[IR] Add a target extension type to LLVM.

Target-extension types represent types that need to be preserved through
optimization, but otherwise are not introspectable by target-independent
optimizations. This patch doesn't add any uses of these types by an existing
backend, it only provides basic infrastructure such that these types would work
correctly.

Reviewed By: nikic, barannikov88

Differential Revision: https://reviews.llvm.org/D135202

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 339fae04..26994b1 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1052,6 +1052,18 @@ void ModuleBitcodeWriter::writeTypeTable() {
         TypeVals.push_back(true);
       break;
     }
+    case Type::TargetExtTyID: {
+      TargetExtType *TET = cast<TargetExtType>(T);
+      Code = bitc::TYPE_CODE_TARGET_TYPE;
+      writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, TET->getName(),
+                        StructNameAbbrev);
+      TypeVals.push_back(TET->getNumTypeParameters());
+      for (Type *InnerTy : TET->type_params())
+        TypeVals.push_back(VE.getTypeID(InnerTy));
+      for (unsigned IntParam : TET->int_params())
+        TypeVals.push_back(IntParam);
+      break;
+    }
     case Type::TypedPointerTyID:
       llvm_unreachable("Typed pointers cannot be added to IR modules");
     }