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video_core: rasterizer_cache: Use u16 for cached page count. 

- Greatly reduces the risk of overflow, at the cost of doubling the size of this array.
This commit is contained in:
bunnei 2021-05-27 14:47:24 -07:00
parent 9110cfdefb
commit 4b95b0df97
2 changed files with 9 additions and 9 deletions
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6
src/video_core/rasterizer_accelerated.cpp
View File

@ -18,10 +18,10 @@ RasterizerAccelerated::~RasterizerAccelerated() = default;
void RasterizerAccelerated::UpdatePagesCachedCount(VAddr addr, u64 size, int delta) { void RasterizerAccelerated::UpdatePagesCachedCount(VAddr addr, u64 size, int delta) {
const auto page_end = Common::DivCeil(addr + size, Core::Memory::PAGE_SIZE); const auto page_end = Common::DivCeil(addr + size, Core::Memory::PAGE_SIZE);
for (auto page = addr >> Core::Memory::PAGE_BITS; page != page_end; ++page) { for (auto page = addr >> Core::Memory::PAGE_BITS; page != page_end; ++page) {
auto& count = cached_pages.at(page >> 3).Count(page); auto& count = cached_pages.at(page >> 2).Count(page);
if (delta > 0) { if (delta > 0) {
ASSERT_MSG(count < UINT8_MAX, "Count may overflow!"); ASSERT_MSG(count < UINT16_MAX, "Count may overflow!");
} else if (delta < 0) { } else if (delta < 0) {
ASSERT_MSG(count > 0, "Count may underflow!"); ASSERT_MSG(count > 0, "Count may underflow!");
} else { } else {
@ -29,7 +29,7 @@ void RasterizerAccelerated::UpdatePagesCachedCount(VAddr addr, u64 size, int del
} }
// Adds or subtracts 1, as count is a unsigned 8-bit value // Adds or subtracts 1, as count is a unsigned 8-bit value
count += static_cast<u8>(delta); count += static_cast<u16>(delta);
// Assume delta is either -1 or 1 // Assume delta is either -1 or 1
if (count == 0) { if (count == 0) {

12
src/video_core/rasterizer_accelerated.h
View File

@ -29,20 +29,20 @@ private:
public: public:
CacheEntry() = default; CacheEntry() = default;
std::atomic_uint8_t& Count(std::size_t page) { std::atomic_uint16_t& Count(std::size_t page) {
return values[page & 7]; return values[page & 3];
} }
const std::atomic_uint8_t& Count(std::size_t page) const { const std::atomic_uint16_t& Count(std::size_t page) const {
return values[page & 7]; return values[page & 3];
} }
private: private:
std::array<std::atomic_uint8_t, 8> values{}; std::array<std::atomic_uint16_t, 4> values{};
}; };
static_assert(sizeof(CacheEntry) == 8, "CacheEntry should be 8 bytes!"); static_assert(sizeof(CacheEntry) == 8, "CacheEntry should be 8 bytes!");
std::array<CacheEntry, 0x800000> cached_pages; std::array<CacheEntry, 0x1000000> cached_pages;
Core::Memory::Memory& cpu_memory; Core::Memory::Memory& cpu_memory;
}; };