operator_examples

operator_examples — operator-correctness audit + fixes (Enhancement-37)

A systematic audit of the arithmetic, relational, logical, bitwise/shift, ternary and concatenation operator families, using the committed openvaf-r and ngspice-46 — with the three real defects it found, fixed.

What was broken

• ~x (bitwise NOT) was lowered as arithmetic negation: ~12 gave −12 instead of −13 — silent wrong answers in bit-manipulating models;
• constant folding of >> sign-extended (the >>> semantics): -16 >> 2 folded to −4 instead of the zero-filled 1073741820, and disagreed with the (correct) runtime LLVM path for the same expression;
• the ternary operator rejected string operands (c ? "a" : "b" was a type error).

Everything else — truncation/sign rules of / and %, ** incl. negative exponents, all relationals/logicals, & | ^ ~^, shift semantics, precedence, nested ternaries, concat/replication — checked out exactly correct.

The audit design

operator_audit.va: five self-checking modules, one per family. Each failing check adds a distinct power of two to a score emitted on a signal-flow output — v(out) == 0 ⇔ all checks pass; any nonzero value is a bitmask naming the failing check. 60+ checks total.

Run

python3 verify_operators.py

Checks (ALL PASS): the audit compiles (string ternaries used to error); all five family scores are exactly 0; the three formerly-broken cases asserted directly (~12 == -13, -16 >> 2 == 1073741820, string ternary).