SimplifyCFG: Expose phi node folding cost threshold as command line parameter
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130528 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index e0125f7..18b8573 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -37,6 +37,10 @@
#include <map>
using namespace llvm;
+static cl::opt<unsigned>
+PHINodeFoldingThreshold("phi-node-folding-threshold", cl::Hidden, cl::init(1),
+ cl::desc("Control the amount of phi node folding to perform (default = 1)"));
+
static cl::opt<bool>
DupRet("simplifycfg-dup-ret", cl::Hidden, cl::init(false),
cl::desc("Duplicate return instructions into unconditional branches"));
@@ -1246,7 +1250,8 @@
// instructions. While we are at it, keep track of the instructions
// that need to be moved to the dominating block.
SmallPtrSet<Instruction*, 4> AggressiveInsts;
- unsigned MaxCostVal0 = 1, MaxCostVal1 = 1;
+ unsigned MaxCostVal0 = PHINodeFoldingThreshold,
+ MaxCostVal1 = PHINodeFoldingThreshold;
for (BasicBlock::iterator II = BB->begin(); isa<PHINode>(II);) {
PHINode *PN = cast<PHINode>(II++);