Allow DW_OP_rot, DW_OP_neg, and DW_OP_abs in DIExpression (#160757)

The Ada front end can emit somewhat complicated DWARF expressions for
the offset of a field. While working in this area I found that I needed
DW_OP_rot (to implement a branch-free computation -- it looked more
difficult to add support for branching); and DW_OP_neg and DW_OP_abs
(just basic functionality).

Author: tromey

llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp

@@ -618,12 +618,15 @@ bool DwarfExpression::addExpression(
     case dwarf::DW_OP_dup:
     case dwarf::DW_OP_push_object_address:
     case dwarf::DW_OP_over:
+    case dwarf::DW_OP_rot:
     case dwarf::DW_OP_eq:
     case dwarf::DW_OP_ne:
     case dwarf::DW_OP_gt:
     case dwarf::DW_OP_ge:
     case dwarf::DW_OP_lt:
     case dwarf::DW_OP_le:
+    case dwarf::DW_OP_neg:
+    case dwarf::DW_OP_abs:
       emitOp(OpNum);
       break;
     case dwarf::DW_OP_deref:

llvm/lib/IR/DebugInfoMetadata.cpp

@@ -1768,13 +1768,16 @@ bool DIExpression::isValid() const {
     case dwarf::DW_OP_bregx:
     case dwarf::DW_OP_push_object_address:
     case dwarf::DW_OP_over:
+    case dwarf::DW_OP_rot:
     case dwarf::DW_OP_consts:
     case dwarf::DW_OP_eq:
     case dwarf::DW_OP_ne:
     case dwarf::DW_OP_gt:
     case dwarf::DW_OP_ge:
     case dwarf::DW_OP_lt:
     case dwarf::DW_OP_le:
+    case dwarf::DW_OP_neg:
+    case dwarf::DW_OP_abs:
       break;
     }
   }

llvm/test/Bitcode/DW_OP_rot_neg_abs.ll

@@ -0,0 +1,10 @@
+;; This test checks the validity of DWARF operators DW_OP_rot, DW_OP_neg, and DW_OP_abs.
+
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
+
+; CHECK: !DIExpression(DW_OP_push_object_address, DW_OP_lit0, DW_OP_lit0, DW_OP_neg, DW_OP_abs, DW_OP_rot, DW_OP_rot, DW_OP_rot, DW_OP_plus, DW_OP_plus)
+
+; ModuleID = 'DW_OP_rot_neg_abs.adb'
+source_filename = "/dir/DW_OP_rot_neg_abs.ll"
+
+!named = !{!DIExpression(DW_OP_push_object_address, DW_OP_lit0, DW_OP_lit0, DW_OP_neg, DW_OP_abs, DW_OP_rot, DW_OP_rot, DW_OP_rot, DW_OP_plus, DW_OP_plus)}