Do not fold IF with 'bx condition before V3Unknown (#2438)

Fixes #2425
2026-10-08 02:53:12 +02:00 · 2020-06-20 04:16:07 +01:00
parent fa828ac9ba
commit aa595d40de
7 changed files with 177 additions and 1 deletions
@@ -1935,9 +1935,12 @@ private:
                if (constp->isZero()) {
                    UINFO(4, "IF(0,{any},{x}) => {x}: " << nodep << endl);
                    keepp = nodep->elsesp();
-                } else {
+                } else if (!m_doV || constp->isNeqZero()) {  // Might be X in Verilog
                    UINFO(4, "IF(!0,{x},{any}) => {x}: " << nodep << endl);
                    keepp = nodep->ifsp();
+                } else {
+                    UINFO(4, "IF condition is X, retaining: " << nodep << endl);
+                    return;
                }
                if (keepp) {
                    keepp->unlinkFrBackWithNext();