toolchain/gcc-linaro-6.3.1-2017.02-x8.../share/doc/gcc/Blackfin-Options.html

316 lines
15 KiB
HTML
Raw Permalink Normal View History

2024-03-22 05:10:17 +00:00
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 1988-2016 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Funding Free Software", the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
"GNU Free Documentation License".
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development. -->
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Using the GNU Compiler Collection (GCC): Blackfin Options</title>
<meta name="description" content="Using the GNU Compiler Collection (GCC): Blackfin Options">
<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Blackfin Options">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Submodel-Options.html#Submodel-Options" rel="up" title="Submodel Options">
<link href="C6X-Options.html#C6X-Options" rel="next" title="C6X Options">
<link href="AVR-Options.html#AVR-Options" rel="prev" title="AVR Options">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Blackfin-Options"></a>
<div class="header">
<p>
Next: <a href="C6X-Options.html#C6X-Options" accesskey="n" rel="next">C6X Options</a>, Previous: <a href="AVR-Options.html#AVR-Options" accesskey="p" rel="prev">AVR Options</a>, Up: <a href="Submodel-Options.html#Submodel-Options" accesskey="u" rel="up">Submodel Options</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Blackfin-Options-1"></a>
<h4 class="subsection">3.18.6 Blackfin Options</h4>
<a name="index-Blackfin-Options"></a>
<dl compact="compact">
<dt><code>-mcpu=<var>cpu</var><span class="roman">[</span>-<var>sirevision</var><span class="roman">]</span></code></dt>
<dd><a name="index-mcpu_003d"></a>
<p>Specifies the name of the target Blackfin processor. Currently, <var>cpu</var>
can be one of &lsquo;<samp>bf512</samp>&rsquo;, &lsquo;<samp>bf514</samp>&rsquo;, &lsquo;<samp>bf516</samp>&rsquo;, &lsquo;<samp>bf518</samp>&rsquo;,
&lsquo;<samp>bf522</samp>&rsquo;, &lsquo;<samp>bf523</samp>&rsquo;, &lsquo;<samp>bf524</samp>&rsquo;, &lsquo;<samp>bf525</samp>&rsquo;, &lsquo;<samp>bf526</samp>&rsquo;,
&lsquo;<samp>bf527</samp>&rsquo;, &lsquo;<samp>bf531</samp>&rsquo;, &lsquo;<samp>bf532</samp>&rsquo;, &lsquo;<samp>bf533</samp>&rsquo;,
&lsquo;<samp>bf534</samp>&rsquo;, &lsquo;<samp>bf536</samp>&rsquo;, &lsquo;<samp>bf537</samp>&rsquo;, &lsquo;<samp>bf538</samp>&rsquo;, &lsquo;<samp>bf539</samp>&rsquo;,
&lsquo;<samp>bf542</samp>&rsquo;, &lsquo;<samp>bf544</samp>&rsquo;, &lsquo;<samp>bf547</samp>&rsquo;, &lsquo;<samp>bf548</samp>&rsquo;, &lsquo;<samp>bf549</samp>&rsquo;,
&lsquo;<samp>bf542m</samp>&rsquo;, &lsquo;<samp>bf544m</samp>&rsquo;, &lsquo;<samp>bf547m</samp>&rsquo;, &lsquo;<samp>bf548m</samp>&rsquo;, &lsquo;<samp>bf549m</samp>&rsquo;,
&lsquo;<samp>bf561</samp>&rsquo;, &lsquo;<samp>bf592</samp>&rsquo;.
</p>
<p>The optional <var>sirevision</var> specifies the silicon revision of the target
Blackfin processor. Any workarounds available for the targeted silicon revision
are enabled. If <var>sirevision</var> is &lsquo;<samp>none</samp>&rsquo;, no workarounds are enabled.
If <var>sirevision</var> is &lsquo;<samp>any</samp>&rsquo;, all workarounds for the targeted processor
are enabled. The <code>__SILICON_REVISION__</code> macro is defined to two
hexadecimal digits representing the major and minor numbers in the silicon
revision. If <var>sirevision</var> is &lsquo;<samp>none</samp>&rsquo;, the <code>__SILICON_REVISION__</code>
is not defined. If <var>sirevision</var> is &lsquo;<samp>any</samp>&rsquo;, the
<code>__SILICON_REVISION__</code> is defined to be <code>0xffff</code>.
If this optional <var>sirevision</var> is not used, GCC assumes the latest known
silicon revision of the targeted Blackfin processor.
</p>
<p>GCC defines a preprocessor macro for the specified <var>cpu</var>.
For the &lsquo;<samp>bfin-elf</samp>&rsquo; toolchain, this option causes the hardware BSP
provided by libgloss to be linked in if <samp>-msim</samp> is not given.
</p>
<p>Without this option, &lsquo;<samp>bf532</samp>&rsquo; is used as the processor by default.
</p>
<p>Note that support for &lsquo;<samp>bf561</samp>&rsquo; is incomplete. For &lsquo;<samp>bf561</samp>&rsquo;,
only the preprocessor macro is defined.
</p>
</dd>
<dt><code>-msim</code></dt>
<dd><a name="index-msim"></a>
<p>Specifies that the program will be run on the simulator. This causes
the simulator BSP provided by libgloss to be linked in. This option
has effect only for &lsquo;<samp>bfin-elf</samp>&rsquo; toolchain.
Certain other options, such as <samp>-mid-shared-library</samp> and
<samp>-mfdpic</samp>, imply <samp>-msim</samp>.
</p>
</dd>
<dt><code>-momit-leaf-frame-pointer</code></dt>
<dd><a name="index-momit_002dleaf_002dframe_002dpointer-1"></a>
<p>Don&rsquo;t keep the frame pointer in a register for leaf functions. This
avoids the instructions to save, set up and restore frame pointers and
makes an extra register available in leaf functions. The option
<samp>-fomit-frame-pointer</samp> removes the frame pointer for all functions,
which might make debugging harder.
</p>
</dd>
<dt><code>-mspecld-anomaly</code></dt>
<dd><a name="index-mspecld_002danomaly"></a>
<p>When enabled, the compiler ensures that the generated code does not
contain speculative loads after jump instructions. If this option is used,
<code>__WORKAROUND_SPECULATIVE_LOADS</code> is defined.
</p>
</dd>
<dt><code>-mno-specld-anomaly</code></dt>
<dd><a name="index-mno_002dspecld_002danomaly"></a>
<p>Don&rsquo;t generate extra code to prevent speculative loads from occurring.
</p>
</dd>
<dt><code>-mcsync-anomaly</code></dt>
<dd><a name="index-mcsync_002danomaly"></a>
<p>When enabled, the compiler ensures that the generated code does not
contain CSYNC or SSYNC instructions too soon after conditional branches.
If this option is used, <code>__WORKAROUND_SPECULATIVE_SYNCS</code> is defined.
</p>
</dd>
<dt><code>-mno-csync-anomaly</code></dt>
<dd><a name="index-mno_002dcsync_002danomaly"></a>
<p>Don&rsquo;t generate extra code to prevent CSYNC or SSYNC instructions from
occurring too soon after a conditional branch.
</p>
</dd>
<dt><code>-mlow-64k</code></dt>
<dd><a name="index-mlow_002d64k"></a>
<p>When enabled, the compiler is free to take advantage of the knowledge that
the entire program fits into the low 64k of memory.
</p>
</dd>
<dt><code>-mno-low-64k</code></dt>
<dd><a name="index-mno_002dlow_002d64k"></a>
<p>Assume that the program is arbitrarily large. This is the default.
</p>
</dd>
<dt><code>-mstack-check-l1</code></dt>
<dd><a name="index-mstack_002dcheck_002dl1"></a>
<p>Do stack checking using information placed into L1 scratchpad memory by the
uClinux kernel.
</p>
</dd>
<dt><code>-mid-shared-library</code></dt>
<dd><a name="index-mid_002dshared_002dlibrary"></a>
<p>Generate code that supports shared libraries via the library ID method.
This allows for execute in place and shared libraries in an environment
without virtual memory management. This option implies <samp>-fPIC</samp>.
With a &lsquo;<samp>bfin-elf</samp>&rsquo; target, this option implies <samp>-msim</samp>.
</p>
</dd>
<dt><code>-mno-id-shared-library</code></dt>
<dd><a name="index-mno_002did_002dshared_002dlibrary"></a>
<p>Generate code that doesn&rsquo;t assume ID-based shared libraries are being used.
This is the default.
</p>
</dd>
<dt><code>-mleaf-id-shared-library</code></dt>
<dd><a name="index-mleaf_002did_002dshared_002dlibrary"></a>
<p>Generate code that supports shared libraries via the library ID method,
but assumes that this library or executable won&rsquo;t link against any other
ID shared libraries. That allows the compiler to use faster code for jumps
and calls.
</p>
</dd>
<dt><code>-mno-leaf-id-shared-library</code></dt>
<dd><a name="index-mno_002dleaf_002did_002dshared_002dlibrary"></a>
<p>Do not assume that the code being compiled won&rsquo;t link against any ID shared
libraries. Slower code is generated for jump and call insns.
</p>
</dd>
<dt><code>-mshared-library-id=n</code></dt>
<dd><a name="index-mshared_002dlibrary_002did"></a>
<p>Specifies the identification number of the ID-based shared library being
compiled. Specifying a value of 0 generates more compact code; specifying
other values forces the allocation of that number to the current
library but is no more space- or time-efficient than omitting this option.
</p>
</dd>
<dt><code>-msep-data</code></dt>
<dd><a name="index-msep_002ddata"></a>
<p>Generate code that allows the data segment to be located in a different
area of memory from the text segment. This allows for execute in place in
an environment without virtual memory management by eliminating relocations
against the text section.
</p>
</dd>
<dt><code>-mno-sep-data</code></dt>
<dd><a name="index-mno_002dsep_002ddata"></a>
<p>Generate code that assumes that the data segment follows the text segment.
This is the default.
</p>
</dd>
<dt><code>-mlong-calls</code></dt>
<dt><code>-mno-long-calls</code></dt>
<dd><a name="index-mlong_002dcalls-3"></a>
<a name="index-mno_002dlong_002dcalls-1"></a>
<p>Tells the compiler to perform function calls by first loading the
address of the function into a register and then performing a subroutine
call on this register. This switch is needed if the target function
lies outside of the 24-bit addressing range of the offset-based
version of subroutine call instruction.
</p>
<p>This feature is not enabled by default. Specifying
<samp>-mno-long-calls</samp> restores the default behavior. Note these
switches have no effect on how the compiler generates code to handle
function calls via function pointers.
</p>
</dd>
<dt><code>-mfast-fp</code></dt>
<dd><a name="index-mfast_002dfp"></a>
<p>Link with the fast floating-point library. This library relaxes some of
the IEEE floating-point standard&rsquo;s rules for checking inputs against
Not-a-Number (NAN), in the interest of performance.
</p>
</dd>
<dt><code>-minline-plt</code></dt>
<dd><a name="index-minline_002dplt"></a>
<p>Enable inlining of PLT entries in function calls to functions that are
not known to bind locally. It has no effect without <samp>-mfdpic</samp>.
</p>
</dd>
<dt><code>-mmulticore</code></dt>
<dd><a name="index-mmulticore"></a>
<p>Build a standalone application for multicore Blackfin processors.
This option causes proper start files and link scripts supporting
multicore to be used, and defines the macro <code>__BFIN_MULTICORE</code>.
It can only be used with <samp>-mcpu=bf561<span class="roman">[</span>-<var>sirevision</var><span class="roman">]</span></samp>.
</p>
<p>This option can be used with <samp>-mcorea</samp> or <samp>-mcoreb</samp>, which
selects the one-application-per-core programming model. Without
<samp>-mcorea</samp> or <samp>-mcoreb</samp>, the single-application/dual-core
programming model is used. In this model, the main function of Core B
should be named as <code>coreb_main</code>.
</p>
<p>If this option is not used, the single-core application programming
model is used.
</p>
</dd>
<dt><code>-mcorea</code></dt>
<dd><a name="index-mcorea"></a>
<p>Build a standalone application for Core A of BF561 when using
the one-application-per-core programming model. Proper start files
and link scripts are used to support Core A, and the macro
<code>__BFIN_COREA</code> is defined.
This option can only be used in conjunction with <samp>-mmulticore</samp>.
</p>
</dd>
<dt><code>-mcoreb</code></dt>
<dd><a name="index-mcoreb"></a>
<p>Build a standalone application for Core B of BF561 when using
the one-application-per-core programming model. Proper start files
and link scripts are used to support Core B, and the macro
<code>__BFIN_COREB</code> is defined. When this option is used, <code>coreb_main</code>
should be used instead of <code>main</code>.
This option can only be used in conjunction with <samp>-mmulticore</samp>.
</p>
</dd>
<dt><code>-msdram</code></dt>
<dd><a name="index-msdram"></a>
<p>Build a standalone application for SDRAM. Proper start files and
link scripts are used to put the application into SDRAM, and the macro
<code>__BFIN_SDRAM</code> is defined.
The loader should initialize SDRAM before loading the application.
</p>
</dd>
<dt><code>-micplb</code></dt>
<dd><a name="index-micplb"></a>
<p>Assume that ICPLBs are enabled at run time. This has an effect on certain
anomaly workarounds. For Linux targets, the default is to assume ICPLBs
are enabled; for standalone applications the default is off.
</p></dd>
</dl>
<hr>
<div class="header">
<p>
Next: <a href="C6X-Options.html#C6X-Options" accesskey="n" rel="next">C6X Options</a>, Previous: <a href="AVR-Options.html#AVR-Options" accesskey="p" rel="prev">AVR Options</a>, Up: <a href="Submodel-Options.html#Submodel-Options" accesskey="u" rel="up">Submodel Options</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
</div>
</body>
</html>