commit 36e043fa6d468fff9865a00200c0face80dd7727
author Nicolas Capens <capn@google.com> Wed Nov 23 14:24:41 2022 -0500
committer swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com <swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com> Sat Dec 10 03:54:41 2022 +0000
tree 4eb1ae248725a786c6181451ca03c4afee8ef680
parent 6ebc3347af9dc778d1a024801ca27368d0d720c9

Add a macro for indicating unoptimized code paths

This should be used when knowingly leaving some code unoptimized, so it
can more easily be found again later when investigating performance
issues or during optimization efforts.

Bug: b/260246698
Change-Id: I6287e98493c5ad4c6c358d4438233b402bad1d81
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/69829
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Commit-Queue: Nicolas Capens <nicolascapens@google.com>

src/Device/Context.cpp

diff --git a/src/Device/Context.cpp b/src/Device/Context.cpp
index 0d88fce..cb8131f 100644
--- a/src/Device/Context.cpp
+++ b/src/Device/Context.cpp
@@ -350,7 +350,6 @@
 	}
 }
 
-// TODO(b/137740918): Optimize instancing to use a single draw call.
 void Inputs::advanceInstanceAttributes(bool dynamicInstanceStride)
 {
 	for(uint32_t i = 0; i < vk::MAX_VERTEX_INPUT_BINDINGS; i++)

src/System/Debug.hpp

diff --git a/src/System/Debug.hpp b/src/System/Debug.hpp
index 10457b3..f3d3932 100644
--- a/src/System/Debug.hpp
+++ b/src/System/Debug.hpp
@@ -159,4 +159,14 @@
 		} while(0)
 #endif
 
+// A macro to indicate unoptimized code paths.
+#define UNOPTIMIZED(message, ...)                                                            \
+	do                                                                                       \
+	{                                                                                        \
+		if(false)                                                                            \
+		{                                                                                    \
+			sw::warn("%s:%d UNOPTIMIZED: " message "\n", __FILE__, __LINE__, ##__VA_ARGS__); \
+		}                                                                                    \
+	} while(0)
+
 #endif  // Debug_hpp

src/Vulkan/VkCommandBuffer.cpp

diff --git a/src/Vulkan/VkCommandBuffer.cpp b/src/Vulkan/VkCommandBuffer.cpp
index f333d1f..3bfe933 100644
--- a/src/Vulkan/VkCommandBuffer.cpp
+++ b/src/Vulkan/VkCommandBuffer.cpp
@@ -957,7 +957,11 @@
 				}
 			}
 
-			inputs.advanceInstanceAttributes(hasDynamicVertexStride);
+			if(instanceCount > 1)
+			{
+				UNOPTIMIZED("Optimize instancing to use a single draw call.");  // TODO(b/137740918)
+				inputs.advanceInstanceAttributes(hasDynamicVertexStride);
+			}
 		}
 	}
 };