Fix spirv emit that leads to pathological downstream time. (#3546)

1 files changed, 34 insertions, 0 deletions

diff --git a/tests/spirv/array-param-gep.slang b/tests/spirv/array-param-gep.slang
new file mode 100644
index 000000000..1a0de0c39
--- /dev/null
+++ b/tests/spirv/array-param-gep.slang
@@ -0,0 +1,34 @@
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -entry computeMain -stage compute -emit-spirv-directly
+
+// Check that we are not generating spirv that loads a global resource array into a SSA register,
+// instead, these arrays should always be accessed via direct OpAccessChain operations to avoid
+// creating a lot of local load/stores in the driver compiler.
+
+struct Scene
+{
+    SamplerState samplers[256];
+    Texture2D textures[100];
+}
+
+ParameterBlock<Scene> scene;
+struct Material
+{
+    int sampler;
+    int texture;
+}
+
+RWStructuredBuffer<float4> result;
+
+float4 shade(Scene scene, Material mat)
+{
+    return scene.textures[mat.texture].SampleLevel(scene.samplers[mat.sampler], float2(0,0), 0);
+}
+
+[numthreads(1,1,1)]
+void computeMain(uniform Material mat)
+{
+    // CHECK: OpEntryPoint
+    // CHECK-NOT: OpLoad {{.*}} %scene{{.*}}samplers
+    // CHECK-NOT: OpLoad {{.*}} %scene{{.*}}textures
+    result[0] = shade(scene, mat);
+}
\ No newline at end of file