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| <h5 class="subsubsection">9.15.4.2 Compare-and-Branch</h5> |
| |
| <p><a name="index-i960-compare_002fbranch-instructions-1031"></a><a name="index-compare_002fbranch-instructions_002c-i960-1032"></a>The 960 architectures provide combined Compare-and-Branch instructions |
| that permit you to store the branch target in the lower 13 bits of the |
| instruction word itself. However, if you specify a branch target far |
| enough away that its address won't fit in 13 bits, the assembler can |
| either issue an error, or convert your Compare-and-Branch instruction |
| into separate instructions to do the compare and the branch. |
| |
| <p><a name="index-compare-and-jump-expansions_002c-i960-1033"></a><a name="index-i960-compare-and-jump-expansions-1034"></a>Whether <code>as</code> gives an error or expands the instruction depends |
| on two choices you can make: whether you use the ‘<samp><span class="samp">-no-relax</span></samp>’ option, |
| and whether you use a “Compare and Branch” instruction or a “Compare |
| and Jump” instruction. The “Jump” instructions are <em>always</em> |
| expanded if necessary; the “Branch” instructions are expanded when |
| necessary <em>unless</em> you specify <code>-no-relax</code>—in which case |
| <code>as</code> gives an error instead. |
| |
| <p>These are the Compare-and-Branch instructions, their “Jump” variants, |
| and the instruction pairs they may expand into: |
| |
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