The control flow here cannot ever use the uninitialized value, but it's
too hard for the compiler to figure that out. Clang warns:
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: error: variable 'CarrySum' is used uninitialized whenever 'for' loop exits because its condition is false [-Werror,-Wsometimes-uninitialized]
for (unsigned i = 2; i < Factors.size(); ++i)
^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2604:26: note: uninitialized use occurs here
CarrySumPrevDstIdx = CarrySum;
^~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: note: remove the condition if it is always true
for (unsigned i = 2; i < Factors.size(); ++i)
^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2583:22: note: initialize the variable 'CarrySum' to silence this warning
unsigned CarrySum;
^
= 0
llvm-svn: 355818
Factors.push_back(CarrySumPrevDstIdx);
}
- unsigned CarrySum;
+ unsigned CarrySum = 0;
// Add all factors and accumulate all carries into CarrySum.
if (DstIdx != DstParts - 1) {
MachineInstrBuilder Uaddo =