NOTE: The Configure flags -Duselonglong and -Duse64bits have been
deprecated. Use -Duse64bitint instead.
-Any platform that has 64-bit integers either (a) natively as longs or
-ints (b) via special compiler flags, or (c) using long long are able to
-use "quads" (64-bit integers) as follows:
+Any platform that has 64-bit integers either
+
+ (1) natively as longs or ints
+ (2) via special compiler flags
+ (3) using long long or int64_t
+
+are able to use "quads" (64-bit integers) as follows:
=over 4
There are actually two modes of 64-bitness: the first one is achieved
using Configure -Duse64bitint and the second one using Configure
-Duse64bitall. The difference is that the first one is minimal and
-the second one maximal. The first one does only as much as is
-required to get 64-bit integers into Perl (this may mean, for example,
-using "long longs") while your memory may still be limited to 2
-gigabytes (because your pointers are still allowed to be 32-bit); the
-second one goes all the way by attempting to switch also longs (and
-pointers) to being 64-bit. This may create an even more binary
-incompatible Perl than -Duse64bitint: the resulting executable may not
-run at all in a 32-bit box, or you may have to reboot/reconfigure/rebuild
-your operating system to be 64-bit aware.
+the second one maximal.
+
+The C<use64bitint> does only as much as is required to get 64-bit
+integers into Perl (this may mean, for example, using "long longs")
+while your memory may still be limited to 2 gigabytes (because your
+pointers could still be 32-bit). Note that the name C<64bitint> does
+not imply that your C compiler will be using 64-bit C<int>s (it might,
+but it doesn't have to): the C<use64bitint> means that you will be
+able to have 64 bits wide scalar values.
+
+The C<use64bitall> goes all the way by attempting to switch also
+integers (if it can), longs (and pointers) to being 64-bit. This may
+create an even more binary incompatible Perl than -Duse64bitint: the
+resulting executable may not run at all in a 32-bit box, or you may
+have to reboot/reconfigure/rebuild your operating system to be 64-bit
+aware.
Natively 64-bit systems like Alpha and Cray need neither -Duse64bitint
nor -Duse64bitall.
Last but not least: note that due to Perl's habit of always using
-floating point numbers the quads are still not true integers.
+floating point numbers, the quads are still not true integers.
When quads overflow their limits (0...18_446_744_073_709_551_615 unsigned,
-9_223_372_036_854_775_808...9_223_372_036_854_775_807 signed), they
are silently promoted to floating point numbers, after which they will
If you have filesystems that support "large files" (files larger than
2 gigabytes), you may now also be able to create and access them from
-Perl. You have to use Configure -Duselargefiles. Turning on the
-large file support also turns on 64-bit support on many platforms.
-Beware that unless your filesystem also supports "sparse files" seeking
-to umpteen petabytes may be unadvisable.
+Perl. NOTE: the default action is to use the large file support, if
+available on the platform.
+
+If the large file support is on, and you have a Fcntl constant
+O_LARGEFILE, the O_LARGEFILE is automatically added to the flags
+of sysopen().
+
+Beware: unless your filesystem also supports "sparse files" seeking to
+umpteen petabytes may be unadvisable.
Note that in addition to requiring a proper file system to do large
files you may also need to adjust your per-process (or your
constructs now generate a warning, since they may take on new
semantics in later versions of Perl.
+Many diagnostics now report the internal operation in which the warning
+was provoked, like so:
+
+ Use of uninitialized value in concatenation (.) at (eval 1) line 1.
+ Use of uninitialized value in print at (eval 1) line 1.
+
+Diagnostics that occur within eval may also report the file and line
+number where the eval is located, in addition to the eval sequence
+number and the line number within the evaluated text itself. For
+example:
+
+ Not enough arguments for scalar at (eval 4)[newlib/perl5db.pl:1411] line 2, at EOF
+
=head1 Performance enhancements
=head2 Simple sort() using { $a <=> $b } and the like are optimized
=item Fcntl
More Fcntl constants added: F_SETLK64, F_SETLKW64, O_LARGEFILE for
-large file (more than 4GB) access Note that the O_LARGEFILE is
-automatically/transparently added to sysopen() flags if large file
-support has been configured), Free/Net/OpenBSD locking behaviour flags
-F_FLOCK, F_POSIX, Linux F_SHLCK, and O_ACCMODE: the combined mask of
-O_RDONLY, O_WRONLY, and O_RDWR. The seek()/sysseek() constants
-SEEK_SET, SEEK_CUR, and SEEK_END are available via the C<:seek> tag.
-The chmod()/stat() S_IF* constants and S_IS* functions are available
-via the C<:mode> tag.
-
+large file (more than 4GB) access (NOTE: the O_LARGEFILE is
+automatically added to sysopen() flags if large file support has been
+configured, as is the default), Free/Net/OpenBSD locking behaviour
+flags F_FLOCK, F_POSIX, Linux F_SHLCK, and O_ACCMODE: the combined
+mask of O_RDONLY, O_WRONLY, and O_RDWR. The seek()/sysseek()
+constants SEEK_SET, SEEK_CUR, and SEEK_END are available via the
+C<:seek> tag. The chmod()/stat() S_IF* constants and S_IS* functions
+are available via the C<:mode> tag.
=item File::Compare
(F) Compile-time-substitutions (such as overloaded constants and
character names) were not correctly set up.
+=item CORE::%s is not a keyword
+
+(F) The CORE:: namespace is reserved for Perl keywords.
+
=item defined(@array) is deprecated
(D) defined() is not usually useful on arrays because it checks for an
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