tree f876edf17ac6f3ad59b10576126adcf6df0d89b1
parent b5f1a13d48a133e2e7c57f23643808a61c073489
author Nicolas Capens <capn@google.com> 1561133262 -0400
committer Nicolas Capens <nicolascapens@google.com> 1561394126 +0000

Fix initialization of LRU cache keys

In particular this fixes Blitter::Options state having uninitialized
bits after the bitfield, and Blitter::State having uninitialized padding
bytes after Options so 'sourceFormat' is 32-bit aligned.

Defines a Memset<T> class to be used as the first base class of cache
key types, which makes it explicit that their underlying memory will be
fully initialized before any member constructors are run.

Also adds is_memcmparable<T> for checking if memcmp() can be used to
implement operator==() for cache keys. It's equivalent to
std::is_trivially_copyable except it provides a fallback for STL
implementations that don't support it.

Bug: b/134932616
Change-Id: I6569e78b380e67aee02d5bfd39d80d210bd225fd
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/32929
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>