[llvm] Introduce DIExpression::foldConstantMath() (PR #71718)

[Felipe de Azevedo Piovezan via llvm-commits]

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@@ -1998,6 +1997,286 @@ DIExpression::constantFold(const ConstantInt *CI) {
           ConstantInt::get(getContext(), NewInt)};
 }
 
+static bool isConstantVal(uint64_t Op) {
+  return Op == dwarf::DW_OP_constu || Op == dwarf::DW_OP_consts;
+}
+
+static bool isNeutralElement(uint64_t Op, uint64_t Val) {
+  switch (Op) {
+  case dwarf::DW_OP_plus:
+  case dwarf::DW_OP_minus:
+  case dwarf::DW_OP_shl:
+  case dwarf::DW_OP_shr:
+    return Val == 0;
+  case dwarf::DW_OP_mul:
+  case dwarf::DW_OP_div:
+    return Val == 1;
+  default:
+    return false;
----------------
felipepiovezan wrote:

The fact that this function call be called with something that is not one of the ops above strikes me as odd.

https://github.com/llvm/llvm-project/pull/71718