Fix global atomic functions (#582)

Fixes #581

This change adds a new parameter passing mode `__ref` to exist alongisde `in`, `out`, and `inout`.
The `__ref` modifier indicates true by-reference parameter passing (whereas `inout` is copy-in-copy-out).

This is not intended to be something that users interact with directly, but rather a low-level feature that lets us provide a correct signature for the `Interlocked*()` operations in the standard library.
Most of the support for passing what are logically addresses around already exists in the IR, so the majority of the work here is just in introducing the new type `Ref<T>` and then using it appropriately when lowering `__ref` parameters/arguments to the IR.

1 files changed, 16 insertions, 16 deletions

diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index bf235eb3c..152e9faa1 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -617,32 +617,32 @@ __target_intrinsic(glsl, "groupMemoryBarrier()); (barrier()")
 void GroupMemoryBarrierWithGroupSync();
 
 // Atomics
-void InterlockedAdd(in out  int dest,  int value, out  int original_value);
-void InterlockedAdd(in out uint dest, uint value, out uint original_value);
+void InterlockedAdd(__ref  int dest,  int value, out  int original_value);
+void InterlockedAdd(__ref uint dest, uint value, out uint original_value);
 
-void InterlockedAnd(in out  int dest,  int value, out  int original_value);
-void InterlockedAnd(in out uint dest, uint value, out uint original_value);
+void InterlockedAnd(__ref  int dest,  int value, out  int original_value);
+void InterlockedAnd(__ref uint dest, uint value, out uint original_value);
 
-void InterlockedCompareExchange(in out  int dest,  int compare_value,  int value, out  int original_value);
-void InterlockedCompareExchange(in out uint dest, uint compare_value, uint value, out uint original_value);
+void InterlockedCompareExchange(__ref  int dest,  int compare_value,  int value, out  int original_value);
+void InterlockedCompareExchange(__ref uint dest, uint compare_value, uint value, out uint original_value);
 
-void InterlockedCompareStore(in out  int dest,  int compare_value,  int value);
-void InterlockedCompareStore(in out uint dest, uint compare_value, uint value);
+void InterlockedCompareStore(__ref  int dest,  int compare_value,  int value);
+void InterlockedCompareStore(__ref uint dest, uint compare_value, uint value);
 
-void InterlockedExchange(in out  int dest,  int value, out  int original_value);
-void InterlockedExchange(in out uint dest, uint value, out uint original_value);
+void InterlockedExchange(__ref  int dest,  int value, out  int original_value);
+void InterlockedExchange(__ref uint dest, uint value, out uint original_value);
 
-void InterlockedMax(in out  int dest,  int value, out  int original_value);
-void InterlockedMax(in out uint dest, uint value, out uint original_value);
+void InterlockedMax(__ref  int dest,  int value, out  int original_value);
+void InterlockedMax(__ref uint dest, uint value, out uint original_value);
 
 void InterlockedMin(in out  int dest,  int value, out  int original_value);
 void InterlockedMin(in out uint dest, uint value, out uint original_value);
 
-void InterlockedOr(in out  int dest,  int value, out  int original_value);
-void InterlockedOr(in out uint dest, uint value, out uint original_value);
+void InterlockedOr(__ref  int dest,  int value, out  int original_value);
+void InterlockedOr(__ref uint dest, uint value, out uint original_value);
 
-void InterlockedXor(in out  int dest,  int value, out  int original_value);
-void InterlockedXor(in out uint dest, uint value, out uint original_value);
+void InterlockedXor(__ref  int dest,  int value, out  int original_value);
+void InterlockedXor(__ref uint dest, uint value, out uint original_value);
 
 // Is floating-point value finite?
 __generic<T : __BuiltinFloatingPointType> bool isfinite(T x);