Add finalized keywords for autodiff. (#2882)

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

3 files changed, 7 insertions, 2 deletions

diff --git a/source/slang/core.meta.slang b/source/slang/core.meta.slang
index 730c3fcc8..f91137d4a 100644
--- a/source/slang/core.meta.slang
+++ b/source/slang/core.meta.slang
@@ -127,6 +127,9 @@ attribute_syntax [ForwardDifferentiable] : ForwardDifferentiableAttribute;
 /// Marks a function for backward-mode differentiation.
 __attributeTarget(FunctionDeclBase)
 attribute_syntax [BackwardDifferentiable] : BackwardDifferentiableAttribute;
+__attributeTarget(FunctionDeclBase)
+attribute_syntax [Differentiable(order:int = 0)] : BackwardDifferentiableAttribute;
+
 
 /// Interface to denote types as differentiable.
 /// Allows for user-specified differential types as
diff --git a/source/slang/slang-ast-support-types.cpp b/source/slang/slang-ast-support-types.cpp
index 6e3c326fb..b446221ff 100644
--- a/source/slang/slang-ast-support-types.cpp
+++ b/source/slang/slang-ast-support-types.cpp
@@ -62,9 +62,9 @@ Expr* getInnerMostExprFromHigherOrderExpr(Expr* expr, FunctionDifferentiableLeve
 UnownedStringSlice getHigherOrderOperatorName(HigherOrderInvokeExpr* expr)
 {
     if (as<ForwardDifferentiateExpr>(expr))
-        return UnownedStringSlice("__fwd_diff");
+        return UnownedStringSlice("fwd_diff");
     else if (as<BackwardDifferentiateExpr>(expr))
-        return UnownedStringSlice("__bwd_diff");
+        return UnownedStringSlice("bwd_diff");
     return UnownedStringSlice();
 }
 }
diff --git a/source/slang/slang-parser.cpp b/source/slang/slang-parser.cpp
index cce4b7e7b..410395669 100644
--- a/source/slang/slang-parser.cpp
+++ b/source/slang/slang-parser.cpp
@@ -6850,6 +6850,8 @@ namespace Slang
         _makeParseExpr("__TaggedUnion", parseTaggedUnionType),
         _makeParseExpr("__fwd_diff", parseForwardDifferentiate),
         _makeParseExpr("__bwd_diff", parseBackwardDifferentiate),
+        _makeParseExpr("fwd_diff", parseForwardDifferentiate),
+        _makeParseExpr("bwd_diff", parseBackwardDifferentiate),
         _makeParseExpr("__dispatch_kernel", parseDispatchKernel)
     };