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Simplify control flow.

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This commit is contained in:
Thomas Harte 2024-03-24 22:30:26 -04:00
parent 6980fd760c
commit 5da9e0486a
1 changed files with 18 additions and 23 deletions
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41
Machines/Acorn/Archimedes/MemoryController.hpp
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@ -69,14 +69,14 @@ struct MemoryController {
// The MEMC itself isn't on the data bus; all values below should be taken from `address`. // The MEMC itself isn't on the data bus; all values below should be taken from `address`.
switch((address >> 17) & 0b111) { switch((address >> 17) & 0b111) {
case 0b000: ioc_.video().set_frame_start(buffer_address(address)); return true; case 0b000: ioc_.video().set_frame_start(buffer_address(address)); break;
case 0b001: ioc_.video().set_buffer_start(buffer_address(address)); return true; case 0b001: ioc_.video().set_buffer_start(buffer_address(address)); break;
case 0b010: ioc_.video().set_buffer_end(buffer_address(address)); return true; case 0b010: ioc_.video().set_buffer_end(buffer_address(address)); break;
case 0b011: ioc_.video().set_cursor_start(buffer_address(address)); return true; case 0b011: ioc_.video().set_cursor_start(buffer_address(address)); break;
case 0b100: ioc_.sound().set_next_start(buffer_address(address)); return true; case 0b100: ioc_.sound().set_next_start(buffer_address(address)); break;
case 0b101: ioc_.sound().set_next_end(buffer_address(address)); return true; case 0b101: ioc_.sound().set_next_end(buffer_address(address)); break;
case 0b110: ioc_.sound().swap(); return true; case 0b110: ioc_.sound().swap(); break;
case 0b111: case 0b111:
os_mode_ = address & (1 << 12); os_mode_ = address & (1 << 12);
@ -97,7 +97,7 @@ struct MemoryController {
logger.info().append("MEMC Control: %08x -> OS:%d sound:%d video:%d refresh:%d high:%d low:%d size:%d", address, os_mode_, sound_dma_enable_, video_dma_enable_, dynamic_ram_refresh_, high_rom_access_time_, low_rom_access_time_, page_size_); logger.info().append("MEMC Control: %08x -> OS:%d sound:%d video:%d refresh:%d high:%d low:%d size:%d", address, os_mode_, sound_dma_enable_, video_dma_enable_, dynamic_ram_refresh_, high_rom_access_time_, low_rom_access_time_, page_size_);
map_dirty_ = true; map_dirty_ = true;
return true; break;
} }
} break; } break;
@ -107,13 +107,12 @@ struct MemoryController {
return false; return false;
} }
*item = source; *item = source;
return true;
} break; } break;
case Zone::IOControllers: case Zone::IOControllers:
// TODO: have I overrestricted the value type for the IOC area? // TODO: have I overrestricted the value type for the IOC area?
ioc_.write(address, uint8_t(source)); ioc_.write(address, uint8_t(source));
return true; break;
case Zone::VideoController: case Zone::VideoController:
// TODO: handle byte writes correctly. // TODO: handle byte writes correctly.
@ -122,7 +121,7 @@ struct MemoryController {
case Zone::PhysicallyMappedRAM: case Zone::PhysicallyMappedRAM:
physical_ram<IntT>(address) = source; physical_ram<IntT>(address) = source;
return true; break;
case Zone::AddressTranslator: case Zone::AddressTranslator:
// printf("Translator write at %08x; replaces %08x\n", address, pages_[address & 0x7f]); // printf("Translator write at %08x; replaces %08x\n", address, pages_[address & 0x7f]);
@ -131,7 +130,7 @@ struct MemoryController {
break; break;
default: default:
// printf("TODO: write of %08x to %08x [%lu]\n", source, address, sizeof(IntT)); printf("TODO: write of %08x to %08x [%lu]\n", source, address, sizeof(IntT));
break; break;
} }
@ -148,12 +147,12 @@ struct MemoryController {
switch (read_zones_[(address >> 21) & 31]) { switch (read_zones_[(address >> 21) & 31]) {
case Zone::PhysicallyMappedRAM: case Zone::PhysicallyMappedRAM:
source = physical_ram<IntT>(address); source = physical_ram<IntT>(address);
return true; break;
case Zone::LogicallyMappedRAM: { case Zone::LogicallyMappedRAM: {
if(!has_moved_rom_) { // TODO: maintain this state in the zones table. if(!has_moved_rom_) { // TODO: maintain this state in the zones table.
source = high_rom<IntT>(address); source = high_rom<IntT>(address);
return true; break;
} }
const auto item = logical_ram<IntT, true>(address, mode); const auto item = logical_ram<IntT, true>(address, mode);
@ -161,41 +160,37 @@ struct MemoryController {
return false; return false;
} }
source = *item; source = *item;
return true;
} break; } break;
case Zone::LowROM: case Zone::LowROM:
// logger.error().append("TODO: Low ROM read from %08x", address); // logger.error().append("TODO: Low ROM read from %08x", address);
source = IntT(~0); source = IntT(0);
return true; break;
case Zone::HighROM: case Zone::HighROM:
// Real test is: require A24=A25=0, then A25=1. // Real test is: require A24=A25=0, then A25=1.
// TODO: as above, move this test into the zones tables. // TODO: as above, move this test into the zones tables.
has_moved_rom_ = true; has_moved_rom_ = true;
source = high_rom<IntT>(address); source = high_rom<IntT>(address);
return true; break;
case Zone::IOControllers: { case Zone::IOControllers: {
if constexpr (std::is_same_v<IntT, uint8_t>) { if constexpr (std::is_same_v<IntT, uint8_t>) {
ioc_.read(address, source); ioc_.read(address, source);
return true;
} else { } else {
// TODO: generalise this adaptation of an 8-bit device to the 32-bit bus, which probably isn't right anyway. // TODO: generalise this adaptation of an 8-bit device to the 32-bit bus, which probably isn't right anyway.
uint8_t value; uint8_t value;
ioc_.read(address, value); ioc_.read(address, value);
source = value; source = value;
return true;
} }
} } break;
default: default:
logger.error().append("TODO: read from %08x", address); logger.error().append("TODO: read from %08x", address);
break; break;
} }
source = 0; return true;
return false;
} }
void tick_timers() { ioc_.tick_timers(); } void tick_timers() { ioc_.tick_timers(); }