From a2deea1dcf8363f46bda8935283c5c701b5a278d Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Thu, 24 Nov 2011 08:46:04 +0000 Subject: When adding blocks to the list of those which no longer have any CFG conflicts, we should only be adding the first block of the chain to the list, lest we try to merge into the middle of that chain. Most of the places we were doing this we already happened to be looking at the first block, but there is no reason to assume that, and in some cases it was clearly wrong. I've added a couple of tests here. One already worked, but I like having an explicit test for it. The other is reduced from a test case Duncan reduced for me and used to crash. Now it is handled correctly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145119 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineBlockPlacement.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib/CodeGen/MachineBlockPlacement.cpp') diff --git a/lib/CodeGen/MachineBlockPlacement.cpp b/lib/CodeGen/MachineBlockPlacement.cpp index 45d5af2..870e248 100644 --- a/lib/CodeGen/MachineBlockPlacement.cpp +++ b/lib/CodeGen/MachineBlockPlacement.cpp @@ -315,7 +315,7 @@ void MachineBlockPlacement::markChainSuccessors( // This is a cross-chain edge that is within the loop, so decrement the // loop predecessor count of the destination chain. if (SuccChain.LoopPredecessors > 0 && --SuccChain.LoopPredecessors == 0) - BlockWorkList.push_back(*SI); + BlockWorkList.push_back(*SuccChain.begin()); } } } @@ -594,7 +594,7 @@ void MachineBlockPlacement::buildLoopChains(MachineFunction &F, } if (Chain.LoopPredecessors == 0) - BlockWorkList.push_back(*BI); + BlockWorkList.push_back(*Chain.begin()); } buildChain(*L.block_begin(), LoopChain, BlockWorkList, &LoopBlockSet); @@ -692,7 +692,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) { } if (Chain.LoopPredecessors == 0) - BlockWorkList.push_back(BB); + BlockWorkList.push_back(*Chain.begin()); } BlockChain &FunctionChain = *BlockToChain[&F.front()]; -- cgit v1.1