Fix ICE when lowering an associatedtype declref from an derived interface. (#3312)

* Fix ICE when lowering an associatedtype declref from an derived interface.

* Fixes.

* Fix test.

* Fix GLSL/SPIRV image subscript swizzle store regression.

* Fix.

---------

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

3 files changed, 74 insertions, 4 deletions

diff --git a/tests/autodiff/derived-interface.slang b/tests/autodiff/derived-interface.slang
new file mode 100644
index 000000000..68e84ebad
--- /dev/null
+++ b/tests/autodiff/derived-interface.slang
@@ -0,0 +1,55 @@
+//TEST(compute):COMPARE_COMPUTE_EX(filecheck-buffer=CHECK):-slang -compute -shaderobj -output-using-type
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX(filecheck-buffer=CHECK):-vk -compute -shaderobj -output-using-type
+
+//TEST_INPUT:ubuffer(data=[0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+interface IFoo : IDifferentiable
+{
+    [Differentiable]
+    __init<T:IFoo>(T d); 
+    
+    [Differentiable]
+    static This create(Differential d);
+
+    [Differentiable]
+    float getVal();
+}
+
+struct Impl : IFoo
+{
+    float x;
+    [Differentiable]
+    __init<T : IFoo>(T d)
+    {
+        this = (Impl)d;
+    }
+    
+    [Differentiable]
+    static This create(Differential d)
+    {
+        This v;
+        v.x = d.x * d.x;
+        return v;
+    }
+
+    [Differentiable]
+    float getVal() { return x; }
+}
+
+[Differentiable]
+float test<T:IFoo>(T.Differential d)
+{
+    return T.create(d).getVal();
+}
+
+[numthreads(1,1,1)]
+void computeMain(uint threadId: SV_DispatchThreadID)
+{
+    Impl.Differential d;
+    d.x = 3.0;
+    Impl.Differential dd;
+    dd.x = 1.0;
+    outputBuffer[0] = fwd_diff(test<Impl>)(diffPair(d, dd)).d;
+    // CHECK: 6.0
+}
diff --git a/tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang.expected b/tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang.expected
index 3ac7dfa5f..f3382a688 100644
--- a/tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang.expected
+++ b/tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang.expected
@@ -1,9 +1,9 @@
 result code = -1
 standard error = {
-tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang(10): error 38100: type 'Counter' does not provide required interface member 'processValue'
-struct Counter : IThing
-                 ^~~~~~
-tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang(7): note: see declaration of 'processValue'
+tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang(14): error 38105: member 'processValue' does not match interface requirement.
+    [mutating] int processValue(int inValue)
+                   ^~~~~~~~~~~~
+tests/diagnostics/interfaces/mutating-impl-of-non-mutating-req.slang(7): note: see interface requirement declaration of 'processValue'
     int processValue(int inValue);
         ^~~~~~~~~~~~
 }
diff --git a/tests/hlsl-intrinsic/image-swizzle-write.slang b/tests/hlsl-intrinsic/image-swizzle-write.slang
new file mode 100644
index 000000000..e8a006314
--- /dev/null
+++ b/tests/hlsl-intrinsic/image-swizzle-write.slang
@@ -0,0 +1,15 @@
+//TEST:SIMPLE(filecheck=CHECK): -entry computeMain -stage compute -target spirv -emit-spirv-directly
+//TEST:SIMPLE(filecheck=CHECK): -entry computeMain -stage compute -target spirv
+
+layout(rgba6f)
+RWTexture2D<float4> texture;
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    half h = 1.0h;
+    // CHECK: OpImageRead
+    // CEHCK: OpCompositeInsert
+    // CHECK: OpImageWrite
+    texture[dispatchThreadID.xy].a = h;
+}