cl::desc("Max block size to duplicate for jump threading"),
cl::init(6), cl::Hidden);
-static cl::opt<int>
-DebugIterations("jump-threading-debug",
- cl::desc("Stop jump threading after N iterations"),
- cl::init(-1), cl::Hidden);
-
namespace {
/// This pass performs 'jump threading', which looks at blocks that have
/// multiple predecessors and multiple successors. If one or more of the
// If the block is trivially dead, zap it. This eliminates the successor
// edges which simplifies the CFG.
if (pred_begin(BB) == pred_end(BB) &&
- BB != &BB->getParent()->getEntryBlock() &&
- DebugIterations != 0) {
+ BB != &BB->getParent()->getEntryBlock()) {
DOUT << " JT: Deleting dead block '" << BB->getNameStart()
<< "' with terminator: " << *BB->getTerminator();
DeleteDeadBlock(BB);
Changed = true;
-
- if (DebugIterations != -1)
- DebugIterations = DebugIterations-1;
}
}
AnotherIteration = Changed;
/// ProcessBlock - If there are any predecessors whose control can be threaded
/// through to a successor, transform them now.
bool JumpThreading::ProcessBlock(BasicBlock *BB) {
- if (DebugIterations == 0) return false;
- if (DebugIterations != -1)
- DebugIterations = DebugIterations-1;
-
// If this block has a single predecessor, and if that pred has a single
// successor, merge the blocks. This encourages recursive jump threading
// because now the condition in this block can be threaded through