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author | 2022-04-03 03:05:53 +1000 | |
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committer | 2022-04-03 03:07:28 +1000 | |
commit | 530c5abb5da585ac71f9c643c9d6a2171280fe67 (patch) | |
tree | 978357b74d3506db174181e74bb3f4d81c421f64 /src/devices/bus/isa/finalchs.h | |
parent | c4f9ff9790382c1c5b99a2ffbb2a14e04d4c7cea (diff) |
Revert initialisation of device members in headers.
This is problematic in several ways:
* Initialising things at construction that aren't needed until after
start slows down -romident, -validate, -listxml, etc. Slot cards can
be a particular drain on -listxml and -validate as they're
instantiated for every compatible slot. It's more pronounced for
array members, too.
* Splitting member initialisation between declaration in headers and
constructors in source files means you have to look at two places to
check for the initial value, and you always need to check the
constructor even if an initialiser is present in the header because
the constructor initaliser list takes precedence. (This isn't as much
of an issue for driver classes because the constructor is most often
inlined at declaration, so it isn't far from the member declarations.)
* Initialisers in headers for frequently-used devices increases the
frequency of recompiling dependent devices/drivers as they're exposed
to any changes in initialisers.
* Initialisers in frequently-used headers increase build times because
there's more for the compiler to parse/cache. (This affects
makedep.py as well for single-driver builds, but that's a single
pass.) It's not a lot individually, but it adds up given the size of
MAME, which keeps increasing. We've already had one contributor
banned from GitHub actions for resource usage, we don't want to waste
compiler time unnecessarily.
Diffstat (limited to 'src/devices/bus/isa/finalchs.h')
-rw-r--r-- | src/devices/bus/isa/finalchs.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/devices/bus/isa/finalchs.h b/src/devices/bus/isa/finalchs.h index 2b77a4efb08..2b04f69ec6b 100644 --- a/src/devices/bus/isa/finalchs.h +++ b/src/devices/bus/isa/finalchs.h @@ -39,7 +39,7 @@ private: required_device<generic_latch_8_device> m_mainlatch; required_device<generic_latch_8_device> m_sublatch; - bool m_installed = false; + bool m_installed; uint8_t finalchs_r(offs_t offset); void finalchs_w(offs_t offset, uint8_t data); |