CPU unsized array documentation and another example (#1080)

* WIP: Unsized arrays on CPU.

* unbounded-array-of-array working on CPU.

* Test that has an unbounded array of array directly (ie without wrapping with ParameterBlock). Test works on CPU.

* Remove some left over comments.

* Added documention on unsized array usage on CPU targets.

2 files changed, 40 insertions, 0 deletions

diff --git a/tests/compute/unbounded-array-of-array-syntax.slang b/tests/compute/unbounded-array-of-array-syntax.slang
new file mode 100644
index 000000000..fdc04c95e
--- /dev/null
+++ b/tests/compute/unbounded-array-of-array-syntax.slang
@@ -0,0 +1,32 @@
+//DISABLE_TEST:CPU_REFLECTION: -profile cs_5_0 -entry computeMain -target cpp 
+//TEST(compute):COMPARE_COMPUTE_EX:-cpu -compute 
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0 0 0 0], stride=4):dxbinding(0),glbinding(0),out,name outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+//TEST_INPUT:array(size=2):name g_aoa
+RWStructuredBuffer<int> g_aoa[];
+
+//TEST_INPUT:ubuffer(data=[1 2 3 4], stride=4):name=g_aoa[0]
+//TEST_INPUT:ubuffer(data=[8 17 34], stride=4):name=g_aoa[1]
+
+[numthreads(8, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int index = int(dispatchThreadID.x);
+    
+    int baseIndex = index >> 2;
+    int innerIndex = index & 3;
+
+    RWStructuredBuffer<int> buffer = g_aoa[baseIndex];
+
+    // Get the size 
+    uint bufferCount, bufferStride;
+    buffer.GetDimensions(bufferCount, bufferStride);
+
+    if (innerIndex >= bufferCount)
+    {
+        innerIndex = bufferCount - 1;
+    }
+	outputBuffer[index] = buffer[innerIndex]; 
+}
\ No newline at end of file
diff --git a/tests/compute/unbounded-array-of-array-syntax.slang.expected.txt b/tests/compute/unbounded-array-of-array-syntax.slang.expected.txt
new file mode 100644
index 000000000..aeec8496c
--- /dev/null
+++ b/tests/compute/unbounded-array-of-array-syntax.slang.expected.txt
@@ -0,0 +1,8 @@
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