From 716282da485b575457f3de06e1a9cece5cb90535 Mon Sep 17 00:00:00 2001
From: Jake Turner <jake@evansturner.co.uk>
Date: Wed, 4 Feb 2026 13:24:50 +1300
Subject: [PATCH] Add required builtin inputs to the PostVS Task/Mesh entry
 points

If the SPIRV module contains multiple entry points then checking for the existance of the builtin variable is not enough to guarantee it is in the entry point inputs
---
 renderdoc/driver/vulkan/vk_postvs.cpp | 30 +++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/renderdoc/driver/vulkan/vk_postvs.cpp b/renderdoc/driver/vulkan/vk_postvs.cpp
index 6a574d467..70b9311a4 100644
--- a/renderdoc/driver/vulkan/vk_postvs.cpp
+++ b/renderdoc/driver/vulkan/vk_postvs.cpp
@@ -1697,6 +1697,7 @@ static void AddTaskShaderPayloadStores(const rdcarray<SpecConstant> &specInfo,
   }
 
   rdcarray<rdcspv::Id> newGlobals;
+  rdcarray<rdcspv::Id> requiredBuiltInInputs;
 
   newGlobals.push_back(outSlotAddr);
 
@@ -1708,6 +1709,7 @@ static void AddTaskShaderPayloadStores(const rdcarray<SpecConstant> &specInfo,
         ops, ShaderStage::Mesh, rdcspv::BuiltIn::LocalInvocationIndex, uint32Type);
     if(newGlobal != rdcspv::Id())
       newGlobals.push_back(newGlobal);
+    requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::LocalInvocationIndex));
   }
 
   // calculate base address for our task group's data
@@ -1727,6 +1729,8 @@ static void AddTaskShaderPayloadStores(const rdcarray<SpecConstant> &specInfo,
       if(newGlobal != rdcspv::Id())
         newGlobals.push_back(newGlobal);
 
+      requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::WorkgroupId));
+      requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::NumWorkgroups));
       // x + y * xsize + z * xsize * ysize
 
       rdcspv::Id xsize = locationCalculate.add(
@@ -1799,6 +1803,12 @@ static void AddTaskShaderPayloadStores(const rdcarray<SpecConstant> &specInfo,
     editor.Remove(it);
 
     entry.iface.append(newGlobals);
+    for(rdcspv::Id id : requiredBuiltInInputs)
+    {
+      if(entry.iface.contains(id))
+        continue;
+      entry.iface.push_back(id);
+    }
 
     editor.AddOperation(it, entry);
   }
@@ -1909,6 +1919,7 @@ static void ConvertToFixedTaskFeeder(const rdcarray<SpecConstant> &specInfo,
   editor.SetName(baseAddrId, "baseAddr");
 
   rdcarray<rdcspv::Id> newGlobals;
+  rdcarray<rdcspv::Id> requiredBuiltInInputs;
 
   rdcspv::Id entryID;
 
@@ -2037,6 +2048,9 @@ static void ConvertToFixedTaskFeeder(const rdcarray<SpecConstant> &specInfo,
     if(newGlobal != rdcspv::Id())
       newGlobals.push_back(newGlobal);
 
+    requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::WorkgroupId));
+    requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::NumWorkgroups));
+
     // x + y * xsize + z * xsize * ysize
 
     rdcspv::Id xsize =
@@ -2164,6 +2178,12 @@ static void ConvertToFixedTaskFeeder(const rdcarray<SpecConstant> &specInfo,
     editor.Remove(it);
 
     entry.iface.append(newGlobals);
+    for(rdcspv::Id id : requiredBuiltInInputs)
+    {
+      if(entry.iface.contains(id))
+        continue;
+      entry.iface.push_back(id);
+    }
 
     editor.AddOperation(it, entry);
   }
@@ -2211,6 +2231,7 @@ static void AddMeshShaderOutputStores(const ShaderReflection &refl,
   editor.SetName(baseAddrId, "baseAddr");
 
   rdcarray<rdcspv::Id> newGlobals;
+  rdcarray<rdcspv::Id> requiredBuiltInInputs;
 
   newGlobals.push_back(outSlotAddr);
 
@@ -2608,6 +2629,8 @@ static void AddMeshShaderOutputStores(const ShaderReflection &refl,
       if(newGlobal != rdcspv::Id())
         newGlobals.push_back(newGlobal);
 
+      requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::WorkgroupId));
+      requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::NumWorkgroups));
       // x + y * xsize + z * xsize * ysize
 
       rdcspv::Id xsize = locationCalculate.add(
@@ -2689,6 +2712,7 @@ static void AddMeshShaderOutputStores(const ShaderReflection &refl,
         ops, ShaderStage::Mesh, rdcspv::BuiltIn::LocalInvocationIndex, uint32Type);
     if(newGlobal != rdcspv::Id())
       newGlobals.push_back(newGlobal);
+    requiredBuiltInInputs.push_back(editor.GetBuiltInVariable(rdcspv::BuiltIn::LocalInvocationIndex));
   }
 
   // add the globals we registered
@@ -2702,6 +2726,12 @@ static void AddMeshShaderOutputStores(const ShaderReflection &refl,
     editor.Remove(it);
 
     entry.iface.append(newGlobals);
+    for(rdcspv::Id id : requiredBuiltInInputs)
+    {
+      if(entry.iface.contains(id))
+        continue;
+      entry.iface.push_back(id);
+    }
 
     editor.AddOperation(it, entry);
   }