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| <title>Using as: AArch64-Relocations</title> |
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| <a name="AArch64_002dRelocations"></a> |
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| <a name="Relocations"></a> |
| <h4 class="subsubsection">9.1.3.3 Relocations</h4> |
| |
| <a name="index-relocations_002c-AArch64"></a> |
| <a name="index-AArch64-relocations"></a> |
| <a name="index-MOVN_002c-MOVZ-and-MOVK-group-relocations_002c-AArch64"></a> |
| <p>Relocations for ‘<samp>MOVZ</samp>’ and ‘<samp>MOVK</samp>’ instructions can be generated |
| by prefixing the label with ‘<samp>#:abs_g2:</samp>’ etc. |
| For example to load the 48-bit absolute address of <var>foo</var> into x0: |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample"> movz x0, #:abs_g2:foo // bits 32-47, overflow check |
| movk x0, #:abs_g1_nc:foo // bits 16-31, no overflow check |
| movk x0, #:abs_g0_nc:foo // bits 0-15, no overflow check |
| </pre></div> |
| |
| <a name="index-ADRP_002c-ADD_002c-LDR_002fSTR-group-relocations_002c-AArch64"></a> |
| <p>Relocations for ‘<samp>ADRP</samp>’, and ‘<samp>ADD</samp>’, ‘<samp>LDR</samp>’ or ‘<samp>STR</samp>’ |
| instructions can be generated by prefixing the label with |
| ‘<samp>#:pg_hi21:</samp>’ and ‘<samp>#:lo12:</samp>’ respectively. |
| </p> |
| <p>For example to use 33-bit (+/-4GB) pc-relative addressing to |
| load the address of <var>foo</var> into x0: |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample"> adrp x0, #:pg_hi21:foo |
| add x0, x0, #:lo12:foo |
| </pre></div> |
| |
| <p>Or to load the value of <var>foo</var> into x0: |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample"> adrp x0, #:pg_hi21:foo |
| ldr x0, [x0, #:lo12:foo] |
| </pre></div> |
| |
| <p>Note that ‘<samp>#:pg_hi21:</samp>’ is optional. |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample"> adrp x0, foo |
| </pre></div> |
| |
| <p>is equivalent to |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample"> adrp x0, #:pg_hi21:foo |
| </pre></div> |
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