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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Bad floating-point "optimizations""
href="https://bugs.llvm.org/show_bug.cgi?id=43725">43725</a>
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<th>Summary</th>
<td>Bad floating-point "optimizations"
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>8.0
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>enhancement
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>tydeman@tybor.com
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<pre>Is there a way to disable ALL "optimizations" related to floating-point?
My testing has shown that clang does the following:
1. * x => x
0. * x => 0.
x / 1. => x
x / x => 1.
0. / x => 0.
x + 0. => x
x - 0. => x
x - x => 0.
They are all invalid "optimizations" if x is a signaling NaN.
In addition, some are invalid if x is a signed zero or infinity.
In the above, 'x' can be either a variable or a constant.
It might matter if 'x' is float, double, or long double.</pre>
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