[DA] Fix Strong SIV test for symbolic coefficients and deltas (#149977)users/sebpop/pr149977

Fixes GitHub issue #149977 where Strong SIV test incorrectly rejected
dependencies with symbolic coefficients and deltas due to overly conservative
bound checking.

Root cause: The bound constraint check |Delta| > UpperBound * |Coeff| would
prematurely reject dependencies when SCEV couldn't prove the relationship
definitively for symbolic expressions, preventing the analysis from reaching
the division logic.

Solution:
1. Make bound check less conservative for symbolic expressions by adding
   runtime assumptions when SCEV cannot determine the relationship.
2. Enable symbolic division using SE->getUDivExactExpr for Delta/Coeff.
3. Add runtime assumptions where symbolic division cannot be computed.

This enables precise dependence analysis for cases like:
- Coefficient: -k (symbolic)
- Delta: -(2*k + 1) (symbolic)
- Distance: (2*k + 1)/k (computed symbolically)

Test case validates:
- When k = -1: distance = 1, clear flow dependence detected.
- Runtime assumptions ensure bounds are satisfied.

0 files changed, 0 insertions, 0 deletions