Commit 2c653d46 by Richard Biener Committed by Richard Biener

invoke.texi (fwhole-program): Discourage use in combination with -flto.

2013-03-07  Richard Biener  <rguenther@suse.de>

	* doc/invoke.texi (fwhole-program): Discourage use in combination
	with -flto.

From-SVN: r196518
parent 5709153c
2013-03-07 Richard Biener <rguenther@suse.de>
* doc/invoke.texi (fwhole-program): Discourage use in combination
with -flto.
2013-03-06 Jakub Jelinek <jakub@redhat.com>
* config/arm/t-arm (TM_H, OPTIONS_H_EXTRA): Add arm-cores.def.
......
......@@ -8168,15 +8168,11 @@ Enabled by default with @option{-funroll-loops}.
Assume that the current compilation unit represents the whole program being
compiled. All public functions and variables with the exception of @code{main}
and those merged by attribute @code{externally_visible} become static functions
and in effect are optimized more aggressively by interprocedural optimizers. If @command{gold} is used as the linker plugin, @code{externally_visible} attributes are automatically added to functions (not variable yet due to a current @command{gold} issue) that are accessed outside of LTO objects according to resolution file produced by @command{gold}. For other linkers that cannot generate resolution file, explicit @code{externally_visible} attributes are still necessary.
While this option is equivalent to proper use of the @code{static} keyword for
programs consisting of a single file, in combination with option
@option{-flto} this flag can be used to
compile many smaller scale programs since the functions and variables become
local for the whole combined compilation unit, not for the single source file
itself.
This option implies @option{-fwhole-file} for Fortran programs.
and in effect are optimized more aggressively by interprocedural optimizers.
In combination with @code{-flto} using this option should not be used.
Instead relying on a linker plugin should provide safer and more precise
information.
@item -flto[=@var{n}]
@opindex flto
......
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