Table of Contents
One of the major reasons why FORTRAN can chew through numbers so well
is that it is defined to be free of pointer aliasing, an assumption
that C89 is not allowed to make, and neither is C++98. C99 adds a new
keyword, restrict, to apply to individual pointers. The
C++ solution is contained in the library rather than the language
(although many vendors can be expected to add this to their compilers
as an extension).
That library solution is a set of two classes, five template classes,
and "a whole bunch" of functions. The classes are required
to be free of pointer aliasing, so compilers can optimize the
daylights out of them the same way that they have been for FORTRAN.
They are collectively called valarray, although strictly
speaking this is only one of the five template classes, and they are
designed to be familiar to people who have worked with the BLAS
libraries before.
One of the major reasons why FORTRAN can chew through numbers so well d21 1 a21 17
In addition to the other topics on this page, we'll note here some of the C99 features that appear in libstdc++.
The C99 features depend on the --enable-c99 configure flag.
This flag is already on by default, but it can be disabled by the
user. Also, the configuration machinery will disable it if the
necessary support for C99 (e.g., header files) cannot be found.
As of GCC 3.0, C99 support includes classification functions
such as isnormal, isgreater,
isnan, etc.
The functions used for 'long long' support such as strtoll
are supported, as is the lldiv_t typedef. Also supported
are the wide character functions using 'long long', like
wcstoll.
One of the major reasons why FORTRAN can chew through numbers so well d21 1 a21 17
In addition to the other topics on this page, we'll note here some of the C99 features that appear in libstdc++.
The C99 features depend on the --enable-c99 configure flag.
This flag is already on by default, but it can be disabled by the
user. Also, the configuration machinery will disable it if the
necessary support for C99 (e.g., header files) cannot be found.
As of GCC 3.0, C99 support includes classification functions
such as isnormal, isgreater,
isnan, etc.
The functions used for 'long long' support such as strtoll
are supported, as is the lldiv_t typedef. Also supported
are the wide character functions using 'long long', like
wcstoll.
One of the major reasons why FORTRAN can chew through numbers so well d21 1 a21 17
In addition to the other topics on this page, we'll note here some of the C99 features that appear in libstdc++.
The C99 features depend on the --enable-c99 configure flag.
This flag is already on by default, but it can be disabled by the
user. Also, the configuration machinery will disable it if the
necessary support for C99 (e.g., header files) cannot be found.
As of GCC 3.0, C99 support includes classification functions
such as isnormal, isgreater,
isnan, etc.
The functions used for 'long long' support such as strtoll
are supported, as is the lldiv_t typedef. Also supported
are the wide character functions using 'long long', like
wcstoll.