On 10/06/2016 03:15 AM, Richard Biener wrote:
The following guards against (some) remove-current-bit cases. It
would have ICEd for PR77855 instead of producing wrong code.
Bootstrap / regtest running on x86_64-unknown-linux-gnu.
Comments?
Thanks,
Richard.
2016-10-06 Richard Biener <rguent...@suse.de>
* bitmap.c (bitmap_elem_to_freelist): Set indx to -1.
* bitmap.h (bmp_iter_set): When advancing to the next element
check that we didn't remove the current one.
(bmp_iter_and): Likewise.
(bmp_iter_and_compl): Likewise.
Seems like a good idea to me -- I've been bitten by this during patch
development in the past and it looks like you're hitting one of the more
unpleasant cases.
Someone had posted a more robust approach to detecting unsafe
modification of a bitmap during iteration many years ago, but nobody had
the time/inclination to take it to proof-of-concept to see how it'd
perform in the real world.
Jeff
