[DAG] Fix wrong canonicalization performed on shuffle nodes.

[oota-llvm.git] / lib / CodeGen / MachineLICM.cpp

diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp
index 347429141045fe7d3e48c233ba77e3ee694c6ae3..cb14a5cab4b4d0418dd71cb75e17750180f3bffb 100644 (file)
--- a/lib/CodeGen/MachineLICM.cpp
+++ b/lib/CodeGen/MachineLICM.cpp
@@ -49,6 +49,11 @@ AvoidSpeculation("avoid-speculation",
                  cl::desc("MachineLICM should avoid speculation"),
                  cl::init(true), cl::Hidden);
 
+static cl::opt<bool>
+HoistCheapInsts("hoist-cheap-insts",
+                cl::desc("MachineLICM should hoist even cheap instructions"),
+                cl::init(false), cl::Hidden);
+
 STATISTIC(NumHoisted,
           "Number of machine instructions hoisted out of loops");
 STATISTIC(NumLowRP,
@@ -818,7 +823,7 @@ void MachineLICM::InitRegPressure(MachineBasicBlock *BB) {
       if (!TargetRegisterInfo::isVirtualRegister(Reg))
         continue;
 
-      bool isNew = RegSeen.insert(Reg);
+      bool isNew = RegSeen.insert(Reg).second;
       unsigned RCId, RCCost;
       getRegisterClassIDAndCost(MI, Reg, i, RCId, RCCost);
       if (MO.isDef())
@@ -850,7 +855,7 @@ void MachineLICM::UpdateRegPressure(const MachineInstr *MI) {
     if (!TargetRegisterInfo::isVirtualRegister(Reg))
       continue;
 
-    bool isNew = RegSeen.insert(Reg);
+    bool isNew = RegSeen.insert(Reg).second;
     if (MO.isDef())
       Defs.push_back(Reg);
     else if (!isNew && isOperandKill(MO, MRI)) {
@@ -1075,7 +1080,7 @@ bool MachineLICM::CanCauseHighRegPressure(DenseMap<unsigned, int> &Cost,
 
     // Don't hoist cheap instructions if they would increase register pressure,
     // even if we're under the limit.
-    if (CheapInstr)
+    if (CheapInstr && !HoistCheapInsts)
       return true;
 
     for (unsigned i = BackTrace.size(); i != 0; --i) {