Add MachineBasicBlock2IndexFunctor. This is useful for densemaps from

MachineBasicBlocks to an arbitrary type.

llvm-svn: 16068

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/include/llvm/CodeGen/MachineBasicBlock.h b/llvm/include/llvm/CodeGen/MachineBasicBlock.h
index 9d4ede6de1f..fb037402903 100644
--- a/llvm/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/llvm/include/llvm/CodeGen/MachineBasicBlock.h
@@ -220,6 +220,16 @@ private:   // Methods used to maintain doubly linked list of blocks...
   }
 };
 
+// This is useful when building DenseMaps keyed on MachineBasicBlocks
+struct MachineBasicBlock2IndexFunctor
+  : std::unary_function<const MachineBasicBlock*, unsigned> {
+  unsigned operator()(const MachineBasicBlock* MBB) const {
+    assert(MBB->getNumber() != -1 &&
+           "MachineBasicBlock does not belong to a MachineFunction");
+    return MBB->getNumber();
+  }
+};
+
 
 //===--------------------------------------------------------------------===//
 // GraphTraits specializations for machine basic block graphs (machine-CFGs)