Add support for fixed-point types (#129596)

This adds DWARF generation for fixed-point types. This feature is needed
by Ada.

Note that a pre-existing GNU extension is used in one case. This has
been emitted by GCC for years, and is needed because standard DWARF is
otherwise incapable of representing these types.

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index e87e5bd..4879569 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1542,6 +1542,39 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     NextMetadataNo++;
     break;
   }
+  case bitc::METADATA_FIXED_POINT_TYPE: {
+    if (Record.size() < 11)
+      return error("Invalid record");
+
+    IsDistinct = Record[0];
+    DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[6]);
+
+    size_t Offset = 9;
+
+    auto ReadWideInt = [&]() {
+      uint64_t Encoded = Record[Offset++];
+      unsigned NumWords = Encoded >> 32;
+      unsigned BitWidth = Encoded & 0xffffffff;
+      auto Value = readWideAPInt(ArrayRef(&Record[Offset], NumWords), BitWidth);
+      Offset += NumWords;
+      return Value;
+    };
+
+    APInt Numerator = ReadWideInt();
+    APInt Denominator = ReadWideInt();
+
+    if (Offset != Record.size())
+      return error("Invalid record");
+
+    MetadataList.assignValue(
+        GET_OR_DISTINCT(DIFixedPointType,
+                        (Context, Record[1], getMDString(Record[2]), Record[3],
+                         Record[4], Record[5], Flags, Record[7], Record[8],
+                         Numerator, Denominator)),
+        NextMetadataNo);
+    NextMetadataNo++;
+    break;
+  }
   case bitc::METADATA_STRING_TYPE: {
     if (Record.size() > 9 || Record.size() < 8)
       return error("Invalid record");