From 3e20475feebca3bfb29375ac7f3e5acbeb2a95c8 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Wed, 11 Nov 2009 19:31:31 +0000 Subject: Fix liveness calculation when splitting critical edges during PHI elimination. - Edges are split before any phis are eliminated, so the code is SSA. - Create a proper IR BasicBlock for the split edges. - LiveVariables::addNewBlock now has same syntax as MachineDominatorTree::addNewBlock. Algorithm calculates predecessor live-out set rather than successor live-in set. This feature still causes some miscompilations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86867 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/LiveVariables.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/llvm/CodeGen/LiveVariables.h b/include/llvm/CodeGen/LiveVariables.h index c9b92e9e7f..b2be569bc1 100644 --- a/include/llvm/CodeGen/LiveVariables.h +++ b/include/llvm/CodeGen/LiveVariables.h @@ -267,9 +267,11 @@ public: void HandleVirtRegUse(unsigned reg, MachineBasicBlock *MBB, MachineInstr *MI); - /// addNewBlock - Add a new basic block A as an empty predecessor of B. All - /// variables that are live into B will be marked as passing live through A. - void addNewBlock(MachineBasicBlock *A, MachineBasicBlock *B); + /// addNewBlock - Add a new basic block BB as an empty succcessor to + /// DomBB. All variables that are live out of DomBB will be marked as passing + /// live through BB. This method assumes that the machine code is still in SSA + /// form. + void addNewBlock(MachineBasicBlock *BB, MachineBasicBlock *DomBB); }; } // End llvm namespace -- cgit v1.2.3-70-g09d2