Lett users of sparse propagation do their own thing with phi nodes if they want

to. This can be combined with LCSSA or SSI form to store more information on a
PHINode than can be computed by looking at its incoming values.

llvm-svn: 82317

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/SparsePropagation.cpp b/llvm/lib/Analysis/SparsePropagation.cpp
index 17bb73f991e..8a74745dd3f 100644
--- a/llvm/lib/Analysis/SparsePropagation.cpp
+++ b/llvm/lib/Analysis/SparsePropagation.cpp
@@ -223,6 +223,13 @@ void SparseSolver::visitTerminatorInst(TerminatorInst &TI) {
 }
 
 void SparseSolver::visitPHINode(PHINode &PN) {
+  if (LatticeFunc->IsSpecialCasedPHI(&PN)) {
+    LatticeVal IV = LatticeFunc->ComputeInstructionState(PN, *this);
+    if (IV != LatticeFunc->getUntrackedVal())
+      UpdateState(PN, IV);
+    return;
+  }
+
   LatticeVal PNIV = getOrInitValueState(&PN);
   LatticeVal Overdefined = LatticeFunc->getOverdefinedVal();