2010/3/7 Doug Semler <[email protected]>: > On Thu, 04 Mar 2010 17:20:07 Jim Michaels wrote: >> in MSVC, >> __int64 x=12345678901234567i64; >> >> point 1: this type __int64 doesn't require me to #include <windows> to >> define it. in mingw and mingw-w64, one must #include <basetsd.h>. why? >> >> point 2: there are also __int32 __int16 and __int8 types. > > If I remember correctly, anything that starts with two underscores is > implementation defined, which means that __int64 is MS compiler specific, so > including a separate header would make sense to pick it up in mingw > > Since this is a compiler specific (not really mingw but gcc), it makes sense > to > me, in fact IIRC, MSDN specifically states "Microsoft Visual C Specific" for > those types. If you need to be able to compile under multiple compilers, I > would say grab a MS version of stdint.h (since MSVC doesn't have that) and > #include that, and use the types from there (such as int64_t, int32_t, etc). > If you just need a type that is at least 64 bits I believe MSVC from 6.0 on > supports "long long" and "unsigned long long" (at least 64 but could be > longer)
Right, keywords/symbols with two leading underscores are extensions. The support of '__int8, __int16, __int32, __int64, and __int128' are builtin types. As the are combinable by 'signed/unsigned' they can be handled by typedefs. So we use for them at the moment defines in our headers, but of course this is just a work-a-round. The type __int128 will be added to gcc's version 4.6 (a patch for it is already posted but needs review). I would like to have those other extension types supported by VC, too, but well, as those types aren't part of any C-specification, it is a bit hard to put them into gcc. The digit post-fixes 'i32,i64,i128, etc' are alse MS specific extensions (AFAIR long long type was introduced by MS beginning from VC 2005). It would be possible to add these to gcc (in fact it is mainly preprocessor feature), but again here is again the question, if this fits into any specific standards gcc wants to support. >> >> point 3: mingw does not utilize the i64 constant thingy (whatever it's >> called) that tells the compiler that this number is of __int64 type. I do >> not know if there is an i32 or i16 or i8 definition. > > That's another GCC, not mingw thing. GCC supports the suffix of LL and ULL > for > 64 bit wide numbers. MSVC from at least visual studio 2003 (maybe, but don't > quote me, VC6) also supports these... > >> >> >> BTW, 128-bit number type is in the C9X standard. the new integral data >> types in C++ will be something like int64, int32, int128, int16, int8. >> >> http://www.open-std.org/JTC1/sc22/wg14/www/docs/n615.htm >> > > C9X support in MSVC is flaky at best and nonexistent in several spots (see: > stdint.h). I mean the standard has been ratified since what, 2004? even VS > 2008 doesn't have it!) > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Mingw-w64-public mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/mingw-w64-public > Kai -- | (\_/) This is Bunny. Copy and paste | (='.'=) Bunny into your signature to help | (")_(") him gain world domination ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Mingw-w64-public mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
