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- Speed optimization: It is unlikely that one would poke I/O address space with indexed memory access, so those no need to check

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This commit is contained in:
Tamas Rudnai 2019-09-11 19:08:55 -07:00
parent 80d6190fa1
commit 08327ef0a4
1 changed files with 10 additions and 9 deletions
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19
A2Mac/Apple2_mmio.h
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@ -139,15 +139,16 @@ static inline uint8_t memread( uint16_t addr ) {
return RAM[ addr ]; return RAM[ addr ];
} }
/**
Naive implementation of RAM read from address
**/
static inline uint8_t memread8( uint16_t addr ) {
return RAM[ addr ];
}
/** /**
Naive implementation of RAM read from address Naive implementation of RAM read from address
**/ **/
static inline uint16_t memread16( uint16_t addr ) { static inline uint16_t memread16( uint16_t addr ) {
// if ( ( addr >= 0xC000 ) && ( addr < 0xD000 ) ) {
// return mmioRead(addr);
// }
// dbgPrintf("%04X ", * (uint16_t*) (& RAM[ addr ]));
return * (uint16_t*) (& RAM[ addr ]); return * (uint16_t*) (& RAM[ addr ]);
} }
@ -237,7 +238,7 @@ static inline uint16_t addr_abs_X() {
return fetch16() + m6502.X; return fetch16() + m6502.X;
} }
static inline uint8_t src_abs_X() { static inline uint8_t src_abs_X() {
return memread( addr_abs_X() ); return memread8( addr_abs_X() );
} }
static inline uint8_t * dest_abs_X() { static inline uint8_t * dest_abs_X() {
return & RAM[ addr_abs_X() ]; return & RAM[ addr_abs_X() ];
@ -252,7 +253,7 @@ static inline uint16_t addr_abs_Y() {
return abs_addr() + m6502.Y; return abs_addr() + m6502.Y;
} }
static inline uint8_t src_abs_Y() { static inline uint8_t src_abs_Y() {
return memread(addr_abs_Y()); return memread8(addr_abs_Y());
} }
static inline uint8_t * dest_abs_Y() { static inline uint8_t * dest_abs_Y() {
return & RAM[ addr_abs_Y() ]; return & RAM[ addr_abs_Y() ];
@ -293,7 +294,7 @@ static inline uint16_t addr_X_ind() {
return addr_zp_ind( addr_zp() + m6502.X ); return addr_zp_ind( addr_zp() + m6502.X );
} }
static inline uint8_t src_X_ind() { static inline uint8_t src_X_ind() {
return memread( addr_X_ind() ); return memread8( addr_X_ind() );
} }
static inline uint8_t * dest_X_ind() { static inline uint8_t * dest_X_ind() {
return & RAM[ addr_X_ind() ]; return & RAM[ addr_X_ind() ];
@ -310,7 +311,7 @@ static inline uint16_t addr_ind_Y() {
return addr_zp_ind( addr_zp() ) + m6502.Y; return addr_zp_ind( addr_zp() ) + m6502.Y;
} }
static inline uint8_t src_ind_Y() { static inline uint8_t src_ind_Y() {
return memread( addr_ind_Y() ); return memread8( addr_ind_Y() );
} }
static inline uint8_t * dest_ind_Y() { static inline uint8_t * dest_ind_Y() {
return & RAM[ addr_ind_Y() ]; return & RAM[ addr_ind_Y() ];