Variadic Generics Part 2: IR lowering and specialization. (#4849)

* Variadic Generics Part 2: IR lowering and specialization.

* Update design doc status.

* Update design doc.

* Resolve review comments.

3 files changed, 118 insertions, 0 deletions

diff --git a/tests/language-feature/generics/tuple.slang b/tests/language-feature/generics/tuple.slang
new file mode 100644
index 000000000..b8c70f872
--- /dev/null
+++ b/tests/language-feature/generics/tuple.slang
@@ -0,0 +1,27 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj -output-using-type
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+T writeSingle<T : __BuiltinFloatingPointType>(inout int offset, T value)
+{
+    outputBuffer[offset++] = __realCast<float>(value);
+    return value;
+}
+
+void write<each T : __BuiltinFloatingPointType>(Tuple<T> tuple)
+{
+    int offset = 0;
+    expand writeSingle(offset, each tuple);
+}
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    // CHECK: 1.0
+    // CHECK: 2.0
+    // CHECK: 3.0
+    // CHECK: 4.0
+    let tuple = Tuple<float, half, float, float>(1.0, 2.0h, 3.0, 4.0);
+    write(tuple);
+}
diff --git a/tests/language-feature/generics/variadic-0.slang b/tests/language-feature/generics/variadic-0.slang
new file mode 100644
index 000000000..8ee41647f
--- /dev/null
+++ b/tests/language-feature/generics/variadic-0.slang
@@ -0,0 +1,47 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj -output-using-type
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+struct S<T:__BuiltinArithmeticType>
+{
+    T v;
+    __init(T x)
+    {
+        v = x;
+    }
+}
+
+
+S<T> makeS<T:__BuiltinArithmeticType>(T x)
+{
+    return S<T>(x);
+}
+bool cmp<T:__BuiltinArithmeticType>(T a, int b)
+{
+    return a > __int_cast<T>(b);
+}
+void accept<each T>(expand each T value) {}
+
+T writeSingle<T : __BuiltinFloatingPointType>(inout int offset, T value)
+{
+    outputBuffer[offset++] = __realCast<float>(value);
+    return value;
+}
+
+void write<each T : __BuiltinFloatingPointType>(expand S<each T> value)
+{
+    int offset = 0;
+    accept(expand writeSingle(offset, cmp((each value).v, 0) ? (each value).v : __realCast<each T>(0.0)));
+}
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    // CHECK: 1.0
+    // CHECK: 2.0
+    // CHECK: 3.0
+    // CHECK: 4.0
+    write();
+    write(makeS(1.0), makeS(2.0h), makeS(3.0), makeS(4.0));
+}
diff --git a/tests/language-feature/generics/variadic-void.slang b/tests/language-feature/generics/variadic-void.slang
new file mode 100644
index 000000000..d44acbfd4
--- /dev/null
+++ b/tests/language-feature/generics/variadic-void.slang
@@ -0,0 +1,44 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj -output-using-type
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+struct S<T>
+{
+    T v;
+    __init(T x)
+    {
+        v = x;
+    }
+}
+
+
+S<T> makeS<T>(T x)
+{
+    return S<T>(x);
+}
+
+void accept<each T>(expand each T value) {}
+
+void writeSingle<T : __BuiltinFloatingPointType>(T value)
+{
+    static int counter = 0;
+    outputBuffer[counter++] = __realCast<float>(value);
+    //return value;
+}
+
+void write<each T : __BuiltinFloatingPointType>(expand S<each T> value)
+{
+    accept(expand writeSingle((each value).v));
+}
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    // CHECK: 1.0
+    // CHECK: 2.0
+    // CHECK: 3.0
+    // CHECK: 4.0
+    write(makeS(1.0), makeS(2.0), makeS(3.0), makeS(4.0));
+    write();
+}
\ No newline at end of file