src/hotspot/share/adlc/dfa.cpp

*** 757,779 ****
  
    return cost;
  }
  
  int Expr::compute_min(const Expr *c1, const Expr *c2) {
!   int result = c1->_min_value + c2->_min_value;
!   assert( result >= 0, "Invalid cost computation");
  
!   return result;
  }
  
  int Expr::compute_max(const Expr *c1, const Expr *c2) {
!   int result = c1->_max_value + c2->_max_value;
!   if( result < 0 ) {  // check for overflow
!     result = Expr::Max;
    }
  
!   return result;
  }
  
  void Expr::print() const {
    if( _external_name != NULL ) {
      printf("  %s == (%s) === [%d, %d]\n", _external_name, _expr, _min_value, _max_value);
--- 757,787 ----
  
    return cost;
  }
  
  int Expr::compute_min(const Expr *c1, const Expr *c2) {
!   int v1 = c1->_min_value;
!   int v2 = c2->_min_value;
!   assert(0 <= v2 && v2 <= Expr::Max, "sanity");
!   assert(v1 <= Expr::Max - v2, "Invalid cost computation");
  
!   return v1 + v2;
  }
  
+ 
  int Expr::compute_max(const Expr *c1, const Expr *c2) {
!   int v1 = c1->_max_value;
!   int v2 = c2->_max_value;
! 
!   // Check for overflow without producing UB. If v2 is positive
!   // and not larger than Max, the subtraction cannot underflow.
!   assert(0 <= v2 && v2 <= Expr::Max, "sanity");
!   if (v1 > Expr::Max - v2) {
!     return Expr::Max;
    }
  
!   return v1 + v2;
  }
  
  void Expr::print() const {
    if( _external_name != NULL ) {
      printf("  %s == (%s) === [%d, %d]\n", _external_name, _expr, _min_value, _max_value);