From 82d4215f64dc941f21bbae7ec781367d343387b8 Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Tue, 16 Jul 2013 22:01:40 +0000 Subject: [PATCH] Related to r181161 - Indirect branches may not be the last branch in a basic block. Blocks that have an indirect branch terminator, even if it's not the last terminator, should still be treated as unanalyzable. Reducing a useful regression test case is proving difficult - I hope to have one soon. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186461 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMBaseInstrInfo.cpp | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp index d6701782a47..5d012fcc021 100644 --- a/lib/Target/ARM/ARMBaseInstrInfo.cpp +++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp @@ -295,6 +295,11 @@ ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB, if (!isUnpredicatedTerminator(I)) return false; + // Check whether the second-to-last branch is indirect, return + // 'unanalyzeable' here too. + if (I != MBB.begin() && prior(I)->isIndirectBranch()) + return true; + // If there is only one terminator instruction, process it. if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) { if (isUncondBranchOpcode(LastOpc)) { @@ -322,6 +327,8 @@ ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB, LastInst->eraseFromParent(); LastInst = SecondLastInst; LastOpc = LastInst->getOpcode(); + if (I != MBB.begin() && prior(I)->isIndirectBranch()) + return true; // Indirect branches are unanalyzeable. if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) { // Return now the only terminator is an unconditional branch. TBB = LastInst->getOperand(0).getMBB(); -- 2.34.1