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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 | a0754aca17517c539c61408d6cc0c4facf165cd4 (patch) | |
| tree | 789b89c65576604f7c661b90847a36c8c46b4cc8 /lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
| parent | 91ae1e7f8d5ab7e62137da6671f4feb51c56c7ad (diff) | |
| download | external_llvm-a0754aca17517c539c61408d6cc0c4facf165cd4.zip external_llvm-a0754aca17517c539c61408d6cc0c4facf165cd4.tar.gz external_llvm-a0754aca17517c539c61408d6cc0c4facf165cd4.tar.bz2 | |
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
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -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 72b3e36..b937eaf 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" |