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| author | Dan Gohman <gohman@apple.com> | 2009-04-25 17:09:45 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2009-04-25 17:09:45 +0000 |
| commit | 4128700ab11d0db62e5ba7ed8a8fc301c7aaa8b1 (patch) | |
| tree | 789b89c65576604f7c661b90847a36c8c46b4cc8 | |
| parent | 2c73d5fb9e3d68c96bb2242bbbf2930a8db10343 (diff) | |
Add a top-level comment about DAGCombiner's role in the compiler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70052 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 72b3e3627e..b937eaff75 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -10,6 +10,10 @@ // This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run // both before and after the DAG is legalized. // +// This pass is not a substitute for the LLVM IR instcombine pass. This pass is +// primarily intended to handle simplification opportunities that are implicit +// in the LLVM IR and exposed by the various codegen lowering phases. +// //===----------------------------------------------------------------------===// #define DEBUG_TYPE "dagcombine" |