IR: pass through `[unroll]` attribute (#284)

The initial lowering was adding an `IRLoopControlDecoration` to the instruction at the head of a loop, but this was getting dropped when the IR gets cloned for a particular entry point.
The fix was simply to add a case for loop-control decorations to `cloneDecoration`.

1 files changed, 8 insertions, 0 deletions

diff --git a/source/slang/ir.cpp b/source/slang/ir.cpp
index 9ecafbc7d..9068e717b 100644
--- a/source/slang/ir.cpp
+++ b/source/slang/ir.cpp
@@ -3063,6 +3063,14 @@ namespace Slang
                 }
                 break;
 
+            case kIRDecorationOp_LoopControl:
+                {
+                    auto originalDecoration = (IRLoopControlDecoration*)dd;
+                    auto newDecoration = context->builder->addDecoration<IRLoopControlDecoration>(clonedValue);
+                    newDecoration->mode = originalDecoration->mode;
+                }
+                break;
+
             default:
                 // Don't clone any decorations we don't understand.
                 break;