Improve generic type argument inference. (#3370)

* Improve generic type argument inference.

* Fix.

* Fix.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

2 files changed, 61 insertions, 0 deletions

diff --git a/tests/language-feature/generics/generic-overload-disambiguation.slang b/tests/language-feature/generics/generic-overload-disambiguation.slang
new file mode 100644
index 000000000..57d7a6d7e
--- /dev/null
+++ b/tests/language-feature/generics/generic-overload-disambiguation.slang
@@ -0,0 +1,42 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj -output-using-type
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -vk -shaderobj -output-using-type
+
+// Test that calls to overloaded generic functions can be resolved to prefer the
+// generic candidate with more specialized constraints.
+interface IBase
+{
+    float get();
+}
+interface IDerived : IBase
+{
+
+}
+float process<T>(T v)
+{
+    return 0.0;
+}
+float process<T : IBase>(T v)
+{
+    return v.get();
+}
+
+float process<T : IDerived>(T v)
+{
+    return v.get() + 1.0;
+}
+
+struct D : IDerived
+{
+    float get() { return 1.0; }
+}
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    D d;
+    outputBuffer[0] = process(d);
+    // CHECK: 2.0
+}
diff --git a/tests/language-feature/generics/vector-generic.slang b/tests/language-feature/generics/vector-generic.slang
new file mode 100644
index 000000000..6bcd88018
--- /dev/null
+++ b/tests/language-feature/generics/vector-generic.slang
@@ -0,0 +1,19 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj -output-using-type
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -vk -shaderobj -output-using-type
+
+// Test that generic argument inference works when passing a scalar to a generic vector parameter.
+T process<T, let N : int>(vector<T, N> v)
+{
+    return v[0];
+}
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    float a = 1.0;
+    outputBuffer[0] = process(a);
+    // CHECK: 1.0
+}