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Incorporate displacement, switch macro flag.

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This commit is contained in:
Thomas Harte 2022-02-28 09:53:23 -05:00
parent 9f12c009d6
commit afbc57cc0c
2 changed files with 15 additions and 16 deletions
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19
InstructionSets/x86/DataPointerResolver.hpp
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@ -82,9 +82,9 @@ template <Model model, typename RegistersT, typename MemoryT> class DataPointerR
DataT &value) {
const Source source = pointer.source();
#define read_or_write(v, x, allow_write) \
#define read_or_write(v, x, is_for_indirection) \
case Source::x: \
if constexpr(allow_write && is_write) { \
if constexpr(!is_for_indirection && is_write) { \
registers.template write<decltype(v), register_for_source<decltype(v)>(Source::x)>(v); \
} else { \
v = registers.template read<decltype(v), register_for_source<decltype(v)>(Source::x)>(); \
@ -102,7 +102,7 @@ template <Model model, typename RegistersT, typename MemoryT> class DataPointerR
}
return;
#define f(x, y) read_or_write(x, y, true)
#define f(x, y) read_or_write(x, y, false)
ALLREGS(value);
#undef f
@ -121,7 +121,7 @@ template <Model model, typename RegistersT, typename MemoryT> class DataPointerR
using AddressT = typename Instruction<is_32bit(model)>::AddressComponentT;
AddressT base = 0, index = 0;
#define f(x, y) read_or_write(x, y, false)
#define f(x, y) read_or_write(x, y, true)
switch(pointer.base()) {
default: break;
ALLREGS(base);
@ -133,8 +133,12 @@ template <Model model, typename RegistersT, typename MemoryT> class DataPointerR
}
#undef f
// Compute address as 32-bit; its always at least 20 bits
// and at most 32.
// Always compute address as 32-bit.
// TODO: verify application of memory_mask here.
// The point of memory_mask is that 32-bit x86 offers the memory size modifier,
// permitting 16-bit addresses to be generated in 32-bit mode and vice versa.
// To figure out is at what point in the calculation the 16-bit constraint is
// applied when active.
uint32_t address = index;
if constexpr (model >= Model::i80386) {
address <<= pointer.scale();
@ -142,8 +146,7 @@ template <Model model, typename RegistersT, typename MemoryT> class DataPointerR
assert(!pointer.scale());
}
// TODO: verify application of memory_mask here.
address = (address & memory_mask) + (base & memory_mask);
address = (address & memory_mask) + (base & memory_mask) + instruction.displacement();
if constexpr (is_write) {
value = memory.template read<DataT>(

12
OSBindings/Mac/Clock SignalTests/x86DataPointerTests.mm
View File

@ -46,10 +46,8 @@ using namespace InstructionSet::x86;
} registers;
struct Memory {
template<typename DataT> DataT read(Source segment, uint32_t address) {
(void)segment;
(void)address;
printf("Access at %08x\n", address);
template<typename DataT> DataT read(Source, uint32_t address) {
if(address == 01234 + 0x00ee) return 0xff;
return 0;
}
template<typename DataT> void write(Source, uint32_t, DataT) {
@ -58,9 +56,7 @@ using namespace InstructionSet::x86;
} memory;
const auto instruction = Instruction<false>();/*[self
instruction16WithSourceDataPointer:pointer];*/
const auto instruction = Instruction<false>();
const uint8_t value = DataPointerResolver<
Model::i8086, Registers, Memory>::read<uint8_t>(
registers,
@ -69,7 +65,7 @@ using namespace InstructionSet::x86;
pointer
);
printf("%d\n", value);
XCTAssertEqual(value, 0xff);
}
@end