</p>

<h2 id="runtime">Runtime</h2>

<p><!-- CL 543255 -->
  The runtime now keeps type-based garbage collection metadata nearer to each
  heap object, improving the CPU performance (latency or throughput) of Go programs
  by 1&ndash;3%.
  This change also reduces the memory overhead of the majority Go programs by
  approximately 1% by deduplicating redundant metadata.

</p>

<p>
Reads of memory locations larger than a single machine word
are encouraged but not required to meet the same semantics
as word-sized memory locations,
observing a single allowed write <i>w</i>.
For performance reasons,
implementations may instead treat larger operations
as a set of individual machine-word-sized operations
in an unspecified order.
This means that races on multiword data structures