Texture cache: stop the churn, the per-frame image leak and garbage textures

- Unmapped GPU addresses get a stand-in CPU address fixed by the GPU
  address. A fresh one per lookup meant FindImage never found an image
  there again: title 1's bloom chain at 0xf0000-0x15b600 was re-created
  on every use (~5,400 images per 600 frames), filling VRAM.
- ASTC whose blocks carry no alpha (exact endpoint-mode scan reusing the
  decoder's block parsing) is re-compressed to BC1 instead of BC3, half
  the size; about 70% of title 1's ASTC qualifies. Copies between BC1
  and BC3 hosts are skipped (their guest data is uploaded instead).
  EDEN_NX2_ASTC_BC1=0 turns it off.
- Deleting an image cancels every decode still queued for it. An image
  re-decoded mid-decode has two; the first to finish cleared IsDecoding,
  the second was not cancelled and was uploaded into the next image to
  take the slot: garbage textures (the title logo, road patches) and a
  staging overrun when that image was smaller.
- Diagnostics: images created and deleted per 600 frames by shape,
  collector deletions, async decodes, BC1/BC3 split; collector
  thresholds overridable (EDEN_NX2_TC_EXPECTED_MIB/CRITICAL_MIB); GPU
  ASTC decode wait timing (EDEN_NX2_ASTC_FLUSH=1 submits without it).

Title 1 attract loop: device memory 4.8-5.1 GB instead of 5.9-6.1 GB, no
decoded textures evicted, ~17 -> 22-23 fps.

5 files changed, 134 insertions, 30 deletions

diff --git a/src/video_core/texture_cache/image_info.h b/src/video_core/texture_cache/image_info.h
index 7407062d19..79237aa482 100644
--- a/src/video_core/texture_cache/image_info.h
+++ b/src/video_core/texture_cache/image_info.h
@@ -54,6 +54,8 @@ struct ImageInfo {
     bool forced_flushed = false;
     bool dma_downloaded = false;
     bool is_sparse = false;
+    // ASTC data whose blocks carry no alpha: re-compressed to BC1 instead of BC3 (half the size).
+    bool astc_opaque = false;
 };
 
 } // namespace VideoCommon
diff --git a/src/video_core/texture_cache/texture_cache.h b/src/video_core/texture_cache/texture_cache.h
index 7382ef5e4f..fbcd3eefbb 100644
--- a/src/video_core/texture_cache/texture_cache.h
+++ b/src/video_core/texture_cache/texture_cache.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <algorithm>
+#include <cstdlib>
 #include <limits>
 #include <map>
 #include <vector>
@@ -79,6 +80,15 @@ TextureCache<P>::TextureCache(Runtime& runtime_, Tegra::MaxwellDeviceMemoryManag
         critical_memory = DEFAULT_CRITICAL_MEMORY + 1_GiB;
         minimum_memory = 0;
     }
+    // EDEN_NX2_TC_EXPECTED_MIB / EDEN_NX2_TC_CRITICAL_MIB override the collector's thresholds.
+    for (const auto& [name, target] : {std::pair{"EDEN_NX2_TC_EXPECTED_MIB", &expected_memory},
+                                       std::pair{"EDEN_NX2_TC_CRITICAL_MIB", &critical_memory}}) {
+        if (const char* value = std::getenv(name)) {
+            *target = std::strtoull(value, nullptr, 10) << 20;
+        }
+    }
+    LOG_INFO(HW_GPU, "Texture cache thresholds: expected {} MiB, critical {} MiB, minimum {} MiB",
+             expected_memory >> 20, critical_memory >> 20, minimum_memory >> 20);
 
     const bool gpu_unswizzle_enabled = Settings::values.gpu_unswizzle_enabled.GetValue();
 
@@ -151,6 +161,7 @@ void TextureCache<P>::RunGarbageCollector() {
         if (True(image.flags & ImageFlagBits::Tracked)) {
             UntrackImage(image, image_id);
         }
+        ++(True(image.flags & ImageFlagBits::CostlyLoad) ? gc_costly_deletes : gc_deletes);
         UnregisterImage(image_id);
         DeleteImage(image_id, image.scale_tick > frame_tick + 5);
         if (aggressive_mode && total_used_memory < critical_memory) {
@@ -215,6 +226,23 @@ void TextureCache<P>::TickFrame() {
         if constexpr (requires { runtime.LogMemoryStatistics(); }) {
             runtime.LogMemoryStatistics();
         }
+        LOG_INFO(HW_GPU, "Texture cache last 600 frames: created {} images, deleted {} (collector {}, {} costly), {} async decodes, ASTC {} opaque / {} alpha",
+                 images_created, images_deleted, gc_deletes + gc_costly_deletes, gc_costly_deletes,
+                 async_decodes_queued, astc_opaque_images, astc_alpha_images);
+        astc_opaque_images = astc_alpha_images = 0;
+        std::vector<std::pair<u32, u64>> shapes;
+        for (const auto& [key, value] : created_shapes) shapes.emplace_back(value.first, key);
+        std::sort(shapes.rbegin(), shapes.rend());
+        for (size_t i = 0; i < std::min<size_t>(10, shapes.size()); ++i) {
+            const u64 key = shapes[i].second;
+            LOG_INFO(HW_GPU, "  created {}x: format {} type {} levels {} layers {} {}x{} (last at {:#x})",
+                     shapes[i].first, key >> 56, (key >> 52) & 0xF, (key >> 48) & 0xF,
+                     (key >> 36) & 0xFFF, (key >> 18) & 0x3FFFF, key & 0x3FFFF,
+                     created_shapes[key].second);
+        }
+        created_shapes.clear();
+        gc_deletes = gc_costly_deletes = async_decodes_queued = 0;
+        images_created = images_deleted = 0;
     }
     if (total_used_memory > minimum_memory) {
         RunGarbageCollector();
@@ -1323,12 +1351,9 @@ ImageId TextureCache<P>::FindOrInsertImage(const ImageInfo& info, GPUVAddr gpu_a
 template <class P>
 ImageId TextureCache<P>::FindImage(const ImageInfo& info, GPUVAddr gpu_addr,
                                    RelaxedOptions options) {
-    std::optional<DAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr);
+    const std::optional<DAddr> cpu_addr = ImageCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
     if (!cpu_addr) {
-        cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
-        if (!cpu_addr) {
-            return ImageId{};
-        }
+        return ImageId{};
     }
     const bool broken_views =
         runtime.HasBrokenTextureViewFormats() || True(options & RelaxedOptions::ForceBrokenViews);
@@ -1457,6 +1482,7 @@ void TextureCache<P>::QueueAsyncDecode(Image& image, ImageId image_id) {
     LOG_DEBUG(HW_GPU, "Queuing async texture decode {:#x}", image.gpu_addr);
 
     image.flags |= ImageFlagBits::IsDecoding;
+    ++async_decodes_queued;
     auto decode = std::make_unique<AsyncDecodeContext>();
     auto* decode_ptr = decode.get();
     decode->image_id = image_id;
@@ -1516,6 +1542,12 @@ void TextureCache<P>::TickAsyncDecode() {
             continue;
         }
         Image& image = slot_images[async_decode->image_id];
+        if (async_decode->decoded_data.size() > MapSizeBytes(image)) {
+            LOG_ERROR(HW_GPU, "Async decode of {} bytes for a {}-byte image at {:#x}, dropped",
+                      async_decode->decoded_data.size(), MapSizeBytes(image), image.gpu_addr);
+            i = async_decodes.erase(i);
+            continue;
+        }
         auto staging = runtime.UploadStagingBuffer(MapSizeBytes(image));
         std::memcpy(staging.mapped_span.data(), async_decode->decoded_data.data(),
                     async_decode->decoded_data.size());
@@ -1631,17 +1663,31 @@ bool TextureCache<P>::ScaleDown(Image& image) {
 }
 
 template <class P>
+std::optional<DAddr> TextureCache<P>::ImageCpuAddress(GPUVAddr gpu_addr, size_t size) const {
+    if (const std::optional<DAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr)) {
+        return cpu_addr;
+    }
+    if (const std::optional<DAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr, size)) {
+        return cpu_addr;
+    }
+    // No CPU backing (title 1 renders a bloom chain at GPU 0xf0000-0x15b600): a stand-in address
+    // fixed by the GPU address, at or above ~(1 << 40) so TrackImage skips it. A fresh address per
+    // lookup made every use create another image (thousands a minute, never found again).
+    constexpr GPUVAddr StandInRange = 1ULL << 40;
+    if (gpu_addr >= StandInRange || size > StandInRange - gpu_addr - 1) {
+        return std::nullopt;
+    }
+    return ~(1ULL << 40ULL) + gpu_addr;
+}
+
+template <class P>
 ImageId TextureCache<P>::InsertImage(const ImageInfo& info, GPUVAddr gpu_addr,
                                      RelaxedOptions options) {
-    std::optional<DAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr);
+    std::optional<DAddr> cpu_addr = ImageCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
     if (!cpu_addr) {
-        const auto size = CalculateGuestSizeInBytes(info);
-        cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr, size);
-        if (!cpu_addr) {
-            const DAddr fake_addr = ~(1ULL << 40ULL) + virtual_invalid_space;
-            virtual_invalid_space += Common::AlignUp(size, 32);
-            cpu_addr = std::optional<DAddr>(fake_addr);
-        }
+        const DAddr fake_addr = ~(1ULL << 40ULL) + virtual_invalid_space;
+        virtual_invalid_space += Common::AlignUp(CalculateGuestSizeInBytes(info), 32);
+        cpu_addr = std::optional<DAddr>(fake_addr);
     }
     ASSERT_MSG(cpu_addr, "Tried to insert an image to an invalid gpu_addr={:#x}", gpu_addr);
     ImageInfo storage_info = info;
@@ -1760,10 +1806,36 @@ ImageId TextureCache<P>::JoinImages(const ImageInfo& info, GPUVAddr gpu_addr, DA
         }
     }
 
+    if constexpr (requires { runtime.UseOpaqueAstcFormat(); }) {
+        // Opaque ASTC goes to BC1 rather than BC3 when it is re-compressed (the Vulkan runtime
+        // decides). The guest data is already there when an image is first used.
+        constexpr size_t MaxScanBytes = 64_MiB;
+        if (IsPixelFormatASTC(new_info.format) && runtime.UseOpaqueAstcFormat()) {
+            const size_t scan_bytes = CalculateGuestSizeInBytes(new_info);
+            if (scan_bytes <= MaxScanBytes) {
+                astc_scan_buffer.resize(scan_bytes);
+                gpu_memory->ReadBlockUnsafe(gpu_addr, astc_scan_buffer.data(), scan_bytes);
+                new_info.astc_opaque = AstcDataLooksOpaque(astc_scan_buffer);
+                ++(new_info.astc_opaque ? astc_opaque_images : astc_alpha_images);
+            }
+        }
+    }
     const ImageId new_image_id = slot_images.insert(runtime, new_info, gpu_addr, cpu_addr);
     Image& new_image = slot_images[new_image_id];
 
     new_image.allocation_tick = frame_tick;
+    {
+        // Which shapes are being created (periodic log): format, type, levels, layers, size.
+        const u64 key = (u64{static_cast<u32>(new_info.format)} << 56) |
+                        (u64{static_cast<u32>(new_info.type)} << 52) |
+                        (u64{static_cast<u32>(new_info.resources.levels) & 0xF} << 48) |
+                        (u64{static_cast<u32>(new_info.resources.layers) & 0xFFF} << 36) |
+                        (u64{new_info.size.width & 0x3FFFF} << 18) | (new_info.size.height & 0x3FFFF);
+        auto& shape = created_shapes[key];
+        ++shape.first;
+        shape.second = gpu_addr;
+        ++images_created;
+    }
 
     if (!gpu_memory->IsContinuousRange(new_image.gpu_addr, new_image.guest_size_bytes) &&
         new_info.is_sparse) {
@@ -1959,12 +2031,9 @@ std::optional<typename TextureCache<P>::BlitImages> TextureCache<P>::GetBlitImag
 
 template <class P>
 ImageId TextureCache<P>::FindDMAImage(const ImageInfo& info, GPUVAddr gpu_addr) {
-    std::optional<DAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr);
+    const std::optional<DAddr> cpu_addr = ImageCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
     if (!cpu_addr) {
-        cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr, CalculateGuestSizeInBytes(info));
-        if (!cpu_addr) {
-            return ImageId{};
-        }
+        return ImageId{};
     }
     ImageId image_id{};
     boost::container::small_vector<ImageId, 8> image_ids;
@@ -2463,12 +2532,14 @@ void TextureCache<P>::UntrackImage(ImageBase& image, ImageId image_id) {
 template <class P>
 void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
     ImageBase& image = slot_images[image_id];
-    if (True(image.flags & ImageFlagBits::IsDecoding)) {
-        // A worker is still decoding it: keep its context alive but drop the result.
-        for (auto& async_decode : async_decodes) {
-            if (async_decode->image_id == image_id) {
-                async_decode->cancelled = true;
-            }
+    ++images_deleted;
+    // Drop every decode still queued for it, whatever IsDecoding says: an image re-decoded while
+    // a decode was in flight has two, and the first to finish clears the flag. A decode left
+    // behind was uploaded into the next image to take this slot (another texture's data: garbage
+    // textures, and a staging overrun when that image was smaller).
+    for (auto& async_decode : async_decodes) {
+        if (async_decode->image_id == image_id) {
+            async_decode->cancelled = true;
         }
     }
     if (image.HasScaled()) {
@@ -2696,6 +2767,11 @@ template <class P>
 void TextureCache<P>::CopyImage(ImageId dst_id, ImageId src_id, std::vector<ImageCopy> copies) {
     Image& dst = slot_images[dst_id];
     Image& src = slot_images[src_id];
+    if (dst.info.astc_opaque != src.info.astc_opaque) {
+        // BC1 and BC3 blocks differ in size, so the host can't copy between them; both hold the
+        // same guest data, which is uploaded from guest memory instead.
+        return;
+    }
     const bool is_rescaled = True(src.flags & ImageFlagBits::Rescaled);
     if (is_rescaled) {
         ASSERT(True(dst.flags & ImageFlagBits::Rescaled));
diff --git a/src/video_core/texture_cache/texture_cache_base.h b/src/video_core/texture_cache/texture_cache_base.h
index ed9758fdee..f6f083e10a 100644
--- a/src/video_core/texture_cache/texture_cache_base.h
+++ b/src/video_core/texture_cache/texture_cache_base.h
@@ -9,6 +9,7 @@
 #include <atomic>
 #include <deque>
 #include <limits>
+#include <map>
 #include <mutex>
 #include <span>
 #include <type_traits>
@@ -120,6 +121,17 @@ class TextureCache : public VideoCommon::ChannelSetupCaches<TextureCacheChannelI
     static constexpr s64 TARGET_THRESHOLD = 4_GiB;
 #endif
 
+    // Periodic statistics (TickFrame).
+    u64 gc_deletes{};
+    u64 gc_costly_deletes{};
+    u64 async_decodes_queued{};
+    u64 images_created{};
+    u64 astc_opaque_images{};
+    u64 astc_alpha_images{};
+    std::vector<u8> astc_scan_buffer;
+    u64 images_deleted{};
+    std::map<u64, std::pair<u32, GPUVAddr>> created_shapes;
+
     static constexpr s64 DEFAULT_EXPECTED_MEMORY = 1_GiB + 125_MiB;
     static constexpr s64 DEFAULT_CRITICAL_MEMORY = 1_GiB + 625_MiB;
     static constexpr size_t GC_EMERGENCY_COUNTS = 2;
@@ -450,6 +462,9 @@ private:
 
     DAddr virtual_invalid_space{};
 
+    /// The CPU address an image at gpu_addr is keyed by: its backing, or a fixed stand-in.
+    [[nodiscard]] std::optional<DAddr> ImageCpuAddress(GPUVAddr gpu_addr, size_t size) const;
+
     bool has_deleted_images = false;
     bool is_rescaling = false;
     u64 total_used_memory = 0;
diff --git a/src/video_core/texture_cache/util.cpp b/src/video_core/texture_cache/util.cpp
index aae2c7e4fd..7a1a1d89c0 100644
--- a/src/video_core/texture_cache/util.cpp
+++ b/src/video_core/texture_cache/util.cpp
@@ -11,6 +11,7 @@
 
 #include <algorithm>
 #include <array>
+#include <cstring>
 #include <numeric>
 #include <optional>
 #include <span>
@@ -603,6 +604,10 @@ u32 CalculateUnswizzledSizeBytes(const ImageInfo& info) noexcept {
     return NumBlocksPerLayer(info, tile_size) * info.resources.layers * BytesPerBlock(info.format);
 }
 
+bool AstcDataLooksOpaque(std::span<const u8> data) noexcept {
+    return Tegra::Texture::ASTC::IsOpaque(data);
+}
+
 u32 CalculateConvertedSizeBytes(const ImageInfo& info) noexcept {
     if (info.type == ImageType::Buffer) {
         return info.size.width * BytesPerBlock(info.format);
@@ -611,8 +616,10 @@ u32 CalculateConvertedSizeBytes(const ImageInfo& info) noexcept {
     if (IsPixelFormatASTC(info.format) && Settings::values.astc_recompression.GetValue() !=
                                               Settings::AstcRecompression::Uncompressed) {
         const u32 bpp_div =
-            Settings::values.astc_recompression.GetValue() == Settings::AstcRecompression::Bc1 ? 2
-                                                                                               : 1;
+            Settings::values.astc_recompression.GetValue() == Settings::AstcRecompression::Bc1 ||
+                    info.astc_opaque
+                ? 2
+                : 1;
         // NumBlocksPerLayer doesn't account for this correctly, so we have to do it manually.
         u32 output_size = 0;
         for (s32 i = 0; i < info.resources.levels; i++) {
@@ -955,10 +962,11 @@ void ConvertImage(std::span<const u8> input, const ImageInfo& info, std::span<u8
         } else if (astc) {
             // BC1 uses 0.5 bytes per texel
             // BC3 uses 1 byte per texel
-            const auto compress = recompression_setting == Settings::AstcRecompression::Bc1
-                                      ? Tegra::Texture::BCN::CompressBC1
-                                      : Tegra::Texture::BCN::CompressBC3;
-            const auto bpp_div = recompression_setting == Settings::AstcRecompression::Bc1 ? 2 : 1;
+            const bool bc1 =
+                recompression_setting == Settings::AstcRecompression::Bc1 || info.astc_opaque;
+            const auto compress =
+                bc1 ? Tegra::Texture::BCN::CompressBC1 : Tegra::Texture::BCN::CompressBC3;
+            const auto bpp_div = bc1 ? 2 : 1;
 
             const u32 plane_dim = copy.image_extent.width * copy.image_extent.height;
             const u32 level_size = plane_dim * copy.image_extent.depth *
diff --git a/src/video_core/texture_cache/util.h b/src/video_core/texture_cache/util.h
index 590d85b042..89f85e4e8a 100644
--- a/src/video_core/texture_cache/util.h
+++ b/src/video_core/texture_cache/util.h
@@ -36,6 +36,9 @@ struct OverlapResult {
 
 [[nodiscard]] u32 CalculateConvertedSizeBytes(const ImageInfo& info) noexcept;
 
+/// True if no 16-byte ASTC block in `data` decodes to alpha below 1.
+[[nodiscard]] bool AstcDataLooksOpaque(std::span<const u8> data) noexcept;
+
 [[nodiscard]] u32 CalculateLayerStride(const ImageInfo& info) noexcept;
 
 [[nodiscard]] u32 CalculateLayerSize(const ImageInfo& info) noexcept;