[DebugInfo] Add DW_OP_LLVM_extract_bits (#93990)

This operation extracts a number of bits at a given offset and sign or
zero extends them, which is done by emitting it as a left shift followed
by a right shift.

This is being added for use in clang for C++ structured bindings of
bitfields that have offset or size that aren't a byte multiple. A new
operation is being added, instead of shifts being used directly, as it
makes correctly handling it in optimisations (which will be done in a
later patch) much easier.

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/BinaryFormat/Dwarf.cpp b/llvm/lib/BinaryFormat/Dwarf.cpp
index 73242661..0bf4f20 100644
--- a/llvm/lib/BinaryFormat/Dwarf.cpp
+++ b/llvm/lib/BinaryFormat/Dwarf.cpp
@@ -155,6 +155,10 @@ StringRef llvm::dwarf::OperationEncodingString(unsigned Encoding) {
     return "DW_OP_LLVM_implicit_pointer";
   case DW_OP_LLVM_arg:
     return "DW_OP_LLVM_arg";
+  case DW_OP_LLVM_extract_bits_sext:
+    return "DW_OP_LLVM_extract_bits_sext";
+  case DW_OP_LLVM_extract_bits_zext:
+    return "DW_OP_LLVM_extract_bits_zext";
   }
 }
 
@@ -169,6 +173,8 @@ unsigned llvm::dwarf::getOperationEncoding(StringRef OperationEncodingString) {
       .Case("DW_OP_LLVM_entry_value", DW_OP_LLVM_entry_value)
       .Case("DW_OP_LLVM_implicit_pointer", DW_OP_LLVM_implicit_pointer)
       .Case("DW_OP_LLVM_arg", DW_OP_LLVM_arg)
+      .Case("DW_OP_LLVM_extract_bits_sext", DW_OP_LLVM_extract_bits_sext)
+      .Case("DW_OP_LLVM_extract_bits_zext", DW_OP_LLVM_extract_bits_zext)
       .Default(0);
 }