Preliminary support for realtime clock (#2772)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Initial support for realtime clock.

* Add realtime-clock render feature where seems appropriate.

* Fixes to make NVAPI compile properly.
Change realtime-clock.slang check to use maths that can't overflow.

2 files changed, 36 insertions, 0 deletions

diff --git a/tests/slang-extension/realtime-clock.slang b/tests/slang-extension/realtime-clock.slang
new file mode 100644
index 000000000..67d6e2ab0
--- /dev/null
+++ b/tests/slang-extension/realtime-clock.slang
@@ -0,0 +1,31 @@
+// realtime-clock.slang
+
+// TODO(JS):
+// Disable FXC DX11/DX12 because currently FXC can't compile nvHLSLExtns.h 
+
+//DISABLE_TEST(compute):COMPARE_COMPUTE_EX:-cpu -compute -output-using-type -shaderobj
+//DISABLE_TEST(compute):COMPARE_COMPUTE_EX:-dx11 -slang -compute  -output-using-type -nvapi-slot u0 -shaderobj
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX:-vk -compute -render-feature realtime-clock -output-using-type -shaderobj
+//DISABLE_TEST(compute):COMPARE_COMPUTE_EX:-d3d12 -compute -output-using-type -nvapi-slot u0 -shaderobj
+//TEST(compute):COMPARE_COMPUTE_EX:-d3d12 -compute -use-dxil  -output-using-type -nvapi-slot u0 -shaderobj
+//TEST(compute):COMPARE_COMPUTE_EX:-cuda -compute -output-using-type -shaderobj
+
+// The test doesn't directly use this, but having this defined makes the 0 slot available if NVAPI is going to be used
+// Only strictly necessary on the D3D11/D3D12 paths
+//TEST_INPUT:ubuffer(data=[0 0 0 0 ], stride=4):name=nvapiBuffer
+RWStructuredBuffer<int> nvapiBuffer;
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+[numthreads(8, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    uint idx = dispatchThreadID.x;
+    
+    uint ticksLow = getRealtimeClockLow();
+    
+    uint2 ticks = getRealtimeClock();
+    
+    outputBuffer[idx] = int(idx + ((ticksLow ^ ticks.x) ^ (ticks.x ^ ticksLow)));
+}
\ No newline at end of file
diff --git a/tests/slang-extension/realtime-clock.slang.expected.txt b/tests/slang-extension/realtime-clock.slang.expected.txt
new file mode 100644
index 000000000..9d029e9f2
--- /dev/null
+++ b/tests/slang-extension/realtime-clock.slang.expected.txt
@@ -0,0 +1,5 @@
+type: int32_t
+0
+1
+2
+3