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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - __VFP_FP__ not defined for Cortex-M3"
href="https://bugs.llvm.org/show_bug.cgi?id=39536">39536</a>
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<th>Summary</th>
<td>__VFP_FP__ not defined for Cortex-M3
</td>
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<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Frontend
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>jsshin@sor.snu.ac.kr
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
</td>
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<p>
<div>
<pre>arm-none-eabi-gcc defines __VFP_FP__ but clang does not define it.
This caused problem in the newlib build for ARM Cortex-M3.
Following is a code taken from newlib. Since __VFP_FP__ is not defined,
__IEEE_BIG_ENDIAN is defined instead of __IEEE_LITTLE_ENDIAN, which caused
serious problem.
The comments say that __VFP_FP__ will be defined even if soft-float, but clang
seems to only define it when VFP is actually used.
==== newlib/libc/include/machine/ieeefp.h ========
#if (defined(__arm__) || defined(__thumb__)) && !defined(__MAVERICK__)
/* ARM traditionally used big-endian words; and within those words the byte
ordering was big or little endian depending upon the target. Modern
floating-point formats are naturally ordered; in this case __VFP_FP__ will be
defined, even if soft-float. */
#ifdef __VFP_FP__
# ifdef __ARMEL__
# define __IEEE_LITTLE_ENDIAN
# else
# define __IEEE_BIG_ENDIAN
# endif
# if __ARM_FP & 0x8
# define __OBSOLETE_MATH_DEFAULT 0
# endif
#else
# define __IEEE_BIG_ENDIAN
# ifdef __ARMEL__
# define __IEEE_BYTES_LITTLE_ENDIAN
# endif
#endif
#endif
====================================</pre>
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