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  61. <body lang="en">

  62. <a name="Sparc_002dRelocs"></a>

  63. <div class="header">

  64. <p>

  65. Next: <a href="Sparc_002dSize_002dTranslations.html#Sparc_002dSize_002dTranslations" accesskey="n" rel="next">Sparc-Size-Translations</a>, Previous: <a href="Sparc_002dConstants.html#Sparc_002dConstants" accesskey="p" rel="prev">Sparc-Constants</a>, Up: <a href="Sparc_002dSyntax.html#Sparc_002dSyntax" accesskey="u" rel="up">Sparc-Syntax</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>

  66. </div>

  67. <hr>

  68. <a name="Relocations-4"></a>

  69. <h4 class="subsubsection">9.44.3.4 Relocations</h4>

  70. <a name="index-Sparc-relocations"></a>

  71. <a name="index-relocations_002c-Sparc"></a>

  72. 

  73. <p>ELF relocations are available as defined in the 32-bit and 64-bit

  74. Sparc ELF specifications.

  75. </p>

  76. <p><code>R_SPARC_HI22</code> is obtained using &lsquo;<samp>%hi</samp>&rsquo; and <code>R_SPARC_LO10</code>

  77. is obtained using &lsquo;<samp>%lo</samp>&rsquo;.  Likewise <code>R_SPARC_HIX22</code> is

  78. obtained from &lsquo;<samp>%hix</samp>&rsquo; and <code>R_SPARC_LOX10</code> is obtained

  79. using &lsquo;<samp>%lox</samp>&rsquo;.  For example:

  80. </p>

  81. <div class="example">

  82. <pre class="example">sethi %hi(symbol), %g1

  83. or    %g1, %lo(symbol), %g1

  84. 

  85. sethi %hix(symbol), %g1

  86. xor   %g1, %lox(symbol), %g1

  87. </pre></div>

  88. 

  89. <p>These &ldquo;high&rdquo; mnemonics extract bits 31:10 of their operand,

  90. and the &ldquo;low&rdquo; mnemonics extract bits 9:0 of their operand.

  91. </p>

  92. <p>V9 code model relocations can be requested as follows:

  93. </p>

  94. <ul>

  95. <li> <code>R_SPARC_HH22</code> is requested using &lsquo;<samp>%hh</samp>&rsquo;.  It can

  96. also be generated using &lsquo;<samp>%uhi</samp>&rsquo;.

  97. </li><li> <code>R_SPARC_HM10</code> is requested using &lsquo;<samp>%hm</samp>&rsquo;.  It can

  98. also be generated using &lsquo;<samp>%ulo</samp>&rsquo;.

  99. </li><li> <code>R_SPARC_LM22</code> is requested using &lsquo;<samp>%lm</samp>&rsquo;.

  100. 

  101. </li><li> <code>R_SPARC_H44</code> is requested using &lsquo;<samp>%h44</samp>&rsquo;.

  102. </li><li> <code>R_SPARC_M44</code> is requested using &lsquo;<samp>%m44</samp>&rsquo;.

  103. </li><li> <code>R_SPARC_L44</code> is requested using &lsquo;<samp>%l44</samp>&rsquo; or &lsquo;<samp>%l34</samp>&rsquo;.

  104. </li><li> <code>R_SPARC_H34</code> is requested using &lsquo;<samp>%h34</samp>&rsquo;.

  105. </li></ul>

  106. 

  107. <p>The &lsquo;<samp>%l34</samp>&rsquo; generates a <code>R_SPARC_L44</code> relocation because it

  108. calculates the necessary value, and therefore no explicit

  109. <code>R_SPARC_L34</code> relocation needed to be created for this purpose.

  110. </p>

  111. <p>The &lsquo;<samp>%h34</samp>&rsquo; and &lsquo;<samp>%l34</samp>&rsquo; relocations are used for the abs34 code

  112. model.  Here is an example abs34 address generation sequence:

  113. </p>

  114. <div class="example">

  115. <pre class="example">sethi %h34(symbol), %g1

  116. sllx  %g1, 2, %g1

  117. or    %g1, %l34(symbol), %g1

  118. </pre></div>

  119. 

  120. <p>The PC relative relocation <code>R_SPARC_PC22</code> can be obtained by

  121. enclosing an operand inside of &lsquo;<samp>%pc22</samp>&rsquo;.  Likewise, the

  122. <code>R_SPARC_PC10</code> relocation can be obtained using &lsquo;<samp>%pc10</samp>&rsquo;.

  123. These are mostly used when assembling PIC code.  For example, the

  124. standard PIC sequence on Sparc to get the base of the global offset

  125. table, PC relative, into a register, can be performed as:

  126. </p>

  127. <div class="example">

  128. <pre class="example">sethi %pc22(_GLOBAL_OFFSET_TABLE_-4), %l7

  129. add   %l7, %pc10(_GLOBAL_OFFSET_TABLE_+4), %l7

  130. </pre></div>

  131. 

  132. <p>Several relocations exist to allow the link editor to potentially

  133. optimize GOT data references.  The <code>R_SPARC_GOTDATA_OP_HIX22</code>

  134. relocation can obtained by enclosing an operand inside of

  135. &lsquo;<samp>%gdop_hix22</samp>&rsquo;.  The <code>R_SPARC_GOTDATA_OP_LOX10</code>

  136. relocation can obtained by enclosing an operand inside of

  137. &lsquo;<samp>%gdop_lox10</samp>&rsquo;.  Likewise, <code>R_SPARC_GOTDATA_OP</code> can be

  138. obtained by enclosing an operand inside of &lsquo;<samp>%gdop</samp>&rsquo;.

  139. For example, assuming the GOT base is in register <code>%l7</code>:

  140. </p>

  141. <div class="example">

  142. <pre class="example">sethi %gdop_hix22(symbol), %l1

  143. xor   %l1, %gdop_lox10(symbol), %l1

  144. ld    [%l7 + %l1], %l2, %gdop(symbol)

  145. </pre></div>

  146. 

  147. <p>There are many relocations that can be requested for access to

  148. thread local storage variables.  All of the Sparc TLS mnemonics

  149. are supported:

  150. </p>

  151. <ul>

  152. <li> <code>R_SPARC_TLS_GD_HI22</code> is requested using &lsquo;<samp>%tgd_hi22</samp>&rsquo;.

  153. </li><li> <code>R_SPARC_TLS_GD_LO10</code> is requested using &lsquo;<samp>%tgd_lo10</samp>&rsquo;.

  154. </li><li> <code>R_SPARC_TLS_GD_ADD</code> is requested using &lsquo;<samp>%tgd_add</samp>&rsquo;.

  155. </li><li> <code>R_SPARC_TLS_GD_CALL</code> is requested using &lsquo;<samp>%tgd_call</samp>&rsquo;.

  156. 

  157. </li><li> <code>R_SPARC_TLS_LDM_HI22</code> is requested using &lsquo;<samp>%tldm_hi22</samp>&rsquo;.

  158. </li><li> <code>R_SPARC_TLS_LDM_LO10</code> is requested using &lsquo;<samp>%tldm_lo10</samp>&rsquo;.

  159. </li><li> <code>R_SPARC_TLS_LDM_ADD</code> is requested using &lsquo;<samp>%tldm_add</samp>&rsquo;.

  160. </li><li> <code>R_SPARC_TLS_LDM_CALL</code> is requested using &lsquo;<samp>%tldm_call</samp>&rsquo;.

  161. 

  162. </li><li> <code>R_SPARC_TLS_LDO_HIX22</code> is requested using &lsquo;<samp>%tldo_hix22</samp>&rsquo;.

  163. </li><li> <code>R_SPARC_TLS_LDO_LOX10</code> is requested using &lsquo;<samp>%tldo_lox10</samp>&rsquo;.

  164. </li><li> <code>R_SPARC_TLS_LDO_ADD</code> is requested using &lsquo;<samp>%tldo_add</samp>&rsquo;.

  165. 

  166. </li><li> <code>R_SPARC_TLS_IE_HI22</code> is requested using &lsquo;<samp>%tie_hi22</samp>&rsquo;.

  167. </li><li> <code>R_SPARC_TLS_IE_LO10</code> is requested using &lsquo;<samp>%tie_lo10</samp>&rsquo;.

  168. </li><li> <code>R_SPARC_TLS_IE_LD</code> is requested using &lsquo;<samp>%tie_ld</samp>&rsquo;.

  169. </li><li> <code>R_SPARC_TLS_IE_LDX</code> is requested using &lsquo;<samp>%tie_ldx</samp>&rsquo;.

  170. </li><li> <code>R_SPARC_TLS_IE_ADD</code> is requested using &lsquo;<samp>%tie_add</samp>&rsquo;.

  171. 

  172. </li><li> <code>R_SPARC_TLS_LE_HIX22</code> is requested using &lsquo;<samp>%tle_hix22</samp>&rsquo;.

  173. </li><li> <code>R_SPARC_TLS_LE_LOX10</code> is requested using &lsquo;<samp>%tle_lox10</samp>&rsquo;.

  174. </li></ul>

  175. 

  176. <p>Here are some example TLS model sequences.

  177. </p>

  178. <p>First, General Dynamic:

  179. </p>

  180. <div class="example">

  181. <pre class="example">sethi  %tgd_hi22(symbol), %l1

  182. add    %l1, %tgd_lo10(symbol), %l1

  183. add    %l7, %l1, %o0, %tgd_add(symbol)

  184. call   __tls_get_addr, %tgd_call(symbol)

  185. nop

  186. </pre></div>

  187. 

  188. <p>Local Dynamic:

  189. </p>

  190. <div class="example">

  191. <pre class="example">sethi  %tldm_hi22(symbol), %l1

  192. add    %l1, %tldm_lo10(symbol), %l1

  193. add    %l7, %l1, %o0, %tldm_add(symbol)

  194. call   __tls_get_addr, %tldm_call(symbol)

  195. nop

  196. 

  197. sethi  %tldo_hix22(symbol), %l1

  198. xor    %l1, %tldo_lox10(symbol), %l1

  199. add    %o0, %l1, %l1, %tldo_add(symbol)

  200. </pre></div>

  201. 

  202. <p>Initial Exec:

  203. </p>

  204. <div class="example">

  205. <pre class="example">sethi  %tie_hi22(symbol), %l1

  206. add    %l1, %tie_lo10(symbol), %l1

  207. ld     [%l7 + %l1], %o0, %tie_ld(symbol)

  208. add    %g7, %o0, %o0, %tie_add(symbol)

  209. 

  210. sethi  %tie_hi22(symbol), %l1

  211. add    %l1, %tie_lo10(symbol), %l1

  212. ldx    [%l7 + %l1], %o0, %tie_ldx(symbol)

  213. add    %g7, %o0, %o0, %tie_add(symbol)

  214. </pre></div>

  215. 

  216. <p>And finally, Local Exec:

  217. </p>

  218. <div class="example">

  219. <pre class="example">sethi  %tle_hix22(symbol), %l1

  220. add    %l1, %tle_lox10(symbol), %l1

  221. add    %g7, %l1, %l1

  222. </pre></div>

  223. 

  224. <p>When assembling for 64-bit, and a secondary constant addend is

  225. specified in an address expression that would normally generate

  226. an <code>R_SPARC_LO10</code> relocation, the assembler will emit an

  227. <code>R_SPARC_OLO10</code> instead.

  228. </p>

  229. <hr>

  230. <div class="header">

  231. <p>

  232. Next: <a href="Sparc_002dSize_002dTranslations.html#Sparc_002dSize_002dTranslations" accesskey="n" rel="next">Sparc-Size-Translations</a>, Previous: <a href="Sparc_002dConstants.html#Sparc_002dConstants" accesskey="p" rel="prev">Sparc-Constants</a>, Up: <a href="Sparc_002dSyntax.html#Sparc_002dSyntax" accesskey="u" rel="up">Sparc-Syntax</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>

  233. </div>

  234. 

  235. 

  236. 

  237. </body>

  238. </html>