Assign weights to edges to jump table / bit test header when lowering switch statement.

Currently, when lowering switch statement and a new basic block is built for jump table / bit test header, the edge to this new block is not assigned with a correct weight. This patch collects the edge weight from all its successors and assign this sum of weights to the edge (and also the other fall-through edge). Test cases are adjusted accordingly.

Differential Revision: http://reviews.llvm.org/D12166#fae6eca7

llvm-svn: 246104

1 files changed, 7 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 854e6d0f170..537d8e05cf2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -283,12 +283,12 @@ private:
   typedef SmallVector<BitTestCase, 3> BitTestInfo;
 
   struct BitTestBlock {
-    BitTestBlock(APInt F, APInt R, const Value* SV,
-                 unsigned Rg, MVT RgVT, bool E, bool CR,
-                 MachineBasicBlock* P, MachineBasicBlock* D,
-                 BitTestInfo C):
-      First(F), Range(R), SValue(SV), Reg(Rg), RegVT(RgVT), Emitted(E),
-      ContiguousRange(CR), Parent(P), Default(D), Cases(std::move(C)) { }
+    BitTestBlock(APInt F, APInt R, const Value *SV, unsigned Rg, MVT RgVT,
+                 bool E, bool CR, MachineBasicBlock *P, MachineBasicBlock *D,
+                 BitTestInfo C, uint32_t W)
+        : First(F), Range(R), SValue(SV), Reg(Rg), RegVT(RgVT), Emitted(E),
+          ContiguousRange(CR), Parent(P), Default(D), Cases(std::move(C)),
+          Weight(W) {}
     APInt First;
     APInt Range;
     const Value *SValue;
@@ -299,6 +299,7 @@ private:
     MachineBasicBlock *Parent;
     MachineBasicBlock *Default;
     BitTestInfo Cases;
+    uint32_t Weight;
   };
 
   /// Minimum jump table density, in percent.