SCEV validator: Ignore CouldNotCompute/undef on both sides. This is mostly noise and blocks finding more severe bugs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166873 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer 2012-10-27 11:36:07 +00:00
parent cb8b8ea2b6
commit 974d98d730

View File

@ -7005,15 +7005,18 @@ void ScalarEvolution::verifyAnalysis() const {
// Compare the stringified SCEVs. We don't care if undef backedgetaken count
// changes.
// FIXME: We currently ignore SCEV changes towards CouldNotCompute. This
// FIXME: We currently ignore SCEV changes from/to CouldNotCompute. This
// means that a pass is buggy or SCEV has to learn a new pattern but is
// usually not harmful.
if (OldI->second != NewI->second &&
OldI->second.find("undef") == std::string::npos &&
NewI->second.find("undef") == std::string::npos &&
OldI->second != "***COULDNOTCOMPUTE***" &&
NewI->second != "***COULDNOTCOMPUTE***") {
dbgs() << "SCEVValidator: SCEV for Loop '"
dbgs() << "SCEVValidator: SCEV for loop '"
<< OldI->first->getHeader()->getName()
<< "' from '" << OldI->second << "' to '" << NewI->second << "'!";
<< "' changed from '" << OldI->second
<< "' to '" << NewI->second << "'!\n";
std::abort();
}
}