From a9bafd27237262a7ae1e0cff6729573e917f1c4b Mon Sep 17 00:00:00 2001
From: Jake Turner <jake@evansturner.co.uk>
Date: Wed, 6 May 2026 14:47:16 +0100
Subject: [PATCH] Spirv debugger handle quadScope case when subgroupSize >
 workgroupSize

---
 renderdoc/driver/vulkan/vk_shaderdebug.cpp | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/renderdoc/driver/vulkan/vk_shaderdebug.cpp b/renderdoc/driver/vulkan/vk_shaderdebug.cpp
index 83745f6da..303d6be0c 100644
--- a/renderdoc/driver/vulkan/vk_shaderdebug.cpp
+++ b/renderdoc/driver/vulkan/vk_shaderdebug.cpp
@@ -6745,16 +6745,16 @@ ShaderDebugTrace *VulkanReplay::DebugComputeCommon(ShaderStage stage, uint32_t e
         uint32_t quadZ = compData->threadid[2];
         quadId = quadX + (quadY * countQuadX) + (quadZ * countQuadY * countQuadX);
         quadLaneIndex = (compData->threadid[0] % quadW) + (compData->threadid[1] % quadH) * 2;
-
-        apiWrapper->thread_props[lane][(size_t)rdcspv::ThreadProperty::QuadLane] = quadLaneIndex;
-        apiWrapper->thread_props[lane][(size_t)rdcspv::ThreadProperty::QuadId] =
-            quadId + quadIdOffset;
       }
 
       if(hasWorkgroupScope)
       {
         if(hasQuadScope)
         {
+          // There won't be any data them for inactive lanes
+          if(subgroupData->isActive == 0)
+            continue;
+
           // quad scope, derive the lane from the quad layout
           lane = quadId * 4 + quadLaneIndex;
         }
@@ -6766,6 +6766,13 @@ ShaderDebugTrace *VulkanReplay::DebugComputeCommon(ShaderStage stage, uint32_t e
         }
       }
 
+      if(hasQuadScope)
+      {
+        apiWrapper->thread_props[lane][(size_t)rdcspv::ThreadProperty::QuadLane] = quadLaneIndex;
+        apiWrapper->thread_props[lane][(size_t)rdcspv::ThreadProperty::QuadId] =
+            quadId + quadIdOffset;
+      }
+
       if(rdcfixedarray<uint32_t, 3>(compData->threadid) == threadid && subgroupData->isActive)
         laneIndex = lane;