[llvm-commits] CVS: llvm/lib/Transforms/Scalar/PRE.cpp

[Chris Lattner]

Changes in directory llvm/lib/Transforms/Scalar:

PRE.cpp updated: 1.1 -> 1.2

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Diffs of the changes:

Index: llvm/lib/Transforms/Scalar/PRE.cpp
diff -u llvm/lib/Transforms/Scalar/PRE.cpp:1.1 llvm/lib/Transforms/Scalar/PRE.cpp:1.2
--- llvm/lib/Transforms/Scalar/PRE.cpp:1.1	Mon Mar 31 13:55:43 2003
+++ llvm/lib/Transforms/Scalar/PRE.cpp	Thu May 29 15:26:30 2003
@@ -307,6 +307,17 @@
   std::vector<Value*> Values;
   VN->getEqualNumberNodes(Expr, Values);
 
+#if 0
+  // FIXME: This should handle PHI nodes correctly.  To do this, we need to
+  // consider expressions of the following form equivalent to this set of
+  // expressions:
+  //
+  // If an operand is a PHI node, add any occurances of the expression with the
+  // PHI operand replaced with the PHI node operands.  This is only valid if the
+  // PHI operand occurances exist in blocks post-dominated by the incoming edge
+  // of the PHI node.
+#endif
+
   // We have to be careful to handle expression definitions which dominated by
   // other expressions.  These can be directly eliminated in favor of their
   // dominating value.  Keep track of which blocks contain definitions (the key)