Emit [loop] attribute to output HLSL.

3 files changed, 13 insertions, 1 deletions

diff --git a/source/slang/slang-emit-hlsl.cpp b/source/slang/slang-emit-hlsl.cpp
index 5ebd7e9fc..b15680f29 100644
--- a/source/slang/slang-emit-hlsl.cpp
+++ b/source/slang/slang-emit-hlsl.cpp
@@ -673,9 +673,16 @@ void HLSLSourceEmitter::emitVectorTypeNameImpl(IRType* elementType, IRIntegerVal
 
 void HLSLSourceEmitter::emitLoopControlDecorationImpl(IRLoopControlDecoration* decl)
 {
-    if (decl->getMode() == kIRLoopControl_Unroll)
+    switch (decl->getMode())
     {
+    case kIRLoopControl_Unroll:
         m_writer->emit("[unroll]\n");
+        break;
+    case kIRLoopControl_Loop:
+        m_writer->emit("[loop]\n");
+        break;
+    default:
+        SLANG_UNREACHABLE("emit loop control decoration");
     }
 }
 
diff --git a/source/slang/slang-ir-insts.h b/source/slang/slang-ir-insts.h
index 06a5c1412..0ae05311b 100644
--- a/source/slang/slang-ir-insts.h
+++ b/source/slang/slang-ir-insts.h
@@ -42,6 +42,7 @@ struct IRHighLevelDeclDecoration : IRDecoration
 enum IRLoopControl
 {
     kIRLoopControl_Unroll,
+    kIRLoopControl_Loop,
 };
 
 struct IRLoopControlDecoration : IRDecoration
diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index f369729d2..030c5fc74 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -3281,6 +3281,10 @@ struct StmtLoweringVisitor : StmtVisitor<StmtLoweringVisitor>
         {
             getBuilder()->addLoopControlDecoration(inst, kIRLoopControl_Unroll);
         }
+        else if( stmt->findModifier<LoopAttribute>() )
+        {
+            getBuilder()->addLoopControlDecoration(inst, kIRLoopControl_Loop);
+        }
         // TODO: handle other cases here
     }