diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp index 1f5d6752b65..33f96df302f 100644 --- a/lib/CodeGen/BranchFolding.cpp +++ b/lib/CodeGen/BranchFolding.cpp @@ -877,7 +877,7 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) { // Now we know that there was no fall-through into this block, check to // see if it has a fall-through into its successor. bool CurFallsThru = CanFallThrough(MBB, CurUnAnalyzable, CurTBB, CurFBB, - CurCond); + CurCond); if (!MBB->isLandingPad()) { // Check all the predecessors of this block. If one of them has no fall @@ -914,7 +914,13 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) { MachineBasicBlock *SuccBB = *SI; MachineFunction::iterator SuccPrev = SuccBB; --SuccPrev; std::vector SuccPrevCond; - if (SuccBB != MBB && !CanFallThrough(SuccPrev)) { + + // If this block doesn't already fall-through to that successor, and if + // the succ doesn't already have a block that can fall through into it, + // and if the successor isn't an EH destination, we can arrange for the + // fallthrough to happen. + if (SuccBB != MBB && !CanFallThrough(SuccPrev) && + !SuccBB->isLandingPad()) { MBB->moveBefore(SuccBB); MadeChange = true; return OptimizeBlock(MBB);