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use less variables

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This commit is contained in:
Gwenhael Le Moine 2024-09-11 14:15:57 +02:00
parent 780de5f458
commit 901ec9d8f4
No known key found for this signature in database
GPG key ID: FDFE3669426707A7
1 changed files with 31 additions and 43 deletions
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74
src/emu_emulate.c
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@ -206,10 +206,7 @@ static inline void add_address( word_20* dat, int add )
{ {
*dat += add; *dat += add;
if ( *dat & ( word_20 )0xfff00000 ) saturn.CARRY = ( *dat & ( word_20 )0xfff00000 ) ? 1 : 0;
saturn.CARRY = 1;
else
saturn.CARRY = 0;
*dat &= 0xfffff; *dat &= 0xfffff;
} }
@ -257,8 +254,8 @@ static bool step_instruction_00e( void )
bool illegal_instruction = false; bool illegal_instruction = false;
int op2 = read_nibble( saturn.PC + 2 ); int op2 = read_nibble( saturn.PC + 2 );
int op3 = read_nibble( saturn.PC + 3 );
switch ( op3 ) { switch ( read_nibble( saturn.PC + 3 ) ) {
case 0: /* A=A&B */ case 0: /* A=A&B */
saturn.PC += 4; saturn.PC += 4;
and_register( saturn.A, saturn.A, saturn.B, op2 ); and_register( saturn.A, saturn.A, saturn.B, op2 );
@ -334,8 +331,7 @@ static bool step_instruction_00( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op1 = read_nibble( saturn.PC + 1 ); switch ( read_nibble( saturn.PC + 1 ) ) {
switch ( op1 ) {
case 0: /* RTNSXM */ case 0: /* RTNSXM */
saturn.XM = 1; saturn.XM = 1;
saturn.PC = pop_return_addr(); saturn.PC = pop_return_addr();
@ -449,8 +445,7 @@ static bool step_instruction_010( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 2 ); switch ( read_nibble( saturn.PC + 2 ) ) {
switch ( op3 ) {
case 0: /* saturn.R0=A */ case 0: /* saturn.R0=A */
saturn.PC += 3; saturn.PC += 3;
copy_register( saturn.R0, saturn.A, W_FIELD ); copy_register( saturn.R0, saturn.A, W_FIELD );
@ -508,8 +503,7 @@ static bool step_instruction_011( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 2 ); switch ( read_nibble( saturn.PC + 2 ) ) {
switch ( op3 ) {
case 0: /* A=R0 */ case 0: /* A=R0 */
saturn.PC += 3; saturn.PC += 3;
copy_register( saturn.A, saturn.R0, W_FIELD ); copy_register( saturn.A, saturn.R0, W_FIELD );
@ -567,8 +561,7 @@ static bool step_instruction_012( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 2 ); switch ( read_nibble( saturn.PC + 2 ) ) {
switch ( op3 ) {
case 0: /* AR0EX */ case 0: /* AR0EX */
saturn.PC += 3; saturn.PC += 3;
exchange_register( saturn.A, saturn.R0, W_FIELD ); exchange_register( saturn.A, saturn.R0, W_FIELD );
@ -626,8 +619,7 @@ static bool step_instruction_013( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 2 ); switch ( read_nibble( saturn.PC + 2 ) ) {
switch ( op3 ) {
case 0: /* D0=A */ case 0: /* D0=A */
saturn.PC += 3; saturn.PC += 3;
register_to_address( saturn.A, &saturn.D0, 0 ); register_to_address( saturn.A, &saturn.D0, 0 );
@ -833,10 +825,9 @@ static bool step_instruction_015( void )
static bool step_instruction_01( void ) static bool step_instruction_01( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op2 = read_nibble( saturn.PC + 1 );
int op3; int op3;
switch ( op2 ) { switch ( read_nibble( saturn.PC + 1 ) ) {
case 0: case 0:
illegal_instruction = step_instruction_010(); illegal_instruction = step_instruction_010();
break; break;
@ -1011,10 +1002,7 @@ static bool step_instruction_08a( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op2 = read_nibble( saturn.PC + 2 ); switch ( read_nibble( saturn.PC + 2 ) ) {
int op3;
switch ( op2 ) {
case 0: /* ?A=B */ case 0: /* ?A=B */
saturn.CARRY = is_equal_register( saturn.A, saturn.B, A_FIELD ); saturn.CARRY = is_equal_register( saturn.A, saturn.B, A_FIELD );
break; break;
@ -1068,7 +1056,9 @@ static bool step_instruction_08a( void )
} }
if ( saturn.CARRY ) { if ( saturn.CARRY ) {
saturn.PC += 3; saturn.PC += 3;
op3 = read_nibbles( saturn.PC, 2 );
int op3 = read_nibbles( saturn.PC, 2 );
if ( op3 ) { if ( op3 ) {
if ( op3 & 0x80 ) if ( op3 & 0x80 )
op3 |= jumpmasks[ 2 ]; op3 |= jumpmasks[ 2 ];
@ -1179,10 +1169,9 @@ static bool step_instruction_080( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 2 );
int op4; int op4;
switch ( op3 ) { switch ( read_nibble( saturn.PC + 2 ) ) {
case 0: /* OUT=CS */ case 0: /* OUT=CS */
saturn.PC += 3; saturn.PC += 3;
copy_register( saturn.OUT, saturn.C, OUTS_FIELD ); copy_register( saturn.OUT, saturn.C, OUTS_FIELD );
@ -1437,8 +1426,9 @@ static bool step_instruction_0818( void )
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 3 ); int op3 = read_nibble( saturn.PC + 3 );
int op4 = read_nibble( saturn.PC + 4 );
int op5 = read_nibble( saturn.PC + 5 ); int op5 = read_nibble( saturn.PC + 5 );
int op4 = read_nibble( saturn.PC + 4 );
if ( op4 < 8 ) { /* PLUS */ if ( op4 < 8 ) { /* PLUS */
switch ( op4 & 3 ) { switch ( op4 & 3 ) {
case 0: /* A=A+CON */ case 0: /* A=A+CON */
@ -1520,9 +1510,8 @@ static bool step_instruction_081a0( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 3 ); int op3 = read_nibble( saturn.PC + 3 );
int op5 = read_nibble( saturn.PC + 5 );
switch ( op5 ) { switch ( read_nibble( saturn.PC + 5 ) ) {
case 0: /* saturn.R0=A */ case 0: /* saturn.R0=A */
saturn.PC += 6; saturn.PC += 6;
copy_register( saturn.R0, saturn.A, op3 ); copy_register( saturn.R0, saturn.A, op3 );
@ -1580,9 +1569,8 @@ static bool step_instruction_081a1( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 3 ); int op3 = read_nibble( saturn.PC + 3 );
int op5 = read_nibble( saturn.PC + 5 );
switch ( op5 ) { switch ( read_nibble( saturn.PC + 5 ) ) {
case 0: /* A=R0 */ case 0: /* A=R0 */
saturn.PC += 6; saturn.PC += 6;
copy_register( saturn.A, saturn.R0, op3 ); copy_register( saturn.A, saturn.R0, op3 );
@ -1640,9 +1628,8 @@ static bool step_instruction_081a2( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 3 ); int op3 = read_nibble( saturn.PC + 3 );
int op5 = read_nibble( saturn.PC + 5 );
switch ( op5 ) { switch ( read_nibble( saturn.PC + 5 ) ) {
case 0: /* AR0EX */ case 0: /* AR0EX */
saturn.PC += 6; saturn.PC += 6;
exchange_register( saturn.A, saturn.R0, op3 ); exchange_register( saturn.A, saturn.R0, op3 );
@ -1700,8 +1687,7 @@ static bool step_instruction_081a( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op4 = read_nibble( saturn.PC + 4 ); switch ( read_nibble( saturn.PC + 4 ) ) {
switch ( op4 ) {
case 0: case 0:
illegal_instruction = step_instruction_081a0(); illegal_instruction = step_instruction_081a0();
break; break;
@ -1721,9 +1707,8 @@ static bool step_instruction_081a( void )
static bool step_instruction_081b( void ) static bool step_instruction_081b( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op3 = read_nibble( saturn.PC + 3 );
switch ( op3 ) { switch ( read_nibble( saturn.PC + 3 ) ) {
case 2: /* PC=A */ case 2: /* PC=A */
saturn.PC = dat_to_addr( saturn.A ); saturn.PC = dat_to_addr( saturn.A );
break; break;
@ -1758,9 +1743,8 @@ static bool step_instruction_081b( void )
static bool step_instruction_081( void ) static bool step_instruction_081( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op2 = read_nibble( saturn.PC + 2 );
switch ( op2 ) { switch ( read_nibble( saturn.PC + 2 ) ) {
case 0: /* ASLC */ case 0: /* ASLC */
saturn.PC += 3; saturn.PC += 3;
shift_left_circ_register( saturn.A, W_FIELD ); shift_left_circ_register( saturn.A, W_FIELD );
@ -1832,10 +1816,7 @@ static bool step_instruction_08b( void )
{ {
bool illegal_instruction = false; bool illegal_instruction = false;
int op2 = read_nibble( saturn.PC + 2 ); switch ( read_nibble( saturn.PC + 2 ) ) {
int op3;
switch ( op2 ) {
case 0: /* ?A>B */ case 0: /* ?A>B */
saturn.CARRY = is_greater_register( saturn.A, saturn.B, A_FIELD ); saturn.CARRY = is_greater_register( saturn.A, saturn.B, A_FIELD );
break; break;
@ -1889,7 +1870,9 @@ static bool step_instruction_08b( void )
} }
if ( saturn.CARRY ) { if ( saturn.CARRY ) {
saturn.PC += 3; saturn.PC += 3;
op3 = read_nibbles( saturn.PC, 2 );
int op3 = read_nibbles( saturn.PC, 2 );
if ( op3 ) { if ( op3 ) {
if ( op3 & 0x80 ) if ( op3 & 0x80 )
op3 |= jumpmasks[ 2 ]; op3 |= jumpmasks[ 2 ];
@ -2039,6 +2022,7 @@ static bool step_instruction_09( void )
bool illegal_instruction = false; bool illegal_instruction = false;
int op1 = read_nibble( saturn.PC + 1 ); int op1 = read_nibble( saturn.PC + 1 );
int op2 = read_nibble( saturn.PC + 2 ); int op2 = read_nibble( saturn.PC + 2 );
if ( op1 < 8 ) { if ( op1 < 8 ) {
switch ( op2 ) { switch ( op2 ) {
case 0: /* ?A=B */ case 0: /* ?A=B */
@ -2149,7 +2133,9 @@ static bool step_instruction_09( void )
} }
if ( saturn.CARRY ) { if ( saturn.CARRY ) {
saturn.PC += 3; saturn.PC += 3;
int op3 = read_nibbles( saturn.PC, 2 ); int op3 = read_nibbles( saturn.PC, 2 );
if ( op3 ) { if ( op3 ) {
if ( op3 & 0x80 ) if ( op3 & 0x80 )
op3 |= jumpmasks[ 2 ]; op3 |= jumpmasks[ 2 ];
@ -2169,6 +2155,7 @@ static bool step_instruction_0a( void )
bool illegal_instruction = false; bool illegal_instruction = false;
int op1 = read_nibble( saturn.PC + 1 ); int op1 = read_nibble( saturn.PC + 1 );
int op2 = read_nibble( saturn.PC + 2 ); int op2 = read_nibble( saturn.PC + 2 );
if ( op1 < 8 ) { if ( op1 < 8 ) {
switch ( op2 ) { switch ( op2 ) {
case 0: /* A=A+B */ case 0: /* A=A+B */
@ -2318,6 +2305,7 @@ static bool step_instruction_0b( void )
bool illegal_instruction = false; bool illegal_instruction = false;
int op1 = read_nibble( saturn.PC + 1 ); int op1 = read_nibble( saturn.PC + 1 );
int op2 = read_nibble( saturn.PC + 2 ); int op2 = read_nibble( saturn.PC + 2 );
if ( op1 < 8 ) { if ( op1 < 8 ) {
switch ( op2 ) { switch ( op2 ) {
case 0: /* A=A-B */ case 0: /* A=A-B */