Re: 64 bit official Windows builds

["Óscar Fuentes" <ofv@wanadoo.es>]

Eli Zaretskii <eliz@gnu.org> writes:

>> > That thunking is the culprit is my theory, not a fact; however, I
>> > cannot find any other explanation.  If someone does, I'm all ears.
>> 
>> I mentioned some possibilities on a previous message. Did you use the
>> same toolset and libraries for the 32 and 64 bits build?
>
> No.  The program was compiled by mingw.org's MinGW for 32 bits and by
> MinGW64 for 64 bits.

There you have a strong candidate for explaining the difference. That
probably also means that they were different compiler versions.

>> The MinGW and MinGW-w64 (32/64 bits) runtimes diverged quite a bit.
>
> GNU Find uses only msvcrt.dll, no other runtime libraries are involved
> in any significant way.

As you know, there are other code pieces that are linked into the
executable besides the C runtime (which MinGW(-w64) supersede by
providing their implementations for certain functions, plus other
features missing from msvcrt.dll). IIRC some *stat functions are very
slow on Mingw, maybe the MinGW-w64 guys introduced improvements, just a
guess.

Why don't you build both 32 and 64 bits executables of GNU Find with
MinGW-w64 (same toolset version) for comparing its performance?

Not saying that GNU Find will be representative of what you can expect
from Emacs. (GNU Find: I/O bound; Emacs: user bound.)