From 0553e1efcd3f8ccd8b45302e033924d9f85a5d2f Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Sun, 5 May 2013 18:06:32 +0000 Subject: ARM AnalyzeBranch should conservatively return true when it sees a predicated indirect branch at the end of the BB. Otherwise if-converter, branch folding pass may incorrectly update its successor info if it consider BB as fallthrough to the next BB. rdar://13782395 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181161 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMBaseInstrInfo.cpp | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'lib/Target') diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp index 0d1417dd17..6005054271 100644 --- a/lib/Target/ARM/ARMBaseInstrInfo.cpp +++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp @@ -283,14 +283,20 @@ ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB, return false; --I; } - if (!isUnpredicatedTerminator(I)) - return false; // Get the last instruction in the block. MachineInstr *LastInst = I; + unsigned LastOpc = LastInst->getOpcode(); + + // Check if it's an indirect branch first, this should return 'unanalyzable' + // even if it's predicated. + if (isIndirectBranchOpcode(LastOpc)) + return true; + + if (!isUnpredicatedTerminator(I)) + return false; // If there is only one terminator instruction, process it. - unsigned LastOpc = LastInst->getOpcode(); if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) { if (isUncondBranchOpcode(LastOpc)) { TBB = LastInst->getOperand(0).getMBB(); -- cgit v1.2.3-18-g5258