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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - ppc_fp128 math causes: Assertion failed: (!carry), function addOrSubtractSignificand"
href="https://bugs.llvm.org/show_bug.cgi?id=45430">45430</a>
</td>
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<tr>
<th>Summary</th>
<td>ppc_fp128 math causes: Assertion failed: (!carry), function addOrSubtractSignificand
</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>
<tr>
<th>OS</th>
<td>All
</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>Core LLVM classes
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>florian_hahn@apple.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>The code below causes LLVM to crash when running opt -instcombine with the
trace below
define ppc_fp128 @bitcast_bitcast_s_s_s() {
%B2 = fadd ppc_fp128 0xM00000000000000010000000000000000,
0xM00000000000000010000000000000000
%B16 = fmul ppc_fp128 %B2, 0xM7FEFFFFFFFFFFFFF7C8FFFFFFFFFFFFE
%B10 = fadd ppc_fp128 %B2, 0xM00000000000000010000000000000000
%B27 = fdiv ppc_fp128 %B10, %B16
%B11 = fadd ppc_fp128 %B27, %B2
%B1 = fdiv ppc_fp128 %B2, 0xM00000000000000010000000000000000
%B14 = fdiv ppc_fp128 %B11, %B16
%B4 = fdiv ppc_fp128 %B2, %B1
%B12 = fsub ppc_fp128 0xM00000000000000000000000000000000, %B14
%B8 = fsub ppc_fp128 0xM00000000000000000000000000000000, %B12
%B6 = frem ppc_fp128 %B1, %B12
%B18 = fsub ppc_fp128 0xM00000000000000000000000000000000, %B6
%B9 = frem ppc_fp128 %B8, %B18
%B22 = fdiv ppc_fp128 %B4, %B9
%B5 = fmul ppc_fp128 %B22, %B9
ret ppc_fp128 %B5
}
Assertion failed: (!carry), function addOrSubtractSignificand, file
llvm-project/llvm/lib/Support/APFloat.cpp, line 1540.
PLEASE submit a bug report to <a href="https://bugs.llvm.org/">https://bugs.llvm.org/</a> and include the crash
backtrace.
Stack dump:
0. Program arguments: bin/opt -instcombine bugpoint-reduced-simplified.ll
1. Running pass 'Function Pass Manager' on module
'bugpoint-reduced-simplified.ll'.
2. Running pass 'Combine redundant instructions' on function
'@bitcast_bitcast_s_s_s'
0 opt 0x000000010b2c2b35
llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37
1 opt 0x000000010b2c1948 llvm::sys::RunSignalHandlers() +
248
2 opt 0x000000010b2c3126 SignalHandler(int) + 262
3 libsystem_platform.dylib 0x00007fff6e0d85fd _sigtramp + 29
4 libsystem_platform.dylib 000000000000000000 _sigtramp + 18446603338669783584
5 libsystem_c.dylib 0x00007fff6dfae808 abort + 120
6 libsystem_c.dylib 0x00007fff6dfadac6 err + 0
7 opt 0x000000010c545be3
llvm::detail::IEEEFloat::addOrSubtractSignificand(llvm::detail::IEEEFloat
const&, bool) (.cold.3) + 35
8 opt 0x000000010b1d1c90
llvm::detail::IEEEFloat::addOrSubtractSignificand(llvm::detail::IEEEFloat
const&, bool) + 1296
9 opt 0x000000010b1d117d
llvm::detail::IEEEFloat::multiplySignificand(llvm::detail::IEEEFloat const&,
llvm::detail::IEEEFloat) + 589
10 opt 0x000000010b1d3a66
llvm::detail::IEEEFloat::fusedMultiplyAdd(llvm::detail::IEEEFloat const&,
llvm::detail::IEEEFloat const&, llvm::APFloatBase::roundingMode) + 166
11 opt 0x000000010b1dc714
llvm::detail::DoubleAPFloat::multiply(llvm::detail::DoubleAPFloat const&,
llvm::APFloatBase::roundingMode) + 916
12 opt 0x000000010aa899ef
llvm::ConstantFoldBinaryInstruction(unsigned int, llvm::Constant*,
llvm::Constant*) + 5567
13 opt 0x000000010aaa9bd7 llvm::ConstantExpr::get(unsigned
int, llvm::Constant*, llvm::Constant*, unsigned int, llvm::Type*) + 231
14 opt 0x000000010a40d59e
llvm::ConstantFoldBinaryOpOperands(unsigned int, llvm::Constant*,
llvm::Constant*, llvm::DataLayout const&) + 1182
15 opt 0x000000010a40b088
llvm::ConstantFoldInstruction(llvm::Instruction*, llvm::DataLayout const&,
llvm::TargetLibraryInfo const*) + 1224
16 opt 0x000000010ad57323
combineInstructionsOverFunction(llvm::Function&, llvm::InstCombineWorklist&,
llvm::AAResults*, llvm::AssumptionCache&, llvm::TargetLibraryInfo&,
llvm::DominatorTree&, llvm::OptimizationRemarkEmitter&,
llvm::BlockFrequencyInfo*, llvm::ProfileSummaryInfo*, unsigned int,
llvm::LoopInfo*) + 1699
17 opt 0x000000010ad58831
llvm::InstructionCombiningPass::runOnFunction(llvm::Function&) + 913
18 opt 0x000000010ab5a723
llvm::FPPassManager::runOnFunction(llvm::Function&) + 1091
19 opt 0x000000010ab5a9e8
llvm::FPPassManager::runOnModule(llvm::Module&) + 72
20 opt 0x000000010ab5aec2
llvm::legacy::PassManagerImpl::run(llvm::Module&) + 994
21 opt 0x00000001093a7408 main + 10696
22 libdyld.dylib 0x00007fff6dedfcc9 start + 1
[1] 53415 abort bin/opt -instcombine bugpoint-reduced-simplified.ll
Found by <a href="https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20034#c1">https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20034#c1</a></pre>
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