wegamekinglc / Derivatives-Algorithms-Lib / 28700916027

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master: 85%

Pull #204

github

Fix IfElse bStack underflow in compiled evaluator

EvalCompiled reset the thread_local bStack on every entry, including the
recursive call the IfElse case made to evaluate the true branch. That
re-entry wiped the parent frame's bStack (where the just-tested condition
still sat), so the parent's subsequent bStack.Pop() underflowed sp_ and a
later Push wrote into the call frame's locals. Every IfElse whose
condition was true triggered it; Phase 0's UBSAN run confirmed the
diagnostic (stacks.hpp:133,135 'index -1 out of bounds for type bool [128]').

Gate the Reset() calls on a reset param: EvalCompiled keeps the opcode
switch with the master shape (one function, thread_local static stacks
inline), but reset defaults true and is only passed false by the IfElse
true-branch re-entry over (i+3, nodeStream[i+1]). The per-event entry
(event.hpp:136) uses the defaults and resets as before; the re-entrant
call preserves the parent's stacks.

Enabled the two Phase-0 IfElse parity pins
(TestParity_IfElse_ConsecutiveBothTrue, TestParity_IfElse_NestedInTrueBranch)
which go from UBSAN-crash to GREEN. The nested case exercises the
re-entrancy the reset=false path must support.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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