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| <title>Using as: MIPS FP ABI Selection</title> |
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| Next: <a href="MIPS-FP-ABI-Compatibility.html#MIPS-FP-ABI-Compatibility" accesskey="n" rel="next">MIPS FP ABI Compatibility</a>, Previous: <a href="MIPS-FP-ABI-Variants.html#MIPS-FP-ABI-Variants" accesskey="p" rel="prev">MIPS FP ABI Variants</a>, Up: <a href="MIPS-FP-ABIs.html#MIPS-FP-ABIs" accesskey="u" rel="up">MIPS FP ABIs</a> [<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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| <a name="Automatic-selection-of-FP-ABI"></a> |
| <h4 class="subsubsection">9.27.9.3 Automatic selection of FP ABI</h4> |
| <a name="index-_002emodule-fp_003dnn-directive_002c-MIPS"></a> |
| <p>In order to simplify and add safety to the process of selecting the |
| correct floating-point ABI, the assembler will automatically infer the |
| correct <code>.gnu_attribute 4, <var>n</var></code> directive based on command line |
| options and <code>.module</code> overrides. Where an explicit |
| <code>.gnu_attribute 4, <var>n</var></code> directive has been seen then a warning |
| will be raised if it does not match an inferred setting. |
| </p> |
| <p>The floating-point ABI is inferred as follows. If ‘<samp>-msoft-float</samp>’ |
| has been used the module will be marked as soft-float. If |
| ‘<samp>-msingle-float</samp>’ has been used then the module will be marked as |
| single-precision. The remaining ABIs are then selected based |
| on the FP register width. Double-precision is selected if the width |
| of GP and FP registers match and the special double-precision variants |
| for 32-bit ABIs are then selected depending on ‘<samp>-mfpxx</samp>’, |
| ‘<samp>-mfp64</samp>’ and ‘<samp>-mno-odd-spreg</samp>’. |
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