On 11/30/19 1:23 PM, Pavel Begunkov wrote:
bvec_iter_advance() is quite popular, but compilers fail to do proper alias analysis and optimise it good enough. The assembly is checked for gcc 9.2, x86-64. - remove @iter->bi_size from min(...), as it's always less than @bytes. Modify at the beginning and forget about it. - the compiler isn't able to collapse memory dependencies and remove writes in the loop. Help it by explicitely using local vars.
Applied, thanks. -- Jens Axboe
