Make sizeof(T) & alignof(T) of generic types work as compile-time constants (#7213)

* Make sizeof(generic) work as compile-time constant

* format code

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/tests/hlsl-intrinsic/size-of/size-of-compile-time.slang b/tests/hlsl-intrinsic/size-of/size-of-compile-time.slang
new file mode 100644
index 000000000..64e2f640b
--- /dev/null
+++ b/tests/hlsl-intrinsic/size-of/size-of-compile-time.slang
@@ -0,0 +1,41 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK):-cpu -compute -shaderobj
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK):-slang -compute -shaderobj
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK):-slang -compute -dx12 -shaderobj
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=CHECK):-vk -compute -shaderobj
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK):-cuda -compute -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
+
+RWStructuredBuffer<int> outputBuffer;
+
+struct Thing<T>
+{
+    uint8_t data[sizeof(T)];
+};
+
+struct AlignThing<T>
+{
+    uint8_t data[alignof(T)];
+};
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    const int idx = asint(dispatchThreadID.x);
+
+    int size = 0;
+    
+    switch (idx)
+    {   
+        case 0: size = sizeof(Thing<float>); break;
+        case 1: size = sizeof(Thing<float3>); break;
+        case 2: size = sizeof(AlignThing<float>); break;
+        case 3: size = sizeof(AlignThing<float3>); break;
+    }
+
+    // CHECK: 4
+    // CHECK-NEXT: C
+    // CHECK: 4
+    // CHECK-NEXT: 4
+    outputBuffer[idx] = size;
+}