Support generic type constraints when implicitly invoking generic

Fixes #326

This basically just copy-pastes logic from the explicit case over to the implicit case.
After we've solved for the explicit type/value arguments, we loop over the constraints and for each one we try to find a suitable subtype witness to use (after substituting in the arguments solved so far).

This change includes a test case for the new functionality.

1 files changed, 40 insertions, 0 deletions

diff --git a/tests/compute/implicit-generic-app.slang b/tests/compute/implicit-generic-app.slang
new file mode 100644
index 000000000..d917a5f9a
--- /dev/null
+++ b/tests/compute/implicit-generic-app.slang
@@ -0,0 +1,40 @@
+//TEST(compute):COMPARE_COMPUTE:-xslang -use-ir
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):dxbinding(0),glbinding(0),out
+
+// Testing that we can implicitly specialize a generic
+// that has a constrained type parameter.
+
+
+interface ISimple
+{
+	int getVal();
+}
+
+struct Simple : ISimple
+{
+	int val;
+
+	int getVal() { return val; }
+};
+
+int doIt<T : ISimple>(T obj)
+{
+	return obj.getVal();
+}
+
+int test(int val)
+{
+	Simple simple;
+	simple.val = val;
+	return doIt(simple);
+}
+
+RWStructuredBuffer<int> outputBuffer : register(u0);
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+	int tid = (int) dispatchThreadID.x;
+	int outVal = test(tid);
+	outputBuffer[tid] = outVal;
+}
\ No newline at end of file