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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Optimize division of positive signed integer by power of 2 to a simple shift"
href="http://llvm.org/bugs/show_bug.cgi?id=17683">17683</a>
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<th>Summary</th>
<td>Optimize division of positive signed integer by power of 2 to a simple shift
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<th>Product</th>
<td>libraries
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>All
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<th>OS</th>
<td>All
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Scalar Optimizations
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>st@quanttec.com
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
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<th>Classification</th>
<td>Unclassified
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<p>
<div>
<pre>It would be nice if LLVM could optimize the division of a signed integer by a
power of two to a simple shift if the integer can not be negative.
For example, GCC optimizes the division in the following sample to a simple
right shift (without fixup), while LLVM does not:
int divBy4(int x) {
if (x < 0) abort();
return x/4;
}</pre>
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