Fix PR7755: knowing something about an inval for a pred
from the LHS should disable reconsidering that pred on the
RHS. However, knowing something about the pred on the RHS
shouldn't disable subsequent additions on the RHS from
happening.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111349 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index c2caf48..b17f80d 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -341,25 +341,21 @@
else
InterestingVal = ConstantInt::getFalse(I->getContext());
+ SmallPtrSet<BasicBlock*, 4> LHSKnownBBs;
+
// Scan for the sentinel. If we find an undef, force it to the
// interesting value: x|undef -> true and x&undef -> false.
for (unsigned i = 0, e = LHSVals.size(); i != e; ++i)
if (LHSVals[i].first == InterestingVal || LHSVals[i].first == 0) {
Result.push_back(LHSVals[i]);
Result.back().first = InterestingVal;
+ LHSKnownBBs.insert(LHSVals[i].second);
}
for (unsigned i = 0, e = RHSVals.size(); i != e; ++i)
if (RHSVals[i].first == InterestingVal || RHSVals[i].first == 0) {
// If we already inferred a value for this block on the LHS, don't
// re-add it.
- bool HasValue = false;
- for (unsigned r = 0, e = Result.size(); r != e; ++r)
- if (Result[r].second == RHSVals[i].second) {
- HasValue = true;
- break;
- }
-
- if (!HasValue) {
+ if (!LHSKnownBBs.count(RHSVals[i].second)) {
Result.push_back(RHSVals[i]);
Result.back().first = InterestingVal;
}