self-review: specify required feature

Author: Finn Plummer

test/Feature/RootSignatures/StaticSamplers.test

@@ -133,6 +133,8 @@ DescriptorSets:
 # Unsupported: https://github.com/llvm/llvm-project/issues/101558
 # XFAIL: Clang
 
+# REQUIRES: Derivatives
+
 # RUN: split-file %s %t
 # RUN: %dxc_target -T cs_6_6 -Fo %t.o %t/source.hlsl
 # RUN: %offloader %t/pipeline.yaml %t.o

test/lit.cfg.py

@@ -47,6 +47,10 @@
     ToolSubst("imgdiff", FindTool("imgdiff")),
 ]
 
+def getHighestShaderModel(features):
+    sm = features.get("HighestShaderModel", 6.0)
+    major, minor = str(sm).split('.')
+    return int(major), int(minor)
 
 def setDeviceFeatures(config, device, compiler):
     API = device["API"]
@@ -74,6 +78,11 @@ def setDeviceFeatures(config, device, compiler):
 
     config.available_features.add("%s-%s" % (compiler, API))
 
+    HighestShaderModel = getHighestShaderModel(device["Features"])
+    if (6, 6) <= HighestShaderModel:
+        # https://github.com/microsoft/DirectX-Specs/blob/master/d3d/HLSL_ShaderModel6_6.md#derivatives
+        config.available_features.add("Derivatives")
+
     if device["API"] == "DirectX":
         if device["Features"].get("Native16BitShaderOpsSupported", False):
             config.available_features.add("Int16")