On Tue, May 9, 2017 at 10:52 PM, <tbsaunde+...@tbsaunde.org> wrote:
> From: Trevor Saunders <tbsaunde+...@tbsaunde.org>
>
> This gets rid of one allocation per bitmap. Often the bitmap_head is
> now on the stack, when it isn't its part of some other struct on the
> heap instead of being refered to by that struct. On 64 bit platforms
> this will increase the size of such structs by 24 bytes, but its an over
> all win since we don't need an 8 byte pointer pointing at the
> bitmap_head. Given that the auto_bitmap owns the bitmap_head anyway we
> know there would never be a place where two auto_bitmaps would refer to
> the same bitmap_head object.
Ok.
Richard.
> gcc/ChangeLog:
>
> 2017-05-07 Trevor Saunders <tbsaunde+...@tbsaunde.org>
>
> * bitmap.h (class auto_bitmap): Change type of m_bits to
> bitmap_head, and adjust ctor / dtor and member operators.
> ---
> gcc/bitmap.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/gcc/bitmap.h b/gcc/bitmap.h
> index 7508239cff9..49aec001cb0 100644
> --- a/gcc/bitmap.h
> +++ b/gcc/bitmap.h
> @@ -823,10 +823,10 @@ bmp_iter_and_compl (bitmap_iterator *bi, unsigned
> *bit_no)
> class auto_bitmap
> {
> public:
> - auto_bitmap () { bits = BITMAP_ALLOC (NULL); }
> - ~auto_bitmap () { BITMAP_FREE (bits); }
> + auto_bitmap () { bitmap_initialize (&m_bits, &bitmap_default_obstack); }
> + ~auto_bitmap () { bitmap_clear (&m_bits); }
> // Allow calling bitmap functions on our bitmap.
> - operator bitmap () { return bits; }
> + operator bitmap () { return &m_bits; }
>
> private:
> // Prevent making a copy that references our bitmap.
> @@ -837,7 +837,7 @@ class auto_bitmap
> auto_bitmap &operator = (auto_bitmap &&);
> #endif
>
> - bitmap bits;
> + bitmap_head m_bits;
> };
>
> #endif /* GCC_BITMAP_H */
> --
> 2.11.0
>
