Build the Hopfield network incrementally when splitting global live ranges.

It is common for large live ranges to have few basic blocks with register uses
and many live-through blocks without any uses. This approach grows the Hopfield
network incrementally around the use blocks, completely avoiding checking
interference for some through blocks.

llvm-svn: 129188

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/include/llvm/CodeGen/EdgeBundles.h b/llvm/include/llvm/CodeGen/EdgeBundles.h
index 2c5215a7927..8aab3c64f17 100644
--- a/llvm/include/llvm/CodeGen/EdgeBundles.h
+++ b/llvm/include/llvm/CodeGen/EdgeBundles.h
@@ -16,6 +16,7 @@
 #ifndef LLVM_CODEGEN_EDGEBUNDLES_H
 #define LLVM_CODEGEN_EDGEBUNDLES_H
 
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/IntEqClasses.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 
@@ -29,6 +30,9 @@ class EdgeBundles : public MachineFunctionPass {
   ///   2*BB->getNumber()+1 -> Outgoing bundle.
   IntEqClasses EC;
 
+  /// Blocks - Map each bundle to a list of basic block numbers.
+  SmallVector<SmallVector<unsigned, 8>, 4> Blocks;
+
 public:
   static char ID;
   EdgeBundles() : MachineFunctionPass(ID) {}
@@ -40,6 +44,9 @@ public:
   /// getNumBundles - Return the total number of bundles in the CFG.
   unsigned getNumBundles() const { return EC.getNumClasses(); }
 
+  /// getBlocks - Return an array of blocks that are connected to Bundle.
+  ArrayRef<unsigned> getBlocks(unsigned Bundle) { return Blocks[Bundle]; }
+
   /// getMachineFunction - Return the last machine function computed.
   const MachineFunction *getMachineFunction() const { return MF; }