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Contorts somewhat in pursuit of branchless shadowing regardless of page and without extra storage.

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This commit is contained in:
Thomas Harte 2020-10-27 21:37:39 -04:00
parent bdda84dfde
commit 20631a157b
1 changed files with 15 additions and 16 deletions
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31
Machines/Apple/AppleIIgs/MemoryMap.hpp
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@ -27,7 +27,7 @@ class MemoryMap {
void set_storage(std::vector<uint8_t> &ram, std::vector<uint8_t> &rom) {
// Keep a pointer for later; also note the proper RAM offset.
ram_ = ram.data();
ram_base = ram.data();
shadow_offset = ram.size() - (128*1024);
// Establish bank mapping.
@ -209,7 +209,6 @@ class MemoryMap {
Apple::II::LanguageCardSwitches<MemoryMap> language_card_;
friend Apple::II::AuxiliaryMemorySwitches<MemoryMap>;
friend Apple::II::LanguageCardSwitches<MemoryMap>;
uint8_t *ram_ = nullptr;
uint8_t shadow_register_ = 0x08;
uint8_t speed_register_ = 0x00;
@ -245,20 +244,20 @@ class MemoryMap {
};
auto set_no_card = [this](uint32_t bank_base) {
auto &d0_region = regions[region_map[bank_base | 0xd0]];
d0_region.read = ram_;
d0_region.write = ram_;
d0_region.read = ram_base;
d0_region.write = ram_base;
auto &e0_region = regions[region_map[bank_base | 0xe0]];
e0_region.read = ram_;
e0_region.write = ram_;
e0_region.read = ram_base;
e0_region.write = ram_base;
};
if(inhibit_banks0001) {
set_no_card(0x0000);
set_no_card(0x0100);
} else {
apply(0x0000, zero_state ? &ram_[0x10000] : ram_);
apply(0x0100, ram_);
apply(0x0000, zero_state ? &ram_base[0x10000] : ram_base);
apply(0x0100, ram_base);
}
uint8_t *const e0_ram = regions[region_map[0xe000]].write;
@ -309,12 +308,12 @@ class MemoryMap {
// regular RAM (or possibly auxiliary).
const auto auxiliary_state = auxiliary_switches_.main_state();
for(uint8_t region = region_map[0x00c0]; region < region_map[0x00d0]; region++) {
regions[region].read = auxiliary_state.base.read ? &ram_[0x10000] : ram_;
regions[region].write = auxiliary_state.base.write ? &ram_[0x10000] : ram_;
regions[region].read = auxiliary_state.base.read ? &ram_base[0x10000] : ram_base;
regions[region].write = auxiliary_state.base.write ? &ram_base[0x10000] : ram_base;
regions[region].flags &= ~Region::IsIO;
}
for(uint8_t region = region_map[0x01c0]; region < region_map[0x01d0]; region++) {
regions[region].read = regions[region].write = ram_;
regions[region].read = regions[region].write = ram_base;
regions[region].flags &= ~Region::IsIO;
}
} else {
@ -331,7 +330,7 @@ class MemoryMap {
void set_zero_page_paging() {
// Affects bank $00 only, and should be a single region.
auto &region = regions[region_map[0]];
region.read = region.write = auxiliary_switches_.zero_state() ? &ram_[0x10000] : ram_;
region.read = region.write = auxiliary_switches_.zero_state() ? &ram_base[0x10000] : ram_base;
// Switching to or from auxiliary RAM potentially affects the language
// and regular card areas.
@ -373,7 +372,6 @@ class MemoryMap {
// TODO: does inhibiting Super Hi-Res also affect the regular hi-res pages?
#undef apply
}
void set_main_paging() {
@ -381,8 +379,8 @@ class MemoryMap {
#define set(page, flags) {\
auto &region = regions[region_map[page]]; \
region.read = flags.read ? &ram_[0x10000] : ram_; \
region.write = flags.write ? &ram_[0x10000] : ram_; \
region.read = flags.read ? &ram_base[0x10000] : ram_base; \
region.write = flags.write ? &ram_base[0x10000] : ram_base; \
}
set(0x02, state.base);
@ -407,6 +405,7 @@ class MemoryMap {
// Pointers are eight bytes at the time of writing, so the extra level of indirection
// reduces what would otherwise be a 1.25mb table down to not a great deal more than 64kb.
std::array<uint8_t, 65536> region_map;
uint8_t *ram_base = nullptr;
size_t shadow_offset;
struct Region {
@ -432,7 +431,7 @@ class MemoryMap {
if(region.write) { \
region.write[address] = *value; \
if(region.flags & MemoryMap::Region::IsShadowed) { \
region.write[address + map.shadow_offset] = *value; \
map.ram_base[(&region.write[address] - map.ram_base) % (128 * 1024) + map.shadow_offset] = *value; \
} \
}