diff options
Diffstat (limited to 'share/doc/gcc/SH-Function-Attributes.html')
| -rw-r--r-- | share/doc/gcc/SH-Function-Attributes.html | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/share/doc/gcc/SH-Function-Attributes.html b/share/doc/gcc/SH-Function-Attributes.html new file mode 100644 index 0000000..18bc1fc --- /dev/null +++ b/share/doc/gcc/SH-Function-Attributes.html @@ -0,0 +1,179 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- This file documents the use of the GNU compilers. + +Copyright (C) 1988-2023 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 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Using the GNU Compiler Collection (GCC): SH Function Attributes</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): SH Function Attributes"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): SH Function Attributes"> +<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="Indices.html#Indices" rel="index" title="Indices"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Function-Attributes.html#Function-Attributes" rel="up" title="Function Attributes"> +<link href="Symbian-OS-Function-Attributes.html#Symbian-OS-Function-Attributes" rel="next" title="Symbian OS Function Attributes"> +<link href="S_002f390-Function-Attributes.html#S_002f390-Function-Attributes" rel="previous" title="S/390 Function Attributes"> +<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_US" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="SH-Function-Attributes"></a> +<div class="header"> +<p> +Next: <a href="Symbian-OS-Function-Attributes.html#Symbian-OS-Function-Attributes" accesskey="n" rel="next">Symbian OS Function Attributes</a>, Previous: <a href="S_002f390-Function-Attributes.html#S_002f390-Function-Attributes" accesskey="p" rel="previous">S/390 Function Attributes</a>, Up: <a href="Function-Attributes.html#Function-Attributes" accesskey="u" rel="up">Function Attributes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="SH-Function-Attributes-1"></a> +<h4 class="subsection">6.33.29 SH Function Attributes</h4> + +<p>These function attributes are supported on the SH family of processors: +</p> +<dl compact="compact"> +<dd><a name="index-function_005fvector-function-attribute_002c-SH"></a> +<a name="index-calling-functions-through-the-function-vector-on-SH2A"></a> +</dd> +<dt><code>function_vector</code></dt> +<dd><p>On SH2A targets, this attribute declares a function to be called using the +TBR relative addressing mode. The argument to this attribute is the entry +number of the same function in a vector table containing all the TBR +relative addressable functions. For correct operation the TBR must be setup +accordingly to point to the start of the vector table before any functions with +this attribute are invoked. Usually a good place to do the initialization is +the startup routine. The TBR relative vector table can have at max 256 function +entries. The jumps to these functions are generated using a SH2A specific, +non delayed branch instruction JSR/N @(disp8,TBR). You must use GAS and GLD +from GNU binutils version 2.7 or later for this attribute to work correctly. +</p> +<p>In an application, for a function being called once, this attribute +saves at least 8 bytes of code; and if other successive calls are being +made to the same function, it saves 2 bytes of code per each of these +calls. +</p> +<a name="index-interrupt_005fhandler-function-attribute_002c-SH"></a> +</dd> +<dt><code>interrupt_handler</code></dt> +<dd><p>Use this attribute to +indicate that the specified function is an interrupt handler. The compiler +generates function entry and exit sequences suitable for use in an +interrupt handler when this attribute is present. +</p> +<a name="index-nosave_005flow_005fregs-function-attribute_002c-SH"></a> +</dd> +<dt><code>nosave_low_regs</code></dt> +<dd><p>Use this attribute on SH targets to indicate that an <code>interrupt_handler</code> +function should not save and restore registers R0..R7. This can be used on SH3* +and SH4* targets that have a second R0..R7 register bank for non-reentrant +interrupt handlers. +</p> +<a name="index-renesas-function-attribute_002c-SH"></a> +</dd> +<dt><code>renesas</code></dt> +<dd><p>On SH targets this attribute specifies that the function or struct follows the +Renesas ABI. +</p> +<a name="index-resbank-function-attribute_002c-SH"></a> +</dd> +<dt><code>resbank</code></dt> +<dd><p>On the SH2A target, this attribute enables the high-speed register +saving and restoration using a register bank for <code>interrupt_handler</code> +routines. Saving to the bank is performed automatically after the CPU +accepts an interrupt that uses a register bank. +</p> +<p>The nineteen 32-bit registers comprising general register R0 to R14, +control register GBR, and system registers MACH, MACL, and PR and the +vector table address offset are saved into a register bank. Register +banks are stacked in first-in last-out (FILO) sequence. Restoration +from the bank is executed by issuing a RESBANK instruction. +</p> +<a name="index-sp_005fswitch-function-attribute_002c-SH"></a> +</dd> +<dt><code>sp_switch</code></dt> +<dd><p>Use this attribute on the SH to indicate an <code>interrupt_handler</code> +function should switch to an alternate stack. It expects a string +argument that names a global variable holding the address of the +alternate stack. +</p> +<div class="smallexample"> +<pre class="smallexample">void *alt_stack; +void f () __attribute__ ((interrupt_handler, + sp_switch ("alt_stack"))); +</pre></div> + +<a name="index-trap_005fexit-function-attribute_002c-SH"></a> +</dd> +<dt><code>trap_exit</code></dt> +<dd><p>Use this attribute on the SH for an <code>interrupt_handler</code> to return using +<code>trapa</code> instead of <code>rte</code>. This attribute expects an integer +argument specifying the trap number to be used. +</p> +<a name="index-trapa_005fhandler-function-attribute_002c-SH"></a> +</dd> +<dt><code>trapa_handler</code></dt> +<dd><p>On SH targets this function attribute is similar to <code>interrupt_handler</code> +but it does not save and restore all registers. +</p></dd> +</dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Symbian-OS-Function-Attributes.html#Symbian-OS-Function-Attributes" accesskey="n" rel="next">Symbian OS Function Attributes</a>, Previous: <a href="S_002f390-Function-Attributes.html#S_002f390-Function-Attributes" accesskey="p" rel="previous">S/390 Function Attributes</a>, Up: <a href="Function-Attributes.html#Function-Attributes" accesskey="u" rel="up">Function Attributes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |