Make the tail duplication threshold accessible from the command line instead of hardcoded
llvm-svn: 13025
diff --git a/llvm/lib/Transforms/Scalar/TailDuplication.cpp b/llvm/lib/Transforms/Scalar/TailDuplication.cpp
index 40821e4..b687084 100644
--- a/llvm/lib/Transforms/Scalar/TailDuplication.cpp
+++ b/llvm/lib/Transforms/Scalar/TailDuplication.cpp
@@ -28,11 +28,15 @@
#include "llvm/Support/CFG.h"
#include "llvm/Support/ValueHolder.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "Support/CommandLine.h"
#include "Support/Debug.h"
#include "Support/Statistic.h"
using namespace llvm;
namespace {
+ cl::opt<unsigned>
+ Threshold("taildup-threshold", cl::desc("Max block size to tail duplicate"),
+ cl::init(6), cl::Hidden);
Statistic<> NumEliminated("tailduplicate",
"Number of unconditional branches eliminated");
Statistic<> NumPHINodes("tailduplicate", "Number of phi nodes inserted");
@@ -106,7 +110,7 @@
while (isa<PHINode>(*I)) ++I;
for (unsigned Size = 0; I != Dest->end(); ++Size, ++I)
- if (Size == 6) return false; // The block is too large...
+ if (Size == Threshold) return false; // The block is too large...
// Do not tail duplicate a block that has thousands of successors into a block
// with a single successor if the block has many other predecessors. This can