diff options
| -rw-r--r-- | llvm/lib/CodeGen/MachineBlockPlacement.cpp | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp index f5e30564501..ce920a117ae 100644 --- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp +++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp @@ -62,6 +62,13 @@ static cl::opt<unsigned> AlignAllBlock("align-all-blocks", "blocks in the function."), cl::init(0), cl::Hidden); +static cl::opt<unsigned> AlignAllNonFallThruBlocks( + "align-all-nofallthru-blocks", + cl::desc("Force the alignment of all " + "blocks that have no fall-through predecessors (i.e. don't add " + "nops that are executed)."), + cl::init(0), cl::Hidden); + static cl::opt<unsigned> AlignAllLoops("align-all-loops", cl::desc("Force the alignment of all loops in the function."), @@ -1405,6 +1412,15 @@ bool MachineBlockPlacement::runOnMachineFunction(MachineFunction &F) { // Align all of the blocks in the function to a specific alignment. for (MachineBasicBlock &MBB : F) MBB.setAlignment(AlignAllBlock); + else if (AlignAllNonFallThruBlocks) { + // Align all of the blocks that have no fall-through predecessors to a + // specific alignment. + for (auto MBI = std::next(F.begin()), MBE = F.end(); MBI != MBE; ++MBI) { + auto LayoutPred = std::prev(MBI); + if (!LayoutPred->isSuccessor(&*MBI)) + MBI->setAlignment(AlignAllNonFallThruBlocks); + } + } // We always return true as we have no way to track whether the final order // differs from the original order. |
