Matrix swizzle writes (#2713)

* Add a bunch of builder emit wrappers for constant indices

To avoid cluttering any calling code with int instruction construction

* Matrix swizzle stores

Closes https://github.com/shader-slang/slang/issues/2512

* Matrix swizzle store tests

* Squash vs warnings

* Select scalar for singular swizzles

* Test singular swizzle materialization

* Use IRIntegerValue over UInt for IR wrappers

* Correct size of swizzle vector type

* Remove variable shadowing

1 files changed, 36 insertions, 0 deletions

diff --git a/tests/language-feature/swizzles/matrix-swizzle-write-array.slang b/tests/language-feature/swizzles/matrix-swizzle-write-array.slang
new file mode 100644
index 000000000..7d266b8cd
--- /dev/null
+++ b/tests/language-feature/swizzles/matrix-swizzle-write-array.slang
@@ -0,0 +1,36 @@
+//TEST(compute):COMPARE_COMPUTE: -compute -shaderobj -output-using-type
+//TEST(compute, vulkan):COMPARE_COMPUTE: -vk -compute -shaderobj -output-using-type
+
+// Test that matrix swizzle writes work correctly
+// Matrix swizzles can either be one or zero indexed
+// Reference: https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-per-component-math
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float2x2> outputBuffer;
+
+struct MySubscriptable
+{
+    float2x2 m;
+    __subscript() -> float2x2
+    {
+        get { return m; }
+        set { m = newValue; }
+    }
+};
+
+[numthreads(1, 1, 1)]
+void computeMain(uint tid : SV_GroupIndex)
+{
+    MySubscriptable s;
+    s.m = float2x2(0,0,0,0);
+
+    // _ 1
+    // 4 5
+    s[]._12_21_22 = float3(1, 4, 5);
+
+    // 2 1
+    // 4 3
+    s[]._m00_m11 = float2(2, 3);
+
+    outputBuffer[tid] = s.m;
+}