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63<a name="GNU-Object-Attributes"></a>
64<div class="header">
65<p>
66Next: <a href="Defining-New-Object-Attributes.html#Defining-New-Object-Attributes" accesskey="n" rel="next">Defining New Object Attributes</a>, Up: <a href="Object-Attributes.html#Object-Attributes" accesskey="u" rel="up">Object Attributes</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
67</div>
68<hr>
69<a name="GNU-Object-Attributes-1"></a>
70<h3 class="section">8.1 <small>GNU</small> Object Attributes</h3>
71
72<p>The <code>.gnu_attribute</code> directive records an object attribute
73with vendor &lsquo;<samp>gnu</samp>&rsquo;.
74</p>
75<p>Except for &lsquo;<samp>Tag_compatibility</samp>&rsquo;, which has both an integer and a string for
76its value, <small>GNU</small> attributes have a string value if the tag number is odd and
77an integer value if the tag number is even.  The second bit (<code><var>tag</var> &amp;
782</code> is set for architecture-independent attributes and clear for
79architecture-dependent ones.
80</p>
81<a name="Common-GNU-attributes"></a>
82<h4 class="subsection">8.1.1 Common <small>GNU</small> attributes</h4>
83
84<p>These attributes are valid on all architectures.
85</p>
86<dl compact="compact">
87<dt><span class="roman">Tag_compatibility (32)</span></dt>
88<dd><p>The compatibility attribute takes an integer flag value and a vendor name.  If
89the flag value is 0, the file is compatible with other toolchains.  If it is 1,
90then the file is only compatible with the named toolchain.  If it is greater
91than 1, the file can only be processed by other toolchains under some private
92arrangement indicated by the flag value and the vendor name.
93</p></dd>
94</dl>
95
96<a name="M680x0-Attributes"></a>
97<h4 class="subsection">8.1.2 M680x0 Attributes</h4>
98
99<dl compact="compact">
100<dt><span class="roman">Tag_GNU_M68K_ABI_FP (4)</span></dt>
101<dd><p>The floating-point ABI used by this object file.  The value will be:
102</p>
103<ul>
104<li> 0 for files not affected by the floating-point ABI.
105</li><li> 1 for files using double-precision hardware floating-point ABI.
106</li><li> 2 for files using the software floating-point ABI.
107</li></ul>
108</dd>
109</dl>
110
111<a name="MIPS-Attributes"></a>
112<h4 class="subsection">8.1.3 MIPS Attributes</h4>
113
114<dl compact="compact">
115<dt><span class="roman">Tag_GNU_MIPS_ABI_FP (4)</span></dt>
116<dd><p>The floating-point ABI used by this object file.  The value will be:
117</p>
118<ul>
119<li> 0 for files not affected by the floating-point ABI.
120</li><li> 1 for files using the hardware floating-point ABI with a standard
121double-precision FPU.
122</li><li> 2 for files using the hardware floating-point ABI with a single-precision FPU.
123</li><li> 3 for files using the software floating-point ABI.
124</li><li> 4 for files using the deprecated hardware floating-point ABI which used 64-bit
125floating-point registers, 32-bit general-purpose registers and increased the
126number of callee-saved floating-point registers.
127</li><li> 5 for files using the hardware floating-point ABI with a double-precision FPU
128with either 32-bit or 64-bit floating-point registers and 32-bit
129general-purpose registers.
130</li><li> 6 for files using the hardware floating-point ABI with 64-bit floating-point
131registers and 32-bit general-purpose registers.
132</li><li> 7 for files using the hardware floating-point ABI with 64-bit floating-point
133registers, 32-bit general-purpose registers and a rule that forbids the
134direct use of odd-numbered single-precision floating-point registers.
135</li></ul>
136</dd>
137</dl>
138
139<a name="PowerPC-Attributes"></a>
140<h4 class="subsection">8.1.4 PowerPC Attributes</h4>
141
142<dl compact="compact">
143<dt><span class="roman">Tag_GNU_Power_ABI_FP (4)</span></dt>
144<dd><p>The floating-point ABI used by this object file.  The value will be:
145</p>
146<ul>
147<li> 0 for files not affected by the floating-point ABI.
148</li><li> 1 for files using double-precision hardware floating-point ABI.
149</li><li> 2 for files using the software floating-point ABI.
150</li><li> 3 for files using single-precision hardware floating-point ABI.
151</li></ul>
152
153</dd>
154<dt><span class="roman">Tag_GNU_Power_ABI_Vector (8)</span></dt>
155<dd><p>The vector ABI used by this object file.  The value will be:
156</p>
157<ul>
158<li> 0 for files not affected by the vector ABI.
159</li><li> 1 for files using general purpose registers to pass vectors.
160</li><li> 2 for files using AltiVec registers to pass vectors.
161</li><li> 3 for files using SPE registers to pass vectors.
162</li></ul>
163</dd>
164</dl>
165
166<a name="IBM-z-Systems-Attributes"></a>
167<h4 class="subsection">8.1.5 IBM z Systems Attributes</h4>
168
169<dl compact="compact">
170<dt><span class="roman">Tag_GNU_S390_ABI_Vector (8)</span></dt>
171<dd><p>The vector ABI used by this object file.  The value will be:
172</p>
173<ul>
174<li> 0 for files not affected by the vector ABI.
175</li><li> 1 for files using software vector ABI.
176</li><li> 2 for files using hardware vector ABI.
177</li></ul>
178</dd>
179</dl>
180
181<a name="MSP430-Attributes"></a>
182<h4 class="subsection">8.1.6 MSP430 Attributes</h4>
183
184<dl compact="compact">
185<dt><span class="roman">Tag_GNU_MSP430_Data_Region (4)</span></dt>
186<dd><p>The data region used by this object file.  The value will be:
187</p>
188<ul>
189<li> 0 for files not using the large memory model.
190</li><li> 1 for files which have been compiled with the condition that all
191data is in the lower memory region, i.e. below address 0x10000.
192</li><li> 2 for files which allow data to be placed in the full 20-bit memory range.
193</li></ul>
194</dd>
195</dl>
196
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199<p>
200Next: <a href="Defining-New-Object-Attributes.html#Defining-New-Object-Attributes" accesskey="n" rel="next">Defining New Object Attributes</a>, Up: <a href="Object-Attributes.html#Object-Attributes" accesskey="u" rel="up">Object Attributes</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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