Boost Users :
From: degski (degski_at_[hidden])
Date: 2019-07-12 08:12:10
On Fri, 12 Jul 2019 at 10:38, John Maddock via Boost-users <
> Aside: adding a native population count function might well be a useful
> addition to the library...
Native clz/ctz (_BitScanReverse/_BitScanForward) might be useful as well.
> The limb size is always half the width of the largest compiler supported
> integer type - this is a necessary condition to implement arithmetic
> entirely within the language.
This seems a high price to pay [I guess the 'within the language' is key
here]. At some point in time [when 64-bit started to be a general thing]
there was some info regarding this on gmplib.org, which basically stated
that 64-bit limbs [on x64] were 4 times faster than 32-bit limbs. GMP
(MPIR) does 64-bit limbs on Windows, no problem [but yes it's C].
If clang-win can have __int128 support enabled
clang-cl can/will have __int128 support enabled by passing it '-Xclang
-fforce-enable-int128', i.e. pass '-fforce-enable-int128' to clang++.
-- @realdegski https://edition.cnn.com/interactive/2019/06/middleeast/saudi-teen-death-penalty-intl/ "Anyone who believes that exponential growth can go on forever in a finite world is either a madman or an economist" - Kenneth E. Boulding
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