rhi: Speed up buffer and texture tracking

Task-number: QTBUG-78862
Change-Id: If278bd55530081cbbdbab8dd6e14d86e28da558e
Reviewed-by: Christian Strømme <christian.stromme@qt.io>

4 files changed, 30 insertions, 32 deletions

diff --git a/src/gui/rhi/qrhi.cpp b/src/gui/rhi/qrhi.cpp
index fa0c5fadc0..08bafebdec 100644
--- a/src/gui/rhi/qrhi.cpp
+++ b/src/gui/rhi/qrhi.cpp
@@ -5513,7 +5513,7 @@ static inline QRhiPassResourceTracker::BufferStage earlierStage(QRhiPassResource
 void QRhiPassResourceTracker::registerBuffer(QRhiBuffer *buf, int slot, BufferAccess *access, BufferStage *stage,
                                              const UsageState &state)
 {
-    auto it = std::find_if(m_buffers.begin(), m_buffers.end(), [buf](const Buffer &b) { return b.buf == buf; });
+    auto it = m_buffers.find(buf);
     if (it != m_buffers.end()) {
         if (it->access != *access) {
             const QByteArray name = buf->name();
@@ -5529,12 +5529,11 @@ void QRhiPassResourceTracker::registerBuffer(QRhiBuffer *buf, int slot, BufferAc
     }
 
     Buffer b;
-    b.buf = buf;
     b.slot = slot;
     b.access = *access;
     b.stage = *stage;
     b.stateAtPassBegin = state; // first use -> initial state
-    m_buffers.append(b);
+    m_buffers.insert(buf, b);
 }
 
 static inline QRhiPassResourceTracker::TextureStage earlierStage(QRhiPassResourceTracker::TextureStage a,
@@ -5553,7 +5552,7 @@ static inline bool isImageLoadStore(QRhiPassResourceTracker::TextureAccess acces
 void QRhiPassResourceTracker::registerTexture(QRhiTexture *tex, TextureAccess *access, TextureStage *stage,
                                               const UsageState &state)
 {
-    auto it = std::find_if(m_textures.begin(), m_textures.end(), [tex](const Texture &t) { return t.tex == tex; });
+    auto it = m_textures.find(tex);
     if (it != m_textures.end()) {
         if (it->access != *access) {
             // Different subresources of a texture may be used for both load
@@ -5577,11 +5576,10 @@ void QRhiPassResourceTracker::registerTexture(QRhiTexture *tex, TextureAccess *a
     }
 
     Texture t;
-    t.tex = tex;
     t.access = *access;
     t.stage = *stage;
     t.stateAtPassBegin = state; // first use -> initial state
-    m_textures.append(t);
+    m_textures.insert(tex, t);
 }
 
 QRhiPassResourceTracker::BufferStage QRhiPassResourceTracker::toPassTrackerBufferStage(QRhiShaderResourceBinding::StageFlags stages)
diff --git a/src/gui/rhi/qrhi_p_p.h b/src/gui/rhi/qrhi_p_p.h
index 2cb96ebaf5..822da528f1 100644
--- a/src/gui/rhi/qrhi_p_p.h
+++ b/src/gui/rhi/qrhi_p_p.h
@@ -503,28 +503,32 @@ public:
                          const UsageState &state);
 
     struct Buffer {
-        QRhiBuffer *buf;
         int slot;
         BufferAccess access;
         BufferStage stage;
         UsageState stateAtPassBegin;
     };
-    const QVector<Buffer> *buffers() const { return &m_buffers; }
+
+    using BufferIterator = QHash<QRhiBuffer *, Buffer>::const_iterator;
+    BufferIterator cbeginBuffers() const { return m_buffers.cbegin(); }
+    BufferIterator cendBuffers() const { return m_buffers.cend(); }
 
     struct Texture {
-        QRhiTexture *tex;
         TextureAccess access;
         TextureStage stage;
         UsageState stateAtPassBegin;
     };
-    const QVector<Texture> *textures() const { return &m_textures; }
+
+    using TextureIterator = QHash<QRhiTexture *, Texture>::const_iterator;
+    TextureIterator cbeginTextures() const { return m_textures.cbegin(); }
+    TextureIterator cendTextures() const { return m_textures.cend(); }
 
     static BufferStage toPassTrackerBufferStage(QRhiShaderResourceBinding::StageFlags stages);
     static TextureStage toPassTrackerTextureStage(QRhiShaderResourceBinding::StageFlags stages);
 
 private:
-    QVector<Buffer> m_buffers;
-    QVector<Texture> m_textures;
+    QHash<QRhiBuffer *, Buffer> m_buffers;
+    QHash<QRhiTexture *, Texture> m_textures;
 };
 
 Q_DECLARE_TYPEINFO(QRhiPassResourceTracker::Buffer, Q_MOVABLE_TYPE);
diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index 5afba774a9..190385d5de 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -2186,7 +2186,6 @@ void QRhiGles2::executeCommandBuffer(QRhiCommandBuffer *cb)
         {
             GLbitfield barriers = 0;
             QRhiPassResourceTracker &tracker(cbD->passResTrackers[cmd.args.barriersForPass.trackerIndex]);
-            const QVector<QRhiPassResourceTracker::Buffer> *buffers = tracker.buffers();
             // we only care about after-write, not any other accesses, and
             // cannot tell if something was written in a shader several passes
             // ago: now the previously written resource may be used with an
@@ -2194,17 +2193,16 @@ void QRhiGles2::executeCommandBuffer(QRhiCommandBuffer *cb)
             // barrier in theory. Hence setting all barrier bits whenever
             // something previously written is used for the first time in a
             // subsequent pass.
-            for (const QRhiPassResourceTracker::Buffer &b : *buffers) {
-                QGles2Buffer::Access accessBeforePass = QGles2Buffer::Access(b.stateAtPassBegin.access);
+            for (auto it = tracker.cbeginBuffers(), itEnd = tracker.cendBuffers(); it != itEnd; ++it) {
+                QGles2Buffer::Access accessBeforePass = QGles2Buffer::Access(it->stateAtPassBegin.access);
                 if (accessBeforePass == QGles2Buffer::AccessStorageWrite
                         || accessBeforePass == QGles2Buffer::AccessStorageReadWrite)
                 {
                     barriers |= GL_ALL_BARRIER_BITS;
                 }
             }
-            const QVector<QRhiPassResourceTracker::Texture> *textures = tracker.textures();
-            for (const QRhiPassResourceTracker::Texture &t : *textures) {
-                QGles2Texture::Access accessBeforePass = QGles2Texture::Access(t.stateAtPassBegin.access);
+            for (auto it = tracker.cbeginTextures(), itEnd = tracker.cendTextures(); it != itEnd; ++it) {
+                QGles2Texture::Access accessBeforePass = QGles2Texture::Access(it->stateAtPassBegin.access);
                 if (accessBeforePass == QGles2Texture::AccessStorageWrite
                         || accessBeforePass == QGles2Texture::AccessStorageReadWrite)
                 {
diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index b7fc50d259..7e2e914af3 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -3556,12 +3556,11 @@ void QRhiVulkan::recordTransitionPassResources(QVkCommandBuffer *cbD, const QRhi
     if (tracker.isEmpty())
         return;
 
-    const QVector<QRhiPassResourceTracker::Buffer> *buffers = tracker.buffers();
-    for (const QRhiPassResourceTracker::Buffer &b : *buffers) {
-        QVkBuffer *bufD = QRHI_RES(QVkBuffer, b.buf);
-        VkAccessFlags access = toVkAccess(b.access);
-        VkPipelineStageFlags stage = toVkPipelineStage(b.stage);
-        QVkBuffer::UsageState s = toVkBufferUsageState(b.stateAtPassBegin);
+    for (auto it = tracker.cbeginBuffers(), itEnd = tracker.cendBuffers(); it != itEnd; ++it) {
+        QVkBuffer *bufD = QRHI_RES(QVkBuffer, it.key());
+        VkAccessFlags access = toVkAccess(it->access);
+        VkPipelineStageFlags stage = toVkPipelineStage(it->stage);
+        QVkBuffer::UsageState s = toVkBufferUsageState(it->stateAtPassBegin);
         if (!s.stage)
             continue;
         if (s.access == access && s.stage == stage) {
@@ -3575,7 +3574,7 @@ void QRhiVulkan::recordTransitionPassResources(QVkCommandBuffer *cbD, const QRhi
         bufMemBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
         bufMemBarrier.srcAccessMask = s.access;
         bufMemBarrier.dstAccessMask = access;
-        bufMemBarrier.buffer = bufD->buffers[b.slot];
+        bufMemBarrier.buffer = bufD->buffers[it->slot];
         bufMemBarrier.size = VK_WHOLE_SIZE;
         df->vkCmdPipelineBarrier(cbD->cb, s.stage, stage, 0,
                                  0, nullptr,
@@ -3583,13 +3582,12 @@ void QRhiVulkan::recordTransitionPassResources(QVkCommandBuffer *cbD, const QRhi
                                  0, nullptr);
     }
 
-    const QVector<QRhiPassResourceTracker::Texture> *textures = tracker.textures();
-    for (const QRhiPassResourceTracker::Texture &t : *textures) {
-        QVkTexture *texD = QRHI_RES(QVkTexture, t.tex);
-        VkImageLayout layout = toVkLayout(t.access);
-        VkAccessFlags access = toVkAccess(t.access);
-        VkPipelineStageFlags stage = toVkPipelineStage(t.stage);
-        QVkTexture::UsageState s = toVkTextureUsageState(t.stateAtPassBegin);
+    for (auto it = tracker.cbeginTextures(), itEnd = tracker.cendTextures(); it != itEnd; ++it) {
+        QVkTexture *texD = QRHI_RES(QVkTexture, it.key());
+        VkImageLayout layout = toVkLayout(it->access);
+        VkAccessFlags access = toVkAccess(it->access);
+        VkPipelineStageFlags stage = toVkPipelineStage(it->stage);
+        QVkTexture::UsageState s = toVkTextureUsageState(it->stateAtPassBegin);
         if (s.access == access && s.stage == stage && s.layout == layout) {
             if (!accessIsWrite(access))
                 continue;