From 296bff695adde81db7160e668553491f6d2b11a1 Mon Sep 17 00:00:00 2001
From: luciechoi <ychoi0407@gmail.com>
Date: Fri, 17 Oct 2025 00:34:47 +0000
Subject: [PATCH 1/3] Add unit test for maximal reconvergence

---
 .../MaximalReconvergence/loop_peeling.test    | 44 ++++++++++++++++
 .../subgroup_uniform_control_flow.test        | 52 +++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 test/Feature/MaximalReconvergence/loop_peeling.test
 create mode 100644 test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test

diff --git a/test/Feature/MaximalReconvergence/loop_peeling.test b/test/Feature/MaximalReconvergence/loop_peeling.test
new file mode 100644
index 00000000..1143f628
--- /dev/null
+++ b/test/Feature/MaximalReconvergence/loop_peeling.test
@@ -0,0 +1,44 @@
+#--- source.hlsl
+RWStructuredBuffer<uint> Out : register(u0);
+
+[numthreads(8,1,1)]
+void main(uint3 TID : SV_GroupThreadID) {
+    for (uint i = 0; i < 8; i++) {
+        if (i == TID.x) {
+            Out[TID.x] = WaveActiveMax(TID.x);
+            break;
+        }
+    }
+}
+
+//--- pipeline.yaml
+
+---
+Shaders:
+  - Stage: Compute
+    Entry: main
+    DispatchSize: [1, 1, 1]
+Buffers:
+  - Name: Out
+    Format: UInt32
+    Data: [ 0, 0, 0, 0, 0, 0, 0, 0 ]
+DescriptorSets:
+  - Resources:
+    - Name: Out
+      Kind: RWStructuredBuffer
+      DirectXBinding:
+        Register: 0
+        Space: 0
+      VulkanBinding:
+        Binding: 0
+...
+
+#--- end
+
+# RUN: split-file %s %t
+# RUN: %dxc_target -T cs_6_5 -fspv-enable-maximal-reconvergence -Fo %t.o %t/source.hlsl
+# RUN: %offloader %t/pipeline.yaml %t.o | FileCheck %s
+
+# CHECK: Name: Out
+# CHECK: Format: UInt32
+# CHECK: Data: [ 0, 1, 2, 3, 4, 5, 6, 7 ]
diff --git a/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test b/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test
new file mode 100644
index 00000000..ccfe1dbf
--- /dev/null
+++ b/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test
@@ -0,0 +1,52 @@
+#--- source.hlsl
+RWStructuredBuffer<uint> Out : register(u0);
+
+[numthreads(8,1,1)]
+void main(uint3 TID : SV_GroupThreadID) {
+    // First non-uniform branch
+    if (TID.x < 4) {
+        // Second non-uniform branch
+        if (TID.x % 2 == 0) {
+            Out[TID.x] = WaveActiveSum(TID.x);
+        } else {
+            Out[TID.x] = WaveActiveMax(TID.x);
+        }
+        // Must reconverge here with maximal reconvergence
+        Out[TID.x] += WaveActiveMax(TID.x);
+    } else {
+        Out[4] = WaveActiveMax(TID.x);
+    }
+    Out[TID.x] += WaveActiveMax(TID.x);
+}
+
+//--- pipeline.yaml
+
+---
+Shaders:
+  - Stage: Compute
+    Entry: main
+    DispatchSize: [1, 1, 1]
+Buffers:
+  - Name: Out
+    Format: UInt32
+    Data: [ 0, 0, 0, 0, 0, 0, 0, 0 ]
+DescriptorSets:
+  - Resources:
+    - Name: Out
+      Kind: RWStructuredBuffer
+      DirectXBinding:
+        Register: 0
+        Space: 0
+      VulkanBinding:
+        Binding: 0
+...
+
+#--- end
+
+# RUN: split-file %s %t
+# RUN: %dxc_target -T cs_6_0 -fspv-enable-maximal-reconvergence -Fo %t.o %t/source.hlsl
+# RUN: %offloader %t/pipeline.yaml %t.o | FileCheck %s
+
+# CHECK: Name: Out
+# CHECK: Format: UInt32
+# CHECK: Data: [ 12, 13, 12, 13, 14, 7, 7, 7 ]

From 7b90ab1ba51d92a715580172fc9396f255b4291e Mon Sep 17 00:00:00 2001
From: luciechoi <ychoi0407@gmail.com>
Date: Tue, 21 Oct 2025 20:42:18 +0000
Subject: [PATCH 2/3] Trigger pipeline with SPIR-V Tools update


From 557f48fcbbf36af02715995088eb7768a0c1e7c5 Mon Sep 17 00:00:00 2001
From: luciechoi <ychoi0407@gmail.com>
Date: Tue, 21 Oct 2025 21:15:57 +0000
Subject: [PATCH 3/3] Add extension requirement

---
 test/Feature/MaximalReconvergence/loop_peeling.test           | 4 ++++
 .../MaximalReconvergence/subgroup_uniform_control_flow.test   | 1 +
 2 files changed, 5 insertions(+)

diff --git a/test/Feature/MaximalReconvergence/loop_peeling.test b/test/Feature/MaximalReconvergence/loop_peeling.test
index 1143f628..12f1d272 100644
--- a/test/Feature/MaximalReconvergence/loop_peeling.test
+++ b/test/Feature/MaximalReconvergence/loop_peeling.test
@@ -34,6 +34,10 @@ DescriptorSets:
 ...
 
 #--- end
+# UNSUPPORTED: !VK_KHR_shader_maximal_reconvergence
+
+# BUG: https://github.com/llvm/llvm-project/issues/164496
+# XFAIL: Clang
 
 # RUN: split-file %s %t
 # RUN: %dxc_target -T cs_6_5 -fspv-enable-maximal-reconvergence -Fo %t.o %t/source.hlsl
diff --git a/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test b/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test
index ccfe1dbf..841fd8a4 100644
--- a/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test
+++ b/test/Feature/MaximalReconvergence/subgroup_uniform_control_flow.test
@@ -42,6 +42,7 @@ DescriptorSets:
 ...
 
 #--- end
+# UNSUPPORTED: !VK_KHR_shader_maximal_reconvergence
 
 # RUN: split-file %s %t
 # RUN: %dxc_target -T cs_6_0 -fspv-enable-maximal-reconvergence -Fo %t.o %t/source.hlsl