From a0a95a3c1cea79757854cf39ba07734b39e2b0e9 Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Tue, 17 Nov 2009 01:21:04 +0000 Subject: [PATCH] When moving a block for table jumps, make sure the prior block terminator is analyzable so it can be updated. If it's not, be safe and don't move the block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89022 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMConstantIslandPass.cpp | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp index 0eb72272c07..734e33d2e6e 100644 --- a/lib/Target/ARM/ARMConstantIslandPass.cpp +++ b/lib/Target/ARM/ARMConstantIslandPass.cpp @@ -1749,21 +1749,23 @@ AdjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) // heuristic. FIXME: We can definitely improve it. MachineBasicBlock *TBB = 0, *FBB = 0; SmallVector Cond; + SmallVector CondPrior; + MachineFunction::iterator BBi = BB; + MachineFunction::iterator OldPrior = prior(BBi); // If the block terminator isn't analyzable, don't try to move the block - if (TII->AnalyzeBranch(*BB, TBB, FBB, Cond)) - return NULL; + bool B = TII->AnalyzeBranch(*BB, TBB, FBB, Cond); - // If the block ends in an unconditional branch, move it. Be paranoid + // If the block ends in an unconditional branch, move it. The prior block + // has to have an analyzable terminator for us to move this one. Be paranoid // and make sure we're not trying to move the entry block of the function. - if (Cond.empty() && BB != MF.begin()) { - MachineFunction::iterator BBi = BB; - MachineFunction::iterator OldPrior = prior(BBi); + if (!B && Cond.empty() && BB != MF.begin() && + !TII->AnalyzeBranch(*OldPrior, TBB, FBB, CondPrior)) { BB->moveAfter(JTBB); OldPrior->updateTerminator(); BB->updateTerminator(); // Update numbering to account for the block being moved. - MF.RenumberBlocks(OldPrior); + MF.RenumberBlocks(); ++NumJTMoved; return NULL; } -- 2.34.1