Options Controlling The Preprocessor - Red Hat ENTERPRISE LINUX 4 Manual

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reorder-blocks-duplicate-feedback
Used by basic block reordering pass to decide whether to use unconditional branch or du-
plicate the code on its destination. Code is duplicated when its estimated size is smaller
than this value multiplied by the estimated size of unconditional jump in the hot spots of the
program.
The
reorder-block-duplicate-feedback
able and may be set to higher values than
about the hot spots is more accurate.

4.11. Options Controlling the Preprocessor

These options control the C preprocessor, which is run on each C source file before actual compilation.
If you use the option, nothing is done except preprocessing. Some of these options make sense only
-E
together with because they cause the preprocessor output to be unsuitable for actual compilation.
-E
You can use
-Wp,
directly through to the preprocessor. If
into multiple options at the commas. However, many options are modified,
translated or interpreted by the compiler driver before being passed to the
preprocessor, and
direct interface is undocumented and subject to change, so whenever
possible you should avoid using
instead.
-Xpreprocessor
option
Pass as an option to the preprocessor. You can use this to supply system-specific prepro-
option
cessor options which GCC does not know how to recognize.
If you want to pass an option that takes an argument, you must use
once for the option and once for the argument.
-D
name
Predefine
name
-D =
name definition
Predefine
name
enized and processed as if they appeared during translation phase three in a
In particular, the definition will be truncated by embedded newline characters.
If you are invoking the preprocessor from a shell or shell-like program you may need to use the
shell's quoting syntax to protect characters such as spaces that have a meaning in the shell syntax.
If you wish to define a function-like macro on the command line, write its argument list with
surrounding parentheses before the equals sign (if any). Parentheses are meaningful to most
shells, so you will need to quote the option. With
works.
and options are processed in the order they are given on the command line. All
-D -U
and
-include
file
to bypass the compiler driver and pass
option
forcibly bypasses this phase. The preprocessor's
-Wp
as a macro, with definition
as a macro, with definition
options are processed after all
file
Chapter 4. GCC Command Options
is used only when profile feedback is avail-
reorder-block-duplicate
contains commas, it is split
option
and let the driver handle the options
-Wp
.
1
. The contents of
definition
and
sh csh
-D
since information
option
-Xpreprocessor
definition
#define
,
-D' ( )=
name args...
and options.
-U
twice,
are tok-
directive.
'
definition
-imacros