Fix NonUniformResourceIndex legalization for SPIRV. (#4133)

* Fix NonUniformResourceIndex legalization for SPIRV.

* Update gh-4131.slang

1 files changed, 31 insertions, 0 deletions

diff --git a/tests/bugs/gh-4131.slang b/tests/bugs/gh-4131.slang
new file mode 100644
index 000000000..d72bc5d0d
--- /dev/null
+++ b/tests/bugs/gh-4131.slang
@@ -0,0 +1,31 @@
+//TEST:SIMPLE(filecheck=CHECK): -target spirv
+
+//CHECK: OpEntryPoint
+
+struct TypeA {
+  float4 placeholder;
+};
+struct TypeB {
+  float4 placeholder;
+};
+
+[[vk::binding(0, 0)]]
+StructuredBuffer<TypeA> a_buffers[] : register(t0, space0);
+[[vk::binding(0, 1)]]
+StructuredBuffer<TypeB> b_buffer : register(t0, space0);
+
+struct VertexIn {
+  int32_t vert_idx : SV_VertexID;
+  [[KnownBuiltin("DrawIndex")]]
+  uint32_t draw_idx : POSITION0;
+};
+
+[shader("vertex")]
+float4 vert(VertexIn i) : SV_POSITION {
+  // Proper usage of NonUniformResourceIndex works fine
+  float4 a =
+      a_buffers[NonUniformResourceIndex(i.draw_idx)][i.vert_idx].placeholder;
+  // Incorrect usage but dxc compiles this with no warning  
+  float4 b = b_buffer[NonUniformResourceIndex(i.draw_idx)].placeholder;
+  return a + b;
+}