Remove unnecessary parameters from Metal entry point signature (#6131)

* fix metal entry point global params

* address review comments, cleanup and test

* remove dead code

* undo accidental change

* address review comments and cleanup

* minor fix and cleanup

---------

Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/tests/metal/multi-entry-point-params.slang b/tests/metal/multi-entry-point-params.slang
new file mode 100644
index 000000000..11aefe267
--- /dev/null
+++ b/tests/metal/multi-entry-point-params.slang
@@ -0,0 +1,57 @@
+//TEST:SIMPLE(filecheck=CHECK): -target metal -fvk-use-entrypoint-name
+
+struct FirstStruct {
+    uint a;
+}
+
+struct SecondStruct {
+    uint a;
+}
+
+struct ThirdStruct {
+    uint a;
+}
+
+struct FourthStruct {
+    uint a;
+}
+
+StructuredBuffer<uint> globalScopeBuffer;
+
+RWStructuredBuffer<uint> outBuffer;
+
+//
+// Checks for the following:
+//  - Output entry points will only contain parameters that they originally have from the Slang source. 
+//  - Binding offset calculation for global params originating from entry point parameters are done per-whole file.
+//  - Binding offset for global params in global scope are the same for each generated entry point.
+//
+
+// CHECK: main1({{.*}}globalScopeBuffer{{.*}}buffer(0)]], FirstStruct{{.*}}buffer(2)]], SecondStruct{{.*}}buffer(3)]], float{{.*}}buffer(4)]])
+[shader("compute")]
+[numthreads(5, 1, 1)]
+void main1(
+    uint3 dispatchThreadID: SV_DispatchThreadID,
+    RWStructuredBuffer<FirstStruct> custom,
+    RWStructuredBuffer<SecondStruct> other,
+    ConstantBuffer<float> factor
+) {
+    uint index = dispatchThreadID.x;
+    outBuffer[index] = globalScopeBuffer[index] * custom[index].a * other[index].a * uint(factor);
+}
+
+
+// CHECK-NOT: FirstStruct
+// CHECK-NOT: SecondStruct
+// CHECK: main2({{.*}}globalScopeBuffer{{.*}}buffer(0)]], ThirdStruct{{.*}}buffer(5)]], FourthStruct{{.*}}buffer(6)]])
+[shader("compute")]
+[numthreads(5, 1, 1)]
+void main2(
+    uint3 dispatchThreadID: SV_DispatchThreadID,
+    RWStructuredBuffer<ThirdStruct> custom,
+    RWStructuredBuffer<FourthStruct> other,
+) {
+    uint index = dispatchThreadID.x;
+    outBuffer[index] = globalScopeBuffer[index] * custom[index].a * other[index].a;
+}
+