r271409 - in /trunk/libstdc++-v3: ChangeLog inc...

[redi@gcc.gnu.org]

Author: redi
Date: Mon May 20 11:15:03 2019
New Revision: 271409

URL: https://gcc.gnu.org/viewcvs?rev=271409&root=gcc&view=rev
Log:
std::allocator::deallocate support sized-deallocation

Pass the size to the allocator so that it may optimize deallocation.
This was seen to significantly reduce the work required in jemalloc,
with about 40% reduction in CPU cycles in the free path.

Note jemalloc >= 5.2 is required to fix a crash with 0 sizes.

2019-05-20  Pádraig Brady  <pbrady@fb.com>

	* libstdc++-v3/include/ext/new_allocator.h (deallocate): Pass the size
	to the deallocator with -fsized-deallocation.

Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/ext/new_allocator.h