Fix up DXR type emission from IR type system (#498)

* There was a simple typo where we were emitting `RaytracingAccelerationStructureType` instead of `RaytracingAccelerationStructure`

* The IR lowering logic was failing to handle types with an `__intrinsic_type` modifier (which maps them to a single IR opcode) that weren't in one of the various special cases. I added a catch-all case to the handling of `DeclRefType`. This notably affected the `RayDesc` type.

* Even if we lower `RayDesc` to an intrinsic type, we still need to lower its *fields* too, and these were getting emitted with mangled names (as would happen for any user-defined fields). The solution I implemented was to allow for fields to have `__target_intrinsic` modifiers in the stdlib, to specify the un-mangled name they should use on each target.

I'm not 100% happy with this solution, because it seems odd to have `RayDesc` be an intrinsic type, but then to also have field keys used in `getField` instructions as if it were an ordinary `struct`. It seems like a better solution would be to have it lower to an IR `struct`, just with an appropriate modifier.

1 files changed, 16 insertions, 8 deletions

diff --git a/source/slang/emit.cpp b/source/slang/emit.cpp
index e93dfbbb5..71d323c9e 100644
--- a/source/slang/emit.cpp
+++ b/source/slang/emit.cpp
@@ -1095,9 +1095,9 @@ struct EmitVisitor
             {
                 switch (type->op)
                 {
-                case kIROp_HLSLByteAddressBufferType:           Emit("ByteAddressBuffer");           break;
-                case kIROp_HLSLRWByteAddressBufferType:         Emit("RWByteAddressBuffer");         break;
-                case kIROp_RaytracingAccelerationStructureType: Emit("RaytracingAccelerationStructureType");     break;
+                case kIROp_HLSLByteAddressBufferType:           Emit("ByteAddressBuffer");                  break;
+                case kIROp_HLSLRWByteAddressBufferType:         Emit("RWByteAddressBuffer");                break;
+                case kIROp_RaytracingAccelerationStructureType: Emit("RaytracingAccelerationStructure");    break;
 
                 default:
                     SLANG_DIAGNOSE_UNEXPECTED(getSink(), SourceLoc(), "unhandled buffer type");
@@ -1110,9 +1110,9 @@ struct EmitVisitor
             {
                 switch (type->op)
                 {
-                case kIROp_HLSLByteAddressBufferType:           Emit("ByteAddressBuffer");           break;
-                case kIROp_HLSLRWByteAddressBufferType:         Emit("RWByteAddressBuffer");         break;
-                case kIROp_RaytracingAccelerationStructureType: Emit("RaytracingAccelerationStructureType");     break;
+                case kIROp_HLSLByteAddressBufferType:           Emit("ByteAddressBuffer");                  break;
+                case kIROp_HLSLRWByteAddressBufferType:         Emit("RWByteAddressBuffer");                break;
+                case kIROp_RaytracingAccelerationStructureType: Emit("RaytracingAccelerationStructure");    break;
 
                 default:
                     SLANG_DIAGNOSE_UNEXPECTED(getSink(), SourceLoc(), "unhandled buffer type");
@@ -1898,6 +1898,14 @@ struct EmitVisitor
     String getIRName(
         IRInst*        inst)
     {
+        // If the instruction names something
+        // that should be emitted as a target intrinsic,
+        // then use that name instead.
+        if(auto intrinsicDecoration = findTargetIntrinsicDecoration(context, inst))
+        {
+            return intrinsicDecoration->definition;
+        }
+
         // If the instruction has a mangled name, then emit using that.
         if (auto globalValue = as<IRGlobalValue>(inst))
         {
@@ -2498,9 +2506,9 @@ struct EmitVisitor
 
     IRTargetIntrinsicDecoration* findTargetIntrinsicDecoration(
         EmitContext*    /* ctx */,
-        IRFunc*         func)
+        IRInst*         inst)
     {
-        for (auto dd = func->firstDecoration; dd; dd = dd->next)
+        for (auto dd = inst->firstDecoration; dd; dd = dd->next)
         {
             if (dd->op != kIRDecorationOp_TargetIntrinsic)
                 continue;