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GB: Optimize cpuLoad8

This commit is contained in:
Jeffrey Pfau 2016-02-22 21:39:05 -08:00
parent 3b24e94018
commit 05ef05317c
3 changed files with 37 additions and 3 deletions
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36
src/gb/memory.c
View File

@ -33,8 +33,40 @@ static void _GBMBC7(struct GBMemory*, uint16_t address, uint8_t value);
static uint8_t _GBMBC7Read(struct GBMemory*, uint16_t address);
static void _GBMBC7Write(struct GBMemory*, uint16_t address, uint8_t value);
static uint8_t GBFastLoad8(struct LR35902Core* cpu, uint16_t address) {
if (UNLIKELY(address > cpu->memory.activeRegionEnd)) {
cpu->memory.setActiveRegion(cpu, address);
return cpu->memory.cpuLoad8(cpu, address);
}
return cpu->memory.activeRegion[address & cpu->memory.activeMask];
}
static void GBSetActiveRegion(struct LR35902Core* cpu, uint16_t address) {
// TODO
struct GB* gb = (struct GB*) cpu->master;
struct GBMemory* memory = &gb->memory;
switch (address >> 12) {
case GB_REGION_CART_BANK0:
case GB_REGION_CART_BANK0 + 1:
case GB_REGION_CART_BANK0 + 2:
case GB_REGION_CART_BANK0 + 3:
cpu->memory.cpuLoad8 = GBFastLoad8;
cpu->memory.activeRegion = memory->rom;
cpu->memory.activeRegionEnd = GB_BASE_CART_BANK1;
cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
break;
case GB_REGION_CART_BANK1:
case GB_REGION_CART_BANK1 + 1:
case GB_REGION_CART_BANK1 + 2:
case GB_REGION_CART_BANK1 + 3:
cpu->memory.cpuLoad8 = GBFastLoad8;
cpu->memory.activeRegion = memory->romBank;
cpu->memory.activeRegionEnd = GB_BASE_VRAM;
cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
break;
default:
cpu->memory.cpuLoad8 = GBLoad8;
break;
}
}
static void _GBMemoryDMAService(struct GB* gb);
@ -235,6 +267,7 @@ void GBStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
case GB_REGION_CART_BANK1 + 2:
case GB_REGION_CART_BANK1 + 3:
memory->mbc(memory, address, value);
cpu->memory.setActiveRegion(cpu, cpu->pc);
return;
case GB_REGION_VRAM:
case GB_REGION_VRAM + 1:
@ -304,6 +337,7 @@ void GBMemoryDMA(struct GB* gb, uint16_t base) {
}
gb->cpu->memory.store8 = GBDMAStore8;
gb->cpu->memory.load8 = GBDMALoad8;
gb->cpu->memory.cpuLoad8 = GBDMALoad8;
gb->memory.dmaNext = gb->cpu->cycles + 8;
if (gb->memory.dmaNext < gb->cpu->nextEvent) {
gb->cpu->nextEvent = gb->memory.dmaNext;

2
src/lr35902/lr35902.c
View File

@ -129,7 +129,7 @@ static void _LR35902Step(struct LR35902Core* cpu) {
cpu->memory.store8(cpu, cpu->index, cpu->bus);
break;
case LR35902_CORE_READ_PC:
cpu->bus = cpu->memory.load8(cpu, cpu->pc);
cpu->bus = cpu->memory.cpuLoad8(cpu, cpu->pc);
++cpu->pc;
break;
case LR35902_CORE_STALL:

2
src/lr35902/lr35902.h
View File

@ -47,7 +47,6 @@ enum LR35902ExecutionState {
LR35902_CORE_STALL = 19,
LR35902_CORE_OP2 = 23
};
struct LR35902Memory {
uint8_t (*cpuLoad8)(struct LR35902Core*, uint16_t address);
uint8_t (*load8)(struct LR35902Core*, uint16_t address);
@ -55,6 +54,7 @@ struct LR35902Memory {
uint8_t* activeRegion;
uint16_t activeMask;
uint16_t activeRegionEnd;
void (*setActiveRegion)(struct LR35902Core*, uint16_t address);
};