From 37d38bfbbf2b8db2c75b2edbd8cd30c51746fd5d Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Tue, 19 Apr 2011 17:01:08 +0000 Subject: [PATCH] SelectBasicBlock is rather slow even when it doesn't do anything; skip the unnecessary work where possible. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129763 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index 8e599aef7f3..af3188895ed 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -1017,11 +1017,13 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) { else ++NumFastIselBlocks; - // Run SelectionDAG instruction selection on the remainder of the block - // not handled by FastISel. If FastISel is not run, this is the entire - // block. - bool HadTailCall; - SelectBasicBlock(Begin, BI, HadTailCall); + if (Begin != BI) { + // Run SelectionDAG instruction selection on the remainder of the block + // not handled by FastISel. If FastISel is not run, this is the entire + // block. + bool HadTailCall; + SelectBasicBlock(Begin, BI, HadTailCall); + } FinishBasicBlock(); FuncInfo->PHINodesToUpdate.clear(); -- 2.34.1