FIFOQueue: Optimize PopRange() for trivially-copyable types

stenzek · Jul 2, 2024 · da2dc5f · da2dc5f
1 parent 1963d80
commit da2dc5f
Showing 1 changed file with 17 additions and 2 deletions.
diff --git a/src/common/fifo_queue.h b/src/common/fifo_queue.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2019-2022 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
 #pragma once
@@ -71,7 +71,7 @@ class FIFOQueue
   }
 
   // faster version of push_back_range for POD types which can be memcpy()ed
-  template<class Y = T, std::enable_if_t<std::is_standard_layout_v<Y>&& std::is_trivial_v<Y>, int> = 0>
+  template<class Y = T, std::enable_if_t<std::is_standard_layout_v<Y> && std::is_trivial_v<Y>, int> = 0>
   void PushRange(const T* data, u32 size)
   {
     DebugAssert((m_size + size) <= CAPACITY);
@@ -137,10 +137,25 @@ class FIFOQueue
     return val;
   }
 
+  template<class Y = T, std::enable_if_t<std::is_standard_layout_v<Y> && std::is_trivial_v<Y>, int> = 0>
   void PopRange(T* out_data, u32 count)
   {
     DebugAssert(m_size >= count);
+    do
+    {
+      const u32 contig_count = std::min(count, CAPACITY - m_head);
+      std::memcpy(out_data, &m_ptr[m_head], sizeof(T) * contig_count);
+      out_data += contig_count;
+      m_head = (m_head + contig_count) % CAPACITY;
+      m_size -= contig_count;
+      count -= contig_count;
+    } while (count > 0);
+  }
 
+  template<class Y = T, std::enable_if_t<!std::is_standard_layout_v<Y> || !std::is_trivial_v<Y>, int> = 0>
+  void PopRange(T* out_data, u32 count)
+  {
+    DebugAssert(m_size >= count);
     for (u32 i = 0; i < count; i++)
     {
       out_data[i] = std::move(m_ptr[m_head]);