Make PRE actually handle critical edges (by splitting them). Confirmed that bootstrap passes with this change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53762 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 4e4d8c1..c664546 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1136,8 +1136,11 @@
changed |= shouldContinue;
}
- if (EnablePRE)
- changed |= performPRE(F);
+ if (EnablePRE) {
+ bool PREChanged = false;
+ while (PREChanged = performPRE(F))
+ changed |= PREChanged;
+ }
return changed;
}
@@ -1336,7 +1339,7 @@
I = toSplit.begin(), E = toSplit.end(); I != E; ++I)
SplitCriticalEdge(I->first, I->second, this);
- return changed;
+ return changed || toSplit.size();
}
// iterateOnFunction - Executes one iteration of GVN