

 	JMP_rel8( 19, target3 );

 	PUSH_imm32( EXC_SLOT_ILLEGAL ); 

 	JMP_rel8( 12, target4 );

 	PUSH_imm32( EXC_FPU_DISABLED ); 

 	JMP_rel8( 5, target5 );

 	PUSH_imm32( EXC_SLOT_FPU_DISABLED );

 	// target

 	JMP_TARGET(target1);

 	JMP_TARGET(target2);

 	JMP_TARGET(target3);

 	JMP_TARGET(target4);

 	JMP_TARGET(target5);

 	// Raise exception

 	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) );

 	call_func0( sh4_raise_exception );

 	ADD_imm8s_r32( 4, R_ESP );

 	load_spreg( R_EAX, REG_OFFSET(pc) );

 	call_func1(xlat_get_code,R_EAX);

 	POP_r32(R_EBP);

 	RET();

 	sh4_x86_do_backpatch( end_ptr );

     }

 }

 #endif