RFR: 8338197: ubsan: ad_x86.hpp:6417:11: runtime error: shift exponent 100 is too large for 32-bit type 'unsigned int' [v3]

[Boris Ulasevich]

On Fri, 22 Aug 2025 22:43:46 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Yes, if `sizeof(uint)` is 32 bits on all our platforms.
>> 
>> Hmm, may be we should use `uint32_t` for `_mask` here. Then we can use 32 and 31 without confusion.
>
> I mean to use `_mask <<= (n < 32) ? n : 31;`

Good! Let me correct both variants then. The resulting code is:

class Pipeline_Use_Cycle_Mask {
protected:
  uint32_t _mask;

public:
  Pipeline_Use_Cycle_Mask() : _mask(0) {}

  Pipeline_Use_Cycle_Mask(uint32_t mask) : _mask(mask) {}

  bool overlaps(const Pipeline_Use_Cycle_Mask &in2) const {
    return ((_mask & in2._mask) != 0);
  }

  Pipeline_Use_Cycle_Mask& operator<<=(int n) {
    _mask <<= (n < 32) ? n : 31;
    return *this;
  }

  void Or(const Pipeline_Use_Cycle_Mask &in2) {
    _mask |= in2._mask;
  }

  friend Pipeline_Use_Cycle_Mask operator&(const Pipeline_Use_Cycle_Mask &, const Pipeline_Use_Cycle_Mask &);
  friend Pipeline_Use_Cycle_Mask operator|(const Pipeline_Use_Cycle_Mask &, const Pipeline_Use_Cycle_Mask &);

  friend class Pipeline_Use;

  friend class Pipeline_Use_Element;

};



// code generated for arm32:

class Pipeline_Use_Cycle_Mask {
protected:
  uint32_t _mask1, _mask2, _mask3;

public:
  Pipeline_Use_Cycle_Mask() : _mask1(0), _mask2(0), _mask3(0) {}

  Pipeline_Use_Cycle_Mask(uint32_t mask1, uint32_t mask2, uint32_t mask3) : _mask1(mask1), _mask2(mask2), _mask3(mask3) {}

  Pipeline_Use_Cycle_Mask intersect(const Pipeline_Use_Cycle_Mask &in2) {
    Pipeline_Use_Cycle_Mask out;
    out._mask1 = _mask1 & in2._mask1;
    out._mask2 = _mask2 & in2._mask2;
    out._mask3 = _mask3 & in2._mask3;
    return out;
  }

  bool overlaps(const Pipeline_Use_Cycle_Mask &in2) const {
    return ((_mask1 & in2._mask1) != 0) || ((_mask2 & in2._mask2) != 0) || ((_mask3 & in2._mask3) != 0);
  }

  Pipeline_Use_Cycle_Mask& operator<<=(int n) {
    if (n >= 32)
      do {
        _mask3 = _mask2; _mask2 = _mask1; _mask1 = 0;
      } while ((n -= 32) >= 32);

    if (n > 0) {
      uint m = 32 - n;
      uint32_t mask = (1 << n) - 1;
      uint32_t temp2 = mask & (_mask1 >> m); _mask1 <<= n;
      uint32_t temp3 = mask & (_mask2 >> m); _mask2 <<= n; _mask2 |= temp2;
      _mask3 <<= n; _mask3 |= temp3;
    }
    return *this;
  }

  void Or(const Pipeline_Use_Cycle_Mask &);

  friend Pipeline_Use_Cycle_Mask operator&(const Pipeline_Use_Cycle_Mask &, const Pipeline_Use_Cycle_Mask &);
  friend Pipeline_Use_Cycle_Mask operator|(const Pipeline_Use_Cycle_Mask &, const Pipeline_Use_Cycle_Mask &);

  friend class Pipeline_Use;

  friend class Pipeline_Use_Element;

};

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/26890#discussion_r2298235985