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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [TableGen][RISCV] RISCVCompressInstEmitter.cpp - getReqFeatures - undefined behaviour"
href="https://bugs.llvm.org/show_bug.cgi?id=41666">41666</a>
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<th>Summary</th>
<td>[TableGen][RISCV] RISCVCompressInstEmitter.cpp - getReqFeatures - undefined behaviour
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Backend: RISC-V
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>llvm-dev@redking.me.uk
</td>
</tr>
<tr>
<th>CC</th>
<td>asb@lowrisc.org, llvm-bugs@lists.llvm.org, sabuasal@codeaurora.org
</td>
</tr>
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<th>Blocks</th>
<td>41655
</td>
</tr></table>
<p>
<div>
<pre>Reported in <a href="https://www.viva64.com/en/b/0629/">https://www.viva64.com/en/b/0629/</a>
static void getReqFeatures(std::map<StringRef, int> &FeaturesMap,
const std::vector<Record *> &ReqFeatures) {
for (auto &R : ReqFeatures) {
StringRef AsmCondString = R->getValueAsString("AssemblerCondString");
// AsmCondString has syntax [!]F(,[!]F)*
SmallVector<StringRef, 4> Ops;
SplitString(AsmCondString, Ops, ",");
assert(!Ops.empty() && "AssemblerCondString cannot be empty");
for (auto &Op : Ops) {
assert(!Op.empty() && "Empty operator");
if (FeaturesMap.find(Op) == FeaturesMap.end())
FeaturesMap[Op] = FeaturesMap.size();
}
}
}
FeaturesMap[Op] = FeaturesMap.size();
"If the Op element hasn't been found, the program creates a new element in the
map and assigns it the total number of elements in this map. You just don't
know if the size function will be called before or after adding the new
element."
Should this be something like:
if (FeaturesMap.find(Op) == FeaturesMap.end()) {
int NumFeatures = (int)FeaturesMap.size();
FeaturesMap[Op] = NumFeatures;
}</pre>
</div>
</p>
<div id="referenced">
<hr style="border: 1px dashed #969696">
<b>Referenced Bugs:</b>
<ul>
<li>
[<a class="bz_bug_link
bz_status_NEW "
title="NEW - Finding Bugs in LLVM 8 with PVS-Studio"
href="https://bugs.llvm.org/show_bug.cgi?id=41655">Bug 41655</a>] Finding Bugs in LLVM 8 with PVS-Studio
</li>
</ul>
</div>
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