src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/alloc/ComputeBlockOrder.java

@@ -251,18 +251,22 @@
 
     /**
      * Comparator for sorting blocks based on loop depth and probability.
      */
     private static class BlockOrderComparator<T extends AbstractBlockBase<T>> implements Comparator<T> {
+        private static final double EPSILON = 1E-6;
 
         @Override
         public int compare(T a, T b) {
-            // Loop blocks before any loop exit block.
+            // Loop blocks before any loop exit block. The only exception are blocks that are
+            // (almost) impossible to reach.
+            if (a.probability() > EPSILON && b.probability() > EPSILON) {
             int diff = b.getLoopDepth() - a.getLoopDepth();
             if (diff != 0) {
                 return diff;
             }
+            }
 
             // Blocks with high probability before blocks with low probability.
             if (a.probability() > b.probability()) {
                 return -1;
             } else {