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[core] use memcpy instead of hand rolling aligned cases
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Hand rolling memcpy like this is always frowned upon because the compiler has more insight on whats going on (plus the code resolves to a worse version of itself on assembly). This removes some branches that are just straight up redundant. May save stuff especially for systems without fastmem enabled.

Signed-off-by: lizzie <lizzie@eden-emu.dev>
This commit is contained in:
lizzie 2025-10-01 08:04:34 +00:00 • committed by crueter
parent 1a5b3fb239
commit 91432e336a
1 changed files with 36 additions and 167 deletions
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203
src/core/memory.cpp
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@ -10,6 +10,7 @@
#include <mutex>
#include <span>
#include <thread>
#include <type_traits>
#include <vector>
#include "common/assert.h"
@ -681,22 +682,17 @@ struct Memory::Impl {
}
}
[[nodiscard]] u8* GetPointerImpl(u64 vaddr, auto on_unmapped, auto on_rasterizer) const {
template<typename F, typename G>
[[nodiscard]] u8* GetPointerImpl(u64 vaddr, F&& on_unmapped, G&& on_rasterizer) const {
// AARCH64 masks the upper 16 bit of all memory accesses
vaddr = vaddr & 0xffffffffffffULL;
if (!AddressSpaceContains(*current_page_table, vaddr, 1)) [[unlikely]] {
on_unmapped();
return nullptr;
} else {
vaddr &= 0xffffffffffffULL;
if (AddressSpaceContains(*current_page_table, vaddr, 1)) [[likely]] {
// Avoid adding any extra logic to this fast-path block
const uintptr_t raw_pointer = current_page_table->pointers[vaddr >> YUZU_PAGEBITS].Raw();
if (const uintptr_t pointer = Common::PageTable::PageInfo::ExtractPointer(raw_pointer)) {
if (const uintptr_t pointer = Common::PageTable::PageInfo::ExtractPointer(raw_pointer)) [[likely]] {
return reinterpret_cast<u8*>(pointer + vaddr);
} else {
switch (Common::PageTable::PageInfo::ExtractType(raw_pointer)) {
case Common::PageType::Unmapped:
on_unmapped();
return nullptr;
case Common::PageType::Memory:
ASSERT_MSG(false, "Mapped memory page without a pointer @ 0x{:016X}", vaddr);
return nullptr;
@ -707,11 +703,18 @@ struct Memory::Impl {
on_rasterizer();
return host_ptr;
}
case Common::PageType::Unmapped: [[unlikely]] {
on_unmapped();
return nullptr;
}
default:
UNREACHABLE();
}
return nullptr;
}
} else {
on_unmapped();
return nullptr;
}
}
@ -729,172 +732,38 @@ struct Memory::Impl {
GetInteger(vaddr), []() {}, []() {});
}
/**
* Reads a particular data type out of memory at the given virtual address.
*
* @param vaddr The virtual address to read the data type from.
*
* @tparam T The data type to read out of memory. This type *must* be
* trivially copyable, otherwise the behavior of this function
* is undefined.
*
* @returns The instance of T read from the specified virtual address.
*/
/// @brief Reads a particular data type out of memory at the given virtual address.
/// @param vaddr The virtual address to read the data type from.
/// @tparam T The data type to read out of memory.
/// @returns The instance of T read from the specified virtual address.
template <typename T>
T Read(Common::ProcessAddress vaddr) {
// Fast path for aligned reads of common sizes
inline T Read(Common::ProcessAddress vaddr) requires(std::is_trivially_copyable_v<T>) noexcept {
const u64 addr = GetInteger(vaddr);
if constexpr (std::is_same_v<T, u8> || std::is_same_v<T, s8>) {
// 8-bit reads are always aligned
const u8* const ptr = GetPointerImpl(
addr,
[addr]() {
LOG_ERROR(HW_Memory, "Unmapped Read8 @ 0x{:016X}", addr);
},
[&]() { HandleRasterizerDownload(addr, sizeof(T)); });
if (ptr) {
return static_cast<T>(*ptr);
}
return 0;
} else if constexpr (std::is_same_v<T, u16_le> || std::is_same_v<T, s16_le>) {
// Check alignment for 16-bit reads
if ((addr & 1) == 0) {
const u8* const ptr = GetPointerImpl(
addr,
[addr]() {
LOG_ERROR(HW_Memory, "Unmapped Read16 @ 0x{:016X}", addr);
},
[&]() { HandleRasterizerDownload(addr, sizeof(T)); });
if (ptr) {
return static_cast<T>(*reinterpret_cast<const u16*>(ptr));
}
}
} else if constexpr (std::is_same_v<T, u32_le> || std::is_same_v<T, s32_le>) {
// Check alignment for 32-bit reads
if ((addr & 3) == 0) {
const u8* const ptr = GetPointerImpl(
addr,
[addr]() {
LOG_ERROR(HW_Memory, "Unmapped Read32 @ 0x{:016X}", addr);
},
[&]() { HandleRasterizerDownload(addr, sizeof(T)); });
if (ptr) {
return static_cast<T>(*reinterpret_cast<const u32*>(ptr));
}
}
} else if constexpr (std::is_same_v<T, u64_le> || std::is_same_v<T, s64_le>) {
// Check alignment for 64-bit reads
if ((addr & 7) == 0) {
const u8* const ptr = GetPointerImpl(
addr,
[addr]() {
LOG_ERROR(HW_Memory, "Unmapped Read64 @ 0x{:016X}", addr);
},
[&]() { HandleRasterizerDownload(addr, sizeof(T)); });
if (ptr) {
return static_cast<T>(*reinterpret_cast<const u64*>(ptr));
}
}
}
// Fall back to the general case for other types or unaligned access
T result = 0;
const u8* const ptr = GetPointerImpl(
addr,
[addr]() {
LOG_ERROR(HW_Memory, "Unmapped Read{} @ 0x{:016X}", sizeof(T) * 8, addr);
},
[&]() { HandleRasterizerDownload(addr, sizeof(T)); });
if (ptr) {
if (auto const ptr = GetPointerImpl(addr, [addr]() {
LOG_ERROR(HW_Memory, "Unmapped Read{} @ 0x{:016X}", sizeof(T) * 8, addr);
}, [&]() {
HandleRasterizerDownload(addr, sizeof(T));
}); ptr) [[likely]] {
// It may be tempting to rewrite this particular section to use "reinterpret_cast";
// afterall, it's trivially copyable so surely it can be copied ov- Alignment.
// Remember, alignment. memcpy() will deal with all the alignment extremely fast.
T result{};
std::memcpy(&result, ptr, sizeof(T));
return result;
}
return result;
return T{};
}
/**
* Writes a particular data type to memory at the given virtual address.
*
* @param vaddr The virtual address to write the data type to.
*
* @tparam T The data type to write to memory. This type *must* be
* trivially copyable, otherwise the behavior of this function
* is undefined.
*/
/// @brief Writes a particular data type to memory at the given virtual address.
/// @param vaddr The virtual address to write the data type to.
/// @tparam T The data type to write to memory.
template <typename T>
void Write(Common::ProcessAddress vaddr, const T data) {
// Fast path for aligned writes of common sizes
inline void Write(Common::ProcessAddress vaddr, const T data) requires(std::is_trivially_copyable_v<T>) noexcept {
const u64 addr = GetInteger(vaddr);
if constexpr (std::is_same_v<T, u8> || std::is_same_v<T, s8>) {
// 8-bit writes are always aligned
u8* const ptr = GetPointerImpl(
addr,
[addr, data]() {
LOG_ERROR(HW_Memory, "Unmapped Write8 @ 0x{:016X} = 0x{:02X}", addr,
static_cast<u8>(data));
},
[&]() { HandleRasterizerWrite(addr, sizeof(T)); });
if (ptr) {
*ptr = static_cast<u8>(data);
}
return;
} else if constexpr (std::is_same_v<T, u16_le> || std::is_same_v<T, s16_le>) {
// Check alignment for 16-bit writes
if ((addr & 1) == 0) {
u8* const ptr = GetPointerImpl(
addr,
[addr, data]() {
LOG_ERROR(HW_Memory, "Unmapped Write16 @ 0x{:016X} = 0x{:04X}", addr,
static_cast<u16>(data));
},
[&]() { HandleRasterizerWrite(addr, sizeof(T)); });
if (ptr) {
*reinterpret_cast<u16*>(ptr) = static_cast<u16>(data);
return;
}
}
} else if constexpr (std::is_same_v<T, u32_le> || std::is_same_v<T, s32_le>) {
// Check alignment for 32-bit writes
if ((addr & 3) == 0) {
u8* const ptr = GetPointerImpl(
addr,
[addr, data]() {
LOG_ERROR(HW_Memory, "Unmapped Write32 @ 0x{:016X} = 0x{:08X}", addr,
static_cast<u32>(data));
},
[&]() { HandleRasterizerWrite(addr, sizeof(T)); });
if (ptr) {
*reinterpret_cast<u32*>(ptr) = static_cast<u32>(data);
return;
}
}
} else if constexpr (std::is_same_v<T, u64_le> || std::is_same_v<T, s64_le>) {
// Check alignment for 64-bit writes
if ((addr & 7) == 0) {
u8* const ptr = GetPointerImpl(
addr,
[addr, data]() {
LOG_ERROR(HW_Memory, "Unmapped Write64 @ 0x{:016X} = 0x{:016X}", addr,
static_cast<u64>(data));
},
[&]() { HandleRasterizerWrite(addr, sizeof(T)); });
if (ptr) {
*reinterpret_cast<u64*>(ptr) = static_cast<u64>(data);
return;
}
}
}
// Fall back to the general case for other types or unaligned access
u8* const ptr = GetPointerImpl(
addr,
[addr, data]() {
LOG_ERROR(HW_Memory, "Unmapped Write{} @ 0x{:016X} = 0x{:016X}", sizeof(T) * 8,
addr, static_cast<u64>(data));
},
[&]() { HandleRasterizerWrite(addr, sizeof(T)); });
if (ptr) {
if (auto const ptr = GetPointerImpl(addr, [addr, data]() {
LOG_ERROR(HW_Memory, "Unmapped Write{} @ 0x{:016X} = 0x{:016X}", sizeof(T) * 8, addr, u64(data));
}, [&]() { HandleRasterizerWrite(addr, sizeof(T)); }); ptr) [[likely]]
std::memcpy(ptr, &data, sizeof(T));
}
}
template <typename T>