Support `constref` parameters passing. (#3249)

* Support `constref` parameters passing.

* Fix.

* Fix.

* Add test and diagnostic on mix use of __constref and no_diff.

* check for [constref] on differentiable member method.

---------

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

1 files changed, 12 insertions, 0 deletions

diff --git a/source/slang/slang-ir-util.cpp b/source/slang/slang-ir-util.cpp
index 62da8cffd..b4a41f8a5 100644
--- a/source/slang/slang-ir-util.cpp
+++ b/source/slang/slang-ir-util.cpp
@@ -418,6 +418,7 @@ bool isPtrLikeOrHandleType(IRInst* type)
     case kIROp_InOutType:
     case kIROp_PtrType:
     case kIROp_RefType:
+    case kIROp_ConstRefType:
         return true;
     }
     return false;
@@ -970,6 +971,17 @@ bool isOne(IRInst* inst)
     }
 }
 
+IRPtrTypeBase* isMutablePointerType(IRInst* inst)
+{
+    switch (inst->getOp())
+    {
+    case kIROp_ConstRefType:
+        return nullptr;
+    default:
+        return as<IRPtrTypeBase>(inst);
+    }
+}
+
 void initializeScratchData(IRInst* inst)
 {
     List<IRInst*> workList;