[DependenceAnalysis] Check if result of getConstantPart is null
A seg-fault occurs due to a reference of a null pointer, which is
the value returned by getConstantPart. This function returns
null if the constant part is not found. The code that calls this
function needs to check for the null return value.
Differential Revision: http://reviews.llvm.org/D18718
llvm-svn: 265319
diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index 4040ad3..9382890 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -2409,6 +2409,8 @@
Constant = getConstantPart(Product);
else
Constant = cast<SCEVConstant>(Coeff);
+ if (!Constant)
+ return false;
APInt ConstCoeff = Constant->getAPInt();
RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
}
@@ -2427,6 +2429,8 @@
Constant = getConstantPart(Product);
else
Constant = cast<SCEVConstant>(Coeff);
+ if (!Constant)
+ return false;
APInt ConstCoeff = Constant->getAPInt();
RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
}
@@ -2444,6 +2448,8 @@
// or constant, in which case we give up on this direction.
continue;
}
+ if (!Constant)
+ continue;
APInt ConstCoeff = Constant->getAPInt();
RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
DEBUG(dbgs() << "\tRunningGCD = " << RunningGCD << "\n");