gpl: clamp virtual_cts_max_skew_fraction to [0,1]

Signed-off-by: Eder Monteiro <emrmonteiro@precisioninno.com>

Author: eder-matheus

src/gpl/src/replace.cpp

@@ -321,8 +321,19 @@ bool Replace::initNesterovPlace(const PlaceOptions& options,
   }
 
   if (!cb_ && options.virtualCtsMode) {
+    float skew_fraction = options.virtualCtsMaxSkewFraction;
+    // Clamp to a sane range; a negative value yields negative insertion
+    // delays and values above the clock period make no physical sense.
+    if (skew_fraction < 0.0f || skew_fraction > 1.0f) {
+      log_->warn(GPL,
+                 165,
+                 "virtual_cts_max_skew_fraction {} out of range [0, 1]; "
+                 "clamping.",
+                 skew_fraction);
+      skew_fraction = std::clamp(skew_fraction, 0.0f, 1.0f);
+    }
     cb_ = std::make_shared<ClockBase>(sta_, db_, log_);
-    cb_->setMaxSkewFraction(options.virtualCtsMaxSkewFraction);
+    cb_->setMaxSkewFraction(skew_fraction);
   }
 
   if (!np_) {