if jump threading is able to infer interesting values on both
the LHS and RHS of an and/or instruction, don't multiply add
known predecessor values. This fixes the crash on testcase
from PR7498
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108114 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 1a64b2c..f68011a 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -346,8 +346,19 @@
}
for (unsigned i = 0, e = RHSVals.size(); i != e; ++i)
if (RHSVals[i].first == InterestingVal || RHSVals[i].first == 0) {
- Result.push_back(RHSVals[i]);
- Result.back().first = InterestingVal;
+ // 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) {
+ Result.push_back(RHSVals[i]);
+ Result.back().first = InterestingVal;
+ }
}
return !Result.empty();
}