"This patch adds a virtual call to AbstractLatticeFunction to derive a
type lattice value for an Argument*, giving clients the opportunity to
use something other than Top for it if they choose to."
Patch by John McCall!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54589 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Analysis/SparsePropagation.h b/include/llvm/Analysis/SparsePropagation.h
index bc9ae61..a054c76 100644
--- a/include/llvm/Analysis/SparsePropagation.h
+++ b/include/llvm/Analysis/SparsePropagation.h
@@ -24,6 +24,7 @@
namespace llvm {
class Value;
class Constant;
+ class Argument;
class Instruction;
class PHINode;
class TerminatorInst;
@@ -75,6 +76,12 @@
virtual Constant *GetConstant(LatticeVal LV, Value *Val, SparseSolver &SS) {
return 0;
}
+
+ /// ComputeArgument - Given a formal argument value, compute and return a
+ /// lattice value corresponding to the specified argument.
+ virtual LatticeVal ComputeArgument(Argument *I) {
+ return getOverdefinedVal(); // always safe
+ }
/// MergeValues - Compute and return the merge of the two specified lattice
/// values. Merging should only move one direction down the lattice to
diff --git a/lib/Analysis/SparsePropagation.cpp b/lib/Analysis/SparsePropagation.cpp
index 2fda64c..8f042c2 100644
--- a/lib/Analysis/SparsePropagation.cpp
+++ b/lib/Analysis/SparsePropagation.cpp
@@ -57,8 +57,10 @@
return LatticeFunc->getUntrackedVal();
else if (Constant *C = dyn_cast<Constant>(V))
LV = LatticeFunc->ComputeConstant(C);
+ else if (Argument *A = dyn_cast<Argument>(V))
+ LV = LatticeFunc->ComputeArgument(A);
else if (!isa<Instruction>(V))
- // Non-instructions (e.g. formal arguments) are overdefined.
+ // All other non-instructions are overdefined.
LV = LatticeFunc->getOverdefinedVal();
else
// All instructions are underdefined by default.