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LM32_002dModifiers.html 4.8KB

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  15. <title>LM32-Modifiers (Using as)</title>
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  59. Next: <a href="LM32_002dChars.html#LM32_002dChars" accesskey="n" rel="next">LM32-Chars</a>, Previous: <a href="LM32_002dRegs.html#LM32_002dRegs" accesskey="p" rel="prev">LM32-Regs</a>, Up: <a href="LM32-Syntax.html#LM32-Syntax" accesskey="u" rel="up">LM32 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>
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  61. <hr>
  62. <a name="Relocatable-Expression-Modifiers-1"></a>
  63. <h4 class="subsubsection">9.19.2.2 Relocatable Expression Modifiers</h4>
  64. <a name="index-LM32-modifiers"></a>
  65. <a name="index-syntax_002c-LM32"></a>
  66. <p>The assembler supports several modifiers when using relocatable addresses
  67. in LM32 instruction operands. The general syntax is the following:
  68. </p>
  69. <div class="smallexample">
  70. <pre class="smallexample">modifier(relocatable-expression)
  71. </pre></div>
  72. <dl compact="compact">
  73. <dd><a name="index-symbol-modifiers-1"></a>
  74. </dd>
  75. <dt><code>lo</code></dt>
  76. <dd>
  77. <p>This modifier allows you to use bits 0 through 15 of
  78. an address expression as 16 bit relocatable expression.
  79. </p>
  80. </dd>
  81. <dt><code>hi</code></dt>
  82. <dd>
  83. <p>This modifier allows you to use bits 16 through 23 of an address expression
  84. as 16 bit relocatable expression.
  85. </p>
  86. <p>For example
  87. </p>
  88. <div class="smallexample">
  89. <pre class="smallexample">ori r4, r4, lo(sym+10)
  90. orhi r4, r4, hi(sym+10)
  91. </pre></div>
  92. </dd>
  93. <dt><code>gp</code></dt>
  94. <dd>
  95. <p>This modified creates a 16-bit relocatable expression that is
  96. the offset of the symbol from the global pointer.
  97. </p>
  98. <div class="smallexample">
  99. <pre class="smallexample">mva r4, gp(sym)
  100. </pre></div>
  101. </dd>
  102. <dt><code>got</code></dt>
  103. <dd>
  104. <p>This modifier places a symbol in the GOT and creates a 16-bit
  105. relocatable expression that is the offset into the GOT of this
  106. symbol.
  107. </p>
  108. <div class="smallexample">
  109. <pre class="smallexample">lw r4, (gp+got(sym))
  110. </pre></div>
  111. </dd>
  112. <dt><code>gotofflo16</code></dt>
  113. <dd>
  114. <p>This modifier allows you to use the bits 0 through 15 of an
  115. address which is an offset from the GOT.
  116. </p>
  117. </dd>
  118. <dt><code>gotoffhi16</code></dt>
  119. <dd>
  120. <p>This modifier allows you to use the bits 16 through 31 of an
  121. address which is an offset from the GOT.
  122. </p>
  123. <div class="smallexample">
  124. <pre class="smallexample">orhi r4, r4, gotoffhi16(lsym)
  125. addi r4, r4, gotofflo16(lsym)
  126. </pre></div>
  127. </dd>
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