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| <h4 class="subsection">9.31.4 Assembler Directives</h4> |
| |
| <p><code>as</code> for s390 supports all of the standard ELF |
| assembler directives as outlined in the main part of this document. |
| Some directives have been extended and there are some additional |
| directives, which are only available for the s390 <code>as</code>. |
| |
| |
| <a name="index-g_t_0040code_007b_002einsn_007d-directive_002c-s390-1550"></a> |
| <dl><dt><code>.insn</code><dd>This directive permits the numeric representation of an instructions |
| and makes the assembler insert the operands according to one of the |
| instructions formats for ‘<samp><span class="samp">.insn</span></samp>’ (<a href="s390-Formats.html#s390-Formats">s390 Formats</a>). |
| For example, the instruction ‘<samp><span class="samp">l %r1,24(%r15)</span></samp>’ could be written as |
| ‘<samp><span class="samp">.insn rx,0x58000000,%r1,24(%r15)</span></samp>’. |
| <a name="index-g_t_0040code_007b_002eshort_007d-directive_002c-s390-1551"></a><a name="index-g_t_0040code_007b_002elong_007d-directive_002c-s390-1552"></a><a name="index-g_t_0040code_007b_002equad_007d-directive_002c-s390-1553"></a><br><dt><code>.short</code><dt><code>.long</code><dt><code>.quad</code><dd>This directive places one or more 16-bit (.short), 32-bit (.long), or |
| 64-bit (.quad) values into the current section. If an ELF or TLS modifier |
| is used only the following expressions are allowed: |
| ‘<samp><span class="samp">symbol@modifier + constant</span></samp>’, |
| ‘<samp><span class="samp">symbol@modifier + label + constant</span></samp>’, and |
| ‘<samp><span class="samp">symbol@modifier - label + constant</span></samp>’. |
| The following modifiers are available: |
| <dl> |
| <dt><code>@got</code><dt><code>@got12</code><dd>The @got modifier can be used for .short, .long and .quad. The @got12 |
| modifier is synonym to @got. The symbol is added to the GOT. The symbol |
| term is replaced with offset from the start of the GOT to the GOT slot for |
| the symbol. |
| <br><dt><code>@gotoff</code><dd>The @gotoff modifier can be used for .short, .long and .quad. The symbol |
| term is replaced with the offset from the start of the GOT to the address |
| of the symbol. |
| <br><dt><code>@gotplt</code><dd>The @gotplt modifier can be used for .long and .quad. A procedure linkage |
| table entry is generated for the symbol and a jump slot for the symbol |
| is added to the GOT. The symbol term is replaced with the offset from the |
| start of the GOT to the jump slot for the symbol. |
| <br><dt><code>@plt</code><dd>The @plt modifier can be used for .long and .quad. A procedure linkage |
| table entry us generated for the symbol. The symbol term is replaced with |
| the address of the PLT entry for the symbol. |
| <br><dt><code>@pltoff</code><dd>The @pltoff modifier can be used for .short, .long and .quad. The symbol |
| term is replaced with the offset from the start of the PLT to the address |
| of the symbol. |
| <br><dt><code>@tlsgd</code><dt><code>@tlsldm</code><dd>The @tlsgd and @tlsldm modifier can be used for .long and .quad. A |
| tls_index structure for the symbol is added to the GOT. The symbol term is |
| replaced with the offset from the start of the GOT to the tls_index structure. |
| <br><dt><code>@gotntpoff</code><dt><code>@indntpoff</code><dd>The @gotntpoff and @indntpoff modifier can be used for .long and .quad. |
| The symbol is added to the static TLS block and the negated offset to the |
| symbol in the static TLS block is added to the GOT. For @gotntpoff the |
| symbol term is replaced with the offset from the start of the GOT to the |
| GOT slot, for @indntpoff the symbol term is replaced with the address |
| of the GOT slot. |
| <br><dt><code>@dtpoff</code><dd>The @dtpoff modifier can be used for .long and .quad. The symbol term |
| is replaced with the offset of the symbol relative to the start of the |
| TLS block it is contained in. |
| <br><dt><code>@ntpoff</code><dd>The @ntpoff modifier can be used for .long and .quad. The symbol term |
| is replaced with the offset of the symbol relative to the TCB pointer. |
| </dl> |
| |
| <p>For more information about the thread local storage modifiers see the |
| ELF extension documentation ‘<samp><span class="samp">ELF Handling For Thread-Local Storage</span></samp>’. |
| |
| <p><a name="index-g_t_0040code_007b_002eltorg_007d-directive_002c-s390-1554"></a><br><dt><code>.ltorg</code><dd>This directive causes the current contents of the literal pool to be |
| dumped to the current location (<a href="s390-Literal-Pool-Entries.html#s390-Literal-Pool-Entries">s390 Literal Pool Entries</a>). |
| </dl> |
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