Normalize MBB's successors' probabilities in several locations.
This patch adds some missing calls to MBB::normalizeSuccProbs() in several
locations where it should be called. Those places are found by checking if the
sum of successors' probabilities is approximate one in MachineBlockPlacement
pass with some instrumented code (not in this patch).
Differential revision: http://reviews.llvm.org/D15259
llvm-svn: 255455
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp
index 71bd61a..a1835fa 100644
--- a/llvm/lib/CodeGen/IfConversion.cpp
+++ b/llvm/lib/CodeGen/IfConversion.cpp
@@ -1113,7 +1113,7 @@
// RemoveExtraEdges won't work if the block has an unanalyzable branch, so
// explicitly remove CvtBBI as a successor.
- BBI.BB->removeSuccessor(CvtBBI->BB);
+ BBI.BB->removeSuccessor(CvtBBI->BB, true);
} else {
RemoveKills(CvtBBI->BB->begin(), CvtBBI->BB->end(), DontKill, *TRI);
PredicateBlock(*CvtBBI, CvtBBI->BB->end(), Cond);
@@ -1226,7 +1226,7 @@
// RemoveExtraEdges won't work if the block has an unanalyzable branch, so
// explicitly remove CvtBBI as a successor.
- BBI.BB->removeSuccessor(CvtBBI->BB);
+ BBI.BB->removeSuccessor(CvtBBI->BB, true);
} else {
// Predicate the 'true' block after removing its branch.
CvtBBI->NonPredSize -= TII->RemoveBranch(*CvtBBI->BB);
@@ -1512,7 +1512,7 @@
// which can happen here if TailBB is unanalyzable and is merged, so
// explicitly remove BBI1 and BBI2 as successors.
BBI.BB->removeSuccessor(BBI1->BB);
- BBI.BB->removeSuccessor(BBI2->BB);
+ BBI.BB->removeSuccessor(BBI2->BB, true);
RemoveExtraEdges(BBI);
// Update block info.
@@ -1706,7 +1706,7 @@
if (AddEdges) {
// If the edge from ToBBI.BB to Succ already exists, update the
- // probability of this edge by adding NewWeight to it. An example is shown
+ // probability of this edge by adding NewProb to it. An example is shown
// below, in which A is ToBBI.BB and B is FromBBI.BB. In this case we
// don't have to set C as A's successor as it already is. We only need to
// update the edge probability on A->C. Note that B will not be
@@ -1740,6 +1740,10 @@
if (NBB && !FromBBI.BB->isSuccessor(NBB))
FromBBI.BB->addSuccessor(NBB);
+ // Normalize the probabilities of ToBBI.BB's successors with all adjustment
+ // we've done above.
+ ToBBI.BB->normalizeSuccProbs();
+
ToBBI.Predicate.append(FromBBI.Predicate.begin(), FromBBI.Predicate.end());
FromBBI.Predicate.clear();