You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
311 lines
15 KiB
HTML
311 lines
15 KiB
HTML
4 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1988-2018 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 6.4, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>RX Options (Using the GNU Compiler Collection (GCC))</title>
|
||
|
|
|
||
|
|
<meta name="description" content="RX Options (Using the GNU Compiler Collection (GCC))">
|
||
|
|
<meta name="keywords" content="RX Options (Using the GNU Compiler Collection (GCC))">
|
||
|
|
<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="S_002f390-and-zSeries-Options.html#S_002f390-and-zSeries-Options" rel="next" title="S/390 and zSeries Options">
|
||
|
|
<link href="RS_002f6000-and-PowerPC-Options.html#RS_002f6000-and-PowerPC-Options" rel="prev" title="RS/6000 and PowerPC Options">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.indentedblock {margin-right: 0em}
|
||
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
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.nolinebreak {white-space: nowrap}
|
||
|
|
span.roman {font-family: initial; font-weight: normal}
|
||
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<a name="RX-Options"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="S_002f390-and-zSeries-Options.html#S_002f390-and-zSeries-Options" accesskey="n" rel="next">S/390 and zSeries Options</a>, Previous: <a href="RS_002f6000-and-PowerPC-Options.html#RS_002f6000-and-PowerPC-Options" accesskey="p" rel="prev">RS/6000 and PowerPC Options</a>, Up: <a href="Submodel-Options.html#Submodel-Options" accesskey="u" rel="up">Submodel Options</a> [<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="RX-Options-1"></a>
|
||
|
|
<h4 class="subsection">3.18.41 RX Options</h4>
|
||
|
|
<a name="index-RX-Options"></a>
|
||
|
|
|
||
|
|
<p>These command-line options are defined for RX targets:
|
||
|
|
</p>
|
||
|
|
<dl compact="compact">
|
||
|
|
<dt><code>-m64bit-doubles</code></dt>
|
||
|
|
<dt><code>-m32bit-doubles</code></dt>
|
||
|
|
<dd><a name="index-m64bit_002ddoubles-1"></a>
|
||
|
|
<a name="index-m32bit_002ddoubles-1"></a>
|
||
|
|
<p>Make the <code>double</code> data type be 64 bits (<samp>-m64bit-doubles</samp>)
|
||
|
|
or 32 bits (<samp>-m32bit-doubles</samp>) in size. The default is
|
||
|
|
<samp>-m32bit-doubles</samp>. <em>Note</em> RX floating-point hardware only
|
||
|
|
works on 32-bit values, which is why the default is
|
||
|
|
<samp>-m32bit-doubles</samp>.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-fpu</code></dt>
|
||
|
|
<dt><code>-nofpu</code></dt>
|
||
|
|
<dd><a name="index-fpu"></a>
|
||
|
|
<a name="index-nofpu"></a>
|
||
|
|
<p>Enables (<samp>-fpu</samp>) or disables (<samp>-nofpu</samp>) the use of RX
|
||
|
|
floating-point hardware. The default is enabled for the RX600
|
||
|
|
series and disabled for the RX200 series.
|
||
|
|
</p>
|
||
|
|
<p>Floating-point instructions are only generated for 32-bit floating-point
|
||
|
|
values, however, so the FPU hardware is not used for doubles if the
|
||
|
|
<samp>-m64bit-doubles</samp> option is used.
|
||
|
|
</p>
|
||
|
|
<p><em>Note</em> If the <samp>-fpu</samp> option is enabled then
|
||
|
|
<samp>-funsafe-math-optimizations</samp> is also enabled automatically.
|
||
|
|
This is because the RX FPU instructions are themselves unsafe.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mcpu=<var>name</var></code></dt>
|
||
|
|
<dd><a name="index-mcpu-11"></a>
|
||
|
|
<p>Selects the type of RX CPU to be targeted. Currently three types are
|
||
|
|
supported, the generic ‘<samp>RX600</samp>’ and ‘<samp>RX200</samp>’ series hardware and
|
||
|
|
the specific ‘<samp>RX610</samp>’ CPU. The default is ‘<samp>RX600</samp>’.
|
||
|
|
</p>
|
||
|
|
<p>The only difference between ‘<samp>RX600</samp>’ and ‘<samp>RX610</samp>’ is that the
|
||
|
|
‘<samp>RX610</samp>’ does not support the <code>MVTIPL</code> instruction.
|
||
|
|
</p>
|
||
|
|
<p>The ‘<samp>RX200</samp>’ series does not have a hardware floating-point unit
|
||
|
|
and so <samp>-nofpu</samp> is enabled by default when this type is
|
||
|
|
selected.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mbig-endian-data</code></dt>
|
||
|
|
<dt><code>-mlittle-endian-data</code></dt>
|
||
|
|
<dd><a name="index-mbig_002dendian_002ddata"></a>
|
||
|
|
<a name="index-mlittle_002dendian_002ddata"></a>
|
||
|
|
<p>Store data (but not code) in the big-endian format. The default is
|
||
|
|
<samp>-mlittle-endian-data</samp>, i.e. to store data in the little-endian
|
||
|
|
format.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-msmall-data-limit=<var>N</var></code></dt>
|
||
|
|
<dd><a name="index-msmall_002ddata_002dlimit-1"></a>
|
||
|
|
<p>Specifies the maximum size in bytes of global and static variables
|
||
|
|
which can be placed into the small data area. Using the small data
|
||
|
|
area can lead to smaller and faster code, but the size of area is
|
||
|
|
limited and it is up to the programmer to ensure that the area does
|
||
|
|
not overflow. Also when the small data area is used one of the RX’s
|
||
|
|
registers (usually <code>r13</code>) is reserved for use pointing to this
|
||
|
|
area, so it is no longer available for use by the compiler. This
|
||
|
|
could result in slower and/or larger code if variables are pushed onto
|
||
|
|
the stack instead of being held in this register.
|
||
|
|
</p>
|
||
|
|
<p>Note, common variables (variables that have not been initialized) and
|
||
|
|
constants are not placed into the small data area as they are assigned
|
||
|
|
to other sections in the output executable.
|
||
|
|
</p>
|
||
|
|
<p>The default value is zero, which disables this feature. Note, this
|
||
|
|
feature is not enabled by default with higher optimization levels
|
||
|
|
(<samp>-O2</samp> etc) because of the potentially detrimental effects of
|
||
|
|
reserving a register. It is up to the programmer to experiment and
|
||
|
|
discover whether this feature is of benefit to their program. See the
|
||
|
|
description of the <samp>-mpid</samp> option for a description of how the
|
||
|
|
actual register to hold the small data area pointer is chosen.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-msim</code></dt>
|
||
|
|
<dt><code>-mno-sim</code></dt>
|
||
|
|
<dd><a name="index-msim-10"></a>
|
||
|
|
<a name="index-mno_002dsim"></a>
|
||
|
|
<p>Use the simulator runtime. The default is to use the libgloss
|
||
|
|
board-specific runtime.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mas100-syntax</code></dt>
|
||
|
|
<dt><code>-mno-as100-syntax</code></dt>
|
||
|
|
<dd><a name="index-mas100_002dsyntax"></a>
|
||
|
|
<a name="index-mno_002das100_002dsyntax"></a>
|
||
|
|
<p>When generating assembler output use a syntax that is compatible with
|
||
|
|
Renesas’s AS100 assembler. This syntax can also be handled by the GAS
|
||
|
|
assembler, but it has some restrictions so it is not generated by default.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mmax-constant-size=<var>N</var></code></dt>
|
||
|
|
<dd><a name="index-mmax_002dconstant_002dsize"></a>
|
||
|
|
<p>Specifies the maximum size, in bytes, of a constant that can be used as
|
||
|
|
an operand in a RX instruction. Although the RX instruction set does
|
||
|
|
allow constants of up to 4 bytes in length to be used in instructions,
|
||
|
|
a longer value equates to a longer instruction. Thus in some
|
||
|
|
circumstances it can be beneficial to restrict the size of constants
|
||
|
|
that are used in instructions. Constants that are too big are instead
|
||
|
|
placed into a constant pool and referenced via register indirection.
|
||
|
|
</p>
|
||
|
|
<p>The value <var>N</var> can be between 0 and 4. A value of 0 (the default)
|
||
|
|
or 4 means that constants of any size are allowed.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mrelax</code></dt>
|
||
|
|
<dd><a name="index-mrelax-5"></a>
|
||
|
|
<p>Enable linker relaxation. Linker relaxation is a process whereby the
|
||
|
|
linker attempts to reduce the size of a program by finding shorter
|
||
|
|
versions of various instructions. Disabled by default.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mint-register=<var>N</var></code></dt>
|
||
|
|
<dd><a name="index-mint_002dregister"></a>
|
||
|
|
<p>Specify the number of registers to reserve for fast interrupt handler
|
||
|
|
functions. The value <var>N</var> can be between 0 and 4. A value of 1
|
||
|
|
means that register <code>r13</code> is reserved for the exclusive use
|
||
|
|
of fast interrupt handlers. A value of 2 reserves <code>r13</code> and
|
||
|
|
<code>r12</code>. A value of 3 reserves <code>r13</code>, <code>r12</code> and
|
||
|
|
<code>r11</code>, and a value of 4 reserves <code>r13</code> through <code>r10</code>.
|
||
|
|
A value of 0, the default, does not reserve any registers.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-msave-acc-in-interrupts</code></dt>
|
||
|
|
<dd><a name="index-msave_002dacc_002din_002dinterrupts"></a>
|
||
|
|
<p>Specifies that interrupt handler functions should preserve the
|
||
|
|
accumulator register. This is only necessary if normal code might use
|
||
|
|
the accumulator register, for example because it performs 64-bit
|
||
|
|
multiplications. The default is to ignore the accumulator as this
|
||
|
|
makes the interrupt handlers faster.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mpid</code></dt>
|
||
|
|
<dt><code>-mno-pid</code></dt>
|
||
|
|
<dd><a name="index-mpid"></a>
|
||
|
|
<a name="index-mno_002dpid"></a>
|
||
|
|
<p>Enables the generation of position independent data. When enabled any
|
||
|
|
access to constant data is done via an offset from a base address
|
||
|
|
held in a register. This allows the location of constant data to be
|
||
|
|
determined at run time without requiring the executable to be
|
||
|
|
relocated, which is a benefit to embedded applications with tight
|
||
|
|
memory constraints. Data that can be modified is not affected by this
|
||
|
|
option.
|
||
|
|
</p>
|
||
|
|
<p>Note, using this feature reserves a register, usually <code>r13</code>, for
|
||
|
|
the constant data base address. This can result in slower and/or
|
||
|
|
larger code, especially in complicated functions.
|
||
|
|
</p>
|
||
|
|
<p>The actual register chosen to hold the constant data base address
|
||
|
|
depends upon whether the <samp>-msmall-data-limit</samp> and/or the
|
||
|
|
<samp>-mint-register</samp> command-line options are enabled. Starting
|
||
|
|
with register <code>r13</code> and proceeding downwards, registers are
|
||
|
|
allocated first to satisfy the requirements of <samp>-mint-register</samp>,
|
||
|
|
then <samp>-mpid</samp> and finally <samp>-msmall-data-limit</samp>. Thus it
|
||
|
|
is possible for the small data area register to be <code>r8</code> if both
|
||
|
|
<samp>-mint-register=4</samp> and <samp>-mpid</samp> are specified on the
|
||
|
|
command line.
|
||
|
|
</p>
|
||
|
|
<p>By default this feature is not enabled. The default can be restored
|
||
|
|
via the <samp>-mno-pid</samp> command-line option.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mno-warn-multiple-fast-interrupts</code></dt>
|
||
|
|
<dt><code>-mwarn-multiple-fast-interrupts</code></dt>
|
||
|
|
<dd><a name="index-mno_002dwarn_002dmultiple_002dfast_002dinterrupts"></a>
|
||
|
|
<a name="index-mwarn_002dmultiple_002dfast_002dinterrupts"></a>
|
||
|
|
<p>Prevents GCC from issuing a warning message if it finds more than one
|
||
|
|
fast interrupt handler when it is compiling a file. The default is to
|
||
|
|
issue a warning for each extra fast interrupt handler found, as the RX
|
||
|
|
only supports one such interrupt.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mallow-string-insns</code></dt>
|
||
|
|
<dt><code>-mno-allow-string-insns</code></dt>
|
||
|
|
<dd><a name="index-mallow_002dstring_002dinsns"></a>
|
||
|
|
<a name="index-mno_002dallow_002dstring_002dinsns"></a>
|
||
|
|
<p>Enables or disables the use of the string manipulation instructions
|
||
|
|
<code>SMOVF</code>, <code>SCMPU</code>, <code>SMOVB</code>, <code>SMOVU</code>, <code>SUNTIL</code>
|
||
|
|
<code>SWHILE</code> and also the <code>RMPA</code> instruction. These
|
||
|
|
instructions may prefetch data, which is not safe to do if accessing
|
||
|
|
an I/O register. (See section 12.2.7 of the RX62N Group User’s Manual
|
||
|
|
for more information).
|
||
|
|
</p>
|
||
|
|
<p>The default is to allow these instructions, but it is not possible for
|
||
|
|
GCC to reliably detect all circumstances where a string instruction
|
||
|
|
might be used to access an I/O register, so their use cannot be
|
||
|
|
disabled automatically. Instead it is reliant upon the programmer to
|
||
|
|
use the <samp>-mno-allow-string-insns</samp> option if their program
|
||
|
|
accesses I/O space.
|
||
|
|
</p>
|
||
|
|
<p>When the instructions are enabled GCC defines the C preprocessor
|
||
|
|
symbol <code>__RX_ALLOW_STRING_INSNS__</code>, otherwise it defines the
|
||
|
|
symbol <code>__RX_DISALLOW_STRING_INSNS__</code>.
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>-mjsr</code></dt>
|
||
|
|
<dt><code>-mno-jsr</code></dt>
|
||
|
|
<dd><a name="index-mjsr"></a>
|
||
|
|
<a name="index-mno_002djsr"></a>
|
||
|
|
<p>Use only (or not only) <code>JSR</code> instructions to access functions.
|
||
|
|
This option can be used when code size exceeds the range of <code>BSR</code>
|
||
|
|
instructions. Note that <samp>-mno-jsr</samp> does not mean to not use
|
||
|
|
<code>JSR</code> but instead means that any type of branch may be used.
|
||
|
|
</p></dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p><em>Note:</em> The generic GCC command-line option <samp>-ffixed-<var>reg</var></samp>
|
||
|
|
has special significance to the RX port when used with the
|
||
|
|
<code>interrupt</code> function attribute. This attribute indicates a
|
||
|
|
function intended to process fast interrupts. GCC ensures
|
||
|
|
that it only uses the registers <code>r10</code>, <code>r11</code>, <code>r12</code>
|
||
|
|
and/or <code>r13</code> and only provided that the normal use of the
|
||
|
|
corresponding registers have been restricted via the
|
||
|
|
<samp>-ffixed-<var>reg</var></samp> or <samp>-mint-register</samp> command-line
|
||
|
|
options.
|
||
|
|
</p>
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="S_002f390-and-zSeries-Options.html#S_002f390-and-zSeries-Options" accesskey="n" rel="next">S/390 and zSeries Options</a>, Previous: <a href="RS_002f6000-and-PowerPC-Options.html#RS_002f6000-and-PowerPC-Options" accesskey="p" rel="prev">RS/6000 and PowerPC Options</a>, Up: <a href="Submodel-Options.html#Submodel-Options" accesskey="u" rel="up">Submodel Options</a> [<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>
|